DD290906A5 - METHOD FOR STABILIZING POLYOLEFINES AND THEIR COPOLYMERISES BY ESTERS OF THE PHOSPHORUS AND PHOSPHONIC SAWS - Google Patents

Abstract

The invention relates to a process for the stabilization of polyolefins and their copolymers against thermal and photooxidative degradation by hydrolysis-stable esters of acids of trivalent phosphorus, which are characterized in that one or two ester groups represent derivatives of specific amino alcohols. According to the invention, these stabilizers can be used alone or in combination with other antioxidants and light stabilizers, with a concentration of from 0.01 to 3 *, preferably from 0.05 to 0.5%, necessary for effective inhibition of the oxidation processes. {Antioxidants; stabilizers; Sun protection; phosphite; phosphonite; polyolefins; copolymers; esters; amino alcohols; Photo-oxidation; Thermal oxidation; Polymer stabilization}

Description

R ₁₂ R ₁₁

(O

-GH ^ CH ₂ -O _x

P-O-W

-Clfcf CH ₂ -O '

in which

R9, Rio / R11 / R12 = independently hydrogen, alkyl, cycloalkyl, hydroxyalkyl

Ri3iRi4 = independently hydrogen, alkyl, cycloalkyl, hydroxyalkyl or

carbalkoxyl

R ₁₅ -R ₂₂ = independently of one another hydrogen, alkyl, cycloalkyl, aralkyl

mean.

2. The method according to claim 1, characterized in that the compounds according to the invention are added in a concentration of 0.01 to 3 wt .-%, preferably 0.05 to 0.5Gew .-%.

Field of application of the invention

The invention relates to a process for the stabilization of polyolefins and their copolymers against thermo - and photooxidative degradation.

Characteristic of the known state of the art

All organic compounds, including organic polymers and hydrocarbons of various molecular weights, undergo thermal and photooxidative degradation processes under the action of air, light, heat, moisture and other environmental factors in the manufacture, processing and use. These lead to a negative influence on the physical and physico-mechanical properties and thus limit the application possibilities for organic materials. By adding stabilizers (antioxidants, light stabilizers, etc.), such degradation reactions can be inhibited. In addition to sterically hindered phenols, some sulfur compounds and aromatic amines phosphorus compounds are increasingly used for it. Of these, particularly sterically hindered phosphites (inter alia DE-OS 2733796, DE-OS 2944254, DD146959, DD 146961) and cyclic phosphites (DD 146464, DD146959, DE-OS 2656999) show good activity. Almost all previously used phosphite stabilizers have the great disadvantage that they are very easily hydrolytically decomposed, thereby limiting their shelf life and reducing their effectiveness. The proposals for reducing these disadvantages (additions of amines [DE-OS 2135238, DE-OS 26361331, waxing [EP 2243] and soaps [DE-OS 2626255]) can not solve this problem and have a number of new technological and chemical deficiencies Episode.

Purpose of the invention

The object of Erflndung is to find an economically favorable and effective process for the stabilization of polyolefins and their copolymers gegor, thermo and photooxidative degradation.

Explanation of the nature of the invention

The object of the invention is to develop a novel process for the stabilization of polyolefins and their copolymers, which increases the stability of these materials against thermal and photooxidative degradation and avoids the disadvantages of known solutions.

According to the invention the object is achieved in that the organic materials to be stabilized esters of acids of trivalent phosphorus of the general formulas I to III in concentrations between 0.01 and 3 wt .-%, preferably between 0.05 and 0.5 wt .-% alone or added in combination with other stabilizers or other additives during manufacture, prior to or during processing by a single or multiple addition.

¹ H

(R ₁ = monosubstituted or polysubstituted phenyl alkoxyl V ₁ = Hydrogen, oxyl, alkyl, alkenyl, aralkyl, With = Alkyl, cycloalkyl, phenyl or R = Tetra- or pentamethylene rj η = 1 or 2 Rj, R4, Rs » re u = 1 or 2 R ₃ + R ₄ = Rs + Rg m = Ooderi n + u = 3 r = Ooderi

(II)

^R 3 u

Y = aliphatic or cycloaliphatic carbon skeleton Ri = mono- or poly-substituted phenyl R ₂ = alkyl, cycloalkyl, aralkyl, phenyl R ₃ = hydrogen, alkyl, cycloalkyl, aralkyl, phenyl

m = Ooderi η = 1 or 2

n + u = 3 u = 1 or 2

(III)

Ri = hydrogen, oxyl, alkoxyl, alkyl, alkenyl, aralkyl R3, R ", Rs, Re - alkyl, cycloalkyl, phenyl or Ra + FU = Rs + Re = tetra- or pentamethylene

r = Ooderi

W = Y -

8 where

Y = aliphatic or cycloaliphatic carbon skeleton R ₇ = alkyl, cycloalkyl, aralkyl, phenyl

Re = hydrogen, alkyl, cycloalkyl, aralkyl, phenyl V = a bivalent radical consisting of the radicals of the formulas A, B, C, D, E

»9

"9" ^R io -CR

12 (A)

R-C-R

- CH ₂ ^ ^ rCH ₂ -O

-O-W

(E)

where Rs, Rio, Rn, Ru.

₁₂ = independently hydrogen, alkyl, cycloalkyl, hydroxyalkyl

= independently of one another are hydrogen, alkyl, cycloalkyl, hydroxyalkyl or carbalkoxyl = independently of one another hydrogen, alkyl, cycloalkyl, aralkyl. .

The esters according to the invention of acids of the trivalent phosphorus of the general formula I to III, in which one or two ester radicals derive from specific aminoalcohols whose amino function is still strongly basic but inhibited from steric and / or electronic ratios in their chemical reactivity, are characterized by a very good storage stability, which is due to their excellent hydrolysis and oxidation stability. The advantages of the invention lie in the pronounced stabilizing effect against a thermal and photooxidative degradation of polyolefins and other low and high molecular weight hydrocarbons. The effectiveness of the method according to the invention is expressed for. In inhibiting the autoxidation of hydrocarbons and polyolefins - expressed by the induction period t _{! P} and the relative rate of autoxidation - as well as a greatly delayed increase in the carbonyl index in both thermal and photooxidation.

embodiments In the embodiments 1-5 following representatives of the compounds of the invention are used.

1-Di (2,2,6,6-tetramethylpiperidin-4-yl) -2,6-di-tert-butyl-4-methylphenyl phosphite

2 di (2,2,6,6-tetramethylpiperidin-4-yl) -phenylphosphonite

3 di (2,2,6,6-tetramethylpiperidin-4-yl) -2,4-di-tert-pentylphenyl phosphite

4 di- (2,2,6,6-tetramethylpiperidin-4-yl) -2,4-di-tert-butyl-m-cresyl phosphite

5-Di (2,2,6,6-tetramethylpiperidin-4-yl) -2-tert-butyl-m-cresyl phosphite

6-di (2,2,6,6-tetramethyl-piperidin-4-yl) -2-tert-butyl-4-methylphenyl-phosphite

7 di- (2,4-di-tert-butyl-m-cresyl) -2,2,6,6-tetramethylpiperidin-4-yl phosphite

8 2- (2,2,6,6-tetramethyl-4-oxy-piperidinyl) -1,3,2-dioxaphospholane

9 2- (2,2,6,6-tetramethyl-4-oxy-piperidinyl) -5,5-dimethyl-1,3,2-dioxaphosphorinane

10 2- (2,2,6,6-tetramethyl-4-oxy-piperidinyl) dibenzo [d, f] -1,3,2-dioxaphosphenin

11 6- (2,2,6,6-tetramethyl-4-oxy-piperidinyl) -4,8-di-tert-butyl-2,10-dimethyl-12-H-dibenzo [d, g] -1, 3.2 dioxaphosphocin

12 5,5'-spirobi [2-2,2,6, e-tetramethyl-4-oxy-piperidinyl-1,3,2-dioxaphosphorinan]

example 1 hydrolytic stability To test the hydrolytic stability of the compounds according to the invention, these and comparatively known Phosphites treated with an aqueous solution of o-dichlorobenzene and then using ³¹ P NMR spectroscopy

for hydrolysis products (hydrogen phosphite, H ₃ PO ₃ ). In addition, the amounts of phosphite and water were 0.2 molar

Stored and added solutions in the presence of oxygen or nitrogen in sealed 200 ml Erlenmeyer flasks at 75 ⁰ C.

analyzed at certain times. The results are shown in Table 1.

Table 1 connection

Time / h

O ₂ / N ₂

In-C ₈ H ₁₇ O ₃ ) P 15 O ₂ 85.5 N ₂ 69.3 ((0VO) ₃ P ^ ' 50 O, 100 N ₂ 100 (- (O) -O) ₃ P 70 U ₂ 61 \ - / N ₂ 76

Hydrogen phosphite /% H ₃ PO ₃ /%

Spurs traces

19 21

The compounds (1), (3), (5), (6), (7), (9), (11), (12) according to the invention exhibit hydrolysis products neither after oxygen nor under nitrogen after 70 hours.

Example 2 Inhibition of autoxidation of polypropylene Oxygen uptake was monitored in the oxidation of isotactic polypropylene (MW 510000, ash content 0.29%, titanium content

0.017%, aluminum content 0.11%) in the case of If) O ⁰ C in the presence of the compounds according to the invention and of

Followed comparison stabilizers. The concentration was 0.05 moles per kilogram of polypropylene. As a measure of the Wirksar it

of these compounds as antioxidants was the induction period t | _P and the relative autoxidation rate S, indicated after the induction period. The results are shown in Table 2.

Table 2 connection

V / min

S,

45

410

120

230

1020 430 610 450 380 125 140 25Ü 750

0.49

0.7

0.5

0015

0.17

0.032

0,045

0,052

0.72

0.43

0.11

0.10

Example 3 Thermooxidation of polypropylene

100 g of polypropylene powder (unstabilized Propathene HF 20 CGV 170 from ICI) were suspended in methylene chloride and mixed with 0.002 mol of the stabilizers according to the invention. After 24 hours, the solvent was removed and the stabilized polypropylene powder was freed of solvent residues in vacuo at room temperature and then processed in a hydraulic press for 3 minutes at 18O ⁰ C to form films with a thickness of 0.1 mm. For comparison purposes, unstabilized and comparative stabilizer-containing polypropylene films were prepared in the same manner. The films were then tempered in a circulating air cabinet at 100 ⁰ C and the course of the thermal oxidation by measuring the

Carbonyl absorbances of the samples are monitored by IR spectroscopy. The extinction ratios of the bands at 1720 cm '' and

2720cm " ¹ are listed in Table 3 as a function of time.

Table 3

Time / h

Compound 50 70 100 150 220 300 600 900 1200

0.92 5.66 χ

0.20 0.51 2.76 χ

0.19 0.21 1.98 χ

0.16 0.17 0.17 0.18 0.24 0.24 0.37 χ

8th 0.17 0.18 0.18 1.63 χ χ 0.23 * 0.25 0.26 10 0.19 0.75 1.02 3.87 χ 0.23 0.23 0.23 * 0.39 9 0.18 0.19 0.19 0.2 1.30 0.22 0.20 0.21 0.25 11 0.16 0.16 0.17 0.17 0.22 0.19 2 0.20 0.21 0.21 0.21 0.22 1 0.17 0.17 0.19 0.19 0.19

χ - foil breakage

* - beginning of film haze

Example 4 Photooxidation of polypropylene

To test the photooxidative degradation, the polypropylene films heated with a medium-pressure mercury burner (S 180R, VEB "Thelta" Elektroapparate ZeIIa Mehlis) were irradiated analogously to Example 3 and the time increase of the carbon / extinction from the ratio of the extinctions of the bands at 1720 cm " ¹ and 2720cm ~ ^{1 determined by} IR spectroscopy. From the η ratio of the irradiation times for the polypropylene films with and without stabilizer until reaching the value for the carbonyl index, the corresponding improvement factors listed in Table 4 were determined.

Table 4 Connection improvement factor

without 1 (about 200 h)

1.4 1.5

3.6

11 2.4

8 2.6 10 2.9

9 3.2 1 4.0

Example 5 Inhibition of autoxidation of cumene To determine the effectiveness of the compounds of the invention as inhibitors of autoxidation of Hydrocarbons, the influence of these compounds on the AIBN-initiated oxidation of cumene can be used. As a measure of the inhibitory effect is the induction period t _{) P} and the relative autoxidation S, after

the induction period. The oxygen uptake was in the oxidation of cumene (1.71 mol / l) in chlorobenzene at 65 ° C, initiated by AIBN (0.1 mol / l) in the presence of the inventive compounds and known stabilizers (2 10 ^-2 mol / l) followed. The results are shown in Table 5.

Table 5

connection t | p / min S, without 1.5 1.0 BHT 325 1.0 triphenyl 5 1.0 PEP36 67 1.1 Irgafos168 48 1.1 1 69 0.75 3 42 0.72 5 25 0.85 10 345 0.55 11 250 0.22

Claims (1)

1. A process for the stabilization of polyolefins and their copolymers against thermal and photooxidative degradation, characterized in that polyolefins or their copolymers esters of acids of the trivalent phosphorus of the general formula I to III ^R 6 B. "(I) R ₁ = mono- or poly-substituted phenyl R ₂ = hydrogen, oxyl, alkyl, alkenyl, aralkyl, alkoxyl Ra, R4. Re »Re = alkyl, cycloalkyl, phenyl or R ₃ + R ₄ = R ₅ + R ₆ = tetra- or pentamethylene m = Ooderi η = 1 or 2 n + u = 3 u = 1 or 2 r = Ooderi , J ₁ - (0) _m ^ ^ OY-NC ^ ^c j (ID ^R 3 υ Y = aliphatic or cycloaliphatic carbon skeleton Ri = mono- or poly-substituted phenyl R ₂ = alkyl, cycloalkyl, aralkyl, phenyl R ₃ = hydrogen, alkyl, cycloalkyl, aralkyl, phenyl m = Ooderi η = 1 or 2 (III) y y R3, R4, R5, Re = alkyl, cycloalkyl, phenyl or R ₃ + R ₄ = R ₅ + R ₆ = tetra or pentamethylene r = OodeM
or. W = Y - - in which Y = aliphatic or cycloaliphatic carbon skeleton R ₇ = alkyl, cycloalkyl, aralkyl, phenyl R ₈ = hydrogen, alkyl, cycloalkyl, aralkyl, phenyl V = a bivalent radical consisting of the radicals of the formulas A, B, C, D, E. -CR ₁ «