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Claims  |
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We claim:
1. A halogen-free flameproofed thermoplastic molding material, comprising
one or more halogen-free thermoplastic resins of homopolymers of styrene
or copolymers of styrene and acrylonitrile in which some of the styrene
component can be replaced by alkylated styrene (A) and one or more further
halogen-free components wherein the thermoplastic resin
(A) is present in an amount of from 30 to 90% by weight, and the said
molding material contains, as further components,
(B) from 1 to 50% by weight of one or more phenol/aldehyde resins,
(C) from 1 to 50% by weight of one or more nitrogen-containing organic
compounds selected from the group consisting of the triazines,
triazolidines, ureas, guanidines, guanamines, aminoacids, peptides their
derivatives and salts thereof, and
(D) from 3 to 50% by weight of one or more phosphorus-containing organic
compounds selected from the group consisting of the phosphines, phosphine
oxides, phosphinous acids, phosphinic acids, phosphates, hypophosphires,
hypodiphosphates and amides of phosphinic acid, of phosphonic acid and of
phosphoric acid, the percentages in each case being based on the molding
material consisting of A+B+C+D.
2. A thermoplastic molding material as claimed in claim 1, wherein the
thermoplastic resin
(A) is present in an amount of from 30 to 90% by weight, and the said
molding material contains, as further components,
(B) from 5 to 25% by weight of one or more phenol/aldehyde resins,
(C) from 5 to 35% by weight of one or more nitrogen-containing organic
compounds and
(D) from 5 to 35% by weight of one or more phosphorus-containing organic
compounds, the percentages in each case being based on the molding
material consisting of A+B+C+D.
3. A thermoplastic molding material as claimed in claim 1, wherein the
thermoplastic resin (A) employed is a styrene homopolymer or copolymer
which may or may not furthermore contain an elastomer component having a
glass transition temperature Tg<0.degree. C.
4. A molding material as claimed in claim 3, wherein the thermoplastic
resin used is a styrene copolymer consisting of from 50 to 99% by weight
of styrene, or of styrene which is alkylated in the nucleus, or of a
mixture of these, and from 1 to 50% by weight of acrylonitrile.
5. A thermoplastic molding material as claimed in claim 1, wherein the
thermoplastic resin (A) used is a styrene homopolymer or copolymer which
contains an elastomer component having a glass transition temperature Tg
<0.degree. C, this elastomer component being employed in the form of a
graft copolymer of the monomers constituting the component A.
6. A molding material as claimed in claim 4, wherein the styrene copolymer
contains, as copolymerized units, from 50 to 95% by weight of styrene or
of a styrene which is alkylated in the nucleus, or of a mixture of these,
and from 1 to 50% by weight of acrylonitrile, and furthermore consists of
from 5 to 50% by weight, based on the component A, of a graft copolymer
consisting of from 10 to 50% by weight of a grafted shell and from 50 to
90 by weight of an elastomeric grafting base.
7. A thermoplastic molding material as claimed in claim 1, wherein
component (B) employed is a phenol/aldehyde resin which consists of
(b.sub.1) one or more aldehydes of the formula (I)
R.sup.1 -CHO (I)
where R.sup.1 is H, C.sub.1 -C.sub.10 -alkyl, cycloalkyl, C.sub.6
-C.sub.12 -aryl or -aryl-C.sub.1 -C.sub.3 -alkyl, and
(b.sub.2) one or more phenols of the formula (II)
##STR3##
where R.sup.2 and R.sup.6 are each hydrogen, and R.sup.3, R.sup.4 and
R.sup.5 can each alternatively be hydrogen, C.sub.1 -C.sub.20 -alkyl,
cycloalkyl, C.sub.6 -C.sub.10 -aryl, C.sub.1 -C.sub.6 -alkoxy,
cycloalkoxy, C.sub.6 -C.sub.10 -phenoxy, hydroxyl, carbonyl, carboxyl,
cyano, a C.sub.1 -C.sub.6 -alkyl ester radical, a C.sub.6 -C.sub.10 -aryl
ester radical, sulfo, sulfonamido, a sulfonic acid C.sub.1 -C.sub.6 -alkyl
ester radical, a sulfonic acid C.sub.6 -C.sub.10 -aryl ester radical, a
C.sub.1 -C.sub.6 -alkyl- or C.sub.6 -C.sub.10 -arylphosphonic acid radical
or its C.sub.1 -C.sub.6 -alkyl or C.sub.6 -C.sub.10 -aryl ester radical, a
phosphonic acid radical or its mono- or di-C.sub.1 -C.sub.6 -alkyl or
C.sub.6 -C.sub.10 -aryl ester, an 0-phosphoric acid radical or its mono-
or di-C.sub.1 -C.sub.6 -alkyl or C.sub.6 -C.sub.10 -aryl ester, or
-aryl-C.sub.1 -C.sub.6 -alkyl, or R.sup.2 and R.sup.4 are each hydrogen,
and R.sup.3, R.sup.5 and R.sup.6 can have the above meanings.
8. A thermoplastic molding material as claimed in claim 4, wherein the
phenol/aldehyde resin (B) used consists of formaldehyde and phenol or a
monosubstituted or polysubstituted alkylphenol where alkyl is of 2 to 8
carbon atoms, or a mixture of these, and has a number average molecular
weight of from 500 to 2,000.
9. A molding material as claimed in claim 6, wherein a triazine derivative
is employed.
10. A thermoplastic molding material as claimed in claim 8, wherein a
cyclic or dicyclic phosphite, a phosphonate, a phosphate, a hypophosphite
or a hypodiphosphate is used. |
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Claims |
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Description |
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The present invention relates to a halogen-free flameproofed thermoplastic
molding material which consists of a halogen-free thermoplastic resin and
other halogen-free flameproofing components.
The relevant prior art includes the following standard publications on the
flameproofing of thermoplastics:
(1) Vogel, Flammfestmachen von Kunststoffen, Huthig Verlag, Heidelberg
(1966), pages 94-102,
(2) Troitzsch, Brandverhalten von Kunststoffen, Hanser Verlag, Munich
(1982), pages 1-65, and
(3) Hirschler, Developments in Polymer Stabilization, Volume 5, Editor G.
Scott, Applied Science Publishers, London (1982), pages 107-151.
The flameproofing of thermoplastics has been disclosed in (1), (2) and (3).
It is also known that when relatively large amounts of halogen-containing
flameproofing agents are used and at the same time synergistic agents such
as compounds of phosphorus, arsenic, antimony, bismuth, boron or tin are
employed, thermoplastics do not drip flaming particles and are
self-extinguishing after application of a hot flame. It is furthermore
known that, if a synergistic agent is not used, this self-extinguishing
effect occurs only after the addition of a far larger amount of
halogen-containing flameproofing agents.
In addition to the abovementioned possibility of treating thermoplastics
with halogen-containing flameproofing agents, it is also possible to use a
halogen-free flameproofing agent. For example, blends of
poly-(2,6-dimethyl-1,4-phenylene) ether (PPE) and high impact polystyrene
(HIPS) can be flameproofed by means of phosphorus-containing organic
compounds. From 50 to 60% by weight, based on HIPS, of PPE and phosphorus
compounds are added (cf. for example German Laid-Open Applications DOS
3,019,617 and DOS 3,002,792). It has also been disclosed that styrene
polymers can be flameproofed with very large amounts (from 40 to 50% by
weight) of Mg(OH).sub.2 (cf. European Patent 52,868), polyguanamines (cf.
German Laid-Open Application DOS 2,837,378) or phosphinic acidmelamine
adduct/dicyanodiamide/red phosphorus systems (cf. German Laid-Open
Application DOS 2,827,867) or novolak/red phosphorus systems (cf. E.N.
Peters, A.B. Furtek, D.I. Steinbert and D.T. Kwiatkowski, Journal of Fire
Retardant Chemistry, 7 (1980), 69-71). It has also been disclosed that
styrene polymers can be treated with intumescent flameproofing systems,
such as poly(ammonium phosphate) and a resin based on tris(2-hydroxyethyl)
isocyanurate (cf. European Pat. Nos. 26,391 and 45,835), on
2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-4-methanol 1-oxide/melamine
(cf. European Patent 69,500) or on bis(2-hydroxyethyl)
phosphate/melamine/dipentaerythritol (cf. U.S. Pat. No. 4,247,435), and
with melammonium pentaerythritol diphosphate (cf. British Patent No.
2,028,822). However, in the British patent cited, it is pointed out that
the conventional systems have only a moderate effect in styrene polymers.
Finally, British Patent 2,054,610 states that phenol/formaldehyde resins
are not very effective for flameproofing thermoplastics.
The use of halogen-free flameproofing agents, as described above, has not
to date resulted in any striking improvement, as is evident from extensive
series of tests. For example, a large number of thermoplastics have to be
treated with large amounts of flameproofing agents, or a particular
flameproofing system is effective in certain thermoplastics but not at all
in others. Furthermore, certain components of these systems result in an
excessive increase in the flow and a drastic reduction in the heat
distortion resistance. Virtually all halogen-free flameproofing systems
are completely incompatible with the thermoplastics to be treated and lead
to a deterioration in the mechanical properties; in general, the molding
materials treated with halogen-free flameproofing agents drip the
particles on application of a flame.
It is an object of the present invention to provide a halogen-free
flameproofing system which is free of the above disadvantages.
Furthermore, the said flameproofing system, even when used in
thermoplastics which to date could be flameproofed with halogen-free
flameproofing agents only with great difficulty, if at all, should permit
these thermoplastics to be classified UL 94 V 1 and UL 94 VO.
In addition, the halogen-free flameproofing system should prevent molding
materials from dripping flaming or non-flaming particles when a flame is
applied.
We have found that this object is achieved by a halogen-free flameproofed
thermoplastic molding material, consisting of one or more halogen-free
thermoplastic resins (A) and one or more further halogen-free components,
wherein the thermoplastic resin (A) is present in an amount of from 30 to
90% by weight, and the said molding material contains, as further
components,
(B) from 1 to 50% by weight of one or more phenol/aldehyde resins,
(C) from 1 to 50% by weight of one or more nitrogen-containing organic
compounds and
(D) from 3 to 50% by weight of one or more phosphorus-containing organic
compounds,
the percentages in each case being based on the molding material consisting
of A+B+C+D.
The composition of the novel molding material in terms of the components,
and the preparation of these, are described below.
The molding material consists of components A, B, C and D, i.e. the sum of
the amounts of these 4 components is 100%. Each of the components A, B, C
and D is known per se. It is the proposal to use the components B+C+D as
an intumescent system in conjunction with thermoplastic resins (A) in
order to obtain halogen-free flameproofed molding materials which is novel
and inventive.
The molding material according to the invention consists of
1. from 5 to 95, in particular from 30 to 90, preferably from 65 to 75, %
by weight of component A,
2. from 1 to 50, in particular from 5 to 25, preferably from 8 to 12, % by
weight of component B,
3. from 1 to 50, in particular from 5 to 25, preferably from 8 to 12, % by
weight of component C and
4. from 3 to 50, in particular from 5 to 25, preferably from 8 to 12, % by
weight of component D.
Preferably, the components B, C and D which constitute the halogen-free
flameproofing system are used in equal amounts. The amounts of the above
components A, B, C and D are based in each case on the molding material
consisting of A +B +C +D (=100%).
Component A
Component A of the novel molding material comprises one or more commercial
halogen-free thermoplastic resins which may or may not have been
toughened. These resins can be a homopolymer or copolymer of a
thermoplastic. Blends of various thermoplastics which are listed below can
also be used. Suitable thermoplastics are polyethylene, polypropylene,
polyisobutylene, polystyrene and copolymers of styrene with acrylonitrile,
with maleic anhydride, with maleates and with acrylates, which may or may
not have been toughened with rubber. Copolymers of acrylonitrile with
.alpha.(methylstyrene, which may have been toughened with rubber, are also
useful, and other suitable thermoplastics are nylons, polyesters,
polyurethanes, poly(oxyalkylenes), polycarbonates and poly(methyl
methacrylate).
Homopolymers A1
Preferably used homopolymers are polystyrenes (A.sub.1), and some or all of
the styrene component can be replaced by styrene which is alkylated in the
nucleus, eg. p-methylstyrene, in order to improve the heat distortion
resistance. Copolymers A.sub.2.
Copolymers of styrene with acrylonitrile (A.sub.2), with maleic anhydride,
with maleates and with acrylates are particularly preferably used.
From amongst these copolymers, styrene/acrylonitrile copolymers (A.sub.2)
are very particularly preferably used for the preparation of the novel
molding material; these styrene/acrylonitrile copolymers consist of from 1
to 50% by weight of acrylonitrile (a.sub.2) and from 50 to 99% by weight
of styrene (a.sub.1). In order to improve the heat distortion resistance,
some or all of the styrene component can be replaced with styrene which is
alkylated in the nucleus. Styrene/acrylonitrile copolymers (A.sub.2) are
available commercially and can be prepared, for example, as described in
German Published Application DAS 1,001,001 or German Patent No. 1,003,436.
The copolymers can have a molecular weight M.sub.w of from 10.sup.5 to
2.5.times.10.sup.5 (weight average molecular weight from light
scattering).
The elastomer used for toughening the component A of the novel molding
material can be an ungrafted rubber (a.sub.3) or a grafted rubber
(a.sub.4).
The rubber (a.sub.3) should have a glass transition temperature (according
to K. H. Illers and H. Breuer, Kolloid Zeitschrift 176 (1961), 110) of
less than 0.degree. C. Examples of suitable rubbers are polybutadiene (cf.
German Laid-Open Applications DOS 1,420,775 and DOS 1,495,089), copolymers
of butadiene and styrene (cf. British Patent 649,166), copolymers of
butadiene and styrene, polyacrylates which may or may not be crosslinked
(cf. German Laid-Open Application DOS 1,138,921 and German Published
Application DAS 1,224,486 or DAS 1,260,135), copolymers of acrylates and
butadiene (cf. German Published Application DAS 1,238,207), and elastomers
of copolymers of acrylates with styrene, acrylonitrile and vinyl ethers
and copolymers of ethylene and a non-conjugated diene (EPDM rubbers).
For toughening homopolymers (HIPS), it is particularly preferable to use
polybutadiene (a.sub.3), in amounts of from 2 to 20, preferably from 3 to
10, % by weight, based on component A.sub.1.
To prepare particularly impact-resistant copolymers A.sub.2, grafted
rubbers are required, preferably those based on polybutadiene (a.sub.4).
Suitable rubbers of this type are graft copolymers, which can be used in
amounts of from 5 to 50, in particular from 10 to 45, % by weight, based
on the component A.sub.2.
These graft copolymers consist of from 10 to 50, preferably from 15 to 45,
% by weight of a mixture of one or more vinylaromatic monomers (a.sub.1)
of not more than 12 carbon atoms and from 0.1 to 25, preferably from 5 to
20, % by weight of one or more (meth)acrylates and/or acrylonitrile
(a.sub.2) as a grafted shell on from 50 to 90, in particular from 50 to
75, % by weight of an elastomeric grafting base (rubber component
(a.sub.3)) which, if required, can be crosslinked. The vinylaromatic graft
monomers (a.sub.1) are styrene, .alpha.-methylstyrene and/or styrenes of
not more than 12 carbon atoms which are alkylated in the nucleus; suitable
monomers (a.sub.2) are (meth)acrylates of alkanols of not more than 8
carbon atoms, and acrylonitrile and mixtures of these.
The preparation of the graft copolymers (a.sub.4) is known per se. They can
be prepared by, for example, polymerization of a mixture of styrene and
acrylonitrile and/or (meth)acrylates in the presence of a rubber.
Suitable graft rubbers (a.sub.4) are:
a.sub.4a : 75% of polybutadiene rubber grafted with 25% of
styrene/acrylonitrile in a ratio of 90:10,
a.sub.4b : 75% of polybutadiene rubber grafted with 25% of
styrene/acrylonitrile in a ratio of 83:17,
a.sub.4c : 75% of polybutadiene rubber grafted with 25% of
styrene/acrylonitrile in a ratio of 75:25,
a.sub.4d : 75% of polybutadiene rubber grafted with 25% of
styrene/acrylonitrile in a ratio of 70:30,
a.sub.4e : 75% of a rubber consisting of 60 parts of butyl acrylate and 40
parts of butadiene, grafted with 25% of styrene/acrylonitrile | | |
