Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-07-17
2001-07-03
Sanders, Kriellion (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S126000, C524S133000, C524S135000, C252S609000
Reexamination Certificate
active
06255371
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a novel flame retardant combination and to its use, in particular in thermoplastic polymers.
The salts of phosphinic acids (phosphinates) have proven to be effective flame-retardant additives, in particular for thermoplastic polymers (DE-A-2 252 258 and DE-A-2 447 727). Calcium phosphinates and aluminum phosphinates have been described as particularly effective in polyesters, and impair the material properties of the polymer molding compositions less than when the alkali metal salts, for example, are used (EP-A-0 699 708).
SUMMARY OF THE INVENTION
Synergistic combinations of phosphinates with certain nitrogen-containing compounds have also been found and in very many polymers act as more effective flame retardants than the phosphinates alone (PCT/EP97/01664 and also DE-A-197 34 437 and DE-A-197 37 727).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Effective synergists described include melamine and melamine compounds, such as melamine cyanurate and melamine phosphate, which themselves also have a certain flame-retardant action in certain thermoplastics but are markedly more effective in combination with phosphinates.
However, the effectiveness of the combinations in specific thermoplastics is still unsatisfactory since, for example, the specification V-0 under the frequently international standard UL 94 is not achieved or is achieved only when relatively high amounts are added.
Higher-molecular-weight derivatives of melamine have also been described as flame retardants, for example the condensation products melam, melem and melon, and also corresponding reaction products of these compounds with phosphoric acid, such as dimelamine pyrophosphate and melamine polyphosphates. However, the amounts which have to be added in thermoplastics are relatively high, in particular in the case of glass-fiber-reinforced materials.
The object of the present invention is therefore to provide flame retardant combinations which, even when used in small amounts, have excellent effectiveness as flame retardants in the appropriate plastics, in particular in thermoplastic polymers.
This object is achieved by a flame retardant combination comprising, as component A, a phosphinate of the formula (I) and/or a diphosphinate of the formula (II) and/or polymers of these
where
R
1
and R
2
are identical or different and are C
1
-C
6
-alkyl, linear or branched, and/or aryl;
R
3
is C
1
-C
10
-alkylene, linear or branched, C
6
-C
10
-arylene, -alkylarylene or -arylalkylene;
M is magnesium, calcium, aluminum or zinc,
m is 2 or 3;
n is 1 or 3;
x is 1 or 2
and comprising, as component B, condensation products of melamine and/or reaction products of melamine with phosphoric acid and/or reaction products of condensation products of melamine with phosphoric acid and/or comprising a mixture of these.
Surprising, it has now been found that the abovementioned higher-molecular-weight melamine derivatives and, respectively, the phosphoric-acid reaction products of these, in combination with phosphinates, have markedly more effective flame retardancy than the known combinations with the low-molecular-weight melamine derivatives, such as melamine cyanurate or melamine phosphate.
Mixtures of condensation products of melamine and, respectively, of melamine-phosphoric-acid reaction products with phosphinates have stronger synergetic effect and therefore provide more effective flame retardancy for thermoplastic polymers, in particular polyamides, polyesters and blends of PPE/HIPS than do the phosphinates alone or the mixtures previously described in PCT/EP97/01664, and also DE-A-197 34 437 and DE-A-197 37 727.
It has also been found that the novel combinations have better processing properties in polyesters, since they degrade the polyester to a markedly smaller extent during incorporation of the flame retardant than do the known combinations of phosphinates with melamine derivatives in the prior art.
R
1
and R
2
are preferably identical or different and are C
1
-C
6
-alkyl, linear or branched, and/or aryl.
R
1
and R
2
are particularly preferably identical or different and are methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl and/or phenyl.
R
3
is preferably methylene, ethylene, n-propylene, isopropylene, n-butylene, tert-butylene, n-pentylene, n-octylene, n-dodecylene,
or phenylene or naphthylene,
or methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene or tert-butylnaphthylene,
or phenylmethylene, phenylethylene, phenylpropylene or phenylbutylene.
M is preferably aluminum ions or zinc ions.
Component B is preferably condensation products of melamine,
where the condensation products of melamine are preferably melem, melam, melon and/or more highly condensed compounds thereof,
or omponent B is preferably reaction products of melamine with phosphoric acid and/or reaction products of condensation products of melamine with phosphoric acid or a mixture of these,
where the reaction products are preferably dimelamine pyrophosphate, melamine polyphosphate, melem polyphosphate, melam polyphosphate and/or mixed polysalts of this type.
Component B is particularly preferably melamine polyphosphates having chain lengths >2, in particular >10.
The invention also relates to the use of the novel flame retardant combination for rendering thermoplastic polymers flame-retardant.
For the purposes of the present invention, thermoplastic polymers are, as stated by Hans Domininghaus in “Die Kunststoffe und ihre Eigenschaften”, 5
th
Edition (1998), p. 14, polymers having molecular chains with no side branches or with side branches varying in their length and number, and which soften when heated and can be shaped in almost any desired way.
The thermoplastic polymers are preferably HIPS (high-impact polystyrene), polyphenylene ethers, polyamides, polyesters, polycarbonates and blends or polymer blends of the type ABS (acrylonitrile-butadiene-styrene) or PC/ABS (polycarbonate/acrylonitrile-butadiene-styrene) or PPE/HIPS (polyphenylene ether/high-impact polystyrene). High-impact polystyrene is a polystyrene with increased impact strength.
Particularly preferred thermoplastic polymers are polyamides, polyesters and blends of PPE/HIPS.
Thermoplastic polymers which comprise the novel flame retardant combinations and, if desired, fillers and reinforcing materials and/or other additives, as defined below, are hereinafter termed plastic molding compositions.
For the abovementioned use it is preferable for each of the components A and B, independently of one another, to be used at a concentration of from 1 to 30% by weight, based on the plastic molding composition.
For the abovementioned use it is preferable for each of the components A and B, independently of one another, to be used at a concentration of from 3 to 20% by weight, based on the plastic molding composition.
For the abovementioned use it is preferable for each of the components A and B, independently of one another, to be used at a concentration of from 3 to 15% by weight, based on the plastic molding composition.
Finally, the invention also provides a flame-retardant plastic molding composition comprising the novel flame retardant combination.
The plastic is preferably thermoplastic polymers of the type HIPS (high-impact polystyrene), polyphenylene ethers, polyamides, polyesters, polycarbonates and blends or polymer blends of the type ABS (acrylonitrile-butadiene-styrene) or PC/ABS (polycarbonate/acrylonitrile-butadiene-styrene) or PPE/HIPS (polyphenylene ether/high-impact polystyrene).
The polymers of the flame-retardant plastic molding composition are particularly preferably polyamide or polyester or blends of PPE/HIPS.
Component B is condensation products of melamine or reaction products of melamine with phosphoric acid, or reaction products of condensation products of melamine with phosphoric acid, or else a mixture of the abovementioned products.
Examples of condensation products of melamine are melem, melam and melon, and also the more highly condensed compounds of this type
Nass Bernd
Schlosser Elke
Wanzke Wolfgang
Clariant GmbH
Hanf Scott E.
Pang Andrew
Sanders Kriellion
LandOfFree
Flame-retardant combination does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flame-retardant combination, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flame-retardant combination will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2437435