HK1226765B - Halogen-free solid flame retardant mixture and use thereof - Google Patents

Description

Halogen-free solid flame retardant mixture and use thereof

Mixtures of different types of flame retardants are used for the flame-retardant finishing of polymers. It is essential that the components to be added (i.e. the flame retardants) have good flowability and free-flowing properties in typical processes for polymer production so that they can be evenly distributed in the polymer and thus do not negatively affect its properties.

Flowability is influenced by particle properties, such as particle size, particle size distribution, particle surface characteristics, water content or moisture, and different particle shapes. Particles of different sizes roll over each other with varying ease depending on their size or frequency. Round particles with regular surfaces tend to flow more easily than particles with irregular shapes. Flow properties vary depending on chemical surface, moisture, or electrostatic properties.

If powders with poor flow properties are processed, irregular metering often occurs, thus resulting in an inhomogeneous composition and distribution in the polymer, leading to an insufficient flame retardant effect from molding to molding.

According to the prior art, flowability can be increased by incorporating separating agents and foreign substances. Klein, 1968, 849, describes the addition of calcium stearate and fumed silica in amounts of 5,000 to 10,000 ppm as a solution to this problem. The silicate-containing additives proposed in this document for improving free flowability are extremely finely divided. They can be inhaled and are suspected of causing lung problems.

WO 2003/035736A1 describes melamine cyanurate aggregates held together by a binder. The purpose of this document is to improve the uniform distribution of the aggregates by improving free flow. This term is also referred to as the flowability of bulk materials (powders, agglomerates, pellets, etc.). By adding 1,000 ppm to 10% by weight of an organic auxiliary agent, particles of a specific size are bonded into larger aggregates, thereby increasing free flow. The organic auxiliary agent is typically an organic compound, such as a polymer or copolymer based on vinylpyrrolidone, vinyl acetate and vinylcaprolactam, an epoxide, a carbamate, an acrylate, an ester, an amide, a stearate, an olefin, a cellulose derivative, or a mixture thereof. The aggregates can be prepared in particular by pre-dispersing the particles in an aqueous suspension and adding a water-soluble auxiliary agent.

EP-1522551 A1 describes phosphorus-containing flame retardant agglomerates with a relatively low bulk density, which comprise aggregates and/or primary particles of phosphinates and/or diphosphinates and/or polymers thereof and are held together by auxiliary agents. The agglomerates can be obtained by spray granulation.

To ensure the most uniform distribution of the flame retardant agglomerates in the polymer, efforts are focused on achieving particularly good flow behavior in the bulk material. This is achieved by using the aforementioned flame retardant agglomerates, which have a relatively low bulk density but a low dusting tendency. A low dusting tendency is important because it can lead to uneven metering in the extruder during mixing into the polymer, resulting in uneven distribution of the flame retardant in the polymer. This, in turn, can negatively impact the flame retardant effect due to the resulting local underdosing.

EP-1522551 A1 is only concerned with the free flowability or increase in flowability, but not with the improvement of the homogeneity of the free flowability.

JP-2003138264A1 and JP-2003138265A1 describe achieving good flowability of halogen-containing flame retardants by using particularly large particles (0.8 to 2 mm).

In JP-2005171206A1, a flame retardant mixture having good free flowability is obtained by combining finely divided basic metal oxide particles with flaky, fibrous or amorphous finely divided inorganic particles and an inorganic flame retardant.

WO-2010075087A1 describes a free-flowing flame retardant composition consisting of a liquid phosphorus-containing flame retardant, wherein the flame retardant is adsorbed on a carrier.

In particular, flame-retardant polymer molding materials are produced, for example, by introducing the flame-retardant component into the polymer melt via a side inlet of a twin-screw extruder at a temperature of 250 to 310°C. Glass fibers, if desired, are added via a second side inlet. The resulting homogenized polymer strand is removed, cooled in a water bath, and then pelletized.

If the free-flowing properties of the flame-retardant component are uneven, overfilling of the filling hopper or underdosing due to insufficient product replenishment from the storage silo can occur. Both are undesirable production disruptions. Chemicals can potentially spill into the process environment and cause fluctuating product compositions in the flame-retardant polymer molding material. Underdosing can result in insufficient flame retardancy in the polymer molding material.

The present invention was therefore based on the object of providing flame retardant mixtures which have homogeneous free-flowing properties.

Another object of the present invention is to avoid process disturbances when producing flame-retardant polymer molding materials.

The flame retardant mixture according to the invention does not contain a binder to hold the powder particles together to form larger aggregates. Binders only reduce the amount of active substance (i.e. flame retardant) and thus the effectiveness of the flame retardant by the optional combustible auxiliary.

Another object of the present invention is to forgo the use of water-soluble organic additives to improve free flow properties, and also to avoid increasing the particle size of the flame retardant particles.

Surprisingly, it has been found that the halogen-free flame retardant mixture according to the invention has a homogeneous free-flowing property and at the same time achieves a good flame retardant effect.

The present invention therefore relates to a halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of component B, wherein component A comprises 85 to 99.995% by weight of solid diethylphosphinates of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases and 0.005 to 15% by weight of non-combustible additives, and component B is aluminum phosphite.

The halogen-free flame retardant mixture particularly preferably comprises component A in an amount of 20 to 80% by weight and component B in an amount of 20 to 80% by weight.

Preferably, component A of the halogen-free flame retardant mixture comprises 92 to 99.9% by weight of solid aluminum diethylphosphinate and 0.5 to 8% by weight of non-combustible additives.

Preferably, the additive is a dialkylphosphinate of formula (IV)

wherein R ¹ and R ² are identical or different and independently represent ethyl, butyl, hexyl and/or octyl groups, and M represents Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or a protonated nitrogenous base, with the proviso that R ¹ and R ² do not simultaneously represent ethyl groups; and/or the additive is a sulfate, phosphate, phosphonate, nitrate, sulfite and/or acetate, and the sulfate, phosphate, phosphonate, nitrate, sulfite and/or acetate is a compound having an alkali metal cation, an alkaline earth metal cation, a cation of the third main group of the periodic table, a cation of a subgroup and/or a protonated nitrogenous base.

Preferably, the dialkylphosphinate of formula (IV) is ethyl-butylphosphinate, butyl-butylphosphinate, ethyl-hexylphosphinate, butyl-hexylphosphinate and/or hexyl-hexylphosphinate.

Preferably, the cations are cations of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na and/or K.

Preferably, the protonated nitrogenous base is ammonia, a primary amine, a secondary amine, a tertiary amine and/or a quaternary amine.

Preferably, the sulfate is sodium sulfate, sodium aluminum sulfate, alunite, aluminum sulfate, calcium sulfate, cerium sulfate, iron sulfate, potassium hydrogen sulfate, potassium sulfate, magnesium sulfate, manganese sulfate, monolithium sulfate, titanium sulfate, zinc sulfate, tin sulfate, zirconium sulfate and/or hydrates thereof.

Preferably, the phosphate is aluminum phosphate, aluminum hydrogen phosphate, calcium hydrogen phosphate, calcium magnesium phosphate, calcium aluminum phosphate, calcium phosphate carbonate, calcium phosphate, cerium phosphate, cerium hydrogen phosphate, lithium phosphate, lithium hydrogen phosphate, magnesium phosphate, magnesium hydrogen phosphate, potassium phosphate, potassium aluminum phosphate, potassium hydrogen phosphate, sodium hydrogen phosphate, hydrated sodium phosphate, sodium aluminum phosphate and/or hydrates thereof.

Preferably, the phosphonate is a mono-(C _1-18 -alkyl)phosphonate, a mono-(C ₆ -C ₁₀ -aryl)phosphonate and/or a mono-(C _1-18 -aralkyl)phosphonate.

Preferably, the nitrate is aluminum nitrate, calcium nitrate, cerium nitrate, iron nitrate, potassium nitrate, lithium nitrate, magnesium nitrate, manganese nitrate, sodium nitrate, titanium nitrate, zinc nitrate, tin nitrate and/or zirconium nitrate and/or hydrates thereof.

Preferably, the acetate is aluminum acetate, calcium acetate, cerium acetate, iron acetate, lithium acetate, potassium acetate, sodium acetate, magnesium acetate, manganese acetate, titanium acetate, zinc acetate, tin acetate, zirconium acetate and/or a hydrate thereof.

Preferably, the sulfite is potassium sulfite, potassium bisulfite, potassium metabisulfite, sodium sulfite, sodium metabisulfite, sodium bisulfite, ammonium sulfite and/or hydrates thereof.

Preferably, the aluminum phosphite is an aluminum phosphite of formula (I), (II) and/or (III)

Al ₂ (HPO ₃ ) ₃ x(H ₂ O) _q (I)

in

q represents 0 to 4,

Al _2.00 M _z (HPO ₃ ) _y (OH) _v x (H ₂ O) _w (II)

in

M represents an alkali metal ion

z represents 0.01 to 1.5

y represents 2.63 to 3.5

v represents 0 to 2, and

w represents 0 to 4,

Al _2.00 (HPO ₃ ) _u (H ₂ PO ₃ ) _t x(H ₂ O) _s (III)

in

u represents 2 to 2.99

t represents 2 to 0.01, and

s represents 0 to 4,

and/or a mixture of the aluminum phosphite of formula (I) with a sparingly soluble aluminum salt and a nitrogen-free foreign ion, a mixture of the aluminum phosphite of formula (III) with an aluminum salt, 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 phosphite, 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, Al ₄ H ₆ P ₁₆ O ₁₈ and/or 0-99.9 wt % of Al ₂ (HPO ₃ ) A mixture of ₃ *nH ₂ O and 0.1-100 wt% of sodium aluminum phosphite, wherein x=2.27-1.

Preferably, the aluminum phosphite is a mixture of 50-99 wt. % of Al ₂ (HPO ₃ ) ₃ x(H ₂ O) _q and 1-50 wt. % of sodium aluminum phosphite, where q represents 0 to 4.

Preferably, the aluminum phosphite is also a mixture of 50-99 wt.% _Al2 ( _HPO3 ) _3x ( _H2O ) _q and 1-50 wt.% _{Al2.00Mz ( HPO3} ) _y (OH) _vx ( _H2O ) _w (II), wherein q represents 0 to 4, M represents sodium, z represents 0.005 to 0.15, y represents 2.8 to 3.1, v represents 0 to 0.4 and w represents 0 to 4.

Preferably, in the halogen-free flame retardant mixture, component A has a median particle size d50 of 0.05 to 10 μm and component B has a median particle size d50 of 0.05 to 10 μm and a residual moisture content of 0.05 to 8 wt.%.

The invention also relates to a process for preparing a flame retardant mixture according to one or more of claims 1 to 17, characterized in that components A and B are mixed with one another in powder form and optionally sieved.

The present invention also relates to a process for producing a halogen-free flame retardant mixture, characterized in that metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or diethylphosphinates of protonated nitrogenous bases are mixed with non-combustible additives and component B in powder form.

The invention likewise relates to the use of the halogen-free flame retardant mixture according to one or more of claims 1 to 13 as an intermediate for further syntheses, as an adhesive, as a crosslinker or accelerator in the curing of epoxy resins, polyurethanes, unsaturated polyester resins, as a polymer stabilizer, as a plant protection agent, as a chelating agent, as a mineral oil additive, as a corrosion inhibitor, in detergent and cleaning applications, and in electronic applications.

Preference is given to the use of the halogen-free flame retardant mixture according to any one or more of claims 1 to 13 as or for use as a flame retardant, as a flame retardant for varnishes and foam coatings, as or for use as a flame retardant for wood and other cellulose-containing products, as or for use as a reactive and/or non-reactive flame retardant for polymers, for producing flame-retardant polymer molding materials, for producing flame-retardant polymer moldings and/or for imparting flame retardancy to polyester and cellulose pure and blended fabrics by impregnation and/or as a synergist and/or as a synergist in other flame retardant mixtures.

The present invention also relates to thermoplastic or thermosetting flame-retardant polymer molding materials, polymer moldings, polymer films, polymer filaments and/or polymer fibers, which contain 0.1 to 45% by weight of a halogen-free flame retardant mixture according to any one or more of claims 1 to 13, 55 to 99.9% by weight of a thermoplastic or thermosetting polymer or a mixture thereof, 0 to 55% by weight of additives and 0 to 55% by weight of fillers or reinforcing materials, wherein the sum of the components is 100% by weight.

Preference is given here to flame-retardant thermoplastic or thermosetting polymer molding materials, polymer moldings, polymer films, polymer filaments and/or polymer fibers, which contain 1 to 30% by weight of a halogen-free flame retardant mixture according to one or more of claims 1 to 13, 10 to 97% by weight of a thermoplastic or thermosetting polymer or a mixture thereof, 1 to 30% by weight of additives and 1 to 30% by weight of fillers or reinforcing materials, the sum of the components being 100% by weight.

The invention also relates to flame-retardant thermoplastic or thermosetting polymer molding materials, polymer moldings, polymer films, polymer filaments and/or polymer fibers, which contain the halogen-free flame retardant mixture according to one or more of claims 1 to 13, characterized in that the polymer is a thermoplastic polymer of the polystyrene-HI (high impact), polyphenylene ether, polyamide, polyester, polycarbonate type and a blend or polymer blend of the ABS (acrylonitrile-butadiene-styrene) or PC/ABS (polycarbonate/acrylonitrile-butadiene-styrene) or PPE/HIPS (polyphenylene ether/polystyrene-HI) plastic type and/or a thermosetting polymer of the unsaturated polyester or epoxy resin type.

Particularly preferably, the polymer is polyamide 4/6 (poly(tetramethylene adipamide), poly-(tetramethylene-adipamide)), polyamide 6 (polycaprolactam, poly-6-aminocaproic acid), polyamide 6/6 (poly(N,N'-hexamethylene adipamide)) and/or HTN (high temperature nylon).

Particularly preferably, component A comprises 99.1 to 99.95% by weight of solid aluminum diethylphosphinate and 0.05 to 0.9% by weight of non-combustible additives.

In the following text, the term diethylphosphinate always includes diethylphosphinates of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases.

In one embodiment of the present invention, particularly preferred additives are dialkylphosphinic acid telomers of, in particular, the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases, for example ethyl-butylphosphinate, butyl-butylphosphinate, ethyl-hexylphosphinate, butyl-hexylphosphinate, hexyl-hexylphosphinate.

Preferably, the halogen-free flame retardant mixture comprises 1 to 99% by weight of component A and 1 to 99% by weight of component B, wherein component A comprises 85 to 99.995% by weight of diethylphosphinates of the aforementioned metals and 0.005 to 15% by weight of non-combustible additives, and component B is aluminum phosphite.

It is also preferred here that the halogen-free flame retardant mixture comprises 10 to 90% by weight of component A and 10 to 90% by weight of component B, wherein component A comprises 85 to 99.995% by weight of diethylphosphinates of the above-mentioned metals and 0.005 to 15% by weight of non-combustible additives, and component B is aluminum phosphite.

Likewise preferably, the halogen-free flame retardant mixture comprises 20 to 80% by weight of component A and 20 to 80% by weight of component B, wherein component A comprises 85 to 99.995% by weight of diethylphosphinates of the above-mentioned metals and 0.005 to 15% by weight of non-combustible additives, and component B is aluminum phosphite.

Particularly preferably, the halogen-free flame retardant mixture comprises 1 to 99% by weight of component A and 1 to 99% by weight of component B, wherein component A comprises 92 to 99.9% by weight of diethylphosphinates of the above-mentioned metals and 0.1 to 8% by weight of non-combustible additives, and component B is aluminum phosphite.

Particularly preferred non-combustible additives are dialkylphosphinic acid telomers in the form of salts of metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases, for example ethyl-butylphosphinate, butyl-butylphosphinate, ethyl-hexylphosphinate, butyl-hexylphosphinate, hexyl-hexylphosphinate.

Preferred halogen-free flame retardant mixtures according to the invention which contain dialkylphosphinic acid telomers as non-combustible additives are:

I) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 85 to 99.995% by weight of diethylphosphinate and 0.005 to 15% by weight of a dialkylphosphinic acid telomer.

II) A halogen-free flame retardant mixture comprising 10 to 90% by weight of component A and 10 to 90% by weight of aluminum phosphite, wherein component A comprises 85 to 99.995% by weight of diethylphosphinate and 0.005 to 15% by weight of a dialkylphosphinic acid telomer.

III) A halogen-free flame retardant mixture comprising 20 to 80 wt. % of component A and 20 to 80 wt. % of aluminum phosphite, wherein component A comprises 85 to 99.995 wt. % of diethylphosphinate and 0.005 to 15 wt. % of a dialkylphosphinic acid telomer.

IV) Halogen-free flame retardant mixtures comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 92 to 99.9% by weight of diethylphosphinate and 0.1 to 8% by weight of a dialkylphosphinic acid telomer.

The non-combustible additive may also preferably be a sulfate.

Preferred sulfates are those with alkali metal cations, protonated nitrogen-containing base cations (e.g., ammonia, primary, secondary, tertiary, and quaternary amines), alkaline earth metal cations, cations of Group III elements, and cations of subgroup elements. Particularly preferred subgroup elements are titanium, iron, zinc, and mixtures thereof.

Preferred sulfates are sulfates with cations of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases.

Particularly preferred sulfates are sodium sulfate, sodium aluminum sulfate and alunite.

Also preferred sulfates are:

Aluminum sulfate, calcium sulfate, cerium (II) sulfate, cerium (IV) sulfate, cerium sulfate, iron (II) sulfate, iron (III) sulfate, iron sulfate, potassium sulfate, potassium hydrogen sulfate, magnesium sulfate, magnesium sulfate, manganese (II) sulfate, manganese (III) sulfate, manganese (IV) sulfate, manganese sulfate, monolithium sulfate, sodium sulfate, sodium sulfate, titanium (II) sulfate, titanium (III) sulfate, titanium (IV) sulfate, titanium sulfate, zinc sulfate, tin (II) sulfate, tin (III) sulfate, tin (IV) sulfate, tin sulfate, zirconium (II) sulfate, zirconium (IV) sulfate, zirconium sulfate.

Preferred alunite is:

Alumite (Al ₂ (OH) ₄ (SO ₄ ) ^. 7H ₂ O), metalumite (Al ₄ (OH) ₁₀ (SO ₄ )), metalumite (Al ₂ (OH) ₄ (SO ₄ ) ^. 5H ₂ O), white aluminum alum (Al(OH)(SO ₄ ) ^. 5H ₂ O), zaherite (Al ₁₂ O ₁₃ (SO ₄ ) ₅ ^. xH ₂ O), aluminum oxyhydroxide sulfate (Al ₃₀ (OH) ₅₆ O ₈ (SO ₄ ) ₉ ), aluminum oxyhydroxide sulfate hydrate, aluminum oxyhydroxide sulfate (Al(OH) _2.24 (SO ₄ ) _0.38 ), aluminum oxyhydroxide sulfate hydrate, aluminum oxyhydroxide sulfate (Al ₃ (OH) ₅ (SO ₄ ) ₂ ), aluminum oxyhydroxide sulfate nonahydrate, aluminum oxyhydroxide sulfate (Al ₄ (OH) ₁₀ (SO ₄ )), aluminum hydroxide sulfate hydrate, white aluminum alum (Al(OH)(SO ₄ ) ^. 5H ₂ O), aluminum hydroxide sulfate (Al ₇ (OH) ₁₇ (SO ₄ ) ₂ ), aluminum hydroxide sulfate dodecahydrate, sclerocladium (Al ₄ (OH) ₁₀ (SO ₄ ) ^. 10H ₂ O), halogenite (Al ₂ (OH) ₄ (SO ₄ ) ^. 5H ₂ O), tumbleweed alum (Al ₄ (OH) ₁₀ (SO ₄ ) ^. 5H ₂ O), alumite (Al ₂ (OH) ₄ (SO ₄ ) ^. 7H ₂ O), aluminum hydroxide sulfate (Al ₃ (OH) ₇ (SO ₄ )), aluminum hydroxide sulfate hydrate, aluminum hydroxide sulfate (Al ₃ (OH) ₅ (SO ₄ ) ₂ ), aluminum hydroxide sulfate dihydrate, aluminum hydroxide sulfate (Al(OH) ₂ ^. 7(SO ₄ ) _0.15 ), aluminum hydroxide sulfate hydrate, aluminum hydroxide sulfate (Al ₇ (OH) ₁₇ (SO ₄ ) ₂ ), aluminum hydroxide sulfate hydrate, aluminum hydroxide sulfate (Al(OH)(SO ₄ )), aluminum hydroxide sulfate hydrate, aluminum hydroxide sulfate (Al ₄ (OH) ₁₀ (SO ₄ )), aluminum hydroxide sulfate decahydrate, clinopyrite (Al(OH)(SO ₄ ) ^. 5H ₂ O), aluminum hydroxide sulfate (Al ₄ (OH) ₁₀ (SO ₄ )), aluminum hydroxide sulfate pentahydrate, aluminum hydroxide sulfate (Al ₆ (OH) ₁₆ (SO ₄ )), aluminum hydroxide sulfate hydrate, hydroxyaluminite (Al ₄ (OH) ₁₀ (SO ₄ ) ^. 5H ₂ O), aluminum hydroxide sulfate (Al(OH)(SO ₄ )), aluminum hydroxide sulfate pentahydrate, aluminum alkali alum (Na,Ca) _1-x Al ₃ (SO ₄ ) ₂ (OH) ₆ , Sulfated aluminum oxide hydrate Al ₆ O ₅ (SO ₄ ) ₄ *xH ₂ O, Hydroxyaluminum alum-16A Al ₁₂ (SO ₄ ) ₅ (OH) ₂₆ , Hydroxyaluminum sulfate Al ₄ SO ₄ (OH) ₁₀ , Hydroxyaluminum alum-18A Al ₁₂ (SO ₄ ) ₅ (OH) ₂₆ *20H ₂ O, Water-based alumite Al ₄ SO ₄ (OH) ₁₀ *36H ₂ O, Hydroxyaluminum sulfate hydrate Al ₃ (SO ₄ ) ₂ (OH) ₅ *9H ₂ O, Alumite/Hydroxyaluminite Al ₄ SO ₄ (OH) ₁₀ *4H ₂ O, Alumite Al ₂ (SO ₄ )(OH) ₄ *7H ₂ O, Synthetic Hydroxyaluminum alum Al ₄ SO ₄ (OH) ₁₀ *7H ₂ O, Hydroxyaluminite Al ₄ SO ₄ (OH) ₁₀ *5H ₂ O, synthetic alumite Al ₄ SO ₄ (OH) ₄ *5H ₂ O, white aluminum alum Al ₄ SO ₄ (OH)*5H ₂ O, aluminum hydroxide sulfate hydrate 3 Al ₂ O ₃ *4SO ₃ *H ₂ O, sodium alumite NaAl ₃ (SO ₄ ) ₂ (OH) ₆ .

Preferred halogen-free flame retardant mixtures according to the invention containing sulfate as non-combustible additive are:

I) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of sulfate.

II) A halogen-free flame retardant mixture comprising 10 to 90% by weight of component A and 10 to 90% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of sulfate.

III) A halogen-free flame retardant mixture comprising 20 to 80 wt. % of component A and 20 to 80 wt. % of aluminum phosphite, wherein component A comprises 95 to 99.995 wt. % of diethylphosphinate and 0.005 to 5 wt. % of sulfate.

IV) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 99.1 to 99.99% by weight of diethylphosphinate and 0.01 to 0.9% by weight of sulfate.

The non-combustible additive may also preferably be a phosphate.

Preferred phosphates are those with alkali metal cations, cations of protonated nitrogenous bases (e.g., ammonia, primary, secondary, tertiary, and quaternary amines), alkaline earth metal cations, cations of Group III elements, and cations of subgroup elements. Particularly preferred subgroup elements are titanium, iron, zinc, and mixtures thereof.

Preferred phosphates are phosphates with cations of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases.

Preferred phosphates are aluminum phosphates AlPO ₄ , Al ₂ O ₃ *P ₂ O ₅ , Al ₃₆ P ₃₆ O ₁₄₄ , Al ₁₆ P ₁₆ O ₆₄ , Al ₈ P ₈ O ₂₂ , Al ₂ O ₃ *xP ₂ O ₅ , Al ₂ O ₃ *0.95P ₂ O ₅ , Al ₂ O ₃ *0.86P ₂ O ₅ , Al ₁₂ P ₁₂ O ₄₈ , Al ₂ P ₆ O ₁₈ ,

Aluminum phosphate hydrate Al ₂ P _1.94 O _7.85 *2H ₂ O, AlPO ₄ *xH ₂ O, AlPO ₄ *0.45H ₂ O, Al ₃₂ P ₃₂ O ₁₂₈ *xH ₂ O, Al ₆ P ₆ O ₂₄ *4H ₂ O, AlPO ₄ *1.67H ₂ O, Al ₄ (P ₂ O ₇ ) ₃ *12H ₂ O, Al ₂ P ₂ O ₈ *3H ₂ O, AlP ₆ O ₁₈ *9.5H ₂ O, Al ₆ P ₆ O ₂₁ *8H ₂ O,

Aluminum hydrogen phosphate Al(H ₂ PO ₄ ) ₃ , H ₂ (AlPOPO ₄ ) ₃ ,

Aluminum hydrogen phosphate hydrate AlH ₆ (PO ₄ ) ₃ *2H ₂ O, AlH ₃ (PO ₄ ) ₂ *nH ₂ O, Al(HP ₂ O ₇ )*2.5H ₂ O, AlH ₃ (PO ₄ ) ₂ *3H ₂ O,

Calcium hydrogen phosphate Ca ₃ H ₂ P ₄ O ₁₄ , Ca(H ₂ PO ₄ ) ₂ , CaH ₂ PO ₇ , Ca ₄ H ₂ (P ₃ O ₁₀ ) ₂ , CaPO ₃ (OH),

Calcium magnesium phosphate Ca ₃ Mg ₃ (PO ₄ ) ₂ , Ca ₇ Mg ₂ P ₆ O ₂₄ , CaMgP ₂ O ₇ , (Ca,Mg) ₃ (PO ₄ ) ₂ ,

Calcium phosphate Ca ₃ P ₂ O ₇ , CaP ₄ O ₁₁ , Ca ₂ P ₆ O ₁₇ , Ca ₃ (P ₅ O ₁₄ ) ₂ , CaP ₂ O ₆ , CaP ₂ O ₇ , Ca ₄ P ₆ O ₁₉ , Ca ₄ (PO ₄ ) ₂ , Ca _x+2 P _2x O _6x+2 ,

Calcium aluminum phosphate Ca ₉ Al(PO ₄ ) ₇ ,

Calcium carbonate phosphate Ca ₁₀ (PO ₄ ) ₆ CO ₃ ,

Calcium phosphate hydrateCa ₂ P ₂ O ₇ *2H ₂ O, β-Ca ₂ (P ₄ O ₁₂ )*4H ₂ O, Ca ₃ (PO ₃ ) ₆ *10H ₂ O, Ca ₄ P ₈ O ₂₄ *16H ₂ O, Ca ₂ P ₂ O ₇ *2H ₂ O, Ca ₂ (P ₄ O ₁₂ )*4H ₂ O, Ca _{2 P2O7 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7} *2H ₂ O, Ca(H ₂ PO ₄ ) ₂ *H ₂ O, Ca ₃ H ₂ (P ₂ O ₇ ) ₂ *H ₂ O,

Cerium phosphate CePO ₄ , CeP ₂ O ₇ , Ca(PO ₃ ) ₄ , CaP ₅ O ₁₄ , CeP ₃ O ₉ , Ce ₄ (P ₂ O ₇ ) ₃ ,

Calcium phosphate α-Ca ₂ P ₂ O ₇ , β-Ca ₂ P ₂ O ₇ , γ-Ca ₂ P ₂ O ₇ , CaP ₄ O ₁₁ , Ca ₂ P ₆ O ₁₇ , α-CaP ₄ O ₁₁ , Ca ₃ (P ₅ O ₁₄ ) ₂ , β-Ca(PO ₃ ) ₂ , δ-Ca(PO ₃ ) ₂ , γ-Ca(PO ₃ ) ₂ , α-Ca-P ₂ O ₆ , β-Ca-P ₂ O ₆ , Ca ₄ P ₆ O ₁₉ , α-Ca ₃ (PO ₄ ) ₂ , β-Ca ₃ (PO ₄ ) ₂ , γ-Ca ₃ (PO ₄ ) ₂ , Ca _x+2 P _2x O _6x+2 ,

Cerium phosphate CePO ₄ , CeP ₂ O ₇ , Ca(PO ₃ ) ₄ , CeP ₅ O ₁₄ , CeP ₃ O ₉ , Ce ₄ (P ₂ O ₇ ) ₃ , CeP ₅ O ₁₄ ,

Cerium hydrogen phosphate CeH ₂ P ₂ O ₈ ,

Lithium phosphate hydrate Li ₄ P ₄ O ₁₂ *4H ₂ O, Li ₈ P ₈ O ₂₄ *10H ₂ O, Li ₆ P ₆ O ₁₈ *6H ₂ O, Li ₆ P ₈ O ₂₄ *6H ₂ O, Li ₄ P ₄ O ₁₂ *nH ₂ O, Li ₆ P ₆ O ₁₈ *nH ₂ O, Li ₃ P ₃ O ₉ *3H ₂ O,

Lithium hydrogen phosphate Li ₃ HP ₂ O ₇ *H ₂ O,

Magnesium phosphate hydrate Mg ₄ P ₈ O ₂₄ *19H ₂ O, Mg ₂ P ₄ O ₁₂ *8H ₂ O, Mg ₃ (PO ₄ ) ₂ *nH ₂ O, Mg ₂ P ₂ O ₇ *2H ₂ O,

Magnesium hydrogen phosphate hydrate MgHPO ₄ *nH ₂ O, Mg(H ₂ PO ₄ ) ₂ *nH ₂ O,

Potassium phosphate hydrate K ₈ P ₈ O ₂₄ *6H ₂ O, (KPO ₃ ) ₄ *2H ₂ O, K ₆ P ₆ O ₁₈ *3H ₂ O, α-K ₅ P ₃ O ₁₀ *nH ₂ O, β-K ₅ P ₃ O ₁₀ *nH ₂ O, K ₁₀ P ₁₀ O ₃₀ *4H ₂ O, K ₄ P ₂ O ₇ *nH ₂ O, K ₅ P ₃ O ₁₀ *nH ₂ O, K ₃ PO ₄ *nH ₂ O, K ₁₀ P ₆ O ₂₀ *H ₂ O,

Calcium aluminum phosphate hydrate K ₆ Al ₂ P ₆ O ₂₁ *12H ₂ O,

Potassium hydrogen phosphate hydrate K ₂ H ₂ P ₂ O ₇ *nH ₂ O, K ₃ H ₂ P ₂ O ₇ *0.5H ₂ O, KH ₃ P ₂ O ₇ *H ₂ O, K ₃ H ₂ P ₃ O ₁₀ *H ₂ O, K ₄ HP ₃ O ₁₀ *xH ₂ O, KH ₃ (PO ₄ ) ₂ * ₂ H ₂ O, K ₂ H ₃ P ₃ O ₁₀ *2H ₂ O, K ₃ HP ₂ O ₇ *3H ₂ O, K ₂ HPO ₄ *3H ₂ O, K ₃ HP ₂ O ₇ *3H ₂ O,

Sodium hydrogen phosphate hydrate Na ₃ HP ₂ O ₆ *9H ₂ O, Na ₃ HP ₂ O ₇ *H ₂ O, Na ₂ H ₂ P ₂ O ₇ *6H ₂ O, Na ₂ H ₂ P ₂ O ₆ *6H ₂ O, NaH ₂ PO ₄ *12H ₂ O, NaH ₂ PO ₄ *H ₂ O, NaH ₃ P ₂ O ₆ *xH ₂ O, β-Na ₂ HPO ₄ *12H ₂ O, Na ₃ H ₂ P ₃ O ₁₀ *1.4H ₂ O, 2NaH ₂ PO ₄ *Na ₂ HPO ₄ *2H ₂ O, NaH ₂ PO ₄ *2H ₂ O, NaH ₂ PO ₂ *H ₂ O, Na ₂ HPO ₄ *nH ₂ O, Na ₄ HP ₃ O ₁₀ *H ₂ O, Na ₂ HPO ₃ *5H ₂ O, Na ₃ HP ₂ O ₇ *nH ₂ O, Na ₃ H ₂ P ₃ O ₁₀ *1.5H ₂ O,

Hydrated sodium phosphate Na ₃ P ₃ O ₉ *nH ₂ O, Na ₅ P ₃ O ₁₀ *6H ₂ O, (NaPO ₃ ) ₃ *nH ₂ O, Na ₆ P ₆ O ₁₈ *6H ₂ O, Na ₅ (P ₅ O ₁₅ )*4H ₂ O, Na ₄ P ₂ O ₆ *nH ₂ O, Na ₄ P ₂ O ₇ *10H ₂ O, Na ₄ P ₄ O ₁₂ *4H ₂ O, (NaPO ₂ ) ₆ *nH ₂ O,

Sodium aluminum phosphate hydrate Na ₂ AlP ₃ O ₁₀ *4H ₂ O, Na ₂ AlP ₂ O ₁₀ *2H ₂ O, Na ₂ AlP ₃ O ₁₀ , Na ₂ (AlP ₃ O ₁₀ )*2H ₂ O, Na ₃ Al(PO ₄ ) ₂ *1.5H ₂ O, Na ₂ Al ₆ P ₂ O ₁₅ *10H ₂ O.

Preferred halogen-free flame retardant mixtures according to the invention containing phosphates as non-combustible additives are:

I) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of phosphate.

II) A halogen-free flame retardant mixture comprising 10 to 90% by weight of component A and 10 to 90% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of phosphate.

III) A halogen-free flame retardant mixture comprising 20 to 80 wt. % of component A and 20 to 80 wt. % of aluminum phosphite, wherein component A comprises 95 to 99.995 wt. % of diethylphosphinate and 0.005 to 5 wt. % of phosphate.

IV) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 99.3 to 99.95% by weight of diethylphosphinate and 0.05 to 0.7% by weight of phosphate.

The non-flammable additive may also preferably be an organic phosphonate.

Preferred organic phosphonates are those with alkali metal cations, protonated nitrogenous bases (e.g., ammonia, primary amines, secondary amines, tertiary amines, and quaternary amines), alkaline earth metal cations, cations of Group III elements, and cations of subgroup elements. Particularly preferred subgroup elements are titanium, iron, zinc, and mixtures thereof.

Preferred organic phosphonates are those with cations of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases.

Preferred organic phosphonates are, for example, monoorganic phosphonates such as mono(C _1-18 -alkyl)phosphonates, mono(C ₆ -C ₁₀ -aryl)phosphonates, mono(C _7-18 -aralkyl)phosphonates, among which in particular monomethylphosphonate, monoethylphosphonate, monobutylphosphonate, monohexylphosphonate, monophenylphosphonate, monobenzylphosphonate, etc.

Preferred halogen-free flame retardant mixtures according to the invention which contain organic phosphonates as non-combustible additives are:

I) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of an organic phosphonate.

II) A halogen-free flame retardant mixture comprising 10 to 90 wt. % of component A and 10 to 90 wt. % of aluminum phosphite, wherein component A comprises 95 to 99.995 wt. % of diethylphosphinate and 0.005 to 5 wt. % of an organic phosphonate.

III) A halogen-free flame retardant mixture comprising 20 to 80 wt% of component A and 20 to 80 wt% of aluminum phosphite, wherein component A comprises 95 to 99.995 wt% of diethylphosphinate and 0.005 to 5 wt% of an organic phosphonate.

IV) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 98 to 99.95% by weight of diethylphosphinate and 0.05 to 2% by weight of an organic phosphonate.

The non-combustible additive may also preferably be a nitrate.

Preferred nitrates are those with alkali metal cations, cations of protonated nitrogen-containing bases (e.g., ammonia, primary, secondary, tertiary, and quaternary amines), alkaline earth metal cations, cations of Group III elements, and cations of subgroup elements. Particularly preferred subgroup elements are titanium, iron, zinc, and mixtures thereof.

Preferred nitrates are nitrates with cations of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases.

Preferred nitrates are aluminum nitrate (Al(NO ₃ ) ₃ ), calcium nitrate (Ca(NO ₃ ) ₂ ), cerium (II) nitrate (Ce(NO ₃ ) ₂ ), cerium (III) nitrate (Ce(NO ₃ ) ₃ ), cerium (IV) nitrate (Ce(NO ₃ ) ₄ ), cerium nitrate (Ce(NO ₃ ) _x ), iron nitrate (Fe(NO ₃ ) _x ), iron (II) nitrate (Fe(NO ₃ ) ₂ ), iron (III) nitrate (Fe(NO ₃ ) ₃ ), potassium nitrate (KNO ₃ ), lithium nitrate (LiNO ₃ ), magnesium nitrate (Mg _1/2 NO ₃ ), manganese (II) nitrate (Mn _1/2 NO ₃ ), manganese (III) nitrate (Mn _1/3 NO ₃ ), manganese (IV) nitrate (Mn _1/4 NO ₃ ), sodium nitrate (NaNO ₃ ), titanium nitrate (Ti(NO ₃ ) _{x ),} ), titanium (II) nitrate (Ti _1/2 NO ₃ ), titanium (III) nitrate (Ti _1/3 NO ₃ ), titanium (IV) nitrate (Ti _1/4 NO ₃ ), zinc nitrate (Zn _1/2 NO ₃ ), tin nitrate (Sn(NO ₃ ) _x ), tin (II) nitrate (Sn _1/2 NO ₃ ), tin (IV) nitrate ( _{Sn 1/4 NO 3 ) ,} zirconium nitrate (Zr(NO ₃ ) x ), zirconium (II) nitrate (Zr _1/2 NO ₃ ) and/or zirconium (IV) nitrate (Zr _1/4 NO ₃ ).

Preferred halogen-free flame retardant mixtures according to the invention containing nitrates as non-combustible additives are:

I) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of nitrate.

II) a halogen-free flame retardant mixture comprising 10 to 90% by weight of component A and 10 to 90% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of nitrate.

III) A halogen-free flame retardant mixture comprising 20 to 80 wt. % of component A and 20 to 80 wt. % of aluminum phosphite, wherein component A comprises 95 to 99.995 wt. % of diethylphosphinate and 0.005 to 5 wt. % of nitrate.

IV) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 99.79 to 99.99% by weight of diethylphosphinate and 0.01 to 0.21% by weight of nitrate.

The non-flammable additive may also preferably be acetate.

Preferred acetates are acetates with alkali metal cations, cations of protonated nitrogenous bases (e.g., ammonia, primary, secondary, tertiary, and quaternary amines), alkaline earth metal cations, cations of elements of the third main group, and cations of elements of the subgroup. Particularly preferred subgroup elements are titanium, iron, zinc, and mixtures thereof.

Preferred acetates are acetates with cations of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases.

Suitable acetates according to the invention are, for example:

Aluminum acetate (Al _1/3 (C ₂ H ₄ O ₂ )), calcium acetate (Ca _1/2 (C ₂ H ₄ O ₂ )), cerium (II) acetate, cerium (III) acetate (Ce _1/3 (C ₂ H ₄ O ₂ )), cerium (IV) acetate (Ce _1/4 (C ₂ H ₄ O ₂ )), iron acetate (Fe _x (C ₂ H ₄ O ₂ )), iron (II) acetate (Fe _1/2 (C ₂ H ₄ O ₂ )), iron (III) acetate (Fe _1/3 (C 2 H 4 O ₂ )), potassium acetate (K(C ₂ H ₄ O 2 )), lithium acetate (Li(C ₂ H ₄ O ₂ )), magnesium acetate (Mg _1/2 (C ₂ H ₄ O ₂ )), manganese acetate (Mn _x (C ₂ H ₄ O ₂ )), manganese (II) acetate (Mn _1/2 (C ₂ H ₄ O ₂ )), (C ₂ H ₄ O ₂ )), manganese (III) acetate (Mn _1/3 (C ₂ H ₄ O ₂ )), manganese (IV) acetate (Mn _1/4 (C ₂ H ₄ O ₂ )), sodium acetate (Na(C ₂ H ₄ O ₂ )), titanium acetate, titanium (II) acetate, titanium (III) acetate, titanium (IV) acetate (Ti _1/4 (C ₂ H ₄ O ₂ )), zinc acetate (Zn _1/2 (C ₂ H ₄ O ₂ )), tin (II) acetate (Sn _1/2 (C ₂ H ₄ O ₂ )), tin (IV) acetate (Sn _1/4 (C ₂ H ₄ O ₂ )), tin acetate (Sn _x (C ₂ H ₄ O ₂ )), zirconium acetate (Zr _x (C ₂ H ₄ O ₂ )), zirconium (II) acetate (Zr _1/2 (C ₂ H ₄ O ₂ )), zirconium (III) acetate and/or zirconium (IV) acetate (Zr _1/4 (C ₂ H ₄ O ₂ )).

Preferred halogen-free flame retardant mixtures according to the present invention comprising acetate as a non-combustible additive are:

I) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of acetate.

II) A halogen-free flame retardant mixture comprising 10 to 90 wt. % of component A and 10 to 90 wt. % of aluminum phosphite, wherein component A comprises 95 to 99.995 wt. % of diethylphosphinate and 0.005 to 5 wt. % of acetate.

III) A halogen-free flame retardant mixture comprising 20 to 80 wt. % of component A and 20 to 80 wt. % of aluminum phosphite, wherein component A comprises 95 to 99.995 wt. % of diethylphosphinate and 0.005 to 5 wt. % of acetate.

IV) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 99.25 to 99.99% by weight of diethylphosphinate and 0.01 to 0.75% by weight of acetate.

The non-combustible additive may also preferably be sulfite.

Preferred sulfites are those with alkali metal cations, cations of protonated nitrogenous bases (e.g., ammonia, primary, secondary, tertiary, and quaternary amines), alkaline earth metal cations, cations of elements of the third main group, and cations of elements of the subgroup. Particularly preferred subgroup elements are titanium, iron, zinc, and mixtures thereof.

Preferred sulfites are sulfites with cations of the metals Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogenous bases.

Particularly preferred are sodium metabisulfite, sodium sulfite, sodium bisulfite, potassium metabisulfite, potassium sulfite, potassium bisulfite and potassium bisulfate.

Preferred halogen-free flame retardant mixtures according to the invention which contain sulfites as non-combustible additives are:

I) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of sulfite.

II) A halogen-free flame retardant mixture comprising 10 to 90% by weight of component A and 10 to 90% by weight of aluminum phosphite, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of sulfite.

III) A halogen-free flame retardant mixture comprising 20 to 80 wt. % of component A and 20 to 80 wt. % of aluminum phosphite, wherein component A comprises 95 to 99.995 wt. % of diethylphosphinate and 0.005 to 5 wt. % of sulfite.

IV) A halogen-free flame retardant mixture comprising 1 to 99% by weight of component A and 1 to 99% by weight of aluminum phosphite, wherein component A comprises 99.18 to 99.99% by weight of diethylphosphinate and 0.01 to 0.82% by weight of sulfite.

In general, the halogen-free flame retardant mixture preferably comprises 1 to 99% by weight of component A and 1 to 99% by weight of component B, wherein component A comprises 95 to 99.995% by weight of diethylphosphinate and 0.005 to 5% by weight of sulfate, phosphate, phosphonate, nitrate, sulfite and/or acetate, and component B is aluminum phosphite.

In the sense of the present invention, the term "aluminium phosphite" comprises a series of compounds as defined below.

The aluminum phosphite according to the present invention comprises an alkali metal-aluminum mixed phosphite of the formula

Al _2.00 M _z (HPO ₃ ) _y (OH) _v *(H ₂ O) _w (II)

in

M represents an alkali metal ion,

z represents 0.01 to 1.5,

y represents 2.63 to 3.5,

v represents 0 to 2, and w represents 0 to 4,

The aluminum phosphite according to the invention is in particular a mixture of _Al2 ( _HPO3 ) ₃ * _nH2O (wherein n=0-4) and sodium aluminum phosphite. Sodium aluminum phosphite corresponds to formula (II), for _example the overall formula _Al2.0Na0.6 ( _HPO3 ) _2.89 * _0.28H2O .

X-ray powder data for sodium aluminum phosphite are given in Example 78 and X-ray powder data for Al ₂ (HPO ₃ ) ₃ *4H ₂ O are given in Example 82 for comparison.

The aluminum phosphite according to the invention is also a mixture of 0-99.9 wt. % Al ₂ (HPO ₃ ) ₃ *nH ₂ O and 0.1-100 wt. % sodium aluminum phosphite.

A preferred aluminum phosphite according to the invention is a mixture of 1-50 wt. % Al ₂ (HPO ₃ ) ₃ *nH ₂ O and 1-50 wt. % sodium aluminum phosphite.

Very particularly preferably, the aluminum phosphite according to the invention is a mixture of 5 to 75% by weight of Al ₂ (HPO ₃ ) ₃ *nH ₂ O and 5 to 25% by weight of sodium aluminum phosphite.

Aluminum phosphites that can be used according to the invention are also alkali metal-aluminum mixed phosphites according to the formula

Al _x M _z (HPO ₃ ) _y (OH) _v *(H ₂ O) _w (II)

in

x represents 1.00 to 2.0,

M represents an alkali metal ion,

z represents 0.01 to 2.7,

y represents 2.63 to 3.5,

v represents 0 to 2 and w represents 0 to 6,

The aluminum phosphite that can be used according to the invention is also a mixture consisting of:

80-99.9 wt% Al ₂ (HPO ₃ ) ₃

0.1-25% by weight of water

0-10% by weight sulfate

0-15% by weight of sodium

0-10% by weight of phosphate

Likewise, the aluminum phosphite that can be used according to the invention is an aluminum phosphite of the following composition:

80–99.9 wt% Al ₂ (HPO ₃ ) ₃

0.1-25% by weight of water

0-14.8 wt% sodium sulfate

0-7.4 wt% sodium phosphate

The aluminum phosphites that can be used according to the present invention also include aluminum hydrogen phosphites of formula (III)

Al _2.00 (HPO ₃ ) _u (H ₂ PO ₃ ) _t *(H ₂ O) _s (III)

in

u represents 2 to 2.99,

t represents 2 to 0.01, and

s represents 0 to 4.

Aluminum phosphites that can be used according to the invention are also mixtures of aluminum phosphites with sparingly soluble aluminum salts and nitrogen-free foreign ions, said mixtures comprising 80 to 99.898% by weight of aluminum phosphites of the formula (I)

Al ₂ (HPO ₃ ) ₃ *H ₂ O (I)

in

x represents 0 to 4,

0.1 to 10% by weight of a sparingly soluble aluminum salt, and

0.002 to 10% by weight of foreign ions not containing nitrogen.

Preferably, the insoluble aluminum salt is _aluminum hydroxide, polyaluminum hydroxide compounds, aluminum carbonate, hydrotalcite _{( Mg6Al2} (OH) _16CO3 * _nH2O ), sodium aluminum dihydroxycarbonate ₍ NaAl(OH) _2CO3 ), aluminum oxide, aluminum oxide hydrate, mixed aluminum hydroxide, basic aluminum sulfate and/or alunite.

Preferably, the nitrogen-free foreign ions are hydroxides, peroxides, peroxide hydrates, sulfites, sulfates, sulfate hydrates, acid sulfates, hydrogen sulfates, persulfates, hydrogen persulfates; nitrates; carbonates, percarbonates, stannates; borates, perborates, perborate hydrates; formates, acetates, propionates, lactates and/or ascorbates and/or cations of the elements Li, Na, K, Mg, Ca, Ba, Pb, Sn, Cu, Zn, La, Ce, Ti, Zr, V, Cr, Mn, Fe, Co and/or Ni.

The aluminum phosphite that can be used according to the invention is also a mixture of aluminum hydrogen phosphite of formula (III) with an aluminum salt

Al _2.00 (HPO ₃ ) _u (H ₂ PO ₃ ) _t *(H ₂ O) _s (III)

The mixture comprises

91 to 99.9% of aluminum hydrogen phosphite of formula (III)

0.1 to 9% of an aluminum salt, and

0 to 50% (crystallization) water

Wherein in formula (III)

u represents 2 to 2.99,

t represents 2 to 0.01, and

s represents 0 to 4.

Aluminum phosphites that can be used according to the invention include in particular aluminum phosphite (Al(H ₂ PO ₃ ) ₃ ), secondary aluminum phosphite, basic aluminum phosphite (Al(OH)(H ₂ PO ₃ ) ₂ *2aq), aluminum phosphite tetrahydrate (Al ₂ (HPO ₃ ) ₃ *4aq), 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 and/or Al ₄ H ₆ P ₁₆ O ₁₈ , where x=2.27-1.

The halogen-free flame retardant mixture according to the invention preferably has a residual moisture content of 0.01 to 10% by weight, in particular 0.1 to 2% by weight.

Preferably, the halogen-free flame retardant mixture according to the invention has a median particle size d ₅₀ of 0.1 to 1,000 μm, in particular 10 to 100 μm.

Preferably, the bulk density of the halogen-free flame retardant mixture according to the invention is 80 to 800 g/l, in particular 200 to 700 g/l.

The free-flowing properties of the halogen-free flame retardant mixtures according to the invention are determined in accordance with Pfrengle (DIN ISO 4324 Tenside, Pulver und Granulate, Bestimmung des Schüttwinkels, December 1983, Beuth Verlag, Berlin).

The free flowability is determined according to the aforementioned criteria by determining the height of the cone of the powder or granules or the ratio of the cone radius to the cone height. A specific amount of the substance to be investigated is deposited into a confined device using a specific funnel to form a cone. The cone is stacked until the product flows over a circular plate protruding from the bottom, thereby forming a defined cone radius. The radius of the plate is fixed. The funnel has an inner diameter of 10 mm. The plate has a radius of 50 mm. Five determinations are performed and the average is taken. The height in millimeters is measured using a ruler extending from the plate to the top of the cone. The ratio of the cone radius (50 mm) to the cone height is calculated from the average value.

For the halogen-free flame retardant mixtures according to the prior art, stacked cone heights of 29.9 to 49.9 mm corresponding to a span of 20 mm and a radius to height ratio (= cotα) of 1.67 to 1.00 corresponding to a span of 0.67 were determined.

The halogen-free flame retardant mixture according to the present invention can also be prepared according to different methods.

Preferably, aluminum diethylphosphinate is mixed directly with the non-combustible additive and the aluminum phosphite.

It is also preferred that aluminum diethylphosphinate containing non-flammable additives is mixed with aluminum phosphite.

According to the present invention, aluminum diethylphosphinate containing a non-flammable additive is prepared by reacting diethylphosphinate with a simple metal or a metal salt at 0 to 300°C for 0.01 to 1 hour.

Preferred metal salts here are metal oxides, mixed metal oxide-hydroxides, hydroxides and the like.

In another embodiment according to the present invention, aluminum diethylphosphinate containing non-flammable additives is prepared by reacting diethylphosphinic acid with a free base at 0 to 300°C for 0.01 to 1 hour.

In another embodiment, aluminum diethylphosphinate containing non-flammable additives is prepared by reacting diethylphosphinic acid as an alkali metal salt with a salt of the desired cation at 0 to 300°C for 0.01 to 1 hour.

Preferred alkali metal salts are sodium and potassium salts.

Preferred salts which provide the desired cations are acetates, glycolates, nitrates, sulfates, hydroxysulfates, phosphonates and phosphites. Preferably, their concentration in aqueous solution is 5 to 95% (anhydrous solids), particularly preferably 20 to 50% by weight.

In another embodiment, aluminum diethylphosphinate containing non-flammable additives is prepared by reacting diethylphosphinic acid in the form of a reactive derivative with a derivative of the desired cation at 0 to 300° C. for 0.01 to 1 hour. Preferred diethylphosphinic acid derivatives are diethylphosphinic esters, diethylphosphinic acid pyroesters, diethylphosphinic acid phosphates, diethylphosphinic acid acetates, diethylphosphinic acid phenates, and the like.

In the embodiment in which the aluminum diethylphosphinate comprises a dialkylphosphinic acid telomer as non-flammable additive, the dialkylphosphinic acid telomer content is from 50 ppm to 15% by weight, particularly preferably from 1000 ppm to 8% by weight.

In embodiments in which the aluminum diethylphosphinate contains sulfate as a non-combustible additive, the sulfate content is from 50 ppm to 5% by weight, particularly preferably from 100 ppm to 9000 ppm.

In embodiments in which the aluminum diethylphosphinate contains phosphate as a non-combustible additive, the phosphate content is from 50 ppm to 5% by weight, particularly preferably from 500 ppm to 7000 ppm.

In the embodiment in which the aluminum diethylphosphinate comprises an organic phosphonate as a non-combustible additive, the organic phosphonate content is from 50 ppm to 5% by weight, particularly preferably from 500 ppm to 2% by weight.

In embodiments in which the aluminum diethylphosphinate contains nitrate as a non-combustible additive, the nitrate content is from 50 ppm to 5% by weight, particularly preferably from 100 ppm to 2100 ppm.

In embodiments in which the aluminum diethylphosphinate comprises acetate as a non-combustible additive, the acetate content is from 50 ppm to 5% by weight, particularly preferably from 100 ppm to 7500 ppm.

In embodiments in which the aluminum diethylphosphinate comprises sulfite as a non-combustible additive, the sulfite content is from 50 ppm to 5% by weight, particularly preferably from 100 ppm to 8200 ppm.

The present invention also includes a flame retardant polymer molding material comprising

1 to 50% by weight of the halogen-free flame retardant mixture according to the invention

1 to 99% by weight of a polymer or polymer mixture,

0 to 60% by weight of additives, and

0 to 60% by weight of filler.

The present invention preferably comprises a flame retardant polymer molding material comprising

5 to 30% by weight of the halogen-free flame retardant mixture according to the invention

15 to 85% by weight of a polymer or polymer mixture,

5 to 40% by weight of additives, and

5 to 40% by weight of filler.

Preferably, the polymer is derived from a thermoplastic polymer such as polyester, polystyrene or polyamide and/or a thermosetting polymer.

Preferably, the polymers are polymers of monoolefins and diolefins, such as polypropylene, polyisobutylene, polybutene-1, poly-4-methyl-pentene-1, polyisoprene or polybutadiene, and polymers of cyclic olefins, such as cyclopentene or norbornene; and also polyethylene (optionally crosslinked), such as high density polyethylene (HDPE), high density and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene (HDPE-UHMW), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), branched low density polyethylene (VLDPE), and mixtures thereof.

Preferably, the polymers are copolymers of monoolefins and dienes with one another or with other vinyl monomers, for example ethylene-propylene copolymers, linear low-density polyethylene (LLDPE) and mixtures thereof with low-density polyethylene (LDPE), propylene-butene-1 copolymers, propylene-isobutylene copolymers, ethylene-butene-1 copolymers, ethylene-hexene copolymers, ethylene-methylpentene copolymers, ethylene-heptene copolymers, ethylene-octene copolymers, propylene-butadiene copolymers, isobutylene-isoprene copolymers, ethylene-alkyl acrylate copolymers, ethylene-alkyl methacrylate copolymers, ethylene-vinyl acetate copolymers and copolymers thereof with carbon monoxide, or ethylene-acrylic acid copolymers and their salts (ionomers), and terpolymers of ethylene with propylene and a diene, for example hexadiene, dicyclopentadiene or ethylidene norbornene; and also mixtures of said copolymers with one another, for example polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl acetate copolymers, LDPE/ Ethylene-acrylic acid copolymers, LLDPE/ethylene-vinyl acetate copolymers, LLDPE/ethylene-acrylic acid copolymers and polyolefin/carbon monoxide copolymers of alternating or random structure and mixtures thereof with other polymers (e.g. polyamides).

Preferably, the polymer is a hydrocarbon resin (eg _C5 - _C9 ), including hydrogenated modifications thereof (eg tackifying resins) and mixtures of polyolefins and starch.

Preferably, the polymer is polystyrene (polystyrene 143E (BASF), poly-(p-methylstyrene), poly-(α-methylstyrene)).

Preferably, the polymer is a copolymer of styrene or α-methylstyrene with a diene or an acryl derivative, such as styrene-butadiene, styrene-acrylonitrile, styrene-alkyl methacrylate, styrene-butadiene-alkyl acrylate and styrene-butadiene-alkyl methacrylate, styrene-maleic anhydride, styrene-acrylonitrile-methyl acrylate; high-impact mixtures of styrene copolymers and other polymers (such as polyacrylates, diene polymers or ethylene-propylene-diene-terpolymers); and block copolymers of styrene, such as styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene/butylene-styrene or styrene-ethylene/propylene-styrene.

Preferably, the polymer is a graft polymer of styrene or α-methylstyrene, for example styrene grafted onto polybutadiene, styrene grafted onto polybutadiene-styrene copolymer or polybutadiene-acrylonitrile copolymer, styrene and acrylonitrile (or methacrylonitrile) grafted onto polybutadiene; styrene, acrylonitrile and methyl methacrylate grafted onto polybutadiene; styrene and maleic anhydride grafted onto polybutadiene; styrene, acrylonitrile and maleic anhydride or maleimide grafted onto polybutadiene; styrene and maleimide grafted onto polybutadiene; styrene and alkyl acrylate or alkyl methacrylate grafted onto polybutadiene; styrene and acrylonitrile grafted onto ethylene-propylene-diene-terpolymer; styrene and acrylonitrile grafted onto polyalkyl acrylate or polyalkyl methacrylate; styrene and acrylonitrile grafted onto acrylate-butadiene. - copolymers, and mixtures thereof, such as so-called ABS polymers, MBS polymers, ASA polymers or AES polymers.

Preferably, the polymers are polymers derived from α-,β-unsaturated acids and their derivatives, such as polyacrylates and polymethacrylates, polymethyl methacrylate impact-modified with butyl acrylate, polyacrylamide and polyacrylonitrile, and copolymers of said monomers with one another or with other unsaturated monomers, such as acrylonitrile-butadiene copolymers, acrylonitrile-alkyl acrylate copolymers, acrylonitrile-alkoxyalkyl acrylate copolymers or acrylonitrile-alkyl methacrylate-butadiene terpolymers.

Preferably, the polymer is a polymer derived from an unsaturated alcohol and an amine or an acyl derivative or acetal thereof, such as polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl butyral, polyallyl phthalate, polyallyl melamine; and copolymers thereof with olefins.

Preferably, the polymers are homopolymers and copolymers of cyclic ethers, such as polyalkylene glycols, polyethylene oxide, polypropylene oxide or copolymers thereof with diglycidyl ethers.

Preferably, the polymer is a polyacetal, such as polyoxymethylene, and polyoxymethylene containing a comonomer such as ethylene oxide; polyacetal modified with thermoplastic polyurethane, acrylate or MBS.

Preferably, the polymers are polyphenylene oxide and polyphenylene sulfide and mixtures thereof with styrene polymers or polyamides.

Preferably, the polymer is a polyurethane derived from polyethers, polyesters and polybutadienes having terminal hydroxyl groups on the one hand and from aliphatic or aromatic polyisocyanates on the other hand, and precursors thereof.

Preferably, the polymers are polyamides and copolyamides derived from diamines and dicarboxylic acids and/or aminocarboxylic acids or the corresponding lactams, for example polyamide 2/12, polyamide 4 (poly-4-aminobutyric acid, 4, DuPont), polyamide 4/6 (poly(tetramethylene adipamide), poly-(tetramethylene adipamide), 4/6, DuPont), polyamide 6 (polycaprolactam, poly-6-aminocaproic acid, 6, DuPont, K122, DSM; 7301, DuPont; B 29, Bayer), polyamide 6/6 (poly(N,N'-hexamethylene adipamide), 6/6, DuPont, 101, DuPont; A30, AKV, AM, Bayer; A3, BASF), polyamide 6/9 (poly(hexamethylene azelaic acid), Polyamide 6/10 (poly(hexamethylene sebacamide), 6/10, DuPont), polyamide 6/12 (poly(hexamethylene dodecanedioamide), 6/12, DuPont), polyamide 6/66 (poly(hexamethylene adipamide-co-caprolactam), 6/66, DuPont), polyamide 7 (poly-7-aminoheptanoic acid, 7, DuPont), polyamide 7/7 (polyheptamethylene pimelic acid, 7/7, DuPont), polyamide 8 (poly-8-aminooctanoic acid, 8, DuPont), polyamide 8/8 (polyoctamethylene suberamide, 8/8, DuPont), polyamide 9 (poly-9-aminononanoic acid, 9, DuPont), polyamide 9/9 (polynonamethylene azelaic acid, 9/9, DuPont), polyamide 10 (poly-10-amino-decanoic acid, 10, DuPont), polyamide 10/9 (poly(decamethylene azelaic acid), 10/9, DuPont), polyamide 10/10 (polydecamethylene sebacic acid, 10/10, DuPont), polyamide 11 (poly-11-aminoundecanoic acid, 11, DuPont), polyamide 12 (polylauryllactamide, 12, DuPont, L20, Ems Chemie), aromatic polyamides from m-xylene, diamines and adipic acid; polyamides made from hexamethylenediamine and isophthalic acid and/or terephthalic acid (polyhexamethylene isophthalamide, polyhexamethylene terephthalamide) and optionally an elastomer as a modifier, for example poly-2,4,4-trimethylhexamethylene These include polyamides such as terephthalamide or poly-m-phenylene isophthalamide. Block copolymers of these polyamides with polyolefins, olefin copolymers, ionomers, or chemically bonded or grafted elastomers; or block copolymers with polyethers (e.g., polyethylene glycol, polypropylene glycol, or polybutylene glycol). Also included are polyamides or copolyamides modified with EPDM or ABS; and polyamides condensed during processing ("RIM-polyamide systems").

It is also possible to use aromatic polyamides such as PA4T, PA6T, PA9T, PA10T, PA11T and/or MXD6, amorphous polyamides such as 6I/X and TPE-A “hard” and “soft”.

Preferably, the polymer is also polyurea, polyimide, polyamideimide, polyetherimide, polyesterimide, polyhydantoin and polybenzimidazole.

Preferably, the polymers are polyesters derived from dicarboxylic acids and diols and/or from hydroxycarboxylic acids or the corresponding lactones, for example polyethylene terephthalate, polybutylene terephthalate (2500, 2002, Celanese; BASF), poly-1,4-dimethylolcyclohexane terephthalate, polyhydroxybenzoates, and block polyetheresters derived from polyethers having hydroxyl end groups; also polyesters modified with polycarbonate or MBS.

Preferably, the polymers are polycarbonates and polyester carbonates as well as polysulfones, polyethersulfones and polyetherketones.

Preferably, the polymer is a crosslinked polymer derived from aldehydes on the one hand and phenol, urea or melamine on the other hand, such as phenol-formaldehyde resins, urea-formaldehyde resins and melamine-formaldehyde resins.

Preferably, the polymer is a drying and non-drying alkyd resin.

Preferably, the polymer is an unsaturated polyester resin derived from copolyesters of saturated and unsaturated dicarboxylic acids and polyols and a vinyl compound as a crosslinking agent.

Preferably, the polymer is a crosslinkable acrylic resin derived from a substituted acrylate, such as an epoxy acrylate, a urethane acrylate, or a polyester acrylate.

Preferably, the polymers are alkyd resins, polyester resins and acrylate resins crosslinked with melamine resins, urea resins, isocyanates, isocyanurates, polyisocyanates or epoxy resins.

Preferably, the polymer is a crosslinked epoxy resin derived from aliphatic, cycloaliphatic, heterocyclic or aromatic glycidyl compounds crosslinked by common curing agents such as anhydrides or amines with or without accelerators, such as bisphenol-A-diglycidyl ether, bisphenol-F-diglycidyl ether.

Preferably, the polymer is a mixture (mixture) of the above-mentioned polymers, for example PP/EPDM, polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylate, POM/thermoplastic PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA 6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or PBT/PET/PC.

Preferred additives for the halogen-free flame retardant mixtures according to the invention are, for example, synergists.

According to the present invention, preferred synergists are melamine phosphate, dimelamine phosphate, pentamelamine triphosphate, trimelamine diphosphate, tetramelamine triphosphate, hexamelamine pentaphosphate, melamine diphosphate, melamine tetraphosphate, melamine pyrophosphate, melamine polyphosphate, melem polyphosphate, melem polyphosphate and/or cyanuric acid polyphosphate.

Also preferred as synergists are melamine condensation products, such as melam, melem and/or cyanuramide.

Also preferred as synergists according to the invention are oligoesters of tris(hydroxyethyl)isocyanurate with aromatic polycarboxylic acids, benzoguanamine, tris(hydroxyethyl)isocyanurate, allantoin, glycoluril, melamine, melamine cyanurate, urea cyanurate, dicyanamide and/or guanidine.

Also preferred as synergists according to the invention are nitrogen-containing phosphates of the formula (NH ₄ ) _y H _3-y PO ₄ or (NH ₄ PO ₃ ) _z , where y is equal to 1 to 3 and z is equal to 1 to 10,000.

Preferred further additives in the flame retardant composition according to the invention are zinc compounds, such as zinc oxide, zinc hydroxide, tin oxide hydrate, zinc carbonate, zinc stannate, zinc hydroxystannate, basic zinc silicate, zinc phosphate, zinc borate, zinc molybdate or zinc sulfide.

Preferred further additives in the flame retardant composition according to the invention are selected from carbodiimides and/or (poly)isocyanates.

Preferred further additives are selected from hindered phenols (e.g. OSP 1), hindered amines and light stabilizers (e.g. HYDROLYZER 944, type), phosphinates and antioxidants (e.g. P-EPQ from Clariant) and release agents (type from Clariant).

In the flame retardant composition according to the invention, preferred other fillers are silicon oxide compounds, magnesium compounds, such as metal carbonates of metals of the second main group of the periodic table, magnesium oxide, magnesium hydroxide, hydrotalcite, dihydrotalcite, magnesium carbonate or calcium magnesium carbonate, calcium compounds, such as calcium hydroxide, calcium oxide, hydrocalumite, aluminum compounds, such as aluminum oxide, aluminum hydroxide, boehmite, gibbsite or aluminum phosphate, red phosphorus, zinc compounds or aluminum compounds; as well as glass fibers and glass beads.

Mixing devices that can be used according to the invention are multi-zone screw extruders with three-zone screws and/or short compression screws; including, for example, co-kneaders such as MDK/E46-11D and/or laboratory kneaders (MDK 46, L=11D from Coperion Buss Compounding Systems, Pratteln, Switzerland).

Mixing devices which can be used according to the invention are also twin-screw extruders such as the Coperion Werner & Pfleiderer GmbH & Co. KG, Stuttgart (ZSK 25, ZSK 30, ZSK 40, ZSK 58, ZSK MEGAcompounder 40, 50, 58, 70, 92, 119, 177, 250, 320, 350, 380) and/or the Berstorff GmbH, Hanover, Leistritz Extrusionstechnik GmbH, Nuremberg.

Mixing devices that can be used according to the invention are, for example, annular extruders with 3 to 12 rings of small screws rotating around a stationary core from the company LAUFEN 3+Extruder GmbH and/or planetary roller extruders and/or vented extruders and/or cascade extruders and/or Maillefer screws, for example from the company Entex Bochum.

Mixing devices that can be used according to the invention are, for example, mixers with counter-rotating twin screws of the type Compex 37 or 70 from KraussMaffei Berstorff.

In the case of a uniaxial extruder or a single screw extruder, the effective screw length according to the present invention is 20 to 40D.

In the case of a multi-zone screw extruder, the effective screw length (L) according to the present invention is, for example, 25D, including the entry zone (L=10D), the transition zone (L=6D), and the discharge zone (L=9D).

In the case of a twin-screw extruder, the effective screw length according to the invention is 8 to 48D.

Preparation, processing and testing of flame-retardant polymer molding materials and plastic moldings.

The flame retardant component is mixed with the polymer pellets and any additives, and glass-fiber-reinforced PBT is introduced through the side inlet of a twin-screw extruder (Leistritz ZSE 27/44D) at a temperature of 230 to 260°C, PA 6.6 at 260-310°C, or PA 6 at 250-275°C. Glass fibers are added through a second side inlet. The homogenized polymer strands are removed, cooled in a water bath, and then pelletized.

After sufficient drying, the molding material was processed on an injection molding machine (Arburg 320C Allrounder type) at a material temperature of 240 to 300° C. to give test specimens and tested for flame retardancy according to the UL 94 test (Underwriter Laboratories) and classified.

Identification of telomers and determination of their content:

³¹ P-NMR spectra were measured using a Jeol JNM-ECS-400 instrument (400 MHz NMR instrument from JEOL (Germany) GmBH). 100-150 mg of sample was dissolved in 2 ml of 10 wt% NaOD/D ₂ O by gently heating the sample to about 40° C. The measurement was performed in { ¹ H} decoupling mode using 2048 scans.

Table 9 allows the telomer's ³¹ P-NMR signal to be determined from the ³¹ P-NMR spectrum. ^{The 31} P-NMR integral value indicates the percentage content of ³¹ P nuclei based on all ³¹ P nuclei in the sample. For each substance, these values are multiplied by an independent factor (f = MG (telomer of Al salt) divided by 3*AG (phosphorus)) [MG: molecular weight; AG: atomic weight]. All these values and the value for diethylphosphinate are added to determine the total. The value for each isomer is multiplied by 100 and divided by the total to give the telomer content in wt%.

The chemical structure of the telomers can be assigned to the 31 P-NMR signal by combining ³¹ P-NMR and a) the intensity of the signal with LC/MS (combination of liquid chromatography and mass spectrometry), b) by targeted synthesis of the telomers and fortification of ^{the 31} P sample with the obtained reference material, or c) by combining ³¹ P-NMR and ¹³ C-NMR spectroscopy.

The diethyl phosphinate that molecular weight is 122g/mol is LC-MS and the strongest peak in ^P -NMR.A molecular weight of 122 only allows the structure of diethyl phosphinate, ^{and the} P-NMR chemical shift of discovery is listed in Table 9.N-butyl ethyl phosphinate and sec-butyl ethyl phosphinate in LC-MS have a molecular weight of 150g/mol.Described molecular weight only allows the structure of " n-butyl ethyl phosphinate " and " sec-butyl ethyl phosphinate ".LC/MS and ^{the normal} -butyl in P-NMR is more intense than sec-butyl.Therefore the signal (diethyl right side) of n-butyl ethyl phosphinate is more intense, and the signal (diethyl left side) of sec-butyl ethyl phosphinate is not too intense.The signal of discovery is listed in Table 9.

Aluminum tris(n-butylethylphosphinate) is prepared chemically in multiple steps by addition of a butyl group to phosphinic acid, followed by ethyl precipitation, reaction with sodium hydroxide solution to form the sodium salt of butylethylphosphinate, and reaction with aqueous aluminum sulfate. This product can be used to identify n-butylethylphosphinate in unknown samples by spiking. The alkyl identity is clearly predetermined by the choice of starting materials.

Sec-butylethylphosphinate can be identified by recording ¹³ C-NMR and DEPT-135 spectra. "DEPT" stands for distortionless polarization transfer. It is a useful method for distinguishing between CH, CH ₂ and CH ₃ groups.

The characteristic CH group of sec-butyl (-CH(-CH ₃ )-CH ₂ -CH ₃ ) produces a signal at 33.7 ppm ( ¹ Jpc coupling is 91 Hz). ¹ Jpc coupling is defined as the coupling of a phosphorus nucleus to the nearest carbon nucleus via a covalent bond.

Table 9: ³¹ P-NMR chemical shifts of telomers

Example 1

Aluminum diethylphosphinate containing a telomer additive was prepared by dissolving 2.2 kg (20.7 mol) of sodium hypophosphite monohydrate in 8 kg (7.62 liters) of acetic acid and placing the mixture in a 16-liter double-jacketed steel-lined pressure reactor. After heating the reaction mixture to 85°C, ethylene was introduced through a pressure-reducing valve set to 7 bar until the reactor was saturated. The reaction was initiated by metering 56 g (1 mol %) of 2,2'-azabis(2-amidinopropane) dihydrochloride in 250 ml of water with continuous stirring. The rate of addition of the free radical initiator was controlled so that the reaction temperature in the reactor did not exceed 95°C at a jacket temperature of 80°C and a constant supply of ethylene at a moderate pressure of approximately 7 bar. The total metering time was 3 hours. After-reaction was then continued at 85°C for 3 hours. The reactor was depressurized and cooled to room temperature.

The resulting solution was substantially freed of the acetic acid solvent on a rotary evaporator and then mixed with 15.9 liters of water. Over a three-hour period, 4333 g (6.9 mol of Al) of an aqueous aluminum sulfate solution with an Al content of 4.3% by weight was introduced. The resulting solid was then filtered, washed twice with 2 liters of water each, and dried in vacuo at 130°C.

The product comprised 15.9% by weight of aluminum butylethylphosphinate and 0.2% by weight of residual moisture.

Example 2

The processing was carried out using 3 bar ethylene pressure and 95.2 g of sodium peroxodisulfate according to Example 1. The product contained 5.8 weight percent aluminum ethylphosphonate.

Example 3

After decompression and cooling, 800 g of the solution obtained in Example 1 was diluted with 2500 ml of acetic acid, and 42 g (0.54 mol) of aluminum hydroxide was added. The mixture was then heated under reflux for approximately 4 hours, cooled, and filtered. The resulting solid was washed with 1 liter of acetic acid and then dried in vacuo at 130°C. The product contained 5.8% by weight of aluminum acetate.

Example 4 (comparative)

Aluminum diethylphosphinate and aluminum phosphite (amounts in Table 1) were weighed into a polyethylene bottle to give about 1 kg of a flame retardant mixture. The mixture was mixed in an overhead mixer for about 2 hours until homogeneous.

Examples 5 to 13

Aluminum diethylphosphinate and aluminum phosphite (amounts in Table 1) containing a telomer additive were weighed into polyethylene bottles to yield approximately 1 kg of each flame-retardant mixture, which was then mixed in an overhead mixer for approximately 2 hours until homogeneity was achieved. Tests showed that the products of Examples 5 to 13 exhibited a more uniform free-flowing property than the unadditized product of Comparative Example 4. The combination of aluminum butylethylphosphinate and secondary aluminum phosphite (Example 6) or the combination of aluminum butylethylphosphinate and an alkali metal-aluminum mixed phosphite (Example 12) exhibited particularly good results.

Examples 14 and 15

A mixture of aluminum diethylphosphinate and _Al2 ( _HPO3 ) ₃ * _4H2O containing telomer additives and the sodium aluminum phosphite of Example 80 or 81 (previously dried at 220°C to 0.5% by weight of residual moisture) was weighed into a polyethylene bottle to give about 1 kg of the flame-retardant mixture, which was mixed in an overhead mixer for about 2 hours until homogeneity was achieved.

Examples 16 to 24

Aluminum diethylphosphinate and aluminum phosphite, including sulfate additives, were weighed into a polyethylene bottle to yield approximately 1 kg of a flame retardant mixture, which was mixed in an overhead mixer for approximately 2 hours until homogeneous. The tests showed that the products of Examples 16 to 24 had a more uniform free-flowing consistency than the product of Comparative Example 4 without the additives.

Examples 25 to 33

Aluminum diethylphosphinate and aluminum phosphite, including a phosphate additive, were weighed into a polyethylene bottle to yield approximately 1 kg of a flame retardant mixture, which was mixed in an overhead mixer for approximately 2 hours until homogeneous. The tests showed that the products of Examples 25 to 33 had a more uniform free-flowing consistency than the product of Comparative Example 4, which did not contain the additive.

Examples 34 to 42

Aluminum diethylphosphinate and aluminum phosphite, including a phosphonate additive, were weighed into a polyethylene bottle to yield approximately 1 kg of a flame-retardant mixture. The mixture was mixed in an overhead mixer for approximately 2 hours until homogeneous. The test showed a more uniform free-flowing property than the product of Comparative Example 4, which did not contain the additive.

Examples 43 to 51

Aluminum diethylphosphinate and aluminum phosphite, including a nitrate additive, were weighed into a polyethylene bottle to yield approximately 1 kg of a flame-retardant mixture. The mixture was mixed in an overhead mixer for approximately 2 hours until homogeneous. The test showed a more uniform, free-flowing consistency than the product of Comparative Example 4, which did not contain the additive.

Examples 61 to 69

Aluminum diethylphosphinate and aluminum phosphite, including an acetate additive, were weighed into a polyethylene bottle to yield approximately 1 kg of a flame-retardant mixture. The mixture was mixed in an overhead mixer for approximately 2 hours until homogeneous. The test showed a more uniform, free-flowing property than the product of Comparative Example 4, which did not contain the additive.

Example 70

A mixture of 50% by weight of polyamide 6.6, 20% by weight of the halogen-free flame retardant mixture from Example 12, and 30% by weight of glass fiber was processed into a flame-retardant polymer molding material according to the general procedure. After drying, the molding material was processed into polymer moldings on an injection molding machine. A UL-94 rating of V-0 was determined.

Examples 71 to 77

A flame-retardant polymer molding material based on polyamide 6, polyamide 4.6, and polybutylene terephthalate was processed according to Example 70. After drying, the molding material was processed on an injection molding machine to give polymer moldings. A UL-94 rating of V-0 was determined.

Table 8: Composition of flame retardant polymer molding materials and UL 94 flame retardancy test of flame retardant polymer moldings

Example 70 71 72 73 74 75 76 77 Polyamide 6.6 [wt%] 50 50 50 Polyamide 6 [wt%] 50 50 Polyamide 4.6 [wt%] 50 50 Polybutylene terephthalate [wt%] 50 Glass fiber PA [wt%] 30 30 30 30 30 Glass fiber PA 46 [weight %] 30 30 Glass fiber PBT [wt%] 30 Flame retardant of Example 12 [wt%] 20 Flame retardant of Example 23 [wt%] 20 Flame retardant of Example 41 [wt%] 20 Flame retardant of Example 31 [wt%] 20 Flame retardant of Example 50 [wt%] 20 Flame retardant of Example 65 [wt%] 20 Flame retardant of Example 15 [wt%] 20 UL 94 0.8mm[-] V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0

Polybutylene terephthalate: 2500, Ticona

Polyamide 6.6: A3, BASF

Polyamide 6: 7301, Du Pont

Polyamide 4.6: PA 46, DSM

Glass fiber PBT: EC 10 983, Saint-Gobain

Glass fiber PA: PPG 3540, PPG Industries, Inc.

Glass fiber PA 46:995, Saint-Gobain

Example 78

A 3-molar Na ₂ HPO ₃ solution and a 2-molar Al ₂ (SO ₄ ) ₃ solution were crystallized in aqueous solution at 150°C and pH 6.1 within 3 hours, filtered, and air-dried. X-ray powder diffraction studies were performed on the sodium aluminum phosphite. The stoichiometry was Al _2.0 Na _0.6 (HPO ₃ ) _2.89 * 0.28 _{H 2} O.

Example 78:

X-ray powder data of sodium aluminum phosphite

Example 79

3 molar Na ₂ HPO ₃ solution and 2 molar Al ₂ (SO ₄ ) ₃ solution were crystallized in aqueous solution at 150° C. and pH=3.5 within 3 h, filtered and air-dried.

Example 80

3 molar Na ₂ HPO ₃ solution and 2 molar Al ₂ (SO ₄ ) ₃ solution were crystallized in aqueous solution at 150° C. and pH=3.5 within 3 h, filtered and air-dried.

Example 81

3 molar Na ₂ HPO ₃ solution and 2.01 molar Al ₂ (SO ₄ ) ₃ solution were crystallized in aqueous solution at 150° C. and pH=2.5 within 3 h, filtered and air-dried.

Example 82

3 molar Na ₂ HPO ₃ solution and 2.1 molar Al ₂ (SO ₄ ) ₃ solution were crystallized in aqueous solution at 150° C. and pH=1 within 6 h, filtered and air-dried.

Example 82:

X-ray powder data of Al ₂ (HPO ₃ ) ₃ *4H ₂ O

Angle [°2Th] Height [cts] 11.7777 345.54 13.6143 1270.15 14.7988 993.31 15.3862 494.47 16.2983 596.21 20.2051 1455.68 22.5312 1405.43 32.9021 1440.39

Examples 78 to 82:

X-ray powder data of a mixture of Al ₂ (HPO ₃ ) ₃ *4H ₂ O and sodium aluminum phosphite

Claims (11)

1. A halogen-free flame retardant mixture comprising 1 to 99 wt% component A and 1 to 99 wt% component B, wherein component A comprises 85 to 99.995 wt% of metallic Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogen-containing base solid diethylphosphite and 0.005 to 15 wt% of non-flammable additives, and component B is aluminum phosphite, wherein the aluminum phosphite is aluminum phosphite of formula (II) and/or (III). Al _2.00 M _z (HPO ₃ ) _y (OH) _v x(H ₂ O) _w (II) in M represents alkali metal ions. z represents 0.01 to 1.5 y represents 2.63 to 3.5. v represents 0 to 2, and w represents 0 to 4. Al _2.00 (HPO ₃ ) _u (H ₂ PO ₃ ) _t x(H ₂ O) _s (III) in u represents 2 to 2.99 t represents 2 to 0.01, and s represents 0 to 4, And/or 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, Al _{4H 6P 16O 18} and/or a mixture of 0-99.9 wt% Al ₂ (HPO ₃ ) ₃ *nH ₂ O and 0.1-100 wt% sodium aluminum phosphite, where x = 2.27-1; And, the non-flammable additive is a dialkylphosphinate of formula (IV). ^R1 and ^R2 may be the same or different and independently represent ethyl, butyl, hexyl and/or octyl, and M represents Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or protonated nitrogen-containing bases, provided that ^R1 and ^R2 do not simultaneously represent ethyl. 2. The halogen-free flame retardant mixture according to claim 1, comprising 20 to 80% by weight of component A and 20 to 80% by weight of component B. 3. The halogen-free flame retardant mixture according to claim 1 or 2, characterized in that component A comprises 92 to 99.9% by weight of aluminum diethylphosphonate and 0.1 to 8% by weight of non-flammable additives. 4. The halogen-free flame retardant mixture according to claim 1 or 2, characterized in that the dialkyl phosphonate of formula (IV) is ethyl-butyl phosphonate, butyl-butyl phosphonate, ethyl-hexyl phosphonate, butyl-hexyl phosphonate and/or hexyl-hexyl phosphonate. 5. The halogen-free flame retardant mixture according to claim 1 or 2, characterized in that component A has a median particle size d50 of 0.05 to 10 μm and component B has a median particle size d50 of 0.05 to 10 μm and a residual moisture content of 0.05 to 8% by weight. 6. A method for preparing a halogen-free flame retardant mixture according to any one of claims 1 to 5, characterized in that components A and B are mixed with each other in powder form and optionally sieved. 7. Use of the halogen-free flame retardant mixture according to any one of claims 1 to 5, as an intermediate product for further synthesis, as a synergist, as an adhesive, as a crosslinking agent or accelerator in the curing of epoxy resins, polyurethanes, and unsaturated polyester resins, as a polymer stabilizer, as a plant protectant, as a chelating agent, as a mineral oil additive, as a corrosion inhibitor, for detergent and cleaning agent applications, for electronic applications, as a flame retardant, as a flame retardant for varnishes and foaming coatings, as a flame retardant for wood and other cellulose-containing products, as a reactive and/or non-reactive flame retardant for polymers, for the preparation of flame-retardant polymer molding materials, for the preparation of flame-retardant polymer molded articles, and/or for imparting flame retardancy to pure and blended polyester and cellulose fabrics by impregnation and/or as a synergist in other flame retardant mixtures. 8. Flame-retardant thermoplastic or thermosetting polymer molding materials, polymer molded articles, polymer films, polymer filaments and/or polymer fibers, comprising 0.1 to 45% by weight of a halogen-free flame retardant mixture according to any one of claims 1 to 5, 55 to 99.9% by weight of a thermoplastic or thermosetting polymer or a mixture thereof, 0 to 55% by weight of additives and 0 to 55% by weight of fillers or reinforcing materials, wherein the total of the components is 100% by weight. 9. Flame-retardant thermoplastic or thermosetting polymer molding materials, polymer molded articles, polymer films, polymer filaments and/or polymer fibers, comprising 1 to 30% by weight of a halogen-free flame retardant mixture according to any one of claims 1 to 5, 10 to 97% by weight of a thermoplastic or thermosetting polymer or a mixture thereof, 1 to 30% by weight of an additive and 1 to 30% by weight of a filler or reinforcing material, wherein the total of the components is 100% by weight. 10. Flame-retardant thermoplastic or thermosetting polymer molding materials, polymer molded articles, polymer films, polymer filaments and/or polymer fibers, comprising a halogen-free flame retardant mixture according to any one of claims 1 to 5, characterized in that the polymer is a thermoplastic polymer of the type of high-impact polystyrene, polyphenylene ether, polyamide, polyester, or polycarbonate, and a blend of acrylonitrile-butadiene-styrene or polycarbonate/acrylonitrile-butadiene-styrene or polyphenylene ether/high-impact polystyrene plastic, and/or a thermosetting polymer of the type of unsaturated polyester or epoxy resin. 11. The flame-retardant thermoplastic or thermosetting polymer molding material, polymer molded article, polymer film, polymer filament and/or polymer fiber according to any one of claims 8 to 10, characterized in that the polymer is polyamide 4/6, polyamide 6, polyamide 6/6 and/or high-temperature nylon.