CS240010B1 - Light-stabilized polypropylene and propylene's copolymers with ethylene - Google Patents

Abstract

The present invention relates to polypropylene and copolymers propylene with ethylene stabilized light and thermooxidative light stabilizers. Derivatives 2,2,6,6 tetramethylpiperidinol or 4 amino 2, 2,6,6 tetramethylpiperidine forms with esters thiodipropionic acid and 4 pentadecacis (propenyl) 2,6-dimethylphenol synergistic mixture.

Description

(54) Light-stabilized polypropylene and copolymers of propylene with ethylene

The invention relates to polypropylene and propylene-ethylene copolymers stabilized against light by light and thermo-oxidizing stabilizers. The derivatives of 2,2,6,6 tetramethylpiperidinol or 4 amino 2, 2, 6, 6 tetramethylpiperidine form a synergistic mixture with thiodipropionic acid esters and 4 pentadecakis (propenyl) 2,6 dimethylphenol.

240,010 (51) Int. Cl.V

OJ C 08 L 23/10, C 08 K 13/00

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The invention relates to polypropylene and copolymers of propylene with ethylene, stabilized emissions of piperidinol derivatives or 4-amino-2,2,6,6 tetramethylplperidine with phenolic, sulfur and phosphite stabilizers.

Products made of polypropylene and copolymers of propylene and ethylene occupy an important place in many sectors of the national economy. However, if these polymers do not contain protective stabilizers, they will lose valuable mechanical and visual properties very quickly due to degradation processes caused by heat and light. Therefore, it is necessary to protect them with a mixture of thermo-oxidizing and light stabilizers, as alkyl-substituted phenols, thiodipropionic acid esters and phosphorus-containing compounds are generally used as thermo-oxidizing stabillators. Derivatives of hydroxybenzophenone (US 3,349,588, US 4,288,631), hydroxybenztriazole (US 4,278,589, US 4,278,590), 2,2,6,6 tetramethylpiperidinol and 4-amino-2,2,6,6 tetramethylpiperidine have proved to be light stabilizers.

Derivatives of 2,2,6,6-tetramethylpiperidinol and 4-amino 2,2,6,6-tetramethylpiperidine (hereafter referred to as HALS stabillators) outperform the hydroxybenzophenone and hydroxybenztriazole derivatives in a protective action against the harmful effects of sunlight and are protected by a number of U.S. Pat. Nos. 3,640,928, 4,021,432, US 4,08942, GB 04 4760, GB 055 486, KP 22501, IP 22997, CHO 13722, CH 592129, US 416 4480, US 33412, GB 1,415 741.

However, it has been found that sulfur-containing thermo-oxidative stabillizers, such as thiodipropionic acid esters, greatly reduce their effectiveness. Therefore, sulfur-containing additives have been omitted from stabilizing mixtures containing HALS-type light stabilizers and using either a combination of HALS stabilizers with phenolic stabilizers

- 2 - mo ua (JA 56 62835, JA 56 62839, JA 56 62840), or combinations of HALS stabilizers with phosphorus compounds (DT 26 06 026, DT 26 36 130, DT 5459 381, DE 3001 114, JA 81 62 838), JA 8162 836). Only Polymer polypropylene-IPDM rubber blend (AO 231273 ^) showed that the stabilizing effect of HALS light stabilizers in the presence of sulfur stabilizers, namely thiodipropionic acid esters, would not be reduced if the thiodipropionic acid ester concentration did not exceed 0.1% by weight

The present invention provides polypropylene and copolymers of propylene with ethyleneene stabilized by light and temoxidizing stabilizers containing lubricants and optionally carbon blacks or pigments containing 0.05 to 0.25% by weight of 4 pentadecakis (propenyl) 2,6 dimethylphenol, 0.05 to 0 20% by weight of thiodipropionic acid esters of saturated alcohols having 12 to 25 carbon atoms, 0.1 to 0.5% by weight of 2,2,6,6 tetramethylpiperidinol derivatives or 4 amino 2,2,6,6 tetramethylpiperidine or mixtures of these derivatives with hydroxybenzotriazone and / or hydroxybenzophenone derivatives having a weight ratio of 1: 2 to 2: 1 and optionally another phenolic or phosphite stabilizer in a concentration of 0.05 to 0.2% by weight, based on the content of the polypropylene or its copolymers. Polypropylene and copolymers of propylene with ethylene (containing 0,5 to 7% by weight of ethylene), for which mixtures containing, in addition to HALS light stabilizers, a combination of the phenolic stabilizer 4-pentadecakis (propenyl) -2,6-dimethylphenol with acid esters have been used thiodipropionic, have a higher resistance to the degradation effect of sunlight than stabilizing mixtures of HALS with other phenolic or phosphite stabilizers in the absence of sulfur stabilizing additives. In the above mixture of 4-pentadecakis (propenyl) -2,6-dimethylphenol with thiodipropionic acid esters and HALS stabilizers, an unexpected, extremely strong stabilizing effect occurs. It has been found that, in addition to the substances mentioned, the total stabilizing mixture can also contain other substituted phenols, for example 2,6 di-tert. butyl-4-methylphenol, phosphorus-containing stabilizers such as tris (phenylethylphosphite) and hydroxybenzophenone or hydroxybenztriazole derivatives.

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The polypropylene with high resistance to the harmful effects of sunlight according to the invention is prepared in a conventional manner, which can be characterized, for example, by the following process:

First, a masterbatch powder is prepared. The type of polymer to which the stabilizing concentrate is to be added is used. Polymer and powder stabilizers are added to the mixer in a ratio of 60 to 80 parts by weight of polymer to 20 to 40 parts by weight of stabilizing additives. The mixture is mixed and emptied into transport containers, which are then emptied into the stabilizer concentrate containers above the twin screw mixers.

The stabilizing concentrate is metered continuously from the reservoir into a twin-screw mixer. At the same time, unstabilized powdered polymer is metered into the mixer. In the twin-screw mixer, the unstabilized polymer is thoroughly mixed with both the powder stabilizer concentrate and the liquid stabilizer additives, which are dosed by the pump directly from the containers into the mixer. The intensive mixer homogenizes all the components of the blend and melts the blend by the shear forces and the external heat of the blender shell onto the melt flowing through the overflow into a single screw extruder at a temperature of 200 to 280 ° C. The melt is forced through a series of sieves through the screw, enters the extruder die and passes through the holes of the extruder through the water. The solidifying polymer is chopped into granules just below the extruder head. The granulate goes to a granule dryer, where it is dried by its own heat and air flow.

To evaluate the light stability of the prepared polymer, a 0.5 mm thick film is pressed from the granulate. 40 mm x 5 am strips are placed in the Xenotest 450, where they undergo accelerated light aging, the progress of which is controlled by the growth of the carbonyl groups. The time taken to increase the carbonyl groups to Δ. CO * 0.15 is referred to as and is a measure of sample stability.

The invention is illustrated by the following examples given in Table 1.

% in the examples given are by weight.

Used shortcuts :

F 1: pentaerythrityltetrakia (3,5-di-tert-butyl-4-hydroxyphenylpropionate)

F 2: 4-Pentadecakis (propenyl) -2,5-dimethylphenol

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- F 3: 2,6-di-tert-butyl-4-methylphenol

FOS: phosphoric acid tris 4 4 (1'-phenyl) ethylphenyl S 1: distearylthiodipropionate

S 2: Diodes of thiodipropionic acid with a mixture of saturated alcohols having 16 to 23 carbon atoms

Η 1: Succinic acid polyester with N - β - hydroxyethyl2,2,6,6 - tetramethyl-4-hydroxypiperidine

H 2: 4- (2,2,6,6-tetramethyl) piperidinylamide succinic acid

H 3: Mixture of esters prepared by esterification of 2,2,6,6-tetramethyl-4-piperidinol with stearin

H 4: bis (2,2,6,6-tetramethyl-4-piperidinol) sebacate T: 2- (2 * - hydroxy-3 * - tert -butyl-5-methylphenyl) -5-chlorobenztriazole

B; 2-hydroxy-4-n-octyloxybenzophenone

Examples 1 to 24 relate to stabilized polypropylene, examples 25 to 31 relate to a stabilized copolymer of propylene with ethylene with an ethylene content of 1.8%. All mixtures contained 0.15% calcium stearate. Mixture. 17 contained 1.5% titanium dioxide in addition to the ingredients listed in the table and 1.5% carbon black.

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Tab. Efficiency of HALS light stabilizers depending on the presence of thermo-oxidizing components of the stabilizing mixture

.example. no. stabilizer stabilizer stabilizer stabilizer IP _Y p _N species % species % species % species  % throw 1 F 1 0.2 Η 1 0.2 4.200 2 F 1 0.2 H 2 0.2 4.850 3 F 2 0.2 Η 1 0.2 4.240 4 F 2 0.2 H 2 0.2 5.120 5 F 2 0.2 H 3 0.2 6.200 6 FOS 0.2 Η 1 0.2 4.210 7 FOS 0.2 H 2 0.2 4.835 ΐ 8 FOS 0.2 H 3 0.2 5.130 9 F 1 0.1 FOS 0.1 Η 1 0.2 4.350 10 F 1 0.1 FOS 0.1 H 2 0.2 4.940 11 F 2 0.1 FOS 0.1 H 1 0.2 5.110 12 F 2 0.1 FOS 0.1 H 2 0.2 5.800 13 F 1 0.1 S 1 0.15 Η 1 0.2 2.805 14 F 1 0.1 S 1 0.15 H 2 0.2 3.240 15 Dec F 2 0.1 S 1 0.15 Η 1 0.2 5.300 16 F 2 0.1 S 1 0.15 H 2 0.2 6.480 17 F 2 0.1 S 2 0.15 H 3 0.2 7.725 18 F 2 0.1 S 1 0.15 F 3 0.1 Η 1 0.2 5.320 19 Dec F 2 0.2 S 1 0.1 F 3 0.1 H 3 0.2 7.753 20 May F 2 0.1 S 1 0.1 FOS 0.1 Η 1 0.2 5.305 21 F 2 0.2 S 1 0.1 F 3 0.1 Η 1 0.3 6.750 22nd F 2 0.2 S 1 0.1 F 3 0.1 H 3 0.3 9.230 23 F 2 0.2 S 2 0.1 F 3 0.1 H 4 0.2 7.720 24 F 2 0.2 S 2 0.1 F 3 0.1 H 4 0.3 9.110 25 F 2 0.2 S 1 0.1 F 3 0.1 H 4 0.2 11.840 26 F 2 0.2 Η 1 0.2 4.355 27 Mar: F 1 0.1 S 1 0.15 Η 1 0.2 2.860 28 F 2 0.2 - Η 1 0.2 4.380 29 F 2 0.1 S 1 0.15 Η 1 0.2 5.470 30 F 2 0.2 S 1 0.1 T 0.15 H 3 0.15 7.960 31 F 2 0.2 S 1 0.1 (B) 0.15 H 3 0.15 8.120

The measured values show:

1. The presence of a sulfur stabilizing additive significantly reduces the effectiveness of HALS stabilizers when using pentaerythrityltetrakis (3,5-di-tert-butyl-4-hydroxyphenyl propionate) (cf. Example 1 with 13, Example 2 with 14 and Example 6 and 26 with 27).

2. In contrast, using 4-pentadecakis (propenyl) -2,6-dimethylphenol, the presence of a sulfur stabilizer adds to an increase in the efficiency of the HALS light stabilizers (cf. Example 3 with 15, Example 4 with 16, Example 5 with 17, Example 28 with Example) 29) ·

3 · The high efficiency of HALS stabilizers in the presence of a combination of 4-pentadecakis (propenyl) 2,6-dimethylphenol with thiodipropionic acid esters is not reduced when an additional hydroxybenzotriazole or hydroxybenzophenone derivative (Examples 30 and 31), another phenolic stabilizer, have been added to the stabilization mixture , for example 2,6-di-tert-butyl-4-methylformin (cf. Examples 15-17 with Examples 18, 19) or a phosphite stabilizer (cf. Example 15 with Example 20). Other phenolic and phosphite stabilizers are generally added to the stabilizer composition to increase the polymer's resistance to degradation during processing or to achieve a higher degree of whiteness. With increasing HALS concentration, light stability increases (examples 23 and 24) ·

Claims (2)

P R E C O R E C O N E L 2 U Polypropylene and copolymers of propylene and light-stabilized ethylene with light and temoxidized stabilizers, containing lubricants and optionally carbon blacks or pigments, characterized in that they contain from 0.05 to 0.25% by weight of 4-pentadecakis (propenyl) - 2,6 dimethylphenols, 0.5 to 0.2% by weight of esters of Igrselina thiodipropionic with saturated alcohols having from 12 to 25 carbon atoms, 0.1 to 0.5% by weight of derivatives of 2,2,6,6 tetramethylpiperidinol or 4-amino-2,2,6, Or a mixture of these derivatives with hydroxybenzotriazole and / or hydroxybenzophenone derivatives in a weight ratio of 1: 2 to 2: 1 and optionally another phenolic or phosphite stabilizer in a concentration of 0.05 to 0.2% by weight based on the content of the polypropylene or its copolymers.