Mixed alkali-aluminum phosphites, method for producing same, and the use thereof

1. A mixed alkali-aluminum phosphite of the formula (I)

Al 2.00 M z (HPO 3 ) y (OH) v x (H 2 O) w   (I)

wherein

M is alkali metal ions,

z is 0.01 to 1.5,

y is 2.63 to 3.5,

v is 0 to 2, and

w is 0 to 4,

wherein the mixed alkali-aluminum phosphate phosphite includes

a particle size of 0.1 to 1000 pm,

a solubility in water of 0.01 to 10 g/l,

a bulk density of 80 to 800 g/l, and

a thermal stability with respect to PH 3 formation of 325 to 450° C.

2. A synergist, a synergist in flame retardant mixtures and in flame retardants, a flame retardant for clearcoats and intumescent coatings, a flame retardant for wood and other cellulosic products, a reactive and nonreactive flame retardant for polymers, a flame-retardant polymer molding composition, a flame-retardant polymer molding or a polyester and pure and blended cellulose fabric flame- retardant produced by impregnation comprising a mixed alkali-aluminum phosphite of the formula (I)

Al 2.00 M z (HPO 3 ) y (OH) v x (H 2 O) w   (I)

wherein

M is alkali metal ions,

Z is 0.01 to 1.5,

y is 2.63 to 3.5,

v is 0 to 2, and

w is 0 to 4,

wherein the mixed alkali-aluminum phosphate phosphite includes

a particle size of 0.1 to 1000 μm,

a solubility in water of 0.01 to 10 g/l,

a bulk density of 80 to 800 g/l, and

a thermal stability with respect to PH 3 formation of 325 to 450° C.

3. A mixed alkali-aluminum phosphite of the formula (I)

Al 2.00 M z (HPO 3 ) y (OH) v x (H 2 O) w   (I)

wherein

M is alkali metal ions,

z is 0.01 to 1.5,

y is 2.63 to 3.5,

v is 0 to 2, and

w is 0 to 4,

wherein the mixed alkali-aluminum phosphite includes

a particle size of 0.1 to 1000 μm,

a solubility in water of 0.01 to 10 g/l,

a bulk density of 80 to 800 g/l,

a thermal stability with respect to PH 3 formation of 325 to 450° C., and

wherein the mixed alkali-aluminum phosphite has an SO 4 content of between 0.5 and 1.0% by weight.

4. A mixed alkali-aluminum phosphite as claimed in claim 3 , wherein

M is Na or K,

z is 0.1 to 1.2,

y is 2.75 to 3.1,

v is 0.05 to 0.5, and

w is 0 to 1.

5. A mixed alkali-aluminum phosphite as claimed in claim 3 , wherein

M is Na,

z is 0.15 to 0.4,

y is 2.80 to 3,

v is 0.1 to 0.4, and

w is 0.01 to 0.1.

6. A mixed alkali-aluminum phosphite as claimed in claim 3 , selected from the group consisting of:

Al 2.00 Na 0.3 (HPO 03 ) 2.99 (OH) 0.32 x(H 2 O) 0-4 ;

Al 2.00 Na 0.14 (HPO 03 ) 3.06 (OH) 0.02 x(H 2 O) 0-4 ;

Al 2.00 Na 0.19 (HPO 03 ) 2.85 (OH) 0.49 x(H 2 O) 0-4 ;

Al 2.00 Na 0.18 (HPO 03 ) 2.97 (OH) 0.24 x(H 2 O) 0-4 ;

Al 2.00 Na 0.02 (HPO 03 ) 2.83 (OH) 0.36 x(H 2 O) 0-4 ;

Al 2.00 Na 0.13 (HPO 03 ) 2.73 (OH) 0.66 x(H 2 O) 0-4 ;

Al 2.00 Na 0.12 (HPO 03 ) 2.74 (OH) 0.63 x(H 2 O) 0-4 ; and

Al 2.00 Na 1.15 (HPO 03 ) 2.63 (OH) 1.88 x(H 2 O) 0-4 .

7. A synergist, a synergist in flame retardant mixtures and in flame retardants, a flame retardant for clearcoats and intumescent coatings, a flame retardant for wood and other cellulosic products, a reactive and nonreactive flame retardant for polymers, a flame-retardant polymer molding composition, a flame-retardant polymer molding or a polyester and pure and blended cellulose fabric flame-retardant produced by impregnation comprising a mixed alkali-aluminum phosphite of the formula (I)

Al 2.00 M z (HPO 3 ) y (OH) v x (H 2 O) w   (I)

wherein

M is alkali metal ions,

z is 0.01 to 1.5,

y is 2.63 to 3.5,

v is 0 to 2, and

w is 0 to 4,

wherein the mixed alkali-aluminum phosphite includes

a particle size of 0.1 to 1000 μm,

a solubility in water of 0.01 to 10 g/l,

a bulk density of 80 to 800 g/l,

a thermal stability with respect to PH 3 formation of 325 to 450° C., and

wherein the mixed alkali-aluminum phosphite has an SO 4 content of between 0.5 and 1.0% by weight.