AU630179B2

AU630179B2 - Polyolefins suitable for spinning and thermoweldable fibers obtained from them

Info

Publication number: AU630179B2
Application number: AU52952/90A
Authority: AU
Inventors: Millo Branchesi; Luciano Clementini; Leonardo Spagnoli
Original assignee: Himont Inc
Current assignee: Basell North America Inc
Priority date: 1989-04-06
Filing date: 1990-04-05
Publication date: 1992-10-22
Anticipated expiration: 2010-04-05
Also published as: AU5295490A; AU5295290A

Description

cct~1 4 c.4 ~Ij p r f i COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION FOR OFFICE USE Form Short Title: Int. Cl: Application Number: Lodged: o Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: 0~ 9 0 0 0 G 0 00 00 0 40 o TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: HIMONT INCORPORATED 2801 Centerville Road, New Castle County, DELAWARE, U.S.A.

Millo Branchesi; Luciano Clementini and Leonardo Spagnoli GRIFFITH HACK CO 71 YORK STREET SYDNEY NSW 2000 Complete Specification for the invention entitled: POLYOLEFINS SUITABLE FOR SPINNING AND THRMOWELDABLE FIBERS OBTAINED FROM THEM The following statement is a fill description of this invention, including the best method of performing it known to us:- 18765-S:PJW:RK 7111A:rk J0 4L

DESCRIPTION

no 0 o 0 0 0 C O 0 0 0 0 0 00 0 O6s The present invention concerns polyolefins containing one or more organic phospites and/or phosphonites, and/or HALS (Hindered Amine Light Stabilizer), and optionally small quantities of one or more phenolic antioxldants, and thermoweldable fibers of the above mentioned resins that can be obtained through extrusion.

Within the definition of fibers are included also the manufactured products similar to fibers, such as fibrils, monofilaments, and raffia.

Polyolefin fibers are used widely in manufacturing thermally welded products, in particular of nonwoven textiles, through various technologies, the most important of which, like calendering and spun bonding, require that the fibers have the capability of thermowelding at temperatures lower than the melting point of the polyolefins which cosntitute them.

Moreover said fibers and manufactured articles obtained from them must be resistant to aging, yellowing, and to the color variations induced by gas fading and oxidizing (HM 3904 EST) -2-

I

phenomena in general.

Fibers obtained from polyolefins containing the most commonly used stabilizers, such as phenolic stabilizers, have littl welding capability when they are submitted to a thermomechanic treatment carried out at a temperature lower than the melting point'of the polyolefins.

Therefore, the mechanical properties of nonwoven textiles obtained by calendering the above mentioned fibers are poor.

SIn order to increase substantially the strenght of thermowelding among the fibers, it has been suggested that bicomponent olefin fibers, constituted by two polyolefins, such as polypropylene and polyethylene, are used, and the one with the lowest melting temperature is the one covering the surface of the fiber.

The results obtained this way are usually poor because of incompability phenomena between polyolefins of a different SO chemical nature.

Italian patent application n. 22783 A/82 shows that the thermoweldability of polyolefins fibers can be improved by S adding to the polyolefins of a 3,3',4,4'-benzophenone tetracarboxylic acid di-anhydride or one of its alkyl (HM 3904 EST) -3q 4 derivative.

However, fibers obtained this way have a reduced resistance to yellowing and aging.

Unexpectedly, the Applicant found that polyolefin fibers with high thermoweldability, resistant to aging, yellowing, and colour variations due to "gas fading" and oxidizing processes, can be obtained by starting with olefin crystalline polymers in the form of granules or nonextruded particles having a regular geometric form such as flakes or spheroidal particles, containing one or more of the following stabilizers: a) from 0.01 to preferably from 0.05 to 0.15% by weight of one or more organic phosphites and/or phosphonites; b) from 0.005 to preferably from 0.01 to 0.025% by weight of one or more HALS; and optionally one or more phenolic anti-oxidants in a concentration not exceeding 0.02% by weight.

The stabilizers are incorporated during the extrusion and granulation phase of the particles, or the nonextruded particles are coated or impregnated with the stabilizers at least on the surface, preferably after the polymerization ~ro r 'i 1R7ABS stage.

The coating or impregnation of the nonextruded particles, particularly the spheroidal particles having diameters preferably between 0.5 and 4.5 mm, can be done in a variety of ways, such as, for example, the treatment with solution or suspension of the stabilizers and an optional subsequent evaporation of the solvent or suspension medium.

Alternately, in the processes for extrusion spinning described below, the particles of polymer mixed with the o above-mentioned stabilizers can be introduced directly into the extruder.

o eo o o 0 In general the additivated polyolefins used to prepare the fibers according to the present invention have a melt flow index, determined accoridng to ASTM D 1238-L regulation, between 0.5 and 100 g/10 minutes, more preferably between aid 35 g/10 minutes, obtained directly in polymerization or through controlled radical degradation.

In order to obtain the controlled radical degradation, 060 0 organic peroxides are added during the granulation phasee or directly in the fibers' extrusion phase.

The organic phosphites that can be used as additives for polyolefins according to the present invention are preferably (HM 3904 EST) selected among compounds with the following general formulas:

OR

1 I P__OR2

OR

3 where R 1

R

2

R

3 equal or different, are alkyl, aryl, or arylalkyl radicals having 1-18 carbon atoms: i 0 0 0 0 III.&III 0 -P o where R 1 and R 2 equal or different, are radicals having the above-mentioned meaning; S,*ivaQ is a tetravalent alkyl radical;

R

1 O OR 3 III P- O X -O -P

OR

4 where R 1

R

2

R

3

R

4 equal or different, are radicals having the significance already indicated for radicals R, X is a bivalent alkyl, aryl, or arylalkyl radical.

Examples or organic phosphites comprised in the general Sformula I are described in US Patents No. 4,187,212 and No.

(HM 3904 EST) -6- 4,290,941, which are incorporated herein for reference.

Specific examples of compounds included in general formulas I, II, III are: tris(2,4-di-ter-butylphenyl)phosphite sold by CIBA GEIGY under the Irgafos 168 trademark; distearyl pentaerythritol diphosphite sold by BORG-WARNER CHEMICAL under the Weston 618 trademark; 4,4'-butylidenebis(3-methyl-6-ter-butylphenil-dio tridecyl)phosphite sold by ADEKA ARGUS CHEMICAL under the S Mark P trademark; tris(monononyl-phenyl)phosphite; bis(2,4di-ter-butyl)pentaerythritol diphosphite, sold by BORG-WARNER CHEMICAL under the Ultranox 626 trademark.

The organic phosphonites that can be used as additives according to the present invention are preferably selected io 0 among the compounds of general formula: I f-0 B- R 1 IV R 3

-P

*O--R

2 where R 1

R

2

R

3 equal or different, are alkyl, aryl, or 9 0 e arylalkyl radicals having 1-18 carbon atoms.

Alternatively, and this is preferred, the R 3 radical can be substituted by a group (HM 3904 EST) -7- R4 0 V 0 where R4 and R5, equal or different, are radicals having the above indicated significance for the R radicals, and X is a o o bivalent alkyl, aryl, or arylalkyl radical.

Examples of organic phosphonites included in general 0 formula IV, which can conveniently be used accorAing to the present invention, are described in GB patent Nc 1,372,528 0 0 a which is incorporated herein for refernce.

A preferrred example of compounds comprised in general formula IV is the tetrakis(2,4-di-ter-butylphenyl)4,4'diphenylenediphosphonite, sold by Sandoz under the Sandostab P-EPQ trademark.

o The organic phosphites and phosphonites are generally used to inhibit degradation and oxidation of polyolefins in the molten state (process stabilizers), and therefore, according to known state of the art, require the addition of high quantities of phenolic stabilizers to obtain a complete stabilization.

(HM 3904 EST) -8- The HALS, which according to the present invention are also used as polyolefins stabilizers, are amine compounds with steric hindrance of the aminic function, which are generally used as stabilizers for polyolefins in the solid state against oxidation induced by light.

In'this case as well, according to known state of the art, the addition of a high quantity of phenolic stabilizers Sis necessary for a satisfactory stabilization of polyolefin manufactured articles.

The HALS used according to the present invention are Smonomeric or oligomeric compounds containing, in the S0 0 molecule, one or more substituted piperidine groups having the following general formula: i oo i R3

R

3 S: VI R P I R 2 where the R 1 radicals, equal or different,-are C 1

-C

4 alkyl (HM 3904 EST) -9-

S'

radicals, or tetramethylpiperidine radicals, or the alkyl radicals form with the piperidine carbon atoms to which they are linked a C 5

-C

9 cycloalkyl radical; the R 2 radicals, equal or different, are hydrogen or C 1 -C18 alkyl radicals, C 7 -C18 arylalkyl radicals, or the alkyl radical form with the piperidine carbon atoms to which they are linked a C5-C10 cycloalkyl radical; the R 3 radicals, equal or different, are aoO o hydrogen, or C 1

-C

18 alkyl radicals or C 7

-C

18 arylalkyl radicals; the R 4 radical is hydrogen, or a C 1

-C

8 alkyl S radical, or a benzyl radical; Z is hydrogen, or a C 1 -C18 o 0 S alkyl, C 1

-C

12 alkylene, C 3

-C

12 alkenyl, C 3

-C

5 alkynyl, C 7

-C

18 o0 arylalkyl, C 2

-C

4 acyl, C 2

-C

18 alkanoyl, C 3

-C

1 8 alkoxyalkyl,

C

3

-C

18 alkenoyl, oxylic, cyanomethyl, xylylenyl radical, or a radical having a 1 to 4 valence and containing from 1 to 4 hydroxyl groups and, optionally, ether, ester, or >0 heterocyclic groups, being the valences of said radical linked to the nitrogen of piperidine groups, or a bivalent radical containing one or more ester or amide groups, or a N (R5) (R 6 radical where R and R 6 are hydrocarbon radicals.

Preferably Z is a C 1 -C1 2 alkyl radical, or a C3-Cg (HM 3904 EST) o ta i an aa 04 0r 00 0 8 oI( a alkenyl, C 7 -Cll aralkyl radical, or a bivalent radical containing one or more ester groups, being the valences of said radicals linked to the nitrogen atom of piperidine groups.

Specific examples of preferred HALS according to the present invention 'are compounds having the following formula:

N

-N N NH I

I

VII

HH

-n where n generally varies from 2 to 20. A compound of this type is sold by CIBA-GEIGY with the Chimassorb 944 trademark.

VIII RP-NH CH N 6 ^.NCH^ 1 K- 3 2.

(HM 3904 EST) -11sold by CIBA-GEIGY under the Chimassorb 905 trademark, where R is: [4 3C CH4 1 9t 0 0 0 0 0 0 004 0 00 CH-0Y I-I H sold by CIBA-GEIGY under the Tinuvin 770 trademark.

A

(HM 3904 EST) -2 -12xCH 3

CH

3 CH3 CH 3 'H H CH-N0 0 0 N-CH 0-C-(CH.,)B-CO

CH

3

CH

3 OH 2

CH,

sold by CIBA-GEIGY under the Tinuvin 292 trademark a aoK~~~OCH 2 -CH2N OCo~~~c Tinuvin 622 trademark.

*i 0 0 H (HM 3904 EST) -3 -13-

-I

sold by CIBA-GEIGY under the Tinuvin 144 trademark.

FN-4CHI4 -NCH 2 -CH2

H

n.

XIII

where n generally varies from 2 to A compound of this type is sold by CIBA-GEIGY under the Spinuvex A36 trademark.

9 4 9 000 0 (HM 3904 EST)

I

-I

N N-(CHa+N-

NO

H H 0I

XIV

o a a 0.0 a 000 0 where n generally varies from 2 to A compound of this type is sold by AM.CYANAMIDE under the Cyasorb UV 3346 trademark.

As previously said, in addition to the above-mentioned additives, optionally, one or more phenolic antioxidants (sterically hindered phenols) can be used in concentration not higher than 0.02% by weight.

Examples of preferred phenolic antioxidants are: tris(4t-butyl-3-hydroxy-2, 6-dimethylbenzyl) -s-triazine-2, 4,6- (1K, 3H, 5H)trione, sold by CYANAMID under the Cyanox 1790 trademark; calcium bi [ionoethyl 5-di-ter-butyl-4hydroxybenzyl)phosphonate]; 1,3, 5-tris 5-di-ter-butyl-4hydroxybenzyl)-s-triazine-2,4,6(1H,3H,SH) trione; 1,3,5trimethyl-2 6-tris 5-di-ter-butyl-4hydroxybenzyl) benzene; pentaerythritil-tetrakis (KM 3904 EST) i i c- I butyl-4-hydroxyphenyl)propionate], sold by CIBA-GEIGY under the following trademarks: Irganox 1425, Irganox 3114; Irganox 1330; Irganox 1010; 2,6-dimethyl-3-hydroxy-4-ter-butyl benzyl abietate.

The additives commonly used to stabilize polyolefins, particularly Ca, Mg, Zn sterates, can also be used in the preparation of the fibers according to the invention.

The polyolefins which can be used in the present invention include crystalline polymers or copolymers, or their mixtures, of olefins of the R-CH=CH 2 formula where R is a hydrogen atom or a C 1

-C

6 alkyl radical.

Particularly used are: 1) isot'actic or prevailingly isotactic polypropylene; 2) HDPE, LLDPE, LDPE polyethylene; 3) crystalline copolymers of propylene with ethylene and/or other alpha-olefins, such as for instance 1-butene, 1hexene, 1-octene, 4-methyl-l-pentene, where the total comonomer content varies from 0.05% to 20% by weight; 4) heterophasic polymers constituted by a homopolymer fraction of propylene or one of the copolymers mentioned in item and a copolymer fraction made up by ethylene-propylene or ethylene-propylene-diene rubber

I.

(HM 3904 EST) -16i- .1i ft copolymers. Said heterophasic polymers being prepared according to known methods via mixing in the melted state of the above-mentioned components, or seque-.ial copolymerization, and containing the copolymer fraction in quantities from 5% to 80% by weight, and the polypropylene fraction in quantities from 20% to 80% by weight; 5) syndiotactic polypropylene and its random or heterophasic copolymers as described in items and Preferably used are isotactic or prevailingly isotactic polypropylene, and propylene-ethylene crystalline copolymers with a prevalent propylene content.

In order to obtain thermoweldable polyolefin fibers according to the present invention, any spinning process and apparatus for melt extrusion known in the field may be used.

The present invention comprises, therefore, also the S. thermoweldable polyolefin fibers containing the stabilizers in the above-mentioned quantities.

For the preparation of the fibers it's preferable to use extruders with spinners' holes having a length/diameter ratio greater than 2.

(HM 3904 EST) -17- The operation can occur at a spinner's temperature between 260 0 C and 300 0 C, and at a spinning velocity between 0.1 and 0.8 g/min hole.

During the spinning it's possible to introduce in the fibers other additives such as pigments, opacizers, fillers, etc.

The fibers obtained by extrusion are eventually submitted to stretching with stretching ratios generally 0 0 between 1:1.1 and 1:8 and at temperatures between 80 0 C and 150°C, preferably between 1000 and 130 0 C, using 'stretching apparatus heated, with hot air, vapor, or heating plates.

The melt flow index of the fibers obtained In this manner is usually higher with respect to the values of the original polyolefins because of the spinning treatment.

Indicatively, one can obtain melt flow index values for the fibers between 4 and 150 g/10 minutes.

The fibers obtained with the above-mentioned methods can be mono- or multifilament, and may be used for the MI preparation of staples or thermally cohered products, especially of nonwoven textiles.

Optionally, before the transformation to finished (HM 3904 EST) -18manufactured articles, the fibers can be submitted to refinishing treatments such as crimp, thermofixing, etc.

As previously stated, the nonwoven textiles may be prepared with a variety of known technologies, such as the calendering of staple fibers and the spun bonding, operating preferably at a temperature of 10-20 0 C lower than the melt temperature of the polyolefins constituting the fiLers.

Said products have high mechanical properties, thanks to 000 0 the mechanical resistance of the thermowelding that can be o; obtained with the fibers of the present invention.

a 0* 0 The above-mentioned fibers, in fact, are characterized by a high thermowelding strength, determined according to the method described in the examples. Preferably this parameter 0 a varies from 2 to 5 N.

S ee 0 Moreover, the manufactured articles derived from the fibers of the present invention show satisfactory resistance to aging and color changes.

0 *0 Following are some examples which are given to illustrate but not to limit the invention.

EXAMPLES

-ij I. EVALUATION OF THE PROPERTIES OF THE FIBERS PREPARED IN THE

EXAMPLES

(HM 3904 EST) -19- THERMOWELDING STRENGHT Usually, in order to evaluate the thermowelding ability of the fibers it is customary to produce a nonwoven via calendering under special conditions, and measure the stress necessary to tear said nonwoven in a direction transversal to the calendering one, operating according to ASTM 1682 regulation.

oo The stress value determined in this manner is considered 0 0 a measure of the ability of the fiber to thermoweld.

o* The result obtained, however, is influenced 0o. substantially by the finishing characteristics of the fibers (crim, finish, thermofixing, etc.) and the condition of preparation of the card veil fed to the calender.

In order to prevent these inconveniences and obtain a o o more direct evaluation of the thermowelding characteristics of the fibers, a method has been devised which will be schematically described below.

Some samples are prepared starting with a rove of 400 tex (ASTM D 1577-7 regulation) and 0.4 m long, made up of continuous fibers.

After having twisted said rove eighty times, the two extremities are joined, obtaining a manufactured article (HM 3904 EST) where the two halves of the rove are twisted around each other as in a rope.

The two twisted roves are thermowelded at a temperature of about 15 0 C lower than the melting point of the polyolefin which makes up the fibers, operating for a predetermined period of time with a thermowelder of the type commonly used in laboratories for the study of thermoplastic films.

0 o The average force required to detach the two roves of 0 0 each sample at the thermowelded point is measured with a

-C

O dynamometer.

So The result, expressed in N, is obtained by averaging out at least 8 measurements, and it expresses the thermowelding strength among fibers.

In the following examples a Sentinel model 12-12 AS oo thermowelder was used, operating with thermowelding periods of 1 second and a thermowelding pressure of about 2.85 Kg/cm 2 COLOR CHANGES The IXSO/TC38/SC1 norm was used at 60oC and at 130 0 C to measure the resistance of fibers to colorations induced by gas fading, while the resistance to colorations induced by oxidation phenomena was measured by keeping the fibers in an (HM 3904 EST) -21oven at 90 0 C for 2 days, and the coloration was evaluated based on the gray scale, as described in the above-mentioned norm.

RESISTANCE TO ARTIFICIAL AGING The above-mentioned property was evaluated by submitting the fibers to accelerated aging in a ventilated oven at ll 0 C, according to ASTM D 3045-74 regulation.

The time (in days) necessary to reach total decay of the mechanical properties (embrittlement) was determined.

EXAMPLES 1-14 AND COMP.ARATIVE EXAMPLES 1-8 We prepared 5 Kg. samples made up of polypropylene in flake form at controlled granulometry (average diameter of particles 450p m) with the following characteristics: residue insoluble in boiling heptane 96% number average molecular weight 65,700 weight average molecular weight 320,000 melt flow index 12.2 g/10 min ashes at 800 0 C 160 ppm and additivated with calcium stearate at a concentration of 0.05% by weight.

To each sample were added the stabilizers listed in Table 1, through a Henschell type speed mixer for powders.

o aa o 0 00 S oo a o- Soo es ,0 oa o o o on oo a so 9 0c 0 0 (HM 3904 EST) -22- The mixture 1 thus obtained have been granulated by extrusion at 220 0 C, and the granules have been spun in a system with the following main characteristics: extruder with 25 mm diameter screw and length/diameter ratio 25, and a capacity from 1.0 to 6.0 Kg/h; spinner with 19 holes with a diameter of 0.4 mm and length/diameter ratio metering pump; quenching system with air at a temperature of 18-20 0

C;

S gathering device with a speed of 500 to 2000 m/min.; fiber stretching device with hot roller at speed varying from 30 to 300 m/min, and steam stretch oven.

The conditions used for spinning and stretching were: a) temperature of spinner 290 0

C;

0C40 b) hole capacity 0.45 g/min.; S c) gathering speed 1500 m/min; d) stretch ratio 1:1.5.

S The main mechanical characteristics of the fibers thus obtained are included in the following ranges: title (ASTM D 1577-79 regulation) 1.9 2.2 dtex strenght (ASTM D 2101-82 regulation) 15-20 cN/tex elongation to break (ASTM D 2101-82 regulation) 300- (HM 3904 EST) -23- 400%.

In table 1 are shown for all the examples the thermowelding strength (thermowelding temperature 1500C), the accelerated aging resistance values (in days), and the color changes compared to the gray scale.

In particular, for the color changes, the first result reported in Table 1 is relative to the change induced by gas fading at 60 0 C after 4 cycles, the second result is relative to the change induced by gas fading at 130 0 C after o minutes, the third to the coloration induced by. oxidizing S 00 Soo phenomena, determined as described above.

EXAMPLES 15-17 and COMPARATIVE EXAMPLE 9 Kg. samples have been prepared, made up of polypropylene in the form of spheroidal particles with ag a0 diameter between 2 and 3 mm and having the following 0401 6 characteristics: insoluble in xylene at 25 0 C 96.5% ,o number average molecular weight 64,000 weight average molecular weight 325,000 melt flow index 11.8 g/10 min.

ashes at 800 0 C 150 ppm The above-mentioned samples have been surface (HM 3904 EST) -24additivated with the stabilizers shown in Table 2.

The additivation was done by treatment with aqueous suspensions and subsequent drying. The polymer particles have then been further additivated with calcium stearate in weight concentration of 0.05%.

The polymer thus obtained was spun according to methods described in preceding examples.

SThe mechanical properties of the fibers were within the o a ranges described in the preceding examples.

In Table 2 are shown, for all examples, the So thermowelding strength (thermowelding temperature 1500C), the accelerated aging resistance values in days, and color changes, determined as per the preceding examples.

EXAMPLE 18 5 Kg of random crystalline propylene/ethylene copolymer containing 2.3% by weight of ethylene, are additivated with: 0.05% by weight calcium stearate; s" 0.05% by weight of Sandostab

P-EPQ;

0.01% by weight of Chimassorb 944; and then they are granulated by extrusion.

The methods employed are the same as described in exmples 1-14.

(HM 3904 EST) The granules are then spun with the same technologies described in example 1-14.

The mechanical properties of the fibers thus obtained were within the ranges described in examples above-mentioned.

The thermowelding strength (thermowelding temperature 140 0 C) was 3.8 N.

The time of resistance to accelerated aging and the color changes, measured as described above, were respectively 6 and 5 days; 5; EXAMPLES 19-23 O. Operating in the same conditions and same propylene homopolymer of examples 1-14, we prepared samples in the form So of extruded granules containing the following additives (percentage by weight): 0.05% calcium stearate 0.015% Chimassorb 944 0.04% Irgafos 168 0.01% Irganox 1076.

The granules were spun with the same methods of examples 0 o0 1-14 using the gathering speed and the stretching ratios indi cated in Table 3 for each example.

In the same table are also shown the title, strength, (HM 3904 EST) -26and elongation at break values of the fibers obtained, as well as the thermowelding strength (thermowelding temperature 150 0 resistance to aging and color change values, determined as per the preceding examples.

0 00 000 o o 000 6 0000 0 0 a Oo 0 00 080 0 .0 (HM 3904 EST) -27- 0s 0 oo e o 0 0 o 000 ooo o Table 1 Additives by weight Thermowelding Accelerated Colour strength aging change N days Weston 618 Sandostab P-EPQ Irgofos 168 Chimassorb 944 Chimassorb 944 Tinuvin 622 Tinuvin 770 Tinuvin 144 Tinuvin 144 Chimassorb 905 Sandostab P-EPQ Chimassorb 944 I Xrgafos 168 Chimassorb 944 Irgafos 168 Chimassorb 944 Tinuvin 622 Irgafos 168 0,05% 0,05% 0,05% 0,02% 0,05% 0,02% 0.02% 0.02% 0.05% 0,02% 0,05% 0,02% 0.05% 0.02% 0.05% 0.05% 0.02% 0.05% 2.5 2.8 3.0 3,0 3.0 3.0 3.0 3.0 3,0 3.5 4.0 4.2 4.0 5,0 6,0 6.0 10 5; 5; 5; 5; 5; 5; 5; 5; 5; 5; I i. r 1 S a a G a v 0 a a a a a a *00 aj a 0 0 a 00 0 Ova a 0 aoo a a a 0 0 a a a a a a 00 0 C vs a 0 a a a a 0 a a 0 000 00 4 you continued: Table 1 Example Additives -by weight Thermowelding Accelerated Colour.

astrength aging change N dayii.

14 (jSandostab PEPQ 0.05%3.605;;5 (Tinuvin 144 0.02%35605;;5 omparati v Example, No.

1 Irganox 1010 0.05% 1,2 2.0 2; 2; 2 2 Irganox 1425 0.05% 1.4 4.0 3; 3; 3 3 Irganox 3114 0,05% 1,5 2,0 4; 3;-3 4 Cyanox 1790 o. 05% 1.5 3.0 4; 3; 2 Irganox 1010 0,05% 1.0 2.0 2; 2; 2 Irgafos 168 0.05% 6 (Irganox 1010 0.05% Chimassorb 944 0.05% 1'0 10 2; 2; 2 7 Tinuvin 622 0.8% 1,8 15 4; 4; 4 8 (Tinuvin 622 0.8% 252 ;4 Sandostab P-EPQ 0.7% 252 ;4 0.

a 0 0 0 0 a 0 a a 4 0 t 0 000 00 0 0 a a a a 000 0 000 a a a a 00 a a 0 00 0 0 0 00 a a 0 0 a a a a 0 a 000 00 a baa Table 2 [Example Additives by weight Thermowelding -Accelerated Colour No. strength :aging change I days (Chimassorb 9414 0.02% .65;;5 Irgafos 168 0.05%4065; 16 Sandostab P-EPQ 0.05% 3.0 2 5; 5; 17 (Tinuvin 144 0.02%3.6 (Irgafos 168 0.05% 3 omparativi Example No.

9 Irganox 1010 0.05% 142 2 2; 2; 2 o 0 O 0 a 0 a 0 0 0 0 0 000 0 0 000 0 a c. 0 0 3 0 0 0 00 0 0 0 00 S 0 0 0 0 0 a 0 000 00 0 000 Table 3 Example No.

Ga thern g speed Stretching ratio -Ti tle d tex mmin. S' 2000 1500 1000 800 600 1.25 1.7 2.5 3.1 4.1 1.9 2.1 2.0 1.95 2.2 Strength.

15 18 24 27 32 Elongation at break 400 350 280 200 100 3.2 3.1 3.3 3.1 3.0 5; 5, 5; 5; 5; Thjermoweldi ng s treng th

N

Accelerated aging days Colour change I I I_

Claims

1. Crystalline polymers of olefins in the form of granules or nonextruded particles having a regular geometric form, containing one or more of the following stabilizers: a) from 0.01 to 0.5% by weight of one or more organic phosphites and/or phosphonites; b) from 0.005 to 0.5% .y weight of one or more HALS; and optionally one or more phenolic antioxidants in Sconcentration not greater than 0.02% by weight. Polymers of olefins as per claim 1, in the form of spheroidal particles having a diameter from 0.5 to 0 4 mm.

3. Polymers of olefins as per claim 1, constituted of homopolymers or copolymers, or their mixtures, of olefins of the formula R-CH=CH 2 where R is a hydrogen atom or a C 1 -C 6 alkyl radical.

4. Polymers of olefins as per claim 3, selected among with isotactic, or prevailingly isotactic polypropylene, and propylene-ethylene crystalline copolymers containing prevalently propylene. Polymers of olefins as per claim 1, where the (HM 3904 EST) -32- r SI stabilizers content varies from 0.05 to 0.15% by weight, and the stabilizers content varies from 0.01 to 0,025% by weight.

6. Polymers of olefins as per claim 1, where the organic phosphite or phosphites are selected among compounds having the general formulas: R1 I P--OR2 00 0 OR3 where R 1 R 2 R 3 equal or different, are alkyl, aryl, Sor arylalkyl radicals with 1 to 18 carbon atoms: S o o 0 0 0 the above-mentioned meaning; Q is a tetravalent alkyl radical; o R 1 0 OR 3 III R P X--0 -P R 2 0 OR 4 where R 1 R 2 R 3 R, equal or different, are radicals (HM 3904 EST) -33- with the meaning indicated for the R radicals, X is an alkyl, aryl, or arylalkyl bivalent radical.

7. Polymers of olefins as per claims 6, where the organic phosphite or phosphites are selected among tris(2,4 di- ter-butylphenyl)phosphite; distearyl pentaerytritol diphosphite; 4,4'-butylidene-bis(3-methyl-6-ter- butylphenyl-di-tridecyl)phosphite; tris(mononyl- phenyl)phosphite; bis(2,4-di-ter-butyl)pentaerythritol diphospite. 0 f0 S0 8. Polymers of olefins as per claim 1, where the organic phosphonite or phosphonites are selected among compounds 0 o00 of the general formula: i R 1 IV R 3 -P O-R 2 S' where R 1 R 2 R 3 equal or- different, are alkyl, aryl, or arylalkyl radicals with 1 to 18 carbon atoms, or the R 2 radical is substituted by a group *i (HM 3904 EST) -34- R4 O 0o R where R 4 and R 5 equal or different, are radicals with the meaning above indicated for the R radicals, and X is an alkyl, aryl, or arylalkyl bivalent radical.

9. Polymers of olefins as per claim 8, where tetrakis[2,4- Se. di-ter-butylphenyl]4,4'-diphenyl phosphonite is used as S° the organic phosphonite. o a

10. Polymers of olefins as per claim 1 where the HALS are selected among monomer or oligomer compounds which containing in the molecule one or more substituted piperidine groups having the following general formula: 1 R 1 3 3 VI 3 Z z (HIM 3904 EST) f C (R 5 (R 6 radical where R 5 and R 6 are hydrocarbon radicals.

11. Polymers of olefins as per claim 10 where the IiALS is or are selected among the compounds with the formulas: to"' 000 0 a0 VII o 0 0000 0 00 0004 $040 where n varies from 2 to Vill P, R-7PIH- C4 'a NCHIZ .fpliz4-p 0 00 000 0 (HM 3904 EST) -7 -37- where R is: 00 0 0 00 o 00 0000 00 0 0 00 0 tO 000 0 0 0 11 11 f j II C- C1 C-0 o 00 0 0 00 (HM 3904 EST) -8 -38- L 0 0 -O-Cfl 2 -CH 2 -N clz li c -n a. 0 a 0 o ~o 000 0 00.0 00 0 00 0 0 00 000 0 where n varies from 2 to XII 0 0 0000 no 0 a 8 40 400 0 12 n XIII (HM 3904 EST) where n varies from 2 to 0 n where n varies from 2 to

12. Polymers of olefins as per claim 1 where the phenolic *0 antioxidant or antioxidants are selected among tris(4-t- butyl-3-hydroxy-2, 6-dimethylbenzyl) -s-triazine-2 ,4 ,6 calcium bi[monoethyl(3 4-hydroxybenzyl)phosphonate]; 1,3, 5-tris (3 butyl-4 -hydroxybenzyl) -s-triJaz ine-2, 4, 6- (1H,3H,5H)trione; l,3,5-trimethyl--2,4,6-tris(3,5-di-ter- butyl-4-hydroxybenzyl) benzene; pentaerythritil- I tetrakis[3- (3 ,5-di-ter-butyl-4- hydroxyphenyl)propionate]; 2, 6-dimethyl-3-hydroxy-4-ter- butyl benzyl. abietate. (HM 3904 EST) -0

13. Polymers of olefins as claimed in claim 1 substantially as herein described w~ith reference to the non-comoarative examholes.

14. Thermoweldable oolyoleffin -fibers com-orising the Dol%\-ers o: olefins as per claims 1 to 13. T-her-moweldable poiyc.lein fibers as per claim 14 having a thermoweldable str-engtL-h from 2 to 4.5 N.

16. Thermally welded manufactured articles obt ained from 0thermoweldable prolvolef in fibers as per claims 14an

17. Nonwoven tLextiles obtained by calendering or spoun bonding the fibers claimed in claims 14 and Dated this 4th day of April 1990 S HIMONT INCORPORATED By their Patent Attorney GRIFFITH HACX CO. (HMl 3904 EST) -1 -41-