DE1230212B - Process for stabilizing polyolefins - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C08f

German class: 39 b -22/06

Number: 1 230 212

File number: F 44039IV c / 39 b

Filing date: September 23, 1964

Opening day: December 8, 1966

Numerous high polymer compounds, especially thermoplastics such as polyolefins, suffer degradation due to the action of oxygen at higher temperatures and / or light. The macromolecules are split and as a result the technological properties, z. B. the strength, elongation and toughness of the products deteriorated. To such a breakdown Numerous stabilizers have been proposed to prevent or largely enlarge.

So it is z. B. known that many phenolic compounds as well as thioethers are good antioxidants for polyolefins are. For light stabilization, UV absorbers such. B. Benzophenols, Benztriazone or salicylic acid derivatives can be used. To a reasonably sufficient To achieve light stabilization, these UV absorbers usually have to be relatively high Cans are added.

It is known to the person skilled in the art that those produced from the polymers, for example polyolefins Finished products have a particularly high utility value if the polymer material is used at the same time thermally against the high processing temperatures, the effect of oxygen at the changing temperatures to which the material is exposed during use and the effect is stabilized by light.

By using a single type of stabilizer, effective protection against the The three types of damage mentioned in polyolefins have not yet been achieved. Even the known ones synergistic stabilizer combinations usually do not lead to the desired goal, because the synergistic effect of given stabilizer systems is usually only very specific against one of the types of damage mentioned. So is z. B. known that the against the influence of atmospheric oxygen extremely effective synergistic mixtures of phenols at higher temperatures, especially bisphenols and thioethers, only a very small amount compared to the action of light Possess effectiveness. With regard to light stabilization, these stabilizer mixtures do not show any synergistic effect.

There are also stabilizer combinations known through which z. B. the oxidation stability, d. H. the Thermal aging resistance of polyolefins improved, the thermal and processing stability on the other hand, is deteriorated to a large extent, and vice versa. , »■ /

In general, various types of stabilizers can use methods of stabilizing polyolefins

Applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning,

Frankfurt / M.

Named as inventor:

Dipl.-Chem. Dr. Eberhard Prinz,

Frankfurt / M.-Höchst;

Dipl.-Chem. Dr. Felix Schulde,

Neuenhain (Taunus);

Dipl.-Chem. Dr. Otto Mauz,

Frankfurt / M.-Unterliederbach;

Dipl.-Chem. Dr. Dietrich Schleede, Frankfurt / M.

in terms of their effectiveness mutually influence each other positively, negatively or not when they are in Mixtures are used; they can behave additively or, as in the case of the synergistic ones Systems that potentiate their effect, but they can also have a strong impact on one another.

For the reasons mentioned, the effectiveness of stabilizer combinations can in many cases cannot be foreseen, even if the effect of the individual components is known.

A process for stabilizing olefin polymers against the action of light has now been carried out a stabilizer mixture

a) a benzotriazole compound,

b) a phenolic compound and

c) another polyolefin stabilizer

found, which is characterized in that as a) a benzotriazole compound of the general Formula I or II

609 73 (1/446

II

where in formula I Ri and R2 independently of one another hydrogen atoms, hydrocarbon or alkoxy radicals with 1 to 20 carbon atoms or halogen and in formula Hx = hydroxyl, alkoxy or acyloxy groups with 1 to 20 carbon atoms, R ₃ and R4 hydrogen, Halogen or alkyl groups with 1 to 20 carbon atoms mean

as b) a condensation product of alkylphenols with aldehydes, ketones or sulfur chlorides and

as c) an organic amide of phosphoric acid or a polyphosphoric acid, in which the OH groups completely or partially by unsubstituted or with alkyl groups with 1 to 18 carbon atoms or disubstituted amino groups have been replaced, at least one of the amino groups being replaced by at least one alkyl radical must be substituted.

It is known from German Auslegeschrift 1 113 811 that mixtures of organic phosphoramides with condensation products from alkylphenols and aldehydes, ketones or sulfur chlorides have a good oxidation-stabilizing effect at higher temperatures. It was however, in no way can it be foreseen that such will have an advantageous effect with regard to heat aging Stabilizer systems, in combination with benzotriazole derivatives, are one of these for light stabilization show superior synergistic effect, as found according to the invention.

In the laid out documents of the Belgian patent 620 608 stabilizer mixtures are described, those from UV absorbers, which can be benzotriazole derivatives, contain sulfur organic phosphorus compounds and optionally phenolic antioxidants. The results compiled in the test tables of the cited patent show however, that the activities of the stabilizer components behave in an approximately additive manner; h., the The effect of the mixtures is roughly equal to the sum of the component efficiencies, in some cases clearly lower. In no case is the effect of the mixture greater than the sum of the individual effects. In contrast to the mixtures according to the invention, the stabilizer mixtures listed in this Belgian patent do not have a synergistic one Effect can be spoken of.

The laid-out documents of Belgian patent 628 303 describe the stabilization of polyolefins with mixtures of aliphatic thioesters, phenolic antioxidants and oxybenzotriazoles. There is a mixture of two aging stabilizers and one light stabilizer. However, a closer look shows that there is no synergism here.

In contrast, it must be regarded as surprising that, according to the invention, a stabilizer mixture from a phenol derivative and an organic amide 'of phosphoric acid, which is the Prevents heat aging and oxidation at higher temperatures, as a costabilizer for a benzotriazole acts in light stabilization.

The polyolefins to be stabilized according to the invention are high-pressure polyethylene and preferably high molecular weight homopolymers and copolymers of ethylene and / or α-olefins, which according to the known Low pressure polymerization processes were considered. In particular, can be advantageous Polyethylene, polypropylene, polybutene (l) and copolymers of ethylene, propylene and / or butene- (l), which were produced with Ziegler catalysts (cf. Raff-Allison "Polyethylene", P. 72 to 81), stabilize according to the invention. In the case of polypropylene in particular, the inventive method is obtained Stabilization products with excellent light resistance, as in this one So far, even with the addition of significantly more stabilizer than specified according to the invention, no quality has been achieved could be achieved.

Compounds are used as component a) in the stabilizer mixtures according to the invention, which correspond to the given general formulas I and II. The hydrocarbon residues Ri and R2 can e.g. B. mean:

Alkyl, aryl, aralkyl and alkaryl, such as methyl, ethyl, propyl, η-butyl, tert-butyl, octadecyl or phenyl radicals. Benztriazole compounds of the type indicated are particularly suitable, which are used as Alkoxy radicals, e.g. B. ethoxy, propoxy or tert-butoxy radicals. The formula I corresponding o-Hydroxybenztriazoles can by diazotization of substituted o-nitroaniline and coupling with a phenol substituted as indicated and subsequent reduction of the o-nitroazophenol obtained with zinc and a basic compound.

The benzotriazole-1-oxides which can be used as component a) corresponding to the formula II z. B. according to British Patent 932154 substituted by coupling of diazotized o-Nitranilines with phenols and reduction of the resulting substituted o-nitrazobenzene, e.g. B. with Na-dithionite (NaaSaO .;). the In this way obtained derivatives can by alkylation or acylation of the free OH or NH-2 groups can be modified further.

In particular, the following compounds can be used as components a) in the stabilizer mixtures will:

2 - (2 '- Hydroxy - 5' - methyl - phenyl) - benzotriazole, 2 - (T - Hydroxy - 5 '- tert-butyl - phenyl) - benzotriazole, 2- (2'-Hydroxy-5'-octyl- phenyl) -benztriazole, 2- (4'-hydroxyphenyl) -benztriazole-1-oxide, 2- (4'-methoxyphenyl) -benztriazole-1 -oxide, 2- (4'-octoxyphenyl) -benztriazole - 1-oxide, 2- (4'-hydroxy-5'-tert-butylphenyl) -benztriazole-1-oxide.

Component a) is preferably 2- (2'-hydroxy-5'-chlorophenyl) benzotriazole used in the mixtures used according to the invention.

Suitable stabilizing components b) in the mixtures used according to the invention are preferably 4,4'-thio-bis- (3-methyl-6-tert-butylphenol) and the condensation product of acetone

and p-nonylphenol, also the condensation product of crotonaldehyde with 3-methyl-6-tert-butylphenol or the condensation product of dodecyl acetoacetate with o-cresol.

As organic phosphoramides (component c) in the stabilizer mixtures used according to the invention are named for example:

Phosphoric acid - N-methylamide -diamide, phosphoric acid - N, N - dimethylamide - diamide, phosphoric acid-N, N - distearylamide - diamide, phosphoric acid - tri- (Ν, Ν-dimethylamide), Phosphoric acid tri- (N-dodecylamide), diphosphoric acid - di - (N - methyl - N - stearylamide) and condensation products as they are e.g. B. from 2 molecules of phosphoric acid - N - methyl - N - stearylamide-diamide by splitting off NH3. Such a condensation with elimination of When using phosphoramides that have free NH2 groups, NH3 can also be used after the Addition to the polyolefins at the high processing temperatures take place without thereby affecting the stabilizing effectiveness of the phosphorus compound get lost.

Phosphoric acid-N-methyl-N-stearylamide-diamide and di- (phosphoric acid-amide-N-tert-butyl-N-dodecylamide) -imide are preferably used as component c) in the mixtures used according to the invention. The phosphoramides can be z. B. by condensation of POCI3 or P ₂ Os with alkyl-substituted amines in the presence or absence of ammonia. So you get z. B. in the condensation of 1 mole of P2O5 with 2 moles of N-methyl-N-stearylamine in good yield diphosphoric acid-di- (N-methyl-N-stearylamide) and in the condensation of 1 mole of POCI3 with one mole of N-methyl N-stearylamine and 2 moles of NH3 phosphoric acid-N-methyl-N-stearylamide-diamide, which on heating with Nt ^ cleavage to di- (phosphoric acid-N-methyl-N-stearylamide-amide) -imide

O O

Il Il

P - NH - P -

I I

NH ₂ NH ₂

C18H37

40

45

condensed. The preparation of these phosphorus compounds is detailed in the French patent 1 444 488.

The stabilizer components can be used in any proportions in a total concentration from 0.1 to 5 percent by weight, preferably 0.5 to 2 percent by weight, based on the polyolefin, are used will. In most cases, however, it is to achieve an optimal synergistic effect expedient, components a), b) and c) in a ratio of 5: 1: 1 to 1: 1: 5, preferably 3: 1: 1 to 1: 1: 3 to be used.

Of course, other conventional additives such as pigments, dyes, fillers or lubricants can also be used are added to the polyolefins stabilized according to the invention.

The stabilizer components can be mixed into the polyolefins together or in succession and can best be done with a mixture of a lot of stabilizer and a little polyolefin. For this purpose, a concentrated solution of the stabilizer compounds is mixed in a low-boiling point Solvents, e.g. B. acetone or methylene chloride, with a small amount of the to be stabilized powdery polymerization product in such a ratio that the mixture after Evaporation of the solvent contains about 30 to 40 percent by weight stabilizer.

In this procedure, a dry powder is obtained which, in the usual manner, is added to the powder to be stabilized Polymer can be incorporated to achieve the desired concentration of stabilizer to get in the finished mass. The stabilizers can also be used during manufacture the polymers or are introduced during their work-up. This way of working has something special Advantage that the polymer early, d. H. even during the manufacturing or Work-up process before the influence of light and atmospheric oxygen, especially at higher temperatures, is protected. The polyolefins stabilized in this way can be prepared by the known deformation methods, the press, injection molding and extrusion processes are processed.

example 1

400 g of a polypropylene powder having a reduced specific viscosity _ψ β α of 3.61 dl / g (measured in 0, l% acetic Dekahydronaphthalinlösung at 135 ⁰ C), a melt index / 3 of 7.0 g / 10 min. (Measured at 230 C according to ASTM 1238-57 T with 5 kg load) and a density of 0.906 g / cm ³ were mixed with 5% solutions of the stabilizers listed in Table 1 in such a proportion that the stabilizer concentration calculated on polypropylene was 5 times the amount the concentration given in Table 1 was. After drying at 8O ⁰ C in a vacuum, the stabilized polypropylene powder with 1600 g of unstabilized polypropylene powder was thoroughly mixed and the mixture is then granulated in a laboratory extruder at 200 ⁰ C.

The sample pellets were then extruded at a temperature of 150-260 ⁰ C in a flask equipped with deflection and spinneret Kleinewefers extruder into a thread, which after passing through a temperature-controlled at 50 ⁰ C quench bath in a room kept at 95 ° C Reckbad continuously in a ratio was stretched from 1: 6.

The monofilament samples made in this way with a diameter of 0.62 to 0.65 mm were fixed on V 2 A sample frames measuring 200 50 1 mm using two Spacer strips are wound under constant tension so that they are exposed to weathering Thread turns were held at a distance of 3 mm from the sample holding plate. the Sample frames were inclined in Florida at an angle of 45 ° to the south, clamped and the Exposure to the elements. After the weathering times given in Table 1 were 10 threads were tested for their tensile strength and elongation at break for each formulation.

The values given in Table 1 are mean values of 10 individual measurements, they are therefore for the Weather damage of the individual monofilaments representative.

Example 2

In place of the polypropylene powder used in Example 1, an ethylene-butene (1) was -Mischpolymerisat reduced specific viscosity _η τβ α: 2.5 dl / g (measured in 0, l% acetic Dekahydronaphthalinlösung at 135 ⁰ C), melt index h : 1.7 g / 10 min (measured at 190 ⁰ C according to ASTM 1238-57 T with 5 kg of load), density:. 0.942 g / cm ² is used, wherein

whose production with Ziegler catalysts was added 1.5 percent by weight of butene- (l).

The procedure was as in Example 1 with the following changes:

Extruder temperature in the granulation 180 ⁰ C, the temperature range on the small-thrower spinning extruder 130 to 25O ⁰ C, stretching ratio 1: 8.

The weathering and testing of the monofilaments was carried out using the methods described in Example 1 Conditions.

Table 1
Lifetime of Polypropylene Monofilaments Weathered in Florida (Example 1)

Exposure time
Irradiated amount of light (Langley units) Stable
Compo
nents ¹ ) sator
Conc
tration ² )
in % 1 month
15.3 · 10 » Tear
strength ⁶ )
in kp / cm ² 3 months
40.6 · 10 ^:! Tear
strength ⁵ )
in kp / cm ² 5 months
63.1 ■ 10 ³ Tear
strength ⁵ )
in kp / cm ² 9 months
116 · 10 ³ Tear
strength ⁵ )
in kp / cm ² b) 0.5 Tear
elongation ⁴ )
in «/ ο 2830 Tear
elongation ⁴ )
in ° / o - ³ ) Rejß-
elongation ⁴ )
in "/,, Tear
elongation ⁴ )
in % Comparison
attempt 1 a)
b) 0.5
0.5 13.4 4006 - ³ ) 3214 2195 794 2 a)
b) 1.0
0.5 32.4 4100 20.8 3420 15.2 2750 6.0 2100 3 b)
c) 0.5
0.5 34.3 3820 22.1 2340 17.3 1170 14.5 - ³ ) 4th b)
c) 0.5
1.0 29.0 3590 13.8 2430 7.4 465 - ³ ) - ³ ) 5 a)
b)
c) 0.25
0.5
0.5 29.8 4100 14.8 3750 3.4 3410 - ³ ) 2970 Invention
more appropriate
Trial 6 a)
b)
c) 0.5
0.5
0.5 35.9 3920 28.9 4050 24.3 4010 18.7 3650 7th 38.2 37.3 36.7 30.7

') Stabilizer components:

a) = 2- (2'-Hydroxy-5'-tert-butyl-phenyl) -5-chlorobenzotriazole

b) - 2,2'-isopropylidene-bis (p-nonyIphenol)

c) = phosphoric acid-N-methyl-N-stearyl-amide-diamide

-) Weight percent, based on polypropylene

³ ) Samples completely embrittled

⁴ ) clamping length 10 cm, feed rate 200 mm / min.

⁵ ) clamping length 10 cm, feed speed 200 mm / min.

Table 2
Lifetime of ethylene-butene (1) copolymer monofilaments weathered in Florida (Example 2)

Exposure time
Amount of irradiated light (Langley units). Stabih
Compo
nents ¹ ) sator
Conc
tration ² )
in "/" 3 months
40.6 ■ 10 ^{: i} Tear
strength " ¹ )
in kp / cm ² 5 months
63.1 · 10 ³ Tear
strength ⁵ )
in kp / cm ² 9 months
116-10 ³ Tear
strength ⁵ )
in kp / cm ² b) 0.05 Tear
elongation ¹ )
in ⁰ A, 3950 Tear
elongation ⁴ )
in % 2680 Tear
elongation ⁴ )
in % 3 \ Comparison
attempt 1 a)
b) 0.25
0.05 38.0 4070 16.2 3270 _ ₃₎ 1980 2 a)
b) 0.5
0.05 45.2 4110 30.7 4220 10.9 3450 3 b)
c) 0.05
0.25 62.4 3420 36.4 2720 24.6 1835 4th b)
c) 0.05
0.5 32.5 3450 17.8 2850 7.5 1965 OfI 34.0 19.3 10.9

continuation

10

Exposure time
Irradiated amount of light (Langley units). Stable
Compo
nents ¹ ) sator
Conc
tration ² )
in "/", 3 months
40.6 · 10 ³ Tear
strength ⁵ )
in kp / cm'- 5 months
63.1 · 10 ³ Tear
strength ⁵ )
in kp / cm ² 9 months
116-Iff ¹ Tear
strength ⁵ )
in kp / cm ² a)
b)
c) 0.25
0.05
0.25 Tear
elongation ⁴ )
in "/" 4160 Tear
elongation ⁴ )
in % 4285 Tear
elongation ¹ )
in »/ ο 3980 Invention
more appropriate
Trial 6 59.6 45.7 39.9

¹ J stabilizer components:

a) = 2- (2'-Hydroxy-5'-tert-butyl-phenyl) -5-chlorobenzotriazole

b) == 4,4'-thio-bis- (3-methyl-6-tert-butyl-phenol)

c) - Di- (phosphoric acid amide-N-tert-butyl-N-dodecylamide) imide

² ) Percent by weight, based on polymer

³ ) Samples completely embrittled

⁴ ) clamping length 10 cm, feed rate 200 mm / min.

⁵ ) clamping length 10 cm, feed speed 200 mm / min.

Claims (1)

Claim: Process for stabilizing olefin polymers against the action of light by a Stabilizer mixture (CHs) ₃ C NH ₂ NH ₂ C (CHs) ₃ N - P —NH-Ρ —Ν / Il Il \ H ₂₅ Ci ₂ OOC ₁₂ H ₂₅ a) a benzotriazole compound, b) a phenolic compound and c) another polyolefin stabilizer, characterized in that as a) a benzotriazole compound of the general formula I or II or * N OH where in formula I Ri and R2 are independently hydrogen atoms, hydrocarbon or alkoxy radicals with 1 to 20 carbon atoms or halogen and in formula Hx = hydroxyl, alkoxy or acyloxy groups with 1 to 20 carbon atoms, R ₃ and R ₄ hydrogen atoms, halogen or alkyl groups with 'up to 20 carbon atoms, mean as b) a condensation product of alkylphenols with aldehydes, ketones or sulfur chlorides and as c) an organic amide of phosphoric acid or a polyphosphoric acid, in which the OH groups in whole or in part by unsubstituted or with alkyl groups having 1 to 18 carbon atoms mono- or disubstituted amino groups have been replaced, at least one of the amino groups being replaced by at least one Alkyl radical must be substituted, can be used. Considered publications:
German Auslegeschrift No. 1 113 811;
laid out documents of Belgian patent No. 303. 609 730/446 11.66 © Bundesdruckerei Berlin