DE1494662B2 - STABILIZATION OF POLYOLEFINS AND MIXTURES OF POLYOLEFINS AND BASIC NITROGEN CONDENSATE - Google Patents

Description

It is well known that products based on polyolefins are exposed to certain heat treatment processes Way degraded, especially in the presence of atmospheric oxygen. It is also known that manufactured goods on the basis of crystalline polyolefins against the effects of light and against heat are sensitive. This degrading effect can be achieved through the addition of special protective substances to polymer, particularly during the manufacture of fibers, films and the like.

In general, small amounts of amines, phenolic compounds are used for this purpose. Aminophenols, Triazole compounds, phosphates, thiophosphites, thioesters and thioethers, chelates of Transition metals, organotin compounds, carbamates and thiocarbamates, oximes, polyquinolines and the like used.

It has also already been proposed that polyolefins, in particular, be used against the action of light stabilize, for this purpose mixtures of an aliphatic thioester, a polyvalent Phenol and an oxybenzotriazole compound, optionally in the presence of metal soaps, were used. ■:

In the Italian patent 678 673 a stabilization of polyolefins is also with a stabilizer mixture of an aliphatic thioester, a polyhydric phenol, a nickel phenolate a bis-p-alkylphenol monosulfide, if appropriate with the addition of a metal soap.

The present invention now relates to a stabilizer mixture consisting of

a) aliphatic thioesters,

b) polyhydric phenols, which may contain sulfur,

c) Nickel phenolates of bis-p-alkylphenol monosulfides and

d) oxybenzotriazole compounds,

which shows a very high stabilizing effect when used in proportions of 5% or less with crystalline Olefin polymers is mixed. Such compositions can be based on fibers or the like of polyolefins with particular stability against the effects of heat and light as well as against aging spin.

^: ; The addition of a metal soap, which acts as an acid-binding agent, to the compositions prior to their spinning improves the stability properties of the polymer blends.

Calcium stearate is particularly suitable as the metal soap; however, there are also zinc stearate, aluminum stearate, calcium laurate, zinc laurate and aluminum laurate effective.

The stabilizing mixtures used according to the invention are for stabilizing crystalline Polyolefins, in particular of polypropylene consisting essentially of isotactic macromolecules, as well as compositions based on crystalline polyolefins and basic Nitrogen polycondensates, which give fibers with improved dyeability, against the action of Heat and light as well as anti-aging.

They are also suitable for stabilizing compositions essentially based on crystalline polyolefins, which are obtained by adding organic or inorganic color pigments for the polymer stabilizer mixture before spinning or Squeezing were colored.

In general, the stabilizer mixture is added to the polymer in proportions between 0.02 and 5 percent by weight added.

The stabilizer mixture can be used together with pigments, dyes and fillers.

As aliphatic thioesters, which are particularly suitable as components of the mixture, the following may be mentioned:

a) thioesters of thiodiethylene glycol, such as didodecoylthiodiglycolate, Octadecoyl thiodiglycolate and the like,

b) the thioesters of / 3, / 3'-thiodipropionic acid, such as Lauryl thiodipropionate.

Particularly suitable polyhydric phenols are, for example, 4,4'-thiobis-6-tert.butylmethacresol _? Polyphenols obtained by condensation of aldehydes and ketones with alkylphenols, ortho-hindered and para-substituted phenols, trishydroxyarylpropanes and the like.

The reaction products of alkylphenols with aldehydes (e.g. formaldehyde, acetaldehyde, etc.)

. or ketones (ζ. Β. acetone) have the following general formula:

R "1 R

HO

... or

where R is hydrogen or an alkyl radical (and at least one radical R in each ring is an alkyl radical) and R ¹ and R ^{2 are} hydrogen or an alkyl radical. Such compounds are in Italian patents 606 804, 615 441, 536 250 and

623 440 and in British Patent 571,943. ■ ·. "■ ·» -—

The compounds of tris (hydroxyaryl) propane are described in Italian patent 632 726. '' ■ '·. ■■ - · 7 ^;

Among the particularly suitable nickel phenolates of the alkylphenol monosulfides, there may be mentioned: Nickel phenolates of bis-2-tert-butylphenol monosulfide, of O, O-bis (p-octylphenol) monosulfide and of O, O-bis- (p-amylphenol) monosulfide.

The oxybenzotriazoles which can be used according to the invention are 2'-oxy-3'-tert-butyl - 5 '- methylphenyl - 5 - chlorobenzotriazole and 2' - oxy - 5 '- tert-butylphenyl - 5 - chlorobenzotriazole as proved particularly suitable.

The stabilizer mixture preferably contains 20 to 80% nickel phenolate and oxybenzotriazole.

This stabilizing mixture used according to the invention is added to the polymers in generally by simply mixing the stabilizer mixture in the form of powders with the Polyolefins in motion. However, the stabilizers can also be added by other methods such as by mixing the polyolefins with a solution of the stabilizers in a suitable Solvent and subsequent evaporation of the solvent or by adding the stabilizers to the polyolefins at the end of the polymerization.

Furthermore, the stabilizing effect can be achieved by adding the stabilizing compounds applies to the objects, e.g. B. by immersing the latter in a stabilizer solution or dispersion and subsequent evaporation of the solvent.

The stabilizers used according to the invention show in comparison with those known from the prior art Products have good compatibility with polyolefins in the melt state and do not cause any Staining.

The stabilizer and polymer compositions are granulated and then in a melt spinning device, preferably as described in Italian patent 614 043, and preferably using spinnerets as described in Italian patent 600 248 are described, which have a ratio of length to diameter, ■; - over 1, expressed, '. . '■■ ., ■

Granulating and spinning is done in the absence of means of oxygen, 'preferably carried out in an inert gas atmosphere (nitrogen).

During the mixing of the polyolefins with the stabilizers used according to the invention can optical fillers and organic or inorganic color pigments can also be added.

The threads produced from the stabilized polymers are subjected to a stretching treatment with stretching ratios between 1: 2 and 1:10 at temperatures between 80 and 150 ^° C. in stretching devices that are heated with hot air, steam or the like or by means of a heating plate.

The fibers can then be subjected to a dimensional stabilization treatment under free or hindered shrinkage conditions at 80 to 160 ^° C., as described in Italian patents 566,914 and 588,318. .... ■

Polymers stabilized according to the invention are particularly suitable for the production of single and multiple threads, Fiber strands or staple fibers, voluminous yarns as well as other shaped bodies, like foils or tapes.

The polypropylene used in the following tabular examples had the following properties :

35

Intrinsic viscosity [rj] 1.60,

Ash content .... 0.029%

Residue after the heptane extraction 94.4%

example

Polypropylene

Didodecoyl thiodiglycolate

Lauryl thiodipropionate

4,4'-thiobis-6-tert.butylmethacresol ........

2'-Oxy-5'-tert-butylphenol-5-chlorobenzotriazole ., ...

2'-oxy _: 3 ^; -teVt.butyl-5-methylphenyl-5-chloro- ⁱ :
benzotriazole "; _: ^; '

Nickel phenolate of bis-p-tert-butylphenol monosulfide .. - _r w _; ; ,: * ■

Making the mixture .................

Spinning conditions: ■> -, ■ .- ■ ·· ■ ·,:;, ',.
Screw ^{temperature, 0} C ... t:;.: ... '. "'. ,
Head temperature, ⁰ C '.'....... ^: .'. ".- '.'. <'....

Spinneret temperature, - ⁰ C ..; ...

Spinneret type ... S ......... ,. ·.,. , .- ;.

Maximum pressure (kg / cm ² ) .'....'......;.;.,

Winding speed (m / minute).,.

(a) = 60 / 0.8 x 16 mm.

(b) = 40 / 0.8 x 16 mm.

0.5

0.5

0.2

0.5

; Henschel-
; mixer

v-250

.

0.3

; 0.25
; Henschel mixer

250

250

67

390

0.3 '
■ 0.25
Henschel mixer

250
250
250

(a)

73 '
390

. Hehschelmischer

250
250.
250

ß).

:, 65

■ 390

(Continuation)

Example 2 3

Stretching conditions:

Temperature, ° C

Medium ....... ·. . ■ ';

Stretch ratio

Properties of the stretched fibers:

Tensile strength (g / den)

Strain (%)....

Thermal degradation:

Percent residual intrinsic viscosity [??] after pressing out

Stability against accelerated thermal aging:

Percent retained tenacity after 200 hours at 120 ⁰ C in an oven with air circulation.

Stability to sunlight:

Percent residual tensile strength after 300 hours of exposure to actual exposure Summer sun light up to a change of the 7th shade in the standard blue scale 120

Steam 1: 5

5.5

22.5 ■■ '

brittle

67

example

Polypropylene

Didodecoylthiodiglycolate

Lauryl thiodipropionate

4,4 ^/ -Thiobis-6-tert.butylmethacresol 2'-Öxy-5'-tert.butylphenol-5-chlorobenzo-

2'-Oxy-3'-tert.butyί-5-methylphenyl-5-chloro

benzotfiazole

Nickel phenolate of bis-p-tert-butylphenol

monosulfide .......

Calcium stearate - .... V. ^c

Making the Mix

Spinning Conditions:

Snailite temperature ^{, D C}

. Head temperature, ° C

Spinneret temperature, ^b C

Spinneret type ...; i ;; V.; ..............

Maximum pressure (kg / cm ² ) ................

Winding-up speed (m / minute) ....

Streckbediftguftgen: ^K '■' ■■.

Temperature, ⁰ C ₁ .. ^ .......

r ■■■■■ Medium .... »-,

Pitch ratio

(ä) = 6OA8 * 16 mm.
^ b) 4ÖA8 16mm.

0.5

Henschel mixer

250 250 250 (b)

4δ

390

130

Steam 1: 5

0.5 0.3 0.25

Henschel mixer

250 250 250 (a)

390

130

Steam 1: 5

0.5 0.5 0.5 0.5 0.3 0.25; Henschel Henschel mixer mixer 250 250 V "■"'■ 250 250 ^J " 250 250 ^r (b) ■ (b) " 60 60 350 ^: 350 ^: '- ^v 130 130 ■■■ -: '■ steam steam 1: 5 1: 5 -

(Continuation)

example

Properties of the stretched fibers:

Tensile strength (g / den) '

Strain (%) ..;

Thermal degradation:

Percent residual intrinsic viscosity [^] according to To squeeze

Stability against accelerated thermal aging:

Percent retained tenacity after 200 hours at 120 ⁰ C in an oven with air circulation

Stability to sunlight:

Percentage of residual tensile strength after 300 hours of actual exposure to summer sunlight until the 7th shade changes in the standard blue scale I 5.15 ι 28.5 ^:: -

68

brittle

56

example

10

11th

12th

Polypropylene

Didodecoyl thiodiglycolate

Lauryl thiodipropionate

^ '- Thiobis-o-tert-butylmethacresol

2'-Oxy-5'-tert-butylphenol-5-chlorobenzotriazole

2'-Oxy-3'-tert-butyl-5-methylphenyl-5-chloro benzotriazole

Nickel phenate of bis-p-tert-butylphenol monosulfide

Calcium stearate;

TiO ₂

Making the Mix

Spinning Conditions:

Screw temperature ^{, 0 C}

Head temperature, ° C

Spinneret temperature ^{, 0 C}

Spinneret type

Maximum pressure (kg / cm ² )

Winding speed (m / minute) ...

Stretching conditions:

Temperature, ⁰ C ...... ^r

medium

Stretch ratio

Properties of the stretched fibers:

Tensile strength (g / den)

Strain (%)

(a) = 60 / 0.8 x 16 mm.

(b) = 40 / 0.8 x 16 mm.

0.5
0.2

0.5 0.2.

0.5 0.2

0.3
0.25

Henschel mixer

steam
1: 5

5.5
25th

0.3 .0.25

Henschel. mixer

250

250 '

250

(a) 68 390

130

Steam 1: 5

5.5 23

0.5 0.3 0.25

Henschel mixer

250 250 .250

(a) ■ 390

130:; _: ; Steam ■ 1: 5

5.2 27

0.5 0.2

.0.5

Henschel -., .- mixer.

Steam; CI

27

209509/435

. (Continuation)

10

9 By S
10 play
11th 12th Thermal degradation:
Percent residual viscosity [??] after '':. ■ -.
From addresses. . . .. -.:;■ .. i. ...
78 -
'■ 15 76
18th 76
84 70 ... '..
■■ ··: ■ - ,: ·· 41.; ■ - ·. " Stability versus accelerated
thermal aging:
Percent residual tensile strength after 200 hours
the one at 12O ⁰ C in a heating cabinet
with air circulation ι 50 ^: 54 - 62 ^: ; .- ■■■ 69 Stability to sunlight:
Percent residual tensile strength after 300 hours
Exposure to actual exposure with
Summer sunlight until change of
7. Shades in the standard scale

. Example ,,

14th

15th

Polypropylene

Didodecoyl thiodiglycolate

Lauryl thiodipropionate

4,4 ^/ -Thiobis-6-tert.butylmethacresol .......

2'-Oxy-5'-tert.butylphenol-5-chlorobenzo-

triazole

2'-Oxy-3'-tert-butyl-5-methylphenyl-5-chloro

benzotriazole

Nickel phenolate of bis-p-tert-butylphenol-

monosulfide .. ^:

Calcium stearate

TiO ₂

Making the Mix

Spinneret Conditions:

Screw temperature, ° C v: ·! '..

Head temperature, ⁰ C; ... : '. ... ... ': ■

Spinridüsentemperätur, ⁰ C ^.......::.: '.

Spinneret type;

Maximum pressure (kg / cm ² ) ...... I,

Winding speed (m / minute)

Stretching conditions:

Temperature, ⁰ C ..... \ "1.

Stretch ratio .. '..'

Properties of the drawn fibers: tensile strength (g / den). y; I ......

Thermal degradation:;

Percent residual intrinsic viscosity [»;] after pressing out ~.

0.5 0.2

^j 0.5 '· ■ 0.3

0.25

Henschel mixer

250
250
250 ^:

(a)
67
390

130 "■ ::;

Steam ■ 1: 5 '"

5.8- '

22 ;; r :.

72

0.5

; q, 2

0.5 0.5 ■

: ■ o, 3

'0.25 Henschel: mixer'

250 250 250 (a)

, 75 ,. -390 I.

130 '' steam

: 5.3 21 ...

0.5 0.2.

0.5

'"- ■ 0.5

0.3

■ '- ■■ "- 0.25'

Henschel

mixer

250 250 250 (a)

67,. ·;

390 '

,. ' 'Steam.'.

(a) = 60 / 0.8 x 16 mm.

(b) = 40 / 0.8 x 16 mm.

0.5 0.2

^r 0.5 0.3 0.25

Henschel mixer

250

250

250

; V,; i3ö; .- ■.

,Steam

i'.l'Ti Ot ■ '' · ".. '■:' '■; ■

(Continuation)

12th

example

13th

15th

Stability versus accelerated
thermal aging:

Percent retained tenacity after 200 hours at 120 ⁰ C in an oven with air circulation

Stability to sunlight:

Percent residual tensile strength after 300 hours of actual exposure to exposure Summer sunlight until the 7th shade changes in the standard scale

82

60

93

Claims (1)

Claim: Use of mixtures of a) aliphatic thioesters, b) polyhydric phenols, which may contain sulfur, c) nickel phenolates of alkylphenol monosulfides, d) Oxybenzotriazoles and e) metallic soaps to stabilize polyolefins, mixtures of polyolefins and basic nitrogen condensates as well as by melt spinning polyolefins or mixtures of polyolefins and basic nitrogen condensates produced fibers against the effects of heat and light as well against aging. '