Flame Retardant-Stabilizer Combination for Thermoplastic Polymers

Abstract

The invention relates to a novel flame retardant-stabilizer combination for thermoplastic polymers, comprising, as component A, from 25 to 99.9% by weight of a phosphinic acid salt of the formula (I) wherein R.sup.1, R.sup.2 are the same or different and are each C.sub.1-C.sub.18-alkyl, linear or branched, C.sub.6-C.sub.18-aryl, C.sub.7-C.sub.18-arylalkyl or C.sub.7-C.sub.18-alkylaryl, or R.sup.1 and R.sup.2 form one or more rings with each other, M is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K and/or a protonated nitrogen base; m is from 1 to 4; as component B, from 0 to 75% by weight of a synergist or of a phosphorus/nitrogen flame retardant and, as component C, from 0.1 to 50% by weight of magnesium oxide, zinc oxide, manganese oxide, tin oxide, dihydrotalcite, hydrocalumite, magnesium hydroxide, calcium hydroxide, zinc hydroxide, tin oxide hydrate, manganese hydroxide, zinc borate, basic zinc silicate, zinc stannate or mixtures of these substances, the sum of the component s always being 100% by weight, and wherein the angle of repose of said flame retardant-stabilizer combination is between 5 and 45.

##STR00001##

Claims

1. A flame retardant-stabilizer combination for thermoplastic polymers, comprising, as component A, from 25 to 99.9% by weight of a phosphinic acid salt of the formula (I) ##STR00004## wherein R.sup.1, R.sup.2 are the same or different and are each C.sub.1-C.sub.18-alkyl, linear or branched, C.sub.6-C.sub.18-aryl, C.sub.7-C.sub.18-arylalkyl or C.sub.7-C.sub.18-alkylaryl, or R.sup.1 and R.sup.2 form one or more rings with each other, M is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K and/or a protonated nitrogen base; m is from 1 to 4; as component B, from 0 to 75% by weight of a synergist or of a phosphorus/nitrogen flame retardant and, as component C, from 0.1 to 50% by weight of magnesium oxide, zinc oxide, manganese oxide, tin oxide, dihydrotalcite, hydrocalumite, magnesium hydroxide, calcium hydroxide, zinc hydroxide, tin oxide hydrate, manganese hydroxide, zinc borate, basic zinc silicate, zinc stannate or mixtures of these substances, the sum of the components always being 100% by weight, and wherein the angle of repose of said flame retardant-stabilizer combination is between 5 and 45.

2. A flame retardant-stabilizer combination as claimed in claim 1, wherein the angle of repose of said flame retardant-stabilizer combination is between 20 and 40.

3. A flame retardant-stabilizer combination as claimed in claim 1, wherein R.sup.1, R.sup.2 are the same or different and are each methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methylbutyl, 3-methylbutyl (iso-methyl), 3-methylbut-2-yl, 2-methylbut-2-yl, 2,2-dimethylpropyl (neopentyl), hexyl, heptyl, octyl, nonyl, decyl, cyclopentyl, cyclopentylethyl, cyclohexyl, cyclohexylethyl, phenyl, phenylethyl, methylphenyl und/oder methylphenylethyl.

4. A flame retardant-stabilizer combination as claimed in claim 1, wherein M is a calcium, aluminum, zinc, titanium or iron ion.

5. A flame retardant-stabilizer combination as claimed in claim 1, wherein component B comprises one or more of groups a)-e) a) condensation products of melamine, b) reaction products of melamine with polyphosphoric acid and/or reaction products of condensation products of melamine with polyphosphoric acid or mixtures thereof, c) phosphates of the formulae (NH.sub.4).sub.y H.sub.3-y PO.sub.4 or (NH.sub.4 PO.sub.3).sub.z, where y is from 1 to 3 and z is from 1 to 10 000, d) N-synergists of the formulae (III) to (VIII) or mixtures thereof. ##STR00005## where R.sup.5 to R.sup.7 are each hydrogen, C.sub.1-C.sub.8-alkyl, C.sub.5-C.sub.16-cycloalkyl or -alkylcycloalkyl, possibly substituted by a hydroxyl or a C.sub.1-C.sub.4-hydroxyalkyl function, C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, -acyl, -acyloxy, C.sub.6-C.sub.12-aryl or -arylalkyl, OR.sup.8 and N(R.sup.8)R.sup.9, N-alicyclic or N-aromatic, R.sup.8 is hydrogen, C.sub.1-C.sub.8-alkyl, C.sub.5-C.sub.16-cycloalkyl or -alkylcycloalkyl, possibly substituted by a hydroxyl or a C.sub.1-C.sub.4-hydroxyalkyl function, C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, -acyl, -acyloxy or C.sub.6-C.sub.12-aryl or -arylalkyl, R.sup.9 to R.sup.13 are each the same groups as R.sup.8 and also OR.sup.8, m and n are each independently of 1, 2, 3 or 4, X is an acid which can form adducts with triazine compounds (III); or oligomeric esters of tris(hydroxyethyl) isocyanurate with aromatic polycarboxylic acids, e) aluminium phosphites.

6. A flame retardant-stabilizer combination as claimed in claim 5, wherein the condensation products a) of melamine are melem, melam, melon and/or more highly condensed compounds thereof; the reaction products of melamine b) are dimelamine pyrophosphate, melamine polyphosphate, melem polyphosphate, melam polyphosphate, melon polyphosphate and/or mixed polysalts of this type; the phosphates c) are ammonium hydrogenphosphate, ammonium dihydrogenphosphate and/or ammonium polyphosphate; the N-synergists d) are benzoguanamine, tris(hydroxyethyl) isocyanurate, allantoin, glycouril, melamine, melamine cyanurate, dicyandiamide and/or guanidine; the aluminium phosphites e) are of the formula (IX), (II) and/or (X)
Al.sub.2(HPO.sub.3).sub.3x(H.sub.2O).sub.q(IX) where q is 0 to 4
Al.sub.2.00M.sub.z(HPO.sub.3).sub.y(OH).sub.vx(H.sub.2O).sub.w(II) where M are Alkali metal ions z 0.01 to 1.5 y 2.63 to 3.5 v 0 to 2 and w 0 to 4,
Al.sub.2.00(HPO.sub.3).sub.u(H.sub.2PO.sub.3).sub.tx(H.sub.2O).sub.s(X) where u is 2 to 2.99 t 2 to 0.01 and s 0 to 4, and/or mixtures of aluminium phosphite of formula (IX) with aluminium salt of limited solubility and nitrogen free ions, mixtures of aluminium phosphite of formula (X) with aluminium salts, aluminium phosphite [Al(H2PO.sub.3).sub.3], secondary aluminium phosphite [Al.sub.2(HPO.sub.3).sub.3], basic aluminium phosphite [Al(OH)(H.sub.2PO.sub.3).sub.2*2aq], aluminium phosphite tetrahydrate [Al.sub.2(HPO.sub.3).sub.3*4aq], aluminium phosphonate, Al.sub.7(HPO.sub.3).sub.9(OH).sub.6(1,6-hexandiamine).sub.1.5*12H.sub.2O, Al.sub.2(HPO.sub.3).sub.3*xAl.sub.2O.sub.3*nH.sub.2O with x=2.27-1, Al.sub.4H.sub.6P.sub.16O.sub.18 and/or mixtures of 0-99.9 wt.-% Al.sub.2(HPO.sub.3).sub.3*nH.sub.2O with 0.1-100 Gew.-% sodium aluminium phosphite.

7. A flame retardant-stabilizer combination as claimed in claim 6, wherein the aluminium phosphite is a mixture of 50-99 wt.-% Al.sub.2(HPO.sub.3).sub.3x(H.sub.2O).sub.q where q is 0 to 4 with 1-50 wt.-% sodium aluminium phosphite.

8. A flame retardant-stabilizer combination as claimed in claim 6, wherein the aluminium phosphite is a mixture of 50-99 wt.-% Al.sub.2(HPO.sub.3).sub.3x(H.sub.2O).sub.q where q is 0 to 4 with 1-50 wt.-% Al.sub.2.00M.sub.z(HPO.sub.3).sub.y(OH).sub.vx(H.sub.2O).sub.w (II) where M is sodium, z is 0.005 to 0.15, y is 2.8 to 3.1, v is 0 to 0.4 and w is 0 to 4.

9. A flame retardant-stabilizer combination as claimed in claim 1, wherein component B is melamine polyphosphate.

10. A flame retardant-stabilizer combination as claimed in claim 1, wherein component C is a basic or amphoteric oxide, metal oxide, magnesium oxide, zinc oxide, manganese oxide, tin oxide, a metal hydroxide, magnesium hydroxide, hydrotalcite, hydrocalumite, dihydrotalcite, calcium hydroxide, zinc hydroxide, tin oxide hydrate, manganese hydroxide, silicate, zeolithe, silicic acid, glas-, glas-ceramic or ceramic-powder; magnesium carbonate magnesium-calcium-carbonate (dolomite); zinc stannate, zinc hydroxyl stannate, zinc phosphate, zinc sulfide, aluminium oxide, aluminium hydroxide, boehmite, aluminium sulfate hydroxide, aluminium phosphate, calcium oxide, manganese oxide, tin oxide, tin oxide hydrate, manganese hydroxide, basic zinc silicate.

11. A flame retardant-stabilizer combination as claimed in claim 1, wherein from 50 to 99% by weight of component A, from 0 to 50% by weight of component B and from 1 to 20% by weight of component C are present.

12. A flame retardant-stabilizer combination as claimed in claim 1, wherein from 50 to 78% by weight of component A, from 20 to 50% by weight of component B and from 2 to 20% by weight of component C are present.

13. A flame retardant-stabilizer combination as claimed in claim 1, wherein from 60 to 98% by weight of component A and from 2 to 40% by weight of component C are present.

14. A flame retardant-stabilizer combination as claimed in claim 1, wherein the residual moisture content of said flame retardant-stabilizer combination is between 0.01 wt.-% and 10 wt.-%.

15. A flame retardant-stabilizer combination as claimed in claim 1, wherein the residual moisture content of said flame retardant-stabilizer combination is between 0.1 wt.-% and 1 wt.-%.

16. A flame retardant-stabilizer combination as claimed in claim 1, wherein the particle size of said flame retardant-stabilizer combination is between 1 m and 100 m.

17. A flame retardant-stabilizer combination as claimed in claim 1, wherein the bulk density of said flame retardant-stabilizer combination is between 100 g/L and 1000 g/L.

18. A flame retardant-stabilizer combination as claimed in claim 1, wherein the tap density of said flame retardant-stabilizer combination is between 200 g/L and 1200 g/L.

19. The use of the flame retardant-stabilizer combination as claimed in claim 1, as a flame retardant or as an intermediate for preparation of flame retardants for thermoplastic polymers, for thermoset polymers, for clearcoats, for intumescent coatings, for wood and other cellulosic products, for polymer shaped body, film, thread or fiber, for production of flame-retardant polymer molding compositions, for production of flame-retardant polymer moldings and/or for rendering pure and blended polyester and cellulose fabrics flame-retardant by impregnation.

20. The use as claimed in claim 19, wherein the thermoplastic polymers are polyester, polystyrene and/or polyamide, and the thermoset polymers are unsaturated polyester resins, epoxy resins, polyurethanes and/or acrylates.

21. A flame-retardant plastics molding composition, polymer shaped body, film, thread or fiber comprising the flame retardant-stabilizer combination as claimed in claim 1.

22. A flame-retardant plastics molding composition, polymer shaped body, film, thread or fiber, as claimed in claim 21, wherein the plastics used are thermoplastic polymers of the type high-impact polystyrene, polyphenylene ether, polyamides, polyesters, polycarbonates, thermoplastic polyurethanes and blends or polymer blends of the type ABS (acrylonitrile-butadiene-styrene) or PC/ABS (polycarbonate/acrylonitrile-butadiene-styrene) or PPE/HIPS (polyphenylene ether/HI polystyrene) plastics.

23. A flame-retardant plastics molding composition, polymer shaped body, film, thread or fiber as claimed in claim 21, which comprises the flame retardant-stabilizer combination in an amount of from 2 to 50% by weight, based on the plastics molding composition.

24. A flame-retardant plastics molding composition, polymer shaped body, film, thread or fiber as claimed in claim 21, which comprises the flame retardant-stabilizer combination in an amount of from 10 to 30% by weight, based on the plastics molding composition.

25. A flame-retardant plastics molding composition, polymer shaped body, film, thread or fiber as claimed in claim 21 for the use in or for connectors, power wetted parts in current distributors (RCCB), boards, potting compounds, power connectors, circuit breakers, lamp housing, LED housing, condenser housing, bobbins and fans, protection contacts, connectors, in/on circuit boards, casings for connectors, cables, flexible circuit boards, charger for mobile phones, engine covers, textile coatings, moldings in the form of components for the electrical/electronics sector, in particular for parts of printed circuit boards, housings, films, cables, switches, distribution boards, relays, resistors, capacitors, coils, lamps, diodes, LEDs, transistors, connectors, controllers, memories and sensors, in the form of large-area components, in particular housing parts for cabinets and in the form of elaborately designed components with sophisticated geometry.

Description

EXAMPLES

1. Components Used

Standard Commercial Polymers (Granules):

[0146] PA 6,6 GF: Durethan AKV 30 (Bayer AG, D), contains 30% glass fibers.
PBT GF: Celanex 2300 GV1/30 (Ticona, D), contains 30% glass fibers.

PA 6: Ultramid B 27 E

PA 6,6: Ultramid A 27 E (BASF)

[0147] Glas fiber: PPG Glas fiber HP 3610 EC 10 4.5 mm

Flame Retardant Components (Pulverulent):

[0148] Aluminum salts of diethylphosphinic acid, referred to hereinbelow as DEPAL.

[0149] Melapur 200 (melamine polyphosphate, MPP), referred to hereinbelow as MPP, from BASF, Germany.

[0150] Zinc borate anhydrate (Zn-Borate) Firebrake Rio Tinto

[0151] Aluminiumphosphite (AP) according to DE102014001222 (A1)

[0152] Zinkoxyd aktiv (ZnO), Bayer AG, Germany

2. Production, Processing and Testing of Flame-Retardant Plastics Molding Compositions

[0153] The flame-retardant components were mixed with the polymer granules, lubricants and stabilizers in the ratio specified in the tables and incorporated in a Leistritz LSM 30/34 double-screw extruder at temperatures of from 260 to 310 C. (GFR PA-6,6) or from 240 to 280 C. (GFR PBT). The homogenized polymer strand was drawn off, cooled in a water bath and then granulated.

[0154] After sufficient drying, the molding compositions were processed to give test specimens on a Arburg 320 C Allrounder injection molding machine at temperatures of from 270 to 320 C. (GFR PA-6,6) or from 260 to 280 C. (GFR PBT) and, with the aid of the UL 94 test (Underwriter Laboratories), were tested for flame resistance and classified.

[0155] The flowability of the molding composition was determined by determining the melt volume index (MVR) at 275 C./2.16 kg. A sharp rise in the MVR value indicated polymer degradation.

[0156] The processing properties in polyester were assessed with reference to the specific viscosity (SV). After sufficient drying, the plastics molding composition granules were used to prepare a 1.0% solution in dichloroacetic acid and the SV value was determined. The higher the SV value is, the lower was the polymer degradation during the incorporation of the flame retardant.

[0157] Unless stated otherwise, all experiments of a particular series were carried out under identical conditions (temperature program, screw geometries, injection molding parameters, etc.) for the purpose of comparability.

[0158] Thus, for the inventive flame retardant-stabilizer combinations of phosphinate, synergist and component C, an improvement in the angle of repose can be detected.

[0159] It is evident from the examples that the additives according to the invention (mixture of the components phosphinate, synergist and oxide or hydroxide or mixed oxide hydroxide or oxide hydroxide carbonate) distinctly improve the processability of the polymers without impairing the flame retardancy.

[0160] In the flame-retardants polyester (PBT), the employment of the inventive combination of phosphinate, synergist and metal oxide or hydroxide leads to distinctly reduced polymer degradation, recognizable by high SV values.

[0161] Unless stated otherwise, the amounts quoted are always in percent by weight.

[0162] In the present invention, angle of repose were used to evaluate the flowability of said dialkylphosphinate. For example, to measure the angle of repose, the powder sample was poured through a funnel and dropped down to a round plate with a radius of r. The powder was continuously poured into the funnel and accumulated into a cone-shaped pile growing up until the height of the pile did not increase. The height of the pile, h, was measured and the angle of repose, a, was calculated according to formula (1)

tg=h/r(1)

[0163] The smaller is, the better the flowability of the powder is. Generally, when is smaller than 30, the powder can flow freely; when is between 30 and 40, the powder can meet the processing requirements; when is greater than 40, the powder cannot meet the processing requirements.

Example 1a (Comparison)

[0164] A sample produced according to CN-A-104059101 was tested for its angle of repose. The result is listed in Table 1.

Example 1b (Comparison)

[0165] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate, component B in types and amounts according to table 1. It was tested for its angle of repose, the result is worse than pure aluminium-phosphinate and listed in table 1.

Example 2

[0166] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate and component C in types and amounts according to table 1. It was tested for its angle of repose, the result is listed in table 1 and is better than comparative example 1.

Example 3

[0167] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate and component C in types and amounts according to table 1. It was tested for its angle of repose, the result is listed in table 1 and is better than comparative example 1.

Example 4

[0168] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate, component B and component C in types and amounts according to table 1. It was tested for its angle of repose, the very good result is listed in table 1.

Example 5

[0169] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate, component B and component C in types and amounts according to table 1. It was tested for its angle of repose, the very good result is listed in table 1.

Example 6

[0170] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate and component C in types and amounts according to table 1. It was tested for its angle of repose, the result is listed in table 1 and is better than comparative example 1.

Example 7

[0171] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate, component B and component C in types and amounts according to table 1. It was tested for its angle of repose, the very good result is listed in table 1.

Example 8

[0172] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate, component B and component C in types and amounts according to table 1. It was tested for its angle of repose, the very good result is listed in table 1.

Example 9

[0173] A flame retardant-stabilizer combination according to the invention was mixed from aluminiumdiethylphosphinate, component B and component C in types and amounts according to table 1. It was tested for its angle of repose, the very good result is listed in table 1.

TABLE-US-00001 TABLE 1 Compositions of flame retardant-stabilizer combinations and angles of repose Aluminium- component Angle of Exam- phospinate B C repose ple [wt.-%] [wt.-%] [wt.-%] [] 1a 100 25 (Comp.) 1b 67.0 MPP 33.0 35 (Comp.) 2 99.9 0 ZnO 0.1 24.9 3 80 0 ZnO 20 23 4 66.9 MPP 33.0 ZnO 0.1 27 5 53.6 MPP 26.4 ZnO 20 30 6 99.8 Zn-Borate 0.2 22 7 65.7 MPP 32.3 Zn-Borate 2 26 8 60.3 MPP 29.7 Zn-Borate 10 27 9 81.2 AP 17.8 Zn-borate 1 26

[0174] It can be seen from table 1 that components C improve the repose angle (i.e. decrease the numeric value). Aluminiumdiethylphosphinate plus components C are better than pure aluminiumdiethylphosphinate.

[0175] Component B (although important for flame retardancy) worsen the repose angle (i.e. decrease the numeric value).

[0176] But the inventive combination of aluminiumdiethylphosphinate/component B plus components C improves the repose angle in comparison to only aluminiumdiethylphosphinate and component B.

Example 10

[0177] An inventive flame-retardant molding composition comprising the combination of aluminiumdiethylphosphinate, component B and component C in glass fiber-reinforced PA-6 was produced in the composition according to table using a melt temperature on injection molding of 290 C.

Example 11

[0178] An inventive flame-retardant molding composition comprising the combination of aluminiumdiethylphosphinate, component B and component C in glass fiber-reinforced PA-6,6 was produced in the composition according to table using a melt temperature on injection molding of 300 C.

Example 12

[0179] An inventive flame-retardant molding composition comprising the combination of aluminiumdiethylphosphinate, component B and component C in glass fiber-reinforced PA-6,6 was produced in the composition according to table using a melt temperature on injection molding of 300 C.

Example 13

[0180] An inventive flame-retardant molding composition comprising the combination of aluminiumdiethylphosphinate, component B and component C in glass fiber-reinforced PA-6,6 was produced in the composition according to table using a melt temperature on injection molding of 300 C.

Example 14

[0181] An inventive flame-retardant molding composition comprising the combination of aluminiumdiethylphosphinate, component B and component C in glass fiber-reinforced PA-6,6 was produced in the composition according to table using a melt temperature on injection molding of 300 C.

Example 15

[0182] An inventive flame-retardant molding composition comprising the combination of aluminiumdiethylphosphinate, component B and component C in glass fiber-reinforced PBT was produced in the composition according to table using a melt temperature on injection molding of 275 C.

TABLE-US-00002 TABLE 2 Compositions of flame-retardant molding compositions and test results Flame retard.- Glas stab. UL 94 fiber comb class Exam- Polymer (calc.) acc. (0.8 mm) ple Type [wt.-%] [wt.-%] to exp. [wt.-%] [-] 10 PA 6 52 30 7 18 V-0 11 PA 6.6 80 0 2 20 V-0 12 PA 6.6 72 10 9 18 V-0 13 PA 6.6 GF 82 (24.6) 7 18 V-0 14 PA 6.6 42 40 6 18 V-0 15 PBT GF 82 (24.6) 8 18 V-0