FLAME-RETARDANT POLYESTER COMPOSITIONS AND THE USE THEREOF

Abstract

The invention relates to flame-retardant polyester compositions comprising thermoplastic polyester as component A, fillers and/or reinforcers as component B, phosphinic salt of the formula (I) as component C

##STR00001## in which R.sub.1 and R.sub.2 are ethyl, M is Al, Fe, TiO.sub.p or Zn, m is 2 to 3, and p=(4m)/2 compound selected from the group of the Al, Fe, TiO.sub.p and Zn salts of ethylbutylphosphinic acid, of dibutylphosphinic acid, of ethylhexylphosphinic acid, of butylhexylphosphinic acid and/or of dihexylphosphinic acid as component D phosphonic salt of the formula II as component E

##STR00002## in which R.sub.3 is ethyl, Met is Al, Fe, TiO.sub.q or Zn, n is 2 to 3, and q=(4n)/2, inorganic phosphonate as component F, and wax selected from the group consisting of the polyolefin waxes, amide waxes, natural waxes, long-chain aliphatic carboxylic acids and/or esters or salts thereof as component G.

The polyester compositions can be used for production of fibers, films and moldings, especially for uses in the electricals and electronics sector.

Claims

1. A flame-retardant polyester composition comprising: thermoplastic polyester as component A; fillers and/or reinforcers as component B; phosphinic salt of the formula (I) as component C ##STR00006## in which R.sub.1 and R.sub.2 are ethyl, M is Al, Fe, TiO.sub.p or Zn, m is 2 to 3, and p=(4m)/2; compound selected from the group of the Al, Fe, TiO.sub.p and Zn salts of ethylbutylphosphinic acid, of dibutylphosphinic acid, of ethylhexylphosphinic acid, of butylhexylphosphinic acid and/or of dihexylphosphinic acid as component D; phosphonic salt of the formula II as component E ##STR00007## in which R.sub.3 is ethyl, Met is Al, Fe, TiO.sub.q or Zn, n is 2 to 3, and q=(4n)/2; inorganic phosphonate as component F; and wax selected from the group consisting of the polyolefin waxes, amide waxes, natural waxes, long-chain aliphatic carboxylic acids and/or esters or salts thereof as component G.

2. The flame-retardant polyester composition as claimed in claim 1, wherein M and Met are Al, m and n are 3, and components D and F are aluminum salts.

3. The flame-retardant polyester composition as claimed in claim 1, wherein the proportion of component A is 25% to 95% by weight, the proportion of component B is 1% to 45% by weight, the proportion of component C is 1% to 35% by weight, the proportion of component D is 0.01% to 3% by weight, the proportion of component E is 0.001% to 1% by weight, the proportion of component F is 0.005% to 6% by weight, and the proportion of component G is 0.05% to 5% by weight, where the percentages are based on the total amount of the polyester composition.

4. The flame-retardant polyester composition as claimed in claim 3, wherein the proportion of component A is 25% to 75% by weight, the proportion of component B is 20% to 40% by weight, the proportion of component C is 5% to 20% by weight, the proportion of component D is 0.05% to 1.5% by weight, the proportion of component E is 0.01% to 0.6% by weight, the proportion of component F is 0.05% to 2% by weight, and the proportion of component G is 0.1% to 2% by weight.

5. The flame-retardant polyester composition as claimed in claim 1, which contain iron in an amount within the range from 0.0001% to 0.2% by weight, preferably from 0.0002% to 0.05% by weight.

6. The flame-retardant polyester composition as claimed in claim 5, wherein at least one of the flame-retardant components C, D, E and F contains iron.

7. The flame-retardant polyester composition as claimed in claim 1, which comprises a melamine polyphosphate having an average degree of condensation of 2 to 200 as component H, preferably a melamine polyphosphate having an average degree of condensation of 20 to 200.

8. The flame-retardant polyester composition as claimed in claim 7, which comprises melamine cyanurate as component I.

9. The flame-retardant polyester composition as claimed in claim 1, which has a comparative tracking index measured according to International Electrotechnical Commission Standard IEC-60112/3 of not less than 500 V.

10. The flame-retardant polyester composition as claimed in claim 1, which attains a UL-94 V-0 assessment at thickness from 3.2 mm to 0.4 mm.

11. The flame-retardant polyester composition as claimed in claim 1, which has a glow wire flammability index according to IEC-60695-2-12 of at least 960 C. at thickness 0.75-3 mm.

12. The flame-retardant polyester composition as claimed in claim 1, which has a glow wire ignition temperature according to IEC-60695-2-13 of at least 750 C. at thickness 0.75-3 mm.

13. The flame-retardant polyester composition as claimed in claim 1, wherein component A comprises one or more polyalkylene terephthalates.

14. The flame-retardant polyester composition as claimed in claim 13, wherein component A is a polyethylene terephthalate.

15. The flame-retardant polyester composition as claimed in claim 13, wherein component A is a polybutylene terephthalate.

16. The flame-retardant polyester composition as claimed in claim 15, wherein the specific viscosity of the polybutylene terephthalate is within the range between 65 and 150 cm.sup.3/g, preferably between 100 and 129 cm.sup.3/g.

17. The flame-retardant polyester composition as claimed in claim 1, wherein glass fibers are used as component B.

18. The flame-retardant polyester composition as claimed in claim 8, wherein components C, D, E, F, H and I are in particulate form, where the median particle size d.sub.50 of these components is 1 to 100 m.

19. The flame-retardant polyester composition as claimed in claim 1, which comprises an inorganic phosphonate of the formula (III) as component F ##STR00008## in which Me is Fe, TiO.sub.r, Zn or especially Al, o is 2 to 3, and r=(4o)/2.

20. The flame-retardant polyester composition as claimed in claim 1, wherein component G is an ester or a salt of long-chain aliphatic carboxylic acids having a chain length of C.sub.14 to C.sub.40.

21. The flame-retardant polyester composition as claimed in claim 1, wherein component G is a polyamide wax which has been prepared by reaction of ammonia or alkylenediamine with saturated and/or unsaturated fatty acids having 14 to 40 carbon atoms.

22. The flame-retardant polyester composition as claimed in claim 8, which comprises further additives as component J, where the further additives are selected from the group consisting of antioxidants, UV stabilizers, gamma ray stabilizers, hydrolysis stabilizers, costabilizers for antioxidants, antistats, emulsifiers, nucleating agents, plasticizers, processing auxiliaries, impact modifiers, dyes, pigments and/or further flame retardants other than components C, D, E, F, H and I.

23. The use of the polyester compositions as claimed in claim 1 for production of fibers, films and moldings, especially for uses in the electricals and electronics sector.

24. The flame-retardant polyester composition as claimed in claim 1, wherein components C, D, E, and F are in particulate form, where the median particle size d.sub.50 of these components is 1 to 100 m.

25. The flame-retardant polyester composition as claimed in claim 1, which comprises further additives as component J, where the further additives are selected from the group consisting of antioxidants, UV stabilizers, gamma ray stabilizers, hydrolysis stabilizers, costabilizers for antioxidants, antistats, emulsifiers, nucleating agents, plasticizers, processing auxiliaries, impact modifiers, dyes, pigments and/or further flame retardants other than components C, D, E, and F.

Description

EXAMPLES 1-6 AND COMPARATIVE EXAMPLES C1-C10 WITH PBT

[0227] The results of the experiments with PBT molding compounds are listed in the examples adduced in the table which follows. All amounts are reported as % by weight and are based on the PBT molding compound including the flame retardants, additives and reinforcers.

TABLE-US-00001 TABLE 1 PA 6,6 GF 30 Test results (1-6 inventive; C1-C10 comparisons) Example No. 1 1a 1b C1 2 C2 3 C3 4 A: PBT 51.3 51.8 51.8 51.5 51.3 51.5 51.3 51.5 51.3 B: EC10 glass fibers 30 30 30 30 30 30 30 30 30 C + D + E: FM 1 18 12 12 18 C + D + E: FM 2 18 18 C + D + E: FM 3 18 18 C + D + E: FM 4 18 C: FM 5 C + E: FM 6 F: FM 7 F: FM 8 0.5 0.5 0.5 0.5 0.5 0.5 0.5 H: FM 9 6 I: FM 10 6 G: wax 1 0.2 0.2 0.2 0.2 0.2 0.2 G: wax 2 UL 94 0.4 mm/[sec.] V-0/20 V-0/21 V-0/24 V-0/20 V-0/15 V-0/15 V-0/35 V-0/35 V-0/20 GWFI [ C.] 960 960 960 960 960 960 960 960 960 GWIT [ C.] 750 750 750 750 750 750 750 750 750 CTI [volts] 600 600 600 500 600 500 600 500 600 Surface smooth smooth smooth rough*.sup.) smooth rough*.sup.) smooth rough*.sup.) smooth Example No. C4 5 C5 6 C6 C7 C8 C9 C10 A: PBT 51.5 53.78 53.98 51.3 51.5 51.3 51.8 47.8 51.3 B: EC10 glass fibers 30 30 30 30 30 30 30 30 30 C + D + E: FM 1 C + D + E: FM 2 16 16 18 18 18 22 C + D + E: FM 3 C + D + E: FM 4 18 C: FM 5 18 C + E: FM 6 18 F: FM 7 0.02 0.02 F: FM 8 0.5 0.5 0.5 0.5 0.5 H: FM 9 I: FM 10 G: wax 1 0.2 0.2 0.2 0.2 0.2 G: wax 2 0.2 UL 94 0.4 mm/[sec.] V-0/20 V-0/05 V-0/05 V-0/10 V-0/10 V-0/40 V-2/90 V-1/75 V-0/45 GWFI [ C.] 960 960 960 960 960 960 850 900 960 GWIT [ C.] 750 750 725 750 700 750 700 725 750 CTI [volts] 500 600 500 550 500 500 600 600 500 Surface rough*.sup.) smooth rough*.sup.) smooth rough*.sup.) smooth smooth smooth smooth *.sup.)major problems in demolding the molding from the mold

[0228] The inventive polyester compositions of examples 1 to 6 are molding compounds which attain the UL 94 V-0 fire class at 0.4 mm, simultaneously have CTI 600 volts/550 volts, GWFI 960 C. and GWIT 750 C., and smooth surfaces. The exchange of wax 2 for wax 1 resulted in an increase in the CTI value. The moldings produced were demoldable without difficulty. The addition of a further component F in example 5 leads to another improvement in flame retardancy, expressed by a reduced afterflame time.

[0229] The omission of component G in comparative examples C1 to C6 led to moldings having rough surfaces that were additionally demoldable only with difficulty. Flame-retardancy and GWFI values corresponded to the values for the moldings which contained component G. The CTI values decreased compared to the moldings which contained component G.

[0230] The omission of component D in comparative example C7 resulted not only in a prolonged afterflame time compared to examples 1-4 but also in a reduced CTI value.

[0231] The omission of component F in comparative example C8 resulted not only in a deterioration in the fire protection class compared to example 2 but also in reduced GWFI and GWIT values.

[0232] In comparative example C9, increasing the concentration of components C, D and E resulted in an improvement in the fire protection class compared to example C8. However, this polyester composition still showed a lower fire protection class and reduced GWFI and GWIT values compared to example 2.

[0233] The omission of components D and E in comparative example C10 resulted not only in a prolonged afterflame time but in a reduced CTI value compared to examples 1-4.

EXAMPLES 7-12 AND COMPARATIVE EXAMPLES C11-C20 WITH PET

[0234] The results of the experiments with PET molding compounds are listed in the examples adduced in the table below. All amounts are reported as % by weight and relate to the polyester molding compound including the flame retardants, additives and reinforcers.

TABLE-US-00002 TABLE 2 PET GF 30 test results (7-12 inventive; C11-C20 comparisons) Example No. 7 V11 8 V12 9 V13 10 V14 A: PET 57.3 57.5 57.3 57.5 57.3 57.5 57.3 57.5 B: EC10 glass fibers 30 30 30 30 30 30 30 30 C + D + E: FM 1 12 12 C + D + E: FM 2 12 12 C + D + E: FM 3 12 12 C + D + E: FM 4 12 12 C: FM 5 C + E: FM 6 F: FM 7 F: FM 8 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 G: wax 1 0.2 0.2 0.2 0.2 G: wax 2 UL 94 0.4 mm/[sec.] V-0/18 V-0/18 V-0/12 V-0/12 V-0/32 V-0/32 V-0/16 V-0/16 GWFI [ C.] 960 960 960 960 960 960 960 960 GWIT [ C.] 775 750 775 750 800 750 750 675 CTI [volts] 600 500 600 500 600 500 600 500 surface smooth rough*.sup.) smooth rough*.sup.) smooth rough*.sup.) smooth rough*.sup.) Example No. 11 V15 12 V16 V17 V18 V19 V20 A: PET 57.3 57.5 57.3 57.5 57.3 57.8 52.8 57.3 B: EC10 glass fibers 30 30 30 30 30 30 30 30 C + D + E: FM 1 C + D + E: FM 2 10 10 12 12 12 17 C + D + E: FM 3 C + D + E: FM 4 C: FM 5 12 C + E: FM 6 12 F: FM 7 2 2 F: FM 8 0.5 0.5 0.5 0.5 0.5 0.5 G: wax 1 0.2 0.2 0.2 0.2 0.2 G: wax 2 0.2 UL 94 0.4 mm/[sec.] V-0/03 V-0/03 V-0/08 V-0/08 V-0/35 V-2/85 V-1/70 V-0/39 GWFI [ C.] 960 960 960 960 960 850 900 960 GWIT [ C.] 750 750 775 750 750 725 750 750 CTI [volts] 600 500 550 500 500 600 600 500 surface smooth rough*.sup.) smooth rough*.sup.) smooth smooth smooth smooth *.sup.)major problems in demolding the molding from the mold

[0235] The inventive polyester compositions of examples 7 to 12 are molding compounds which attain the UL 94 V-0 fire class at 0.4 mm, simultaneously have CTI 600 volts/550 volts, GWFI 960 C. and GWIT 750-775 C., and have smooth surfaces. The replacement of wax 2 by wax 1 resulted in an increase in the CTI value. The moldings produced were demoldable without difficulty. The addition of a further component F in example 11 leads to another improvement in flame retardancy, expressed by a reduced afterflame time.

[0236] The omission of component G in comparative examples C11 to C16 led to moldings with rough surfaces that were additionally demoldable only with difficulty. Flame retardancy, GWFI and GWIT values corresponded to the values for the moldings which contained component G. The CTI values decreased compared to the moldings which contained component G.

[0237] The omission of component D in comparative example C17 resulted not only in a prolonged afterflame time compared to examples 7-10 but also in a reduced CTI value.

[0238] The omission of component F in comparative example C18 resulted not only in a deterioration in fire protection class compared to example 8 but also in reduced GWFI and GWIT values.

[0239] In comparative example C19, increasing the concentration of components C, D and E compared to example C18 did achieve an improvement in the fire protection class. However, this polyester composition still exhibited a lower fire protection class and reduced GWFI and GWIT values compared to example 8.

[0240] The omission of components D and E in comparative example C20 resulted not only in a prolonged afterflame time compared to examples 7-10 but also in a reduced CTI value.

EXAMPLES 13-15

[0241] Production, processing and testing of flame-retardant polyester molding compounds and polyester moldings were effected as described in examples 1-12 and C1-C20. In accordance with the aforementioned general method, flame-retardant polyamide molding compounds and flame-retardant polyester moldings were produced.

[0242] The composition thereof was 51.3% by weight of polybutylene terephthalate (Ultradur 4500), 30% by weight of glass fibers (Vectrotex EC 10 P 952), 18% by weight of flame retardants used in accordance with the invention of components C, D and E according to the details above, 0.5% by weight of aluminum salt of phosphorous acid, and 0.2% by weight of wax (Licowax E).

[0243] The thermal stability of the polyester compositions examined was ascertained with the aid of thermogravimetry (TGA). The temperature reported is that at which there was a weight loss of 2% by weight.

[0244] The processing window of the polyester compositions examined was likewise determined by TGA. This is done by measuring the weight loss in % by weight at 330 C. after 1 h. TGA is conducted under an air atmosphere.

[0245] Since the lower limit of the processing window is unaffected, the measure determined for the processing window is the breakdown of the flame-retardant polyester molding compound at the upper limit. This is done using the weight loss at a defined temperature.

EXAMPLE 13

[0246] The flame retardant used was the above-described FM 2, which consisted of components C), D) and E) in the form Al salts. A thermal stability of 325 C. was ascertained, and a processing window of 8%.

EXAMPLE 14

[0247] The flame retardant used was a modified FM 2 in which some of the Al cations had been replaced by Fe cations. The total iron content was 20 ppm. A thermal stability of 335 C. was ascertained, and a processing window of 5%.

EXAMPLE 15

[0248] The flame retardant used was a modified FM 2 in which some of the Al cations had been replaced by Fe cations. The total iron content was 1000 ppm. A thermal stability of 375 C. was ascertained, and a processing window of 4.5%.