DE102017215775A1 - Flame retardant polyamide compositions with high heat resistance and their use - Google Patents

Abstract

worin R₁ und R₂ Ethyl bedeuten,
M Al, Fe, TiO_p oder Zn ist,
m 2 bis 3 bedeutet, und
p = (4-m)/2 ist
- Verbindung ausgewählt aus der Gruppe der Al-, Fe-, TiO_p- oder Zn-Salze der Ethylbutylphosphinsäure, der Dibutylphosphinsäure, der Ethylhexylphosphinsäure, der Butylhexylphosphinsäure und/oder der Dihexylphosphinsäure als Komponente D, und
- Phosphonsäuresalz der Formel (II) als Komponente E

worin R₃ Ethyl bedeutet,
Met Al, Fe, TiO_q oder Zn ist,
n 2 bis 3 bedeutet, und
q = (4 - n) / 2 ist, wobei
das Röntgenpulverdiffraktrogramm der Zusammensetzungen folgende Reflexe enthält:
im Winkelbereich 2θ von 9,099° bis 9,442°, von 18,619° bis 18,984° und von 26,268° bis 26,679° und/oder im Winkelbereich 2θ von 5,112° bis 5,312°, von 6,097° bis 6,297°, von 10,082° bis 10,282°, von 10,350° bis 10,550° und von 12,308° bis 12,508° und/oder im Winkelbereich 2θ von 9,117° bis 9,317° und von 18,537° bis 18,737° und/oder im Winkelbereich 2θ von 8,300° bis 8,500° und von 14,765° bis 15,076°.
Die Polyamidzusammensetzungen lassen sich zur Herstellung von Fasern, Folien und Formkörpern, insbesondere für Anwendungen im Elektro- und Elektronikbereich einsetzen.The invention relates to flame-retardant polyamide compositions containing
Polyamide having a melting point greater than or equal to 290 ° C. as component A,
Fillers and / or reinforcing materials as component B,
- Phosphinic acid salt of the formula (I) as component C

wherein R ₁ and R _{2 are} ethyl,
M is Al, Fe, TiO _p or Zn,
m means 2 to 3, and
p = (4-m) / 2
- A compound selected from the group of Al, Fe, TiO _p - or Zn-salts of Ethylbutylphosphinsäure, the dibutylphosphinic, the Ethylhexylphosphinsäure, the Butylhexylphosphinsäure and / or the Dihexylphosphinsäure as component D, and
- Phosphonic acid salt of the formula (II) as component E

wherein R _{3 is} ethyl,
Met is Al, Fe, TiO is _q or Zn,
n 2 to 3 means, and
q = (4-n) / 2, where
the powder X-ray diffraction pattern of the compositions contains the following reflexes:
in the angular range 2θ from 9.099 ° to 9.442 °, from 18.619 ° to 18.984 ° and from 26.268 ° to 26.679 ° and / or in the angular range 2θ of 5.125 ° to 5.312 °, from 6.097 ° to 6.297 °, from 10.082 ° to 10.282 °, from 10.350 ° to 10.5050 ° and from 12.308 ° to 12.508 ° and / or Angular range 2θ of 9.117 ° to 9.317 ° and 18.537 ° to 18.737 ° and / or in the angular range 2θ of 8.300 ° to 8.500 ° and 14.765 ° to 15.076 °.
The polyamide compositions can be used for the production of fibers, films and moldings, in particular for applications in the electrical and electronics sector.

Description

The present invention relates to flame-retardant polyamide compositions and moldings produced therefrom, which are characterized by a very good flame retardancy, a high heat resistance and very good electrical properties.

Flammable plastics generally have to be equipped with flame retardants in order to achieve the high flame retardance requirements demanded by plastics processors and in part by the legislature. Preferably - also for ecological reasons - non-halogenated flame retardant systems are used, which form little or no flue gases.

Among these flame retardants, the salts of phosphinic acids (phosphinates) have proven to be particularly effective for thermoplastic polymers ( DE 2 252 258 A and DE 2 447 727 A ).

In addition, synergistic combinations of phosphinates with certain nitrogenous compounds are known to be more effective than flame retardants in a variety of polymers as the flame retardant phosphinates ( WO-2002/28953 A1 such as DE 197 34 437 A1 and DE 197 37 727 A1 ).

From the US 7,420,007 B2 It is known that dialkylphosphinates containing a small amount of selected telomers are suitable as flame retardants for polymers, wherein the polymer undergoes only a rather low degradation during incorporation of the flame retardant into the polymer matrix.

Flame retardants must often be added in high dosages in order to ensure a sufficient flame retardancy of the plastic according to international standards. Due to their chemical reactivity, which is required for flame retardancy at high temperatures, flame retardants, especially at higher dosages, can affect the processing stability of plastics. It can lead to increased polymer degradation, crosslinking reactions, outgassing or discoloration.

From the WO 98/03515 A1 X-ray reflections of high-temperature modifications of aluminum salts of phosphinic acids are known. These phosphinic acid salts are produced at high temperature.

From the WO 2014/135256 A1 Polyamide molding compositions are known which have a significantly improved thermal stability, a reduced tendency to migrate and good electrical and mechanical properties.

However, flame-retardant phosphine-containing polyamide compositions have so far failed to achieve all the required properties at the same time, such as good electrical properties, excellent heat distortion resistance and effective flame retardancy.

It was therefore an object of the present invention to provide flame-retardant polyamide compositions based on phosphinate-containing flame retardant systems which have all the aforementioned properties at the same time and which in particular have good electrical values (GWFI, CTI), excellent heat resistance (HDT-A) and high flame retardancy. characterized by the shortest possible afterburning times (UL-94), own.

• - Polyamid mit einem Schmelzpunkt von größer gleich 290 °C, vorzugsweise von größer gleich 290 °C und ganz besonders bevorzugt von größer gleich 300 °C, als Komponente A,
• - Füllstoffe und/oder Verstärkungsstoffe, vorzugsweise Glasfasern, als Komponente B,
• - Phosphinsäuresalz der Formel (I) als Komponente C
  
  worin R₁ und R₂ Ethyl bedeuten, M Al, Fe, TiO_p oder Zn ist, m 2 bis 3, vorzugsweise 2 oder 3, bedeutet, und p = (4 - m) / 2 ist
• - Verbindung ausgewählt aus der Gruppe der Al-, Fe-, TiO_p- oder Zn-Salze der Ethylbutylphosphinsäure, der Dibutylphosphinsäure, der Ethylhexylphosphinsäure, der Butylhexylphosphinsäure und/oder der Dihexylphosphinsäure als Komponente D, und
• - Phosphonsäuresalz der Formel (II) als Komponente E
  
  worin R₃ Ethyl bedeutet, Met Al, Fe, TiO_q oder Zn ist, n 2 bis 3, vorzugsweise 2 oder 3, bedeutet, und q = (4 - n) / 2 ist, wobei das Röntgenpulverdiffraktrogramm der Zusammensetzungen folgende Reflexe enthält:
  • im Winkelbereich 2θ von 9,099° bis 9,442°, von 18,619° bis 18,984° und von 26,268° bis 26,679° und/oder
  • im Winkelbereich 2θ von 5,112° bis 5,312°, von 6,097° bis 6,297°, von 10,082° bis 10,282°, von 10,350° bis 10,550° und von 12,308° bis 12,508° und/oder im Winkelbereich 2θ von 9,117° bis 9,317° und von 18,537° bis 18,737° und/oder im Winkelbereich 2θ von 8,300° bis 8,500°.

The invention therefore provides flame-retardant polyamide compositions containing

• Polyamide having a melting point greater than or equal to 290 ° C., preferably greater than or equal to 290 ° C., and very particularly preferably greater than or equal to 300 ° C., as component A,
• Fillers and / or reinforcing materials, preferably glass fibers, as component B,
• - Phosphinic acid salt of the formula (I) as component C
  
  wherein R ₁ and R _{2 are} ethyl, M is Al, Fe, TiO, or Zn _p, m is 2 to 3, preferably 2 or 3, group, and p = (4 - m) / 2
• - A compound selected from the group of Al, Fe, TiO _p - or Zn-salts of Ethylbutylphosphinsäure, the dibutylphosphinic, the Ethylhexylphosphinsäure, the Butylhexylphosphinsäure and / or the Dihexylphosphinsäure as component D, and
• - Phosphonic acid salt of the formula (II) as component E
  
  wherein R _{3 is} ethyl, Met is Al, Fe, TiO _q or Zn, n is 2 to 3, preferably 2 or 3, and q = (4 - n) / 2, wherein the powder X-ray diffraction pattern of the compositions contains the following reflexes:
  • in the angular range 2θ from 9.099 ° to 9.442 °, from 18.619 ° to 18.984 ° and from 26.268 ° to 26.679 ° and / or
  • in the angular range 2θ of 5.125 ° to 5.312 °, from 6.097 ° to 6.297 °, from 10.082 ° to 10.282 °, from 10,350 ° to 10,550 ° and from 12,308 ° to 12,508 ° and / or in the angular range 2θ of 9.117 ° to 9.317 ° and from 18.537 ° to 18.737 ° and / or in the angular range 2θ of 8.300 ° to 8.500 °.

The X-ray spectra are measured with an X-ray powder diffractometer, for example with an X'Pert-MPD device from Phillips. The sample is irradiated with Cu-K-alpha radiation and the step time is 1 second.

Preferred polyamide compositions according to the invention are those whose X-ray powder diffractogram contains the following reflections: in the angle range 2θ of 9.099 ° to 9.442 °, of 18.619 ° to 18.984 ° and of 26.268 ° to 26.679 °.

In the polyamide composition of the invention, the proportion of component A is usually 25 to 95 wt .-%, preferably 25 to 75 wt .-%.

In the polyamide composition of the invention, the proportion of component B is usually 1 to 45 wt .-%, preferably 20 to 40 wt .-%.

In the polyamide composition of the invention, the proportion of component C is usually 1 to 35 wt .-%, preferably 5 to 20 wt .-%.

In the polyamide composition of the invention, the proportion of component D is usually 0.01 to 3 wt .-%, preferably 0.05 to 1.5 wt .-%.

In the polyamide composition according to the invention, the proportion of component E is usually 0.001 to 1 wt .-%, preferably 0.01 to 0.6 wt .-%.

The percentages for the proportions of components A to E are based on the total amount of the polyamide composition.

• - der Anteil von Komponente A 25 bis 95 Gew.-%,
• - der Anteil von Komponente B 1 bis 45 Gew.-%,
• - der Anteil von Komponente C 1 bis 35 Gew.-%,
• - der Anteil von Komponente D 0,01 bis 3 Gew.-%, und
• - der Anteil von Komponente E 0,001 bis 1 Gew.-%

beträgt, wobei die Prozentangaben sich auf die Gesamtmenge der Polyamidzusammensetzung beziehen.Flame retardant polyamide compositions are preferred in which

• - the proportion of component A is from 25 to 95% by weight,
• the proportion of component B is from 1 to 45% by weight,
• the proportion of component C 1 to 35% by weight,
• the proportion of component D is from 0.01 to 3% by weight, and
• the proportion of component E is 0.001 to 1% by weight

is, wherein the percentages are based on the total amount of the polyamide composition.

• - der Anteil von Komponente A 25 bis 75 Gew.-%,
• - der Anteil von Komponente B 20 bis 40 Gew.-%,
• - der Anteil von Komponente C 5 bis 20 Gew.-%,
• - der Anteil von Komponente D 0,05 bis 1,5 Gew.-%, und
• - der Anteil von Komponente E 0,01 bis 0,6 Gew.-%

beträgt.Particularly preferred are flame retardant polyamide compositions in which

• the proportion of component A is from 25 to 75% by weight,
• the proportion of component B is from 20 to 40% by weight,
• the proportion of component C is from 5 to 20% by weight,
• the proportion of component D is 0.05 to 1.5% by weight, and
• the proportion of component E is from 0.01 to 0.6% by weight

is.

Preferred salts of component C are those in which M ^{m +} Zn ²⁺ , Fe ³⁺ or in particular Al ³⁺ .

Preferred salts of component D are zinc, iron or in particular aluminum salts.

Preferably used salts of component E are those in which Met ^{n +} Zn ²⁺ , Fe ³⁺ or in particular Al ³⁺ .

Very particular preference is given to flame-retardant polyamide compositions in which M and Met are Al, m and n are 3 and in which the compounds of component D are present as aluminum salts.

In a preferred embodiment, the above-described flame retardant polyamide compositions contain inorganic phosphonate as further component F.

The use of the inventively used as component F inorganic phosphonates or salts of phosphorous acid (phosphites) are known as flame retardants. So revealed WO 2012/045414 A1 Flammschutzmittelkombinationen, which in addition to phosphinic salts also salts of phosphorous acid (= phosphites).

The inorganic phosphonate (component F) preferably corresponds to the general formulas (IV) or (V) [(HO) PO ₂ ] ^2- _{p / 2} cat ^{p +} (IV) [(HO) ₂ PO] ^- _p cat ^{p +} (V) wherein Kat is a p-valent cation, in particular a cation of an alkali metal, alkaline earth metal, an ammonium cation and / or a cation of Fe, Zn or in particular Al including the cations Al (OH) or Al (OH) ₂ , and p 1, 2, 3 or 4 means.

The inorganic phosphonate (component F) is preferably aluminum phosphite [Al (H ₂ PO ₃ ) ₃ ], secondary aluminum phosphite [ Al ₂ (HPO ₃ ) ₃ ], basic aluminum phosphite [Al (OH) (H ₂ PO ₃ ) ₂ * 2aq], aluminum phosphite tetrahydrate [Al ₂ (HPO ₃ ) ₃ * 4aq], aluminum phosphonate, Al ₇ (HPO ₃ ) ₉ ( OH) ₆ (1,6-hexanediamine) _1.5 * 12H ₂ O, Al ₂ (HPO ₃ ) ³ * xAl ₂ O ₃ * nH ₂ O with x = 2.27-1 and / or Al ₄ H ₆ P ₁₆ o ₁₈ .

The inorganic phosphonate (component F) is preferably also aluminum phosphites of the formulas (VI), (VII) and / or (VIII) Al ₂ (HPO ₃ ) ₃ x (H ₂ O) _q (VI), where q is 0 to 4, Al ₂ , ₀₀ M _z (HPO ₃ ) _y (OH) _v x (H ₂ O) _w (VII), wherein M is alkali metal cations, z is 0.01 to 1.5 and y is 2.63 to 3.5 and v is 0 to 2 and w is 0 to 4; Al _2,00 (HPO ₃ ) _u (H ₂ PO ₃ ) _t x (H ₂ O) _s (VIII), where u is 2 to 2.99 and t is 2 to 0.01 and s is 0 to 4,
and or
aluminum phosphite to [Al (H2PO _{3) 3]} to secondary aluminum phosphite [Al ₂ (HPO _{3) 3]} to basic aluminum phosphite [Al (OH) (H ₂ PO _{3) 2} * 2aq] to
Aluminum phosphite tetrahydrate [Al ₂ (HPO ₃ ) ₃ * 4aq] to give aluminum phosphonate to give Al ₇ (HPO ₃ ) ₉ (OH) ₆ (1,6-hexanediamine) _1.5 * 12H ₂ O, Al ₂ (HPO ₃ ) ³ * xAl ₂ O ₃ * nH ₂ O with x = 2.27 - 1 and / or Al ₄ H ₆ P ₁₆ O ₁₈ .

Preferred inorganic phosphonates (component F) are water-insoluble or sparingly soluble salts.

Particularly preferred inorganic phosphonates are aluminum, calcium and zinc salts.

Component F is particularly preferably a reaction product of phosphorous acid and an aluminum compound.

Particularly preferred components F are aluminum phosphites having the CAS numbers 15099-32-8, 119103-85-4, 220689-59-8, 56287-23-1, 156024-71-4, 71449-76-8 and 15099-32 -8th.

The preparation of the preferably used aluminum phosphites is carried out by reacting an aluminum source with a phosphorus source and optionally a template in a solvent at 20-200 ° C for a period of up to 4 days. The aluminum source and the phosphorus source are mixed for 1 to 4 hours, heated under hydrothermal conditions or at reflux, filtered off, washed and z. B. dried at 110 ° C.

Preferred aluminum sources are aluminum isopropoxide, aluminum nitrate, aluminum chloride, aluminum hydroxide (eg pseudoboehmite).

Preferred phosphorous sources are phosphorous acid, (acidic) ammonium phosphite, alkali phosphites or alkaline earth phosphites.

Preferred alkali metal phosphites are disodium phosphite, disodium phosphite hydrate, trisodium phosphite, potassium hydrogen phosphite

Preferred Dinatriumphosphithydrat is Brüggolen ^® H10 of the company. Brüggemann.

Preferred templates are 1,6-hexanediamine, guanidine carbonate or ammonia.

Preferred alkaline earth metal phosphite is calcium phosphite.

The preferred ratio of aluminum to phosphorus to solvent is 1: 1: 3.7 to 1: 2.2: 100 mol. The ratio of aluminum to template is 1: 0 to 1: 17 mol. The preferred pH of the reaction solution is 3 to 9. Preferred solvent is water.

Particularly preferably, the same salt of phosphinic acid as the phosphorous acid is used in the application, so z. For example, aluminum diethylphosphinate together with aluminum phosphite or Zinkdiethylphosphinat together with zinc phosphite.

worin Me Fe, TiO_r, Zn oder insbesondere Al ist,
o 2 bis 3, vorzugsweise 2 oder 3, bedeutet, und
r = (4 - o) / 2 ist.In a preferred embodiment, the above-described flame retardant polyamide compositions contain, as component F, a compound of the formula (III)

in which Me is Fe, TiO _r , Zn or in particular Al,
o is 2 to 3, preferably 2 or 3, and
r = (4-o) / 2.

Preferred compounds of the formula III are those in which Me is ^{O +} Zn ²⁺ , Fe ³⁺ or in particular Al ³⁺ .

Component F is preferably present in an amount of from 0.005 to 10% by weight, more preferably in an amount of from 0.02 to 5% by weight, based on the total amount of the polyamide composition.

The flame-retardant polyamide compositions according to the invention have a high heat deflection temperature (HDT-A) DIN EN ISO 75-3 of at least 280 ° C, preferably of at least 290 ° C and more preferably of at least 300 ° C on.

Preference is given to flame retardant polyamide compositions according to the invention which have a Comparative Tracking Index, measured in accordance with International Electrotechnical Commission Standard IEC-60112/3, of greater than or equal to 500 volts.

Likewise preferred flame-retardant polyamide compositions according to the invention achieve a rating of V0 according to UL-94, in particular measured on moldings of 3.2 mm to 0.4 mm thickness.

Further preferred flame retardant polyamide compositions according to the invention have a Glow Wire Flammability Index according to IEC 60695-2-12 of at least 960 ° C., in particular measured on shaped parts of 0.75-3 mm thickness.

The polyamide compositions according to the invention contain as component A one or more thermoplastic polyamides having a melting point greater than or equal to 290 ° C. The melting point is determined by means of differential scanning calorimetry (DSC) at a heating rate of 10 K / second.

According to Hans Domininghaus in "Die Kunststoffe und ihre Eigenschaften", 5th edition (1998), page 14, thermoplastic polyamides are understood to be polyamides whose molecular chains have no or even more or less long and in number different side branches, which in soften the heat and are almost arbitrarily malleable.

The inventively preferred polyamides can be prepared by various methods and synthesized from very different building blocks and in special applications alone or in combination with processing aids, stabilizers or polymeric alloying partners, preferably elastomers, are equipped to materials with specially set property combinations. Also suitable are blends with proportions of other polymers, preferably of polyethylene, polypropylene, ABS, it being possible where appropriate to use one or more compatibilizers. The properties of the polyamides can be improved by adding elastomers, for. In terms of impact strength, especially if they are reinforced polyamides. The multitude of possible combinations enables a very large number of products with different properties.

For the preparation of polyamides, a variety of procedures have become known, depending on the desired end product different monomer units, various chain regulators for setting a desired molecular weight or monomers with reactive groups are used for later intended post-treatments.

The technically relevant processes for the preparation of polyamides usually run via the polycondensation in the melt. In this context, the hydrolytic polymerization of lactams is understood as a polycondensation.

Preferred polyamides to be used as component A are partially crystalline and aromatic or partially aromatic polyamides which can be prepared starting from diamines and dicarboxylic acids and / or lactams with at least 5 ring members or corresponding amino acids.

As starting materials are mainly aromatic dicarboxylic acids, preferably isophthalic acid and / or terephthalic acid or its polyamide-forming derivatives, such as salts, into consideration, alone or in combination with aliphatic dicarboxylic acids or their polyamide-forming derivatives, preferably adipic acid, 2,2,4- and 2,4 , 4-trimethyladipic acid, azelaic acid and / or sebacic acid, together with aliphatic and / or aromatic diamines, preferably tetramethylenediamine, hexamethylenediamine, 1,9-nonanediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, the isomeric diaminodicyclohexylmethanes, Diaminodicyclohexylpropanen, bis (aminomethyl) cyclohexanes, phenylenediamines and / or xylylenediamines, and / or with aminocarboxylic acids, preferably aminocaproic acid or the corresponding lactams. Copolyamides of several of the monomers mentioned are included.

Also particularly suitable are aromatic and partially aromatic polyamides, ie compounds in which at least some of the repeat units are composed of aromatic structural units. These polymers may optionally be used in combination with smaller amounts, such as up to 20% by weight, based on the amount of polyamide, of aliphatic polyamides, in particular PA6 and / or PA6.6, if therewith a heat deflection temperature of the molding composition or of the latter obtained molded body reached at least 290 ° C.

Preferably suitable are aromatic polyamides starting from xylylenediamine and adipic acid; or polyamides prepared from hexamethylenediamine and iso- and / or terephthalic acid and optionally an elastomer as modifier, e.g. As poly-2,4,4-trimethylhexamethylene terephthalamide or poly-m-phenylene-isophthalamide, block copolymers of the aforementioned polyamides with polyolefins, olefin copolymers, ionomers or chemically bonded or grafted elastomers, or with polyethers, such as. B. with polyethylene glycol, polypropylene glycol or polytetramethylene glycol. Further modified with EPDM or ABS polyamides or copolyamides; and during processing condensed polyamides ("RIM polyamide systems").

In a preferred embodiment, component A is an aromatic or partially aromatic polyamide or a mixture of a plurality of aromatic or partially aromatic polyamides or a mixture of polyamide 6.6 and one or more aromatic or partially aromatic polyamides.

The polymers which can be used in addition to the thermoplastic polyamide in a preferred embodiment may be admixed in the melt or applied to the surface of customary additives, in particular mold release agents, stabilizers and / or flow aids. Starting materials for the thermoplastic polyamides of component A may be synthetically z. B. from petrochemical raw materials and / or chemical or biochemical processes resulting from renewable resources

As component B fillers and / or preferably reinforcing materials are used, preferably glass fibers. It is also possible to use mixtures of two or more different fillers and / or reinforcing materials.

Preferred fillers are mineral particulate fillers based on talc, mica, silicate, quartz, titanium dioxide, wollastonite, kaolin, amorphous silicas, nanoscale minerals, particularly preferably montmorillonites or nano-boehmites, magnesium carbonate, chalk, feldspar, glass beads and / or barium sulfate. Particular preference is given to mineral particulate fillers based on talc, wollastonite and / or kaolin.

Furthermore, needle-shaped mineral fillers are also used with particular preference. According to the invention, needle-shaped mineral fillers are understood to mean a mineral filler with a pronounced needle-like character. Needlelike wollastonites are preferred. Preferably, the mineral has a length to diameter ratio of 2: 1 to 35: 1, more preferably from 3: 1 to 19: 1, particularly preferably from 4: 1 to 12: 1. The mean particle size of the needle-shaped mineral fillers used according to the invention as component B is preferably less than 20 μm, particularly preferably less than 15 μm, particularly preferably less than 10 μm, determined using a CILAS granulometer.

The components B preferably used according to the invention are reinforcing materials. These may be, for example, reinforcing materials based on carbon fibers and / or glass fibers.

In a preferred embodiment, the filler and / or reinforcing agent may be surface-modified, preferably with a primer or an adhesion promoter system, particularly preferably based on silane. In particular, when using glass fibers, polymer dispersions, film formers, branching agents and / or glass fiber processing aids may be used in addition to silanes.

The glass fibers preferably used according to the invention as component B may be short glass fibers and / or long glass fibers. As short or long glass fibers, cut fibers can be used. Short glass fibers can also be used in the form of ground glass fibers. In addition, glass fibers can also be used in the form of continuous fibers, for example in the form of rovings, monofilaments, filament yarns or twines, or glass fibers can be used in the form of textile fabrics, for example as glass fabric, as glass braid or as glass mat.

Typical fiber lengths for short glass fibers prior to incorporation into the polyamide matrix range from 0.05 to 10 mm, preferably from 0.1 to 5 mm. After incorporation into the polyamide matrix, the length of the glass fibers has decreased. Typical fiber lengths for short glass fibers after incorporation into the polyamide matrix range from 0.01 to 2 mm, preferably from 0.02 to 1 mm.

The diameters of the individual fibers can vary within wide ranges. Typical diameters of the individual fibers range from 5 to 20 μm.

The glass fibers can have any cross-sectional shapes, for example round, elliptical, n-cornered or irregular cross-sections. Glass fibers with mono- or multilobal cross-sections can be used.

Glass fibers can be used as continuous fibers or as cut or ground glass fibers.

The glass fibers themselves, regardless of their cross-sectional area and their length, can be selected, for example, from the group of E-glass fibers, A-glass fibers, C-glass fibers, D-glass fibers, M-glass fibers, S-glass fibers, R-glass fibers and / or ECR glass fibers, the E glass fibers, R glass fibers, S glass fibers and ECR glass fibers being particularly preferred. The glass fibers are preferably provided with a size which preferably contains polyurethane as film former and aminosilane as adhesion promoter.

Particularly preferably used E glass fibers have the following chemical composition: SiO ₂ 50-56%; Al ₂ O ₃ 12-16%; CaO 16-25%; MgO ≤ 6%; B ₂ O ₃ 6-13%; F ≤ 0.7%; Na ₂ O 0.3-2%; K ₂ O 0.2-0.5%; Fe ₂ O ₃ 0.3%.

Particularly preferably used R glass fibers have the following chemical composition: SiO ₂ 50-65%; Al ₂ O ₃ 20-30%; CaO 6-16%; MgO 5-20%; Na ₂ O 0.3-0.5%; K ₂ O 0.05-0.2%; Fe ₂ O ₃ 0.2-0.4%, TiO ₂ 0.1-0.3%.

Particularly preferably used ECR glass fibers have the following chemical composition: SiO ₂ 57.5-58.5%; Al ₂ O ₃ 17.5-19.0%; CaO 11.5-13.0%; MgO 9.5-11.5.

The salts of diethylphosphinic acid used according to the invention as component C are known flameproofing agents for polymeric molding compositions.

Salts of diethylphosphinic acid with fractions of the phosphinic and phosphonic acid salts used according to the invention as components D and E are known flame retardants. The preparation of this combination of substances is z. In US 7,420,007 B2 described.

The salts of diethylphosphinic acid of component C used according to the invention may contain small amounts of salts of component D and of salts of component E, for example up to 10% by weight of component D, preferably 0.01 to 6% by weight, and in particular 0 , 2 to 2.5% by weight thereof, and up to 10% by weight of Component E, preferably 0.01 to 6% by weight, and more preferably 0.2 to 2.5% by weight thereof on the amount of components C, D and E.

The salts of ethylphosphonic acid used according to the invention as component E are likewise known, for example from, as additives to diethyl phosphates in flame retardants for polymeric molding compositions WO 2016/065971 A1 ,

In a further preferred embodiment, components C, D and E are in particulate form, the average particle size (d ₅₀ ) being 1 to 100 μm.

Preferably, the salts of diethylphosphinic acid used according to the invention as component C according to the in the DE 103 59 815 A1 prepared method described.

The polyamide compositions according to the invention may contain as component G further additives. Preferred components G for the purposes of the present invention are antioxidants, UV stabilizers, gamma ray stabilizers, hydrolysis stabilizers, co-stabilizers for antioxidants, antistatic agents, emulsifiers, nucleating agents, plasticizers, processing aids, impact modifiers, dyes, pigments and / or other flameproofing agents which are differ from components C, D, E and F.

The further additives are known per se as additives to polyamide compositions and can be used alone or mixed or in the form of masterbatches.

The abovementioned components A, B, C, D, E and optionally F and / or G can be processed in a wide variety of combinations with the flame-retardant polyamide composition according to the invention. It is thus possible to mix the components into the polyamide melt at the beginning or at the end of the polycondensation or in a subsequent compounding process. Furthermore, there are processing processes in which individual components are added later. This is especially practiced when using pigment or additive masterbatches. In addition, it is possible, in particular pulverulent components aufzutrommeln on the possibly by the drying process warm polymer granules.

Also, two or more of the components of the polyamide compositions of the present invention may be combined by mixing prior to incorporation into the polyamide matrix. In this case, conventional mixing units can be used, in which the components in a suitable mixer, for. B. 0.01 to 10 hours at 0 to 300 ° C mixed.

From two or more of the components of the polyamide compositions according to the invention it is also possible to produce granules which can subsequently be introduced into the polyamide matrix.

For this purpose, two or more components of the polyamide composition according to the invention with granulation aids and / or binders can be processed into granules in a suitable mixer or granulating plate.

The initially formed crude product can be dried in a suitable dryer or tempered for further grain buildup.

The polyamide composition of the present invention or two or more components thereof may be prepared by roll compaction in one embodiment.

The polyamide composition according to the invention or two or more components thereof may in one embodiment be prepared by mixing, extruding, chopping (or optionally breaking and classifying) the ingredients and drying (and optionally coating).

The polyamide composition of the present invention or two or more components thereof may be prepared by spray granulation in one embodiment.

The flame-retardant polymer molding composition according to the invention is preferably in granular form, for. B. as an extrudate or as a compound before. The granules preferably have a cylindrical shape with a circular, elliptical or irregular base, spherical shape, pillow shape, cube shape, cuboid shape, prism shape.

Typical length to diameter ratio of the granules are 1 to 50 to 50 to 1, preferably 1 to 5 to 5 to 1.

The granules preferably have a diameter of 0.5 to 15 mm, more preferably of 2 to 3 mm and preferably a length of 0.5 to 15 mm, particularly preferably 2 to 5 mm.

The invention also relates to moldings produced from the above-described flame-retardant polyamide composition comprising the components A, B, C, D and E and optionally components F and / or G.

The molded parts according to the invention may be any desired formations. Examples thereof are fibers, films or moldings obtainable from the flame-retardant polyamide molding compositions according to the invention by any desired molding processes, in particular by injection molding or extrusion.

The preparation of the flame-retardant polyamide molded body according to the invention can be carried out by any desired molding process. Examples include injection molding, pressing, foam injection molding, internal gas pressure injection molding, blow molding, film casting, calendering, lamination or coating at higher temperatures with the flame-retardant polyamide molding compound.

The molded parts are preferably injection-molded parts or extruded parts.

The flame-retardant polyamide compositions according to the invention are suitable for the production of fibers, films and moldings, in particular for applications in the electrical and electronics sector.

The invention preferably relates to the use of the flame-retardant polyamide compositions according to the invention in or for connectors, current-carrying parts in power distributors (RCD), circuit boards, potting compounds, power connectors, circuit breakers, lamp housings, LED housings, capacitor housings, bobbins and fans, protective contacts, plugs, in / on circuit boards, housings for plugs, cables, flexible printed circuit boards, charging cables for mobile phones, engine covers or textile coatings.

The invention likewise preferably relates to the use of the flame-retardant polyamide compositions according to the invention for the production of shaped articles in the form of components for the electrical / electronics sector, in particular for parts of printed circuit boards, housings, foils, lines, switches, distributors, relays, resistors, capacitors, coils, lamps , Diodes, LEDs, transistors, connectors, controllers, memories and sensors, in the form of large-area components, in particular of housing parts for control cabinets and in the form of agile designed components with sophisticated geometry.

The wall thickness of the shaped bodies according to the invention can typically be up to 10 mm. Particularly suitable are moldings with less than 1.5 mm wall thickness, more preferably less than 1 mm wall thickness and particularly preferably less than 0.5 mm wall thickness.

The following examples illustrate the invention without limiting it.

The following examples illustrate the invention without limiting it.

Used components

Commercially available polyamides (component A):

Polyamide 6T / 6.6 (Melting range 310-320 ° C): Vestamid ^® HT plus 1000 (Evonik) Polyamide 6T / 6I (amorphous): Grivory ^® G21, (EMS)

Glass fibers (component B):

Glass fibers PPG HP 3610 10μm diameter, 4.5mm length (PPG, NL),

Flame retardant FM 1 (components C, D and E):

Aluminum salt of diethylphosphinic acid containing 0.9 mol% of aluminum ethyl butylphosphinate and 0.5 mol% of aluminum ethyl phosphonate prepared according to Example 3 of US 7,420,007 B2

Flame retardant FM 2 (components C, D and E):

Aluminum salt of diethylphosphinic acid containing 2.7 mol% of aluminum-Ethylbutylphospinat and 0.8 mol% of aluminum ethylphosphonate prepared according to Example 4 of US 7,420,007 B2

Flame retardant FM 3 (components C, D and E):

Aluminum salt of diethylphosphinic acid containing 0.5 mol% of aluminum ethyl butylphosphinate and 0.05 mol% of aluminum ethyl phosphonate prepared by the method according to US 7,420,007 B2

Flame retardant FM 4 (components C, D and E):

Aluminum salt of diethylphosphinic acid containing 10 mol% of aluminum ethyl butylphosphate and 5 mol% of aluminum ethyl phosphonate prepared by the method according to US 7,420,007 B2

Flame retardant FM 5 (component C):

Aluminum salt of diethylphosphinic acid prepared in analogy to Example 1 of DE 196 07 635 A1

Flame retardant FM 6 (components C and E):

Aluminum salt of diethylphosphinic acid containing 8.8 mol% of aluminum ethylphosphonate prepared according to Example 2 of DE 10 2010 018 864 A1

Flame retardant FM 7 (component F):

Aluminum salt of phosphonic acid prepared according to Example 1 of DE 10 2011 120 218 A1

Production, processing and testing of flame retardant polyamide molding compounds

The flame retardant components were mixed together in the proportions shown in the tables and incorporated via the side feeder of a twin-screw extruder (Leistritz ZSE 27 / 44D type) at temperatures of 310 to 330 ° C. The glass fibers were added via a second side feed. The homogenized polymer strand was stripped off, cooled in a water bath and then granulated.

After sufficient drying, the molding materials were processed on an injection molding machine (type Arburg 320 C Allrounder) at mass temperatures of 300 to 320 ° C to test specimens and tested and classified by the UL 94 test (Underwriter Laboratories) on flame retardancy and classified. In addition to the classification, the afterburning time was also indicated.

The Comparative Tracking Index of the molded parts was determined according to the International Electrotechnical Commission Standard IEC-60112/3.

The Glow Wire Flammability Index (GWIT Index) was determined according to the IEC-60695-2-12 standard.

The heat deflection temperature (HDT) was after DIN EN ISO 75-3 determined.

When determining the HDT, a standard test piece with a rectangular cross-section is subjected to a three-point bend under constant load. Depending on the height of the specimen, σ _f of 1.80 (method A), 0.45 (method B) or 8.00 N / mm ² (method C) is applied by means of weights and / or springs of a force in order to achieve a so-called edge fiber tension. Subsequently, the loaded samples are subjected to heating at a constant heating rate of 120 K / h (or 50 K / h). If the deflection of the sample reaches an edge fiber strain of 0.2%, the associated temperature corresponds to the HDT value.

The X-ray spectra (X-ray powder diffractograms, "XRD values") of the polyamide compositions are measured using an X-ray powder diffractometer (X'Pert-MPD, Phillips). The sample was irradiated with Cu-K-alpha radiation and the step time was 1 second.

All tests of the respective series were carried out under similar conditions (such as temperature programs, screw geometries and injection molding parameters), unless otherwise stated.

Examples 1-5 and Comparative Examples V1-V3 with PA 6T / 6.6

The results of the experiments with PA 6T / 6.6 molding compositions are listed in the examples listed in the table below. All amounts are expressed as weight percent and refer to the polyamide molding compound including the flame retardants and reinforcing agents. Table 1: PA 6T / 6.6 GF 30 test results (1-5 according to the invention, V1-V3 comparisons) Example no. 1 2 3 4 5 V1 V2 V3 A: PA 6T / 6.6 58 58 58 58 58 58 55 58 B: glass fibers HP3610 30 30 30 30 30 30 30 30 C + D + E: FM 1 12 - - - - - - - C + D + E: FM 2 - 12 - - 11 - - - C + D + E: FM 3 - - 12 - - - - - C + D + E: FM 4 - - - 12 - - - - C: FM 5 - - - - - - - 12 C + E: FM 6 - - - - - 12 15 - Q: FM 7 - - - - 1 - - - HDT-A [° C] 290 290 290 290 290 280 290 280 UL 94 0.4 mm / time [sec.] V-0/28 V-0/22 V-0/42 V-0/28 V-0/14 V-0/46 V-0/41 V-0/49 GWFI [° C] 960 960 960 960 960 900 900 900 CTI [Volt] 600 600 600 600 600 500 600 500 XRD 2θ [°] all samples showed reflections in the range of 9.099 ° to 9.442 °, from 18.619 ° to 18.984 ° and from 26.268 ° to 26.679 °

The polyamide compositions according to the invention of Examples 1 to 5 are molding compositions which reach the fire classification UL 94 V-0 at 0.4 mm, while having CTI 600 volts, GWFI 960 ° C and HDT-A 290 ° C. The addition of component F in Example 5 leads to a further improvement of the flame retardancy expressed by a reduced afterburning time.

The omission of Component D in Comparative Example V1 resulted in reduced CTI, GWFI, and HDT / A values, in addition to an extended afterburn time compared to Examples 1-4.

In Comparative Example C2, an improvement in the afterburning time was achieved by increasing the concentration of components C and E compared to Example V2. However, this polyamide composition still showed a lower GWFI value compared to Example 2.

The omission of components D and E in Comparative Example C3 resulted in reduced CTI, GWFI and HDT / A values, in addition to an extended afterburn time compared to Examples 1-4.

Examples 6-10 and Comparative Examples V4-V6 with PA 6T / 6I

The results of the experiments with PA 6T / 6I molding compositions are listed in the examples listed in the table below. All amounts are expressed as weight percent and refer to the polyamide molding compound including the flame retardants and reinforcing agents. Table 2: PA 6T / 6I GF 30 test results (6-10 according to the invention, V4-V6 comparisons) Example no. 6 7 8th 9 10 V4 V5 V6 A: PA 6T / 6I 58 58 58 58 58 58 55 58 B: glass fibers HP3610 30 30 30 30 30 30 30 30 C + D + E: FM 1 12 - - - - - - - C + D + E: FM 2 - 12 - - 11 - - - C + D + E: FM 3 - - 12 - - - - - C + D + E: FM 4 - - - 12 - - - - C: FM 5 - - - - - - - 12 C + E: FM 6 - - - - - 12 15 - Q: FM 7 - - - - 1 - - - HDT-A [° C] 300 300 300 300 300 290 295 290 UL 94 0.4 mm / time [sec.] V-0/26 V-0/20 V-0/39 V-0/26 V-0/11 V-0/44 V-0/38 V-0/48 GWFI [° C] 960 960 960 960 960 900 950 900 CTI [Volt] 600 600 600 600 600 500 600 500 XRD 2θ [°] all samples showed reflections in the range of 9.099 ° to 9.442 °, from 18.619 ° to 18.984 ° and from 26.268 ° to 26.679 °

The polyamide compositions according to the invention of Examples 6 to 10 are molding compositions which reach the fire classification UL 94 V-0 at 0.4 mm, while having CTI 600 volts, GWFI 960 ° C. and HDT-A 300 ° C. The addition of component F in Example 10 leads to a further improvement of the flame retardancy expressed by a reduced afterburning time.

The omission of component D in Comparative Example C4 resulted in reduced HDT-A, GWFI and CTI values in addition to an extended afterburn time compared to Examples 6-9.

In Comparative Example C5, an improvement in the afterburning time was achieved by increasing the concentration of components C and E compared to Example V4. However, this polyamide composition still showed reduced HDT-A and GWFI values compared to Example 7.

The omission of Components D and E in Comparative Example C6 resulted in reduced HDT-A, GWFI and CTI values in addition to an extended afterburn time compared to Examples 6-9.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2252258 A [0003]
• DE 2447727 A [0003]
• WO 2002/28953 A1 [0004]
• DE 19734437 A1 [0004]
• DE 19737727 A1 [0004]
• US 7420007 B2 [0005, 0077, 0107, 0108, 0109, 0110]
• WO 9803515 A1 [0007]
• WO 2014/135256 A1 [0008]
• WO 2012/045414 A1 [0027]
• WO 2016/065971 A1 [0079]
• DE 10359815 A1 [0081]
• DE 19607635 A1 [0111]
• DE 102010018864 A1 [0112]
• DE 102011120218 A1 [0113]

Cited non-patent literature

• DIN EN ISO 75-3 [0047, 0118]

Claims (17)

Flame retardant polyamide compositions comprising - polyamide having a melting point of greater than or equal to 290 ° C as component A, - fillers and / or reinforcing agents as component B, - phosphinic acid salt of the formula (I) as component C.

wherein R ₁ and R _{2 are} ethyl, M is Al, Fe, TiO _p or Zn, m is 2 to 3, and p = (4 - m) / 2 - compound selected from the group of Al, Fe, TiO _p - or Zn-salts of Ethylbutylphosphinsäure, the dibutylphosphinic, the Ethylhexylphosphinsäure, the Butylhexylphosphinsäure and / or the Dihexylphosphinsäure as component D, and - phosphonic acid salt of formula (II) as component e,

wherein R _{3 is} ethyl, Met is Al, Fe, TiO _q or Zn, n is 2 to 3, and q = (4 - n) / 2, wherein the powder X-ray diffraction pattern of the compositions contains the following reflections: in the angle range 2θ of 9.099 ° to 9.442 °, from 18.619 ° to 18.984 ° and from 26.268 ° to 26.679 ° and / or in the angular range 2θ from 5.125 ° to 5.312 °, from 6.097 ° to 6.297 °, from 10.082 ° to 10.282 °, from 10.350 ° to 10.550 ° and from 12.308 ° to 12.508 ° and / or in the angular range 2θ of 9.117 ° to 9.317 ° and of 18.537 ° to 18.737 ° and / or in the angular range 2θ of 8.300 ° to 8.500 °. Flame retardant polyamide compositions according to Claim 1 , characterized in that its X-ray powder diffraction gram contains the following reflections: in the angular range 2θ from 9.099 ° to 9.442 °, from 18.619 ° to 18.984 ° and from 26.268 ° to 26.679 °. Flame retardant polyamide compositions according to at least one of Claims 1 to 2 , characterized in that M and Met are Al, m and n are 3 and that component D is an aluminum salt. Flame retardant polyamide compositions according to at least one of Claims 1 to 3 , characterized in that - the proportion of component A 25 to 95 wt .-%, - the proportion of component B 1 to 45 wt .-%, - the proportion of component C is 1 to 35% by weight, the proportion of component D is 0.01 to 3% by weight, and the proportion of component E is 0.001 to 1% by weight, the percentages being refer to the total amount of the polyamide composition. Flame retardant polyamide compositions according to Claim 4 , characterized in that - the proportion of component A 25 to 75 wt .-%, - the proportion of component B 20 to 40 wt .-%, - the proportion of component C 5 to 20 wt .-%, - the proportion from component D 0.05 to 1.5 wt .-%, and - the proportion of component E is 0.01 to 0.6 wt .-%. Flame retardant polyamide compositions according to at least one of Claims 1 to 5 , characterized in that the polyamide compositions contain inorganic phosphonate as further component F. Flame retardant polyamide compositions according to Claim 6 , characterized in that the inorganic phosphonate is a compound of formula (III)

where Me is Fe, TiO _r , Zn or in particular Al, o is 2 to 3, and r = (4 - o) / 2, where the compound of the formula (III) is present in an amount of 0.005 to 10% by weight. , in particular in an amount of 0.02 to 5 wt .-%, based on the total amount of the polyamide composition, is present. Flame retardant polyamide compositions according to at least one of Claims 1 to 7 , characterized in that it has a Comparative Tracking Index measured according to the International Electrotechnical Commission Standard IEC-60112/3 of greater than or equal 500 volts. Flame retardant polyamide compositions according to at least one of Claims 1 to 8th , characterized in that they reach a rating of V0 to UL-94 of 3.2 mm to 0.4 mm thickness. Flame retardant polyamide compositions according to at least one of Claims 1 to 9 , characterized in that they have a Glow Wire Flammability Index according to IEC-60695-2-12 of at least 960 ° C at 0.75 - 3 mm thickness. Flame retardant polyamide compositions according to at least one of Claims 1 to 10 , characterized in that they have a heat deflection temperature HDT-A according to DIN EN ISO 75-3 of at least 280 ° C, preferably of at least 300 ° C. Flame retardant polyamide compositions according to at least one of Claims 1 to 11 , characterized in that component A is an aromatic or partially aromatic polyamide or a mixture of a plurality of aromatic or partially aromatic polyamides or a mixture of polyamide 6.6 and one or more aromatic or partially aromatic polyamides. Flame retardant polyamide compositions according to Claim 12 , characterized in that component A is an aromatic or partially aromatic polyamide or a mixture of a plurality of aromatic or partially aromatic polyamides. Flame retardant polyamide compositions according to at least one of Claims 1 to 13 , characterized in that glass fibers are used as component B. Flame retardant polyamide compositions according to at least one of Claims 1 to 14 , characterized in that components C, D, E and optionally F are in particulate form, wherein the mean particle size dso of these components is 1 to 100 microns. Flame retardant polyamide compositions according to at least one of Claims 1 to 15 , characterized in that it contains further additives as component G, the further additives being selected from the group consisting of antioxidants, UV stabilizers, Gamma ray stabilizers, hydrolysis stabilizers, co-stabilizers for antioxidants, antistatic agents, emulsifiers, nucleating agents, plasticizers, processing aids, impact modifiers, dyes, pigments and / or other flame retardants that differ from components C, D, E and F. Use of the polyamide compositions according to one of Claims 1 to 16 for the production of fibers, films and moldings, in particular for applications in the electrical and electronics sector.