CH628073A5 - Flame-retardant and optionally self-extinguishing polyester compositions, and process for the preparation thereof - Google Patents

Description

The present invention relates to flame-retardant and optionally self-extinguishing polyester compositions, which are characterized in that they contain one or more oxalato complexes as the flame-retardant additive.

Particularly suitable oxalato complexes are those which contain a complex anion of the type [Z (C204) n] ~ e, where Z is one or more central atoms, n is the number of ligands and - e is the negative charge of the complex anion. Such oxalato complexes are available from K.V. Krishna-murty and G.M. Harris in Chemical Reviews Vol. 61 (1961), pages 213 to 246. The number of ligands is usually 1, 2, 3 or 4, the charge of the complex anion is - 1, - 2, -3, -4 or - 5 and the number of central atoms is 1, the number of ligands and the charge of Complex anions are determined by the coordination number and the charge of the central atom. For the purposes of the present invention, oxalato complexes with complex anions of the type [Z (C204) n] - e are understood not only to mean those compounds whose composition is exactly stoichiometric, but also those compounds in which the values for n and - e follow Deviate from whole numbers above or below. This is the case, for example, when a small part of the oxalato ligands has been replaced by other ligands. Such compounds can arise from the fact that foreign ligands are incorporated or exchanged in the complex anion during or after the synthesis of the oxalato complexes. The same applies accordingly to the central atom, i.e. Also included in the sense of the present invention are those oxalato complexes whose cationic constituent is not strictly stoichiometric. Here too, the value for the central atom can deviate from an integer. This will be the case if part of the central atom is replaced by another central atom with a different coordination number or a different valence. Such deviations from the exact stoichiometry are known to be found more frequently in complex chemistry and are well known to the person skilled in the art.

The oxalato complexes to be used also include mixed oxalato complexes which contain the corresponding amount of different central atoms instead of the stoichiometric amount of one central atom. Mixtures of different uniform or mixed oxalato complexes are of course also possible.

The central atoms of the oxalato complexes, especially in the preferred compounds with a complex anion of the type [Z (C204) n] ~ e, are the metals Mg, Ca, Sr, Ba, Zr, Hf, Ce, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, B, AI, Ga, In, Sn, Pb and Sb. The cationic constituent of the oxalato complex preferably contains at least one of the ions Li, Na, K, Rb, Cs or NH4 or one of the ions and Ba mentioned.

Oxalato complexes of the general formula are preferred

10th

Me ^ Me l '[Z (C204) m],

(1)

in the Me1 for Li, Na, K, Rb, Cs, or NH4, Me "for one of the aforementioned cations or for Ba, Z for one of the central atoms Mg, Ba, Zr, Fe, Co, Cu, Zn, AI, Sn , Cr and Sb stand and k mean 15 ~ 0.1,2.3 or 4.1 «0 or 1 and m ~ 2.3 or 4. (At this point the symbol = was chosen to again here to make it clear that the values for k, 1 and m can deviate from integers, see also example 1. Alkali-aluminum-oxalatocom-20 complexes of the general formula are particularly preferred

Me 3 [A1 (C204) 3] or MeI [Al (C204) 2] and the oxalato complexes K4 [Zn (C204) 3], K4 [Zr (C204) 4], K3 [Cr (C204) 3], K3 [ Fe (C204) 3], K3 [Sb (C204) 3], KBa [Fe (C204) 3], KBa [AKQO ^], K2 [Mg (C204) 2], K2 [Fe (C204) 2], K2 [Zn (C204) 2], K2 [Cu (C204) 2], Ba (Mg (C204) 2]

With the above-mentioned oxalato complexes, a new class of compounds has now been found which is particularly suitable as a flame retardant for polyester. As a rule, the cesium complexes have the greatest effectiveness, followed by the rubidium, potassium and sodium complexes and finally the lithium complexes with the comparatively least effectiveness. The mixed alkali / barium complexes and the barium / magnesium complex also have a very good flame retardant effect.

Compounds of the above formula (1) with the meaning 1 = 0 and Z = Al are complex lithium, sodium, potassium, rubidium, cesium, ammonium-alumina-40-lato or aluminum trioxalate salts with coordinatively four or hexavalent aluminum atom. They are known and are obtained in a simple manner by precipitation from aqueous solutions of their components, for example by reacting an aluminum sulfate solution with a lithium, sodium, potassium, rubi-45 dium, cesium or ammonium oxalate solution. With regard to the production processes and the properties of these complex salts, reference is made to Gmelin's Handbook of Inorganic Chemistry, 8th edition, “Aluminum”, Part B Delivery 1, Verlag Chemie GmbH Weinheim / Bergstr. Referred in 1933. Another method suitable for the preparation of the potassium aluminum trioxalate salt, according to which freshly precipitated aluminum hydroxide is treated with an aqueous solution of potassium hydrogen oxalate, is described in Inorganic Synthesis, Vol, I, McGraw-Hill Book Comp., Ine, New York and London 1935, page 36 be-55. Of the oxalato complexes with other central atoms, most of the compounds to be used according to the invention are also known and have been sufficiently described. They can be obtained by reacting a salt of the central atom with alkali oxalate. Suitable compounds of the 60 central atom are e.g. Sulphates, chlorides, hydroxides, acetates, carbonates and oxalates. For more details on the preparation of these complexes, reference is made to the following references:

D.P. Graddon, J. Inorg. & Nucl. Chem. 1956, Vol. 3, pages 65 308-322

D.P. Graddon, Inorg. Syntheses, Volume I, page 36

K.V. Krishnamurty et al., Chem. Rev. 61 (1961), pages 213-

246.

628 073 4

Analogously, oxalato complexes, the production of which is related in the cited publications but which is not explicitly described in the selection of cations, can be considered analogously to other oxalato complexes. So it is a be put (see also the following execution- essential requirement for the effectiveness of oxalato-

games). It goes without saying that the number of complexes that the decomposition temperature is below the

Alkali and alkaline earth atoms, i.e. the size of k and 1 and s melting temperature of the burning polymer is. Another-

the size of m due to the valence of the central atom, the oxalato complexes must be chemically completely inert up to the temperature at which it is agreed and that the invention is also used as long as the shaping takes place. For more compounds, the composition of which does not include polyethylene terephthalate-suitable oxalato complexes should have a decomposition temperature which is above stoichiometric in the sense of the formula given above

(1), i.e. thus also those compounds in which the values io of the processing temperature for polyethylene terephthalate for k, 1 and m up or down from integers deviate from approximately 300 ° C., but on the other hand not the temperature of the chen. burning polyethylene terephthalate melt of approx. 560 ° C

Both polyester and copoly are exceeded under polyester. Understand the decomposition temperatures of the oxalatocom-esters. Examples of such polyesters are those, plexes, if not stated in the literature, which can be averaged using one or more of the acids or their ester-forming derivatives easily listed with the aid of thermogravimetric analysis (TGA). Regarding the TGA implementation, Ull-one or more di- or polyvalent aliphatic, mann's encyclopedia of industrial chemistry, 3rd edition of alicyclic, aromatic or araliphatic alcohols (1961), publisher Urban & Schwarzenberg • Munich-Berlin, or a bisphenol are available: Adipic acid, Pimelinsäu- Band 2/1, page 657, referenced. In the following table re, suberic acid, azelaic acid, sebacic acid, nonandicarboxylic acid 20 some examples of decomposition temperatures various, decanedicarboxylic acid, undecanedicarboxylic acid, terephthalate oxalato complexes are listed.

acid, isophthalic acid, alkyl-substituted or halogenated Te-oxalato complex decomposition temperature (° C)

rephthalic and isophthalic acids, nitroterephthalic acid, 4,4'-di- ^ n \ i (C-, 0) 1 430

phenyl ether dicarboxylic acid, 4,4'-diphenyl thio ether dicarboxylic acid3 [A1 (C204) 3] 3 430

right, 4,4'-diphenylsulfone dicarboxylic acid, 4,4'-diphenylalkylene di 25 jç 440

carboxylic acid, naphthalene-2,6-dicarboxylic acid, cyclohexane-1.4-K3 [Cr (C204) 3] 450

dicarboxylic acid and cyclohexane-1,3-dicarboxylic acid. K4 [Zr (C204) 4] 395

Typical for the production of these homo- and copoly- K2 [Mg (C204) 2] 470

Ester-suitable diols or phenols are: ethylene glycol, KBa [Al (C204) 3] 425 diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1.10-decanediol, 1,2-propanediol, 2,2-di -

methyl-1,3-propanediol, 2.2.4-trimethylhexanediol, p-xylenediol, The melting temperature of the burning polymer, i.e. al-

1,4-cyclohexanediol, 1,4-cyclohexanedimethanoI and bisphenol so the temperature in the melt of the air-burning polymer

A. Furthermore, the usual resins are also used on polyester under polyester, e.g. using a thermocouple

Basis unsaturated esters and the usual, for example, can be determined. The measurement is expediently carried out by means of glass fibers, asbestos, carbon and graphite fibers so reinforced that the soldering point of the thermocouple during the

Products understood. Preferably the oxalatocome measurement is constantly covered by dripping melt.

plexes in polyethylene terephthalate, polypropylene terephthalate A very advantageous method for determining the decomposition

and applied to polybutylene terephthalate. Differential thermal analysis (DTA) provides 40 tongue temperatures

The flame retardants are suitable for all common poly darts, since the La ester masses in the DTA diagrams of the oxalato complexes. In the form of granules, chips of the main endothermic effect, the decomposition temperature or strands, as moldings such as plates, foils, films and indicates. With regard to differential thermal analysis, fibers or textile finished products such as Reference was made to yarns, knitted fabrics, relevant textbooks and manuals, for example to nonwovens, cloths and carpets. Ullmann's Encyclopedia of Chemical Engineering, I.e. pages

About the mechanism and the operating principle of the as ** ^ 6 ~ 65? s ™ ie on Franke '0Lefk ° n of physics' Franckh'sche

Oxalato complexes to be used in flame retardants are not very expensive in Stuttgart. u age.

known. However, it can be assumed that these compounds are suitable as flame

not only intervene in the combustion process at one stage, so it is advisable to protect polyester

such as. halogenated flame retardants delay the 50 ^ temperature of the oxalato complex and the melting temperature

Cause combustion by intervening in the radical chain, but together with the burning polymers as optimally as possible

that the flame protection effect according to the invention is the result of the sound. If the operator did the job of several flame-retardant individual processes on different ones, he had to make a very special polymer flame-resistant, which represents the various stages of the combustion process. The values to be used are known as "ict", and the flame retardants used also belong to the group of inert gas-dependent measurements of the melting temperatures of the burning poly-

splitting substances. They have the advantage that they have the equipment required for the DTA measurement

Moles of starting substance up to four moles of carbon dioxide are available, it can be

Probably the most important principles of action are fol- Tef? J Try to get a reliable picture of it soon

end: extraction of thermal energy from the melt by disc; we consider oxalato complexes at all

association of the flame retardant and display of the inert gas, en and "d which ensure the optimal, flame retardant. This, displacement and dilution of the oxygen on the naturally also applies in the event that from any,

Surface of the burning polymer melt due to C02-Ab- unforeseeable reasons despite the suitable location of the

cleavage, formation of oxide and salt layers during the settling temperature of the oxalato complex and the melting

Combustion process and accelerated transport of temperato of the polymer not a satisfactory flame

Radical scavengers such as Alkali atoms in the gas phase. 65 protect educate who "

It is obvious that between the decomposition temperature and flame retardant polyester structure according to the invention and the effectiveness of the impact protection according to the invention can be processed into the usual shaped bodies such as fibers, foils, filing agents on the one hand and the polymers, plates, injection molded articles and the like to be made flame retardant .

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All complex salts according to the invention are excellent flame retardants. The two potassium complex salts K3 [A1 (C204) 3] and K2 [Mg (C204) 2] and the rubidium complex salt Rb3 [Al ~ (C204) 3] are particularly effective in polyethylene terephthalate they not only give the polyester masses flame-retardant, but also self-extinguishing properties. Dripping of the melt when burning is largely prevented. Of the complex salts mentioned, K3 [A1 (C204) 3] is preferred. 10th

The oxalic acid complex salts have a considerable flame retardant effect even at a relatively low dosage. They are preferably used in amounts of 1 to 40 percent by weight, in particular in amounts of 5 to 15 percent by weight, based on the flame-retardant and possibly self-extinguishing polyester. The complex salts are preferably used in anhydrous form.

The invention further relates to a method for producing the above-described anti-false and possibly self-extinguishing polyester compositions. 20th

The process is characterized in that alkali aluminum aluminum oxalic acid complex salts are ground in or in the polyhydric alcohols involved in the polycondensation of the polyester and the suspension of the complex salt obtainable in this way is added directly to the polycondensation mixture. Another way of incorporating the oxalic acid complexes is to melt the polymer mass, mix it with the flame retardant and then process it into granules or deform it directly.

Another possibility is to powder the finely divided flame retardant onto the polymer granulate and process it together with it.

The procedure depends on the intended area of application of the flame-retardant or self-extinguishing polyester compositions and can be selected without difficulty by a person skilled in the art.

25th

30th

35

In the case of larger or thick-walled moldings, the distribution of the flame retardant is relatively unproblematic and it is not difficult to produce the flame retardant in a suitable particle size for this purpose. In contrast, when flame-retardant or self-extinguishing fibers are produced by the process according to the invention, the aim is to use the flame retardants in a very finely divided form in order to enable spinning of the polymer and to ensure good physical properties of the end product. As a rule, no more than 20% by weight of the flame retardant is added to fibers. The suitable particle size also depends on the desired field of application and is easy to select by a person skilled in the art. In the case of fibers, for example, it depends on the titer of the fiber and the desired physical properties of the end product. In the case of textile fibers, the complex salts with particle sizes up to approximately 2 m | x can be used.

The division of the complex salts presents no difficulty. For example, they can be ground very easily, the adhering and the crystal water having to be removed beforehand. The drying of the complex salts is also unproblematic, for example over a period of several hours at 150 ° C and 10 mm mercury. They can be ground dry as well as 60 wet. In wet grinding, the selection of the suitable dispersing liquid will also depend on the area of application of the flame retardant and the method of application. The oxalato complex is preferably ground in the 65 polyhydric alcohol required for the construction of the polyester and the suspension of the oxalato complex obtainable here is added directly to the polycondensation mixture.

When reinforcing polyester by means of glass fibers, it should be noted that in the case of glass types containing alkaline earth, in particular calcium, the effectiveness of the flame retardants according to the invention is somewhat impaired. It is believed that this impairment of effectiveness to the presence of the alkaline earth, e.g. Calcium. Obviously, the calcium in the form of the oxide reacts under melting conditions with the oxalato complex to form calcium oxalate and a complex reduced by one oxalato ligand. This reaction may lead to a gradual breakdown of the flame retardant in the melt, so that the flame retardant can only be effective to a small extent. It has been found that additives which are able to trap alkaline earths, in particular calcium, under the given conditions by forming stable calcium compounds prevent the flame retardant effect from being impaired. Compounds such as MgC03, MgS04, K2C204, K2C03, A12 (S04) 3 and K2S04 are primarily suitable as additives. The additive is used in amounts of 1 to 10 percent by weight, preferably 5 to 10 percent by weight, based on the total weight of polymer, glass fiber, anti-hammer agent and additive. But even without the additional additives described, the anti-hammer effect is still remarkable when using the glass fibers mentioned and is already sufficient for many areas of application.

Of course, the above additives can also be used in the case of other alkaline earth-containing reinforcing fillers and in the presence of other alkaline earth-containing additives.

The flame-retardant and optionally self-extinguishing polyester compositions obtainable by the processes described above, which are obtained using the above-mentioned oxalate complexes, contain in particular the oxalate complex in amounts of 1 to 40% by weight, preferably 5 to 15% by weight.

Homo- and copolyester fibers of terephthalic acid, especially polyethylene terephthalate, which contain 5 to 15 percent by weight of the anti-hamming agent, are preferred.

The complex salts have several advantages over the known anti-hammers. First of all, it should be pointed out that they can be obtained in the simplest manner from the raw materials oxalic acid, an inorganic metal salt or metal hydroxide and, if appropriate, a simple inorganic alkali salt, the preparation being carried out in aqueous solution. Apart from the rubidium and cesium complex salts, they are much cheaper than the conventional products containing halogen, phosphorus, nitrogen and / or Sb303.

Since the effectiveness of the complex salt according to the invention is higher than that of the known film protection agents of the prior art, it is sufficient to add only a few percent by weight to the polymer in order to achieve a comparable hammer protection effect. Therefore, the characteristic properties of the treated materials are changed only to a minor extent.

The compounds are very well tolerated by the skin. They also do not deliver toxic gases during the combustion process. CO 2 is formed as the only gaseous combustion product of these substances. Dripping of polymer melt is largely prevented by the incorporation of the complex salts according to the invention.

After multiple washes, as well as after dry cleaning of textiles, the flame retardancy of the compounds, measured by the LOI values, is not noticeably reduced. Although water-soluble, their washability from textiles is surprisingly low and the flame resistance of these textiles is fully retained even after more than 20 washes.

628 (»73

6

The complex salts are notable for their inert behavior towards the melts of the polymers mentioned and towards the customary vessel materials. As a result, they can be easily added to polymer melts or - with the exception of the lithium complex - as a suspension before polycondensation. In this case, the excess suspending agent can be reused immediately since it is not contaminated with residues of the flame retardant or decomposition products thereof.

example 1

Production of Self-Extinguishing Polyethylene Terephthalate Fibers a) Production and grinding of the flame retardant K3 [A1 (C204) 3] has been described in J.C. Bailar and E.M. Jones in Inorganic Syntheses 1_ (1939), page 36. The complex salt obtained was then dried for 15 hours at 150 ° C. and about 10 torr. The analyzes of samples obtained in different batches ranged between K2.87 [Al (C2O4) 3i02] and K3i36 [A1 (C204) 3i46]. 200 g of the dried complex salt was ground with 400 g of ethylene glycol for about 2 hours in a pearl mill (manufactured by PM1 from Draiswerke, Mannheim) with 410 g of quartz beads with a diameter of 1 to 3 mm. After grinding, the diameter of the largest complex salt particles in the dispersion was approximately 4 μm, while the majority of the particles had a size of 1 μm. The quartz beads were then removed by filtration through a sieve, rinsed with 200 ml of ethylene glycol and the dispersion was mixed with The particles, which had a size of more than 2 μm, were largely separated (sedimentation) by leaving the dispersion to stand in high standing vessels for 72 hours.

b) polycondensation

600 g of this diluted dispersion with a K3 (A1 (C204) 3) content of 150 g were mixed with the transesterification product of 1350 g dimethyl terephthalate and 1200 g ethylene glycol at a stirring speed of 30 rpm and at a temperature of about 245 ° C. into the polycondensation vessel, 150 ppm zinc acetate served as the transesterification catalyst and 200 ppm antimony trioxide as the condensation catalyst.

The polycondensation, which usually takes about 85 minutes, was completed after one hour. The distilled ethylene glycol could be used for new condensation without purification. The polycondensation sat contained 10% by weight of K3 [A1 (C204) 3].

c) Deformation

15 The polycondensate obtained was processed into chips as usual and dried at 125 ° C. and 60 torr for 24 hours. The chips were spun at 296 ° C (spinning head temperature) into a filament yarn with a single titer of 3.0 dtex and a total titer of 150 dtex 48. The Fila-20 ment yarn was drawn in a ratio of 1: 4.2 and then twisted. With regard to light resistance, light fastness and solution viscosity, the textile data of the material obtained largely correspond to that of conventional polyethylene terephthalate, which can be obtained under the conditions specified above without the addition of a flame retardant.

d) Determination of the burning behavior

The filament yarn described above was processed into a four-ply knitted fabric and subjected to the vertical burning test according to DIN 53906 to determine the burning behavior. 30 For comparison, a corresponding sample without flame retardant and a sample with the same amount of the commercially available bromine-containing flame retardant 2,2-bis (4-ethoxy) -3,5-dibromophenylene propane were examined.

The following results were obtained:

Sample without flame sample with 10% by weight han sample with 10% by weight

protective means

Flame exposure full time (sec) burned

Burning time (sec)

Glow duration (sec) Flame exposure full time (sec) burned

Burning time (sec)

Glow duration (sec)

15

delsübl. bromine-containing flame retardant

3rd

88

drips burning

15 39

drips burning

K3 [AI (C204) 3]

3 0 12

15 0 11

Example 2 Sample without flame retardant L.Q.I.

The sample described in Example 1 with K3 [A1 (C204) 3] with a commercially available extinguishing polyethylene terephthalate was converted into a L.O.I.

Plate with a thickness of 2 mm processed. For comparison, sample with K3 [A1 (C204) 3] L.O.I.

a corresponding plate without anti-hammers and a corresponding plate with the same amount of a commercial example 3

customary brominated flame retardant. The flame retardancy of the sample was produced analogously to the manner described in Example 1 by specifying the LOI-Na3 [Al (C204) 3], grinding in ethylene glycol, and a value (limiting oxygen index) was characterized. Polyethylene terephthalate with 10 percent by weight of the complex

The LOI value was produced in accordance with ASTM-D 2863 with the aid of a salt and this was processed into a test plate with a thickness measuring device from Stanton Redcroft, Great Britain, of 2 mm. Measure A measured according to ASTM D 2863. 60 LOI was 4.0.

The LOI (Limiting Oxygen Index) is defined as the oxygen content (in%) of an oxygen-nitrogen mixture, example 4

The rubidium aluminum trioxalato complex was just burning like a flamed sample. The LOI value corresponds to the following synthesized (cf. Chem. Rev. 61 (1961), pages 213-246): the difference from the measured LOI value of the flame-retardant 65 In a warm solution of 9.65 g (0.0144 Mol) A12 (S04) 3 • protected sample and the LOI value of the non-flame retardant 18 H20 in 43 cm3 water was a solution of the sample with stirring. 3.46 g (0.0864 mol) sodium hydroxide in 15 cm3 water

The following results were obtained: wear. The precipitated aluminum hydroxide was filtered off,

: 20.1

: 23.6, ALOI = 3.5: 27.1, ALOI = 7.0

7

628 073

washed out and introduced into the boiling solution of 10.88 g (0.0864 mol) of oxalic acid in 50 cm3 of water. A clear solution was obtained. A solution of 10 g (0.0433 mol) of rubidium carbonate in 13 cm 3 of water was added dropwise to this solution at 100 ° C. and the mixture was then heated for a further 30 minutes. The solution was then freed from a slight turbidity (unreacted aluminum hydroxide formed by neutralization) by filtration and finally cooled. The oxalato complex was then precipitated out by adding methanol, then suction filtered and dried at 150 ° C. in vacuo. The yield was 13 g (82.5% of theory).

The Rb3 [Al- (C204) 3] prepared in the manner described above was ground in ethylene glycol analogously to Example 1 and processed into a polyethylene terephthalate with 10 percent by weight of the complex salt. The A LOI value was measured on a test plate with a thickness of 2 mm in accordance with ASTM D 2863. It was 7.3.

Example 5

Production of self-extinguishing copolyester fibers (polyethylene terephthalate with 7.8 percent by weight azelaic acid) with 9% K3 [AI (C204) 3]

a) Manufacture and milling of the flame retardant K3 [AI (C204) 3] was described in the by J.C. Bailar and E.M. Jones in Inorganic Syntheses 1_ (1939), page 36. The complex salt obtained was then dried for 15 hours at 150 ° C. and about 10 torr. 200 g of the dried complex salt were ground with 400 g of ethylene glycol after predispersion for 15 minutes in an Ultra-Turax mixer for about 2 hours in a bead mill (manufactured by PM1 from Draiswerke, Mannheim) with 410 g of quartz beads with a diameter of 1 to 3 mm. After grinding, the diameter d of the largest complex salt particles in the dispersion was approximately 4 μm, while the majority of the particles had a size d <1 μm. The quartz beads were then removed by filtration through a sieve, rinsed with 200 ml of ethylene glycol and the dispersion was diluted with the rinsing solution. By allowing the dispersion to stand in high standing vessels for 72 hours, the particles which had a size of more than 2 μm were largely separated (sedimentation).

sb) Polycondensation 600 g of this dilute dispersion with a K3 [A1 (C204) 3] content of 150 g were with the transesterification product from 1393 g of dimethyl terephthalate and 1200 g of ethylene glycol at a stirring speed of 30 rpm and at a temperature transferred from about 245 ° C together with 107 g of azelaic acid in the polycondensation vessel. 240 ppm of manganese acetate served as the transesterification catalyst, 400 ppm of antimony trioxide and 300 ppm of triethyl phosphate as the stabilizer as the condensation catalyst. The polycondensation was completed after 106 minutes 15. The distilled ethylene glycol could be used for new condensation without purification. The polycondensate contained 9% by weight of K3 [A1 (C204) 3], c) deformation

The polycondensate obtained was processed into chips 20 as usual and dried at 125 ° C. and 60 torr for 24 hours. The chips were spun at 296 ° C (spinning head temperature) into a filament yarn with a single titer of 3.0 dtex and a total titer of 150 dtex 48. The filament yarn was drawn in a ratio of 1: 4.2 and then twisted. With regard to light resistance, light fastness and solution viscosity, the textile data of the material obtained largely correspond to that of conventional polyethylene terephthalate, which can be obtained under the above conditions without the addition of a flame retardant. 30 d) Determination of the burning behavior

The filament yarn described above was processed into a four-ply knitted fabric and subjected to the vertical burning test according to DIN 53906 to determine the burning behavior. For comparison, a corresponding sample without flame-35 protective agent and a sample with the same amount of the commercially available bromine-containing flame retardant 2,2-bis- (4-ether-oxy) -3.5-dibromophenylpropane were examined.

The following results were obtained:

Sample without flame sample with 10% sample with

Protective means

Full flame 3

time (sec) burned

Burning time glow duration (sec)

Full fire 15

time (sec) burned

Burning time (sec)

Glow duration (sec)

commercial 9%

bromine-containing K3 [A1 (C204) 3] flame retardant

3 3

88 2

drips 12 burning

15 15 39 1

drips 11 burning

Example 6

9 parts by weight of dry polyethylene terephthalate chips, prepared in a known manner with a solution viscosity of 1.61, were intimately mixed with 1 part by weight of Li3 [Al (C204) 3], which had previously been pulverized in a ball mill, in a cross beater mill. The mixture was hot-pressed in a known manner to a 2 mm thick plate. The LOI value of a plate was determined in accordance with ASTM D 2863 and compared with the LOI value of a plate made of pure polyethylene terephthalate:

LOI: comparison 20.1

LOI: plate according to Example 6: 23.6

Example 7

Polyethylene terephthalate molding compounds from 55

% By weight of polyethylene terephthalate, 30% by weight of glass fibers made from 55 a calcium-containing glass type, 10% by weight of K3 [A1 (C204) 3] and 5% by weight of magnesium carbonate. The samples were self-extinguishing.

A comparative sample of 60% by weight of polyethylene terephthalate, 30% by weight of glass fibers and 10% by weight of K3 (A1 (C204) 3) proved to be flame-retardant, but not self-extinguishing.

Example 8

65 A curtain made of 100% polyethylene terephthalate filament yarn was immersed at room temperature in an aqueous liquor of 100 g / 1 K3 [A1 (C204) 3], then dried at 120 ° C. and finally heated at 190 ° C. for 60 seconds.

628 073

8th

The sample was examined according to DIN 53 906 and proved to be flame retardant.

Example 9

a) Preparation of K2 [Zn (C204) 2] / K4 [Zn (C204) 3]

The complex salt was obtained according to the method described by D.P. Graddon in J. Inorg. & Nucl. Chem. 1956, Vol. 3, page 321 method I described.

b) Preparation of the glycolic suspension of the complex salt

The coarse-grained complex salt obtained by the process described above was first comminuted in a ball mill and then dried at about 50 torr and 130 ° C. for about 6 hours. A part by weight of the finely ground complex salt was then dispersed in 4 parts by weight of ethylene glycol using a high-speed stirrer and stirred for about 30 minutes. The suspension obtained in this way is then subjected to fine grinding, for example using a bead mill. The predispersate should be stirred intensively during grinding to prevent settling. As a rule, about 10 minutes at intervals of one hour are sufficient.

In discontinuous operation, the suspension is filtered through a 3600 mesh / cm2 sieve after the end of the milling process in order to separate off the grinding media and any glass debris. The glass beads can be reused for further grinding cycles.

In continuous operation, the suspension can be immediately accumulated and sent for further processing. During the entire process, care must be taken to ensure that the suspension remains as dry as possible (air humidity) since the salt is moderately soluble in water.

The glycolic suspension of the complex salt is stable for several days. Before use, it should be stirred vigorously for at least 10 minutes.

c) condensation of polyethylene terephthalate in the presence of the complex salt

To produce flame-retardant polyethylene terephthalate on a 20 kg scale, 18 kg of dimethyl terephthalate were first transesterified with 13.51 ethylene glycol and 150 ppm zinc acetate as a catalyst. After the elimination of methanol had ended (about 1 hour 56 minutes), 2 kg of the complex salt in the form of a 20% glycolic suspension were added to the transesterification vessel over the course of 20 minutes. The temperature in the transesterification vessel was about 210 ° C. The excess glycol was then distilled off from the transesterification kettle with stirring over a period of about 70 minutes. The total transesterification time was 3 hours 7 minutes.

200 ppm of antimony trioxide, which was added to the transesterification product at 250 ° C., served as the condensation catalyst. The condensation was carried out at 280-284 ° C and was complete after about 95 min.

The autoclave was then flushed with a nitrogen flow of 4-5 atm in about 30 min. emptied.

The following data were determined for the polymer:

Solution viscosity: 1.660-1.700 Melt viscosity: 4800-6000 Poise Softening point: 263-264 ° C

The polycondensate contained 10 percent by weight of the complex salt.

d) deformation

The polycondensate obtained was processed into chips as usual and dried at 150 ° C. and 50 torr for 24 hours. The chips were spun at 296 ° C (spinning head temperature) into a filament yarn with a single titer of 3.0 dtex and a total titer of 150 dtex 48. The filament yarn was drawn in a ratio of 1: 4.2 and then twisted. With regard to light resistance, light fastness and solution viscosity, the textile data of the material obtained largely correspond to that of conventional polyethylene terephthalate, which can be obtained under the conditions specified above without the addition of a flame retardant.

e) Determination of the A LOI value:

The LOI value was determined in accordance with ASTM-D 2863 using an io measuring device from Stanton Redcroft, Great Britain, on knitted stockings with a weight per unit area of approximately 400 g / m2. It was 5.0.

Examples 10 to 16 15 Oxalato complex salts described in more detail below were used to prepare flame-retardant polyethylene terephthalate.

a) K3 [Fe (C204) 3]

20th

Made according to D.P. Graddon, J. Inorg. & Nucl. Chem. 1956, vol. 3,308-322 or Inorg. Synthesis Volume I, p. 36.

b) K3 [Cr (C204) 3]

Made according to D.P. Graddon. I.e.

c) K2 [Mg (C204) 2]

Made according to D.P. Graddon, J. Inorg. & Nucl. Chem. 1956, Vol. 3, page 321, method I:

38 g (0.206 mol) of potassium oxalate monohydrate were dissolved in 50 cm3 of water, the solution was heated to boiling and a solution of 20.3 g (0.1 mol) of magnesium chloride in 100 cm3 of water was added. It was heated for about an hour. After cooling to room temperature, the precipitate was filtered off, washed free of chlorine with water and finally dried at 150 ° C. in vacuo. The yield was 20 g (72% of theory).

d) K2 [Zn (C204) 2] / K4 [Zn (C204) 3]

Made according to D.P. Graddon, J. Inorg. & Nucl. Chem. 1956 Vol. 3, page 321, method I:

A solution of 57.5 g (0.2 mol) of zinc sulfate heptahydrate in 200 cm3 of water was introduced with stirring into a hot solution of 36.8 g (0.2 mol) of potassium oxalate monohydrate in 100 cm3 of water. The zinc oxalate formed was suction filtered while hot and washed with cold water. The zinc oxalate obtained in this way was then introduced into the boiling solution of 75 g (0.47 mol) of potassium oxalate monohydrate. The clear solution obtained was boiled for about 30 minutes, diluted to about 150 cm 3 with water and cooled. When rubbing with a glass rod, a precipitate fell out. It was suctioned off, first vacuum dried at 100 ° C and finally at 150 ° C. The yield was 54 g (55% of theory). The substance consists of a mixture of K4 [Zn (C204) 3l and K2 [Zn (C204) 2] and has a decomposition point of 395 ^ 430 ° C.

e) K4 [Zr (C204) 4]

23.3 g (0.1 mol) of zirconium chloride were dissolved in 150 cm3 of methane noi. The solution was filtered and introduced into a solution of 20 g (0.22 mol) of anhydrous oxalic acid in 100 cm 3 of methanol at room temperature and with stirring. A precipitate fell out. The approach was about 20 hours

30th

35

40

45

50

55

Leave to stand at room temperature and then filter. The precipitate was washed thoroughly with methanol, then dissolved in 100 cm3 of water, then filtered and finally introduced into a hot solution of 40 g (0.24 mol) of potassium oxalate monohydrate in 100 cm3 of water with stirring. The mixture was filtered hot and finally cooled. The precipitate was filtered off, washed with methanol and dried at 150 ° C in a vacuum. The yield was 43 g (72% of theory).

f) KBa [Al (C204) 3]

40.8 g (0.1 mol) of K3 [A1 (C204) 3] were dissolved in 200 cm3 of hot water. The solution was cooled to about 30 ° C. and a solution of 22.4 g (0.1 mol) of barium chloride dihydrate was added dropwise with stirring. A precipitate fell out. The mixture was stirred for about an hour and left to stand for a further two hours. Finally, the precipitate was filtered off, washed chlorine-free with water and dried at 150 ° C. The yield was 46.6 g (46.7% of theory).

g) Cs3 [A1 (C204) 3]

9 628 073

The complex salt was prepared analogously to the synthesis of the rubidium aluminum trioxalato complex described in Example 4. In contrast to the previous exemplary embodiments, 5 or 10 percent by weight of the 5 complex salt was added to the finished polyester in the extruder. The extradât was processed into polyester films of 2 mm thickness. The A LOI values thus obtained are shown in Table 1.

Table 1

example

Complex salt

Amount of

A LOI value

No.

Complex salt% by weight

10th

K3 [Fe (C204) 3]

10th

5.1

11

K3 [Cr (C204) 3]

10th

6.3

12th

K2 [Mg (C204) 3J

10th

5.9

13

K4 [Zn (C204) 3]

10th

5.0

14

K4 [Zr (C204) 4]

10th

5.2

15

KBa [Al (C204) 3]

10th

3.0

16

Cs3 [A1 (C204) 3]

5

6.5

C.

Claims (8)

628 073 2nd PATENT CLAIMS on additives included. The installation of flame retardants 1. Flame-retardant and possibly self-extinguishing po- this quantity and quality in polymers is associated with a number of polyester masses, characterized in that they are associated with flame-retardant effects: Drigender additive one or more oxalato complexes Added in effective amounts, cause such contain. 5 flame retardants mostly an undesirable negative 2. Composition according to claim 1, characterized in that it flows the physical properties and use oxalato complex in quantities of 1 to 40 percent by weight, shade the polyester. So they generally cause a preferably 5 to 15 percent by weight. significant deterioration in breaking strength, elongation, 3. Mass according to claims 1 and 2, characterized gekenn- the initial module, the elasticity and a drawback that the oxalato complex is a complex anion of type 10 of color. In addition, especially in the case of threads, [Z (C204) n] ~ e contains, where Z one or more central atoms - despite the relatively high amount of flame retardants in the polymer, n the number of ligands and - e the negative charge of the material often achieved an insufficient flame retardant effect, means complex anions. so that only a few of the flameproof ones 4. Composition according to claims 1 to 3, characterized-polyester are also self-extinguishing. characterizes that the anion of the oxalato complex is at least one of the known flame retardants of the state of the art of the central atoms Mg, Ca, Sr, Ba, Zr, Hf, Ce, V, Cr, Mn, Fe, and in many cases are also not skin-friendly and often contain Co, Ni, Cu, Zn, Cd, B, Al, Ga, In, Sn, Pb and Sb. substances that are hazardous to health 5. composition according to claims 1 to 4, characterized gekenn- number of bromine-containing compounds skin irritation. Further, that the cationic component of the oxalato complex, many phosphorus compounds, in particular halogenated xes of at least one of the ions Li, Na, K, Rb, Cs or NH4 or 20 te phosphoric acid esters, are highly toxic. contains one of the ions and Ba mentioned. The flame decomposing during the combustion process 6. Composition according to claims 1 to 5, characterized in that protective agents of the prior art also develop to-draws that the oxalato complex has the general formula xical and partly. aggressive gases, such as hydrohalic acids, elemental halogen, halogen-oxygen compounds, stick-Me k Me "[Z (C204)] 25 oxides, nitrogen-hydrogen compounds, possibly even hydrogen cyanide and dicyan. In addition there is one in which Me1 for Li, Na, K, Rb, Cs or NH4, Me »for a series of the well-known anti-hammers when burning of the aforementioned cations or for Ba, Z for one of the ten glossed-down degradation of the polymer melt causes tralatoms Mg, Ba, Zr, Fe, Co, Cu, Zn, Al, Sn, Cr and Sb are qn through an increased dripping of partially burning poly and k = 0,1,2,3 or 4,1 "0 or 1 and m ~ 2,3 or 4 30 merge. mean application of flame retardants in thread and 7. Composition according to claims 1 to 6, characterized in that most commercially available products only have one feature that the polyester is polyethylene terephthalate, polypro-temporal flame retardant, since that is due to multiple wa- pylene terephthalate or polybutylene terephthalate. see or are dry washable. 8. Process for the production of a flame-retardant and non-flammable, The commercially available flame retardants, in particular the self-extinguishing polyester compositions according to products containing bromine, are relatively expensive. For many of these u 1. , x j a 11 v ai • Flame retardants must also be used for the purpose of claim 1, characterized in that alkali-aluminum,. , ",. ", M. . . , • ^ i- tF 1 i-j u - ju-jni bau special techniques are developed in the polymer, such as mum-oxalic acid complex salts in or in the poly- "... u; n / X / T. , ^ • u • , j. , r> 1 ^,,, - ah u e.g. specific dosing via mixer, dosing pumps, condensation of the polyester involved polyhydric alcohol 4n j-i • i. a • ™ r \ r 1 lu j u- i_ • L..UI. , o • j xr 1 40 often grinds the chemical aggressiveness of bromine compounds to corals and the resulting suspension of the complex. w ST ö salt is added directly to the polycondensation mixture. sionspro emenu ^. J ° It has now surprisingly been found that the complex Compounds of oxalic acid as opposed to the simple ones Salts of oxalic acid excellent flame retardants for Po-The present invention relates to flame-retardant and self-45 Ijester represent ^ The use of oxalato complexes were extinguishing polyester masses, which for the manufacture of the other hand only in individual cases, and that exclusively in the fibers, foils, Films, sheets, injection molded articles and others related to the flame retarding of natural and Molded bodies as well as for the production of lacquers and super syntisc en o y ami enann. . . 4.-J j j w, TT ^ 11 a After a m described in DT-OS 1 941 189 warping are suitable, and the process for producing the -n. , ".,. A A r £ t_ lA. ~ same 50 drive for flame retardant disengagement of filler-containing po- 56 There are already many processes for the production of heavily lyamide molding compounds or of B ^ ". n t, ■ left. i- ». y vu i -L ut • u known as a flame retardant mixture of highly brominated poly-flammable polyester. An overview of numerous,. . . . . A. t, J. r 4 r-i u- * u u • • i • j. r i ather and antimony trioxide or antimonyl compounds Developments in this area give, for example, the following ^ Ai n • • n «• A , 6,. TT xrtTTi * ± u set. The following monographs are an example of an antimonyl compound: Hans Vogel, «Flammfestmachen von«. / Ttt \ u j XT t A ®. . ,, rr. ££ K.e JTT..iL. , TT .j «5 benAntimon (III) hydroxide, natural antimony, antimonyl chloride Plastics », Dr. Alfred Huthig Verlag Heidelberg, 1966; , A,. J, t T. t. JTT P t- n i j * rid and antimony potassium tartrate also complex antimony oxala- John W. Lyons, "The Chemistry and Uses of Fire Retardants", ^. XT a \ x t ^ ^ i * i i. u <.u- Wiley Interscience, New York London • Toronto, 1970: Allex called as NaSb (C204) 2. The oxalato complex here Williams, "Flame Resistant Fabrics", Noyes Data Corporation, just one mogie en on rager ar. Park Ridge, New Jersey, London, 1974. Reference should also be made to 6Q. An independent flame retardant effect of oxalic acid - the special issue "Hammhemmende Textilien" of the magazine Complex, in particular for polyesters, is in this Offenle- "Textilveredlung", 10th volume, issue 5 , May 1975. This publication is neither disclosed nor suggested. The known commercial anti-hammers contain from DT-OS 2 152 196 is a process for the improvement mostly the elements phosphorus, halogen and nitrogen. Resistance to hamming of natural and synthetic In many cases it is known to achieve an increased 65 polyamide fibers using titanium complex compounds, The anti-hammers effect is antimony to the anti-hammers, the complex being added with an organic chelating agent, for example in the form of Sb203, so that re-agents or huions are formed. Here too, the oxa gel uses the flame-retardant polymers with relatively high percentages of latocomplex only as one of the possible heavy metal carriers. 3rd 628 073 ger mentioned, citric and tartaric acid complexes are preferred. The flame retardant is usually applied to the textile material to be finished from an aqueous solution. The process is said to be particularly suitable for wool and blends of wool and synthetic fibers, the flame retardant also being said to be absorbed from a treatment liquid. It is not surprising that the process fails when flame retarding fully synthetic fibers, especially hydrophobic polyesters. In the case of mixtures of wool and fully synthetic fibers, only the wool portion is of course made flame-retardant. Therefore, this publication could not suggest the use of oxalato complexes as flame retardants for polyester. The same applies to the process of DT-AS 2 212 718, according to which natural and synthetic polyamide fibers are to be finished with anionic complexes of zirconium with an organic chelating agent or fluoride ions from aqueous solutions at a pH range of 0.5 to 4. Here too, the oxalato complex is mentioned alongside purely inorganic compounds as one of the possible carriers for zircon; here too, the process fails with fully synthetic fibers.