MXPA98003375A - Composition of polymers of olefins that produce smoke, and fiber and film prepared as a whole - Google Patents

Abstract

The present invention relates to a polymer composition and to the fiber, film or sheet prepared therefrom, which contains (i) an olefin polymer containing a non-acidic neutralizing agent different from a metal salt of a saturated or unsaturated fatty acid, and ii) a stabilizer system distributed throughout the polymer, the stabilizer system includes: (a) a phosphite selected from [triethyl-tris (3,3 ', 5,5'-tetra-tert-butyl-1,1-biphen-2-yl) , 2'-diii) phosphite] of 2,2 ', 2"-nitrile and tris (2,4-ditert-butylphenyl) phosphite, and (b) an N, N-dialkylhydroxylamine. a polyolefin fiber, film or sheet, which includes adding the aforementioned stabilizer to an olefin polymer containing a non-acidic neutralizing agent different from a metal salt of a saturated or unsaturated fatty acid, thereby producing a stabilized olefin polymer, and extruding the olefin polymer stabilized through a boquil

Description

COMPOSITION OF OLEFIN POLYMERS THAT PRODUCE LITTLE SMOKE, AND FIBER AND MOVIE PREPARED FROM THIS Olefin polymers, especially polypropylene, which are usually spun into fibers, are prepared as a film or sheet by extruding the molten polymer through nozzle orifices such as a spinneret, film nozzles or sheets, by extinguishing the molten filament, the film or the sheet, orienting the filament, the fiber [sic] or the sheet, and stiffening the filament, the oriented film or sheet before winding them in a coil. A problem associated with the polyolefins produced using the Ziegler-Natta type catalysts is the production of "smoke" visible through the extrusion of the polyolefin melt during spinning and extrusion operations of the film. The "smoke" is released in the nozzle, and is believed to contain volatile organic compounds in the range of 20-50 carbon atoms. These volatile organic compounds released later are condensed and cover the equipment with problems resulting from non-uniformity of the non-woven fabrics that are formed from these fibers or from films due to the deposits in the nozzle caused by the volatile organic compounds.

D Efforts to reduce or eliminate smoke have been partially satisfactory at best. The reduction of the melting temperature and the residence time in the extruder below certain limits can create processing problems. The devolatilization of the polymer feedstock by heating before extrusion can reduce the smoke production by approximately 20%. On the contrary, the present invention can reduce the smoke up to 90% or more. It is known to incorporate various additives into the olefin polymer materials to improve thermal stability, resistance to UV radiation and processability. For example, the inclusion of an acid neutralizing agent in the olefin polymer compositions is necessary due to the small amounts of catalyst residues contained within the olefin polymer. These catalyst residues can cause corrosion of processing equipment such as mold surfaces and nozzle flanges. The addition of a suitable acid neutralizing agent can eliminate or at least reduce the corrosion potential due to these residues. However, the selection of the neutralizing acid agent is important because it can affect the overall acidity / basicity of a polymer composition.

D olefin and influence the reactions of many of the organic additives in the polymer composition. In addition, the release properties of the polyolefin can be affected by the acid neutralizing agent. In practice, metal stearates such as sodium, calcium and zinc are commonly added to olefin polymer materials as an acid neutralizing agent, with calcium stearate being the most common. Although other acid neutralizing agents are known, calcium stearate is predominantly used due to the fact that it functions as an external lubricant and processing aid, in addition to acting as an acid neutralizing agent. The phosphite compounds, including [triethyl-tris- (3,3 ', 5,5'-tetra-tert-butyl-l, l-biphenyl-2,2, -diyl) phosphite] 2,2', 2"-Nitrile is usually added to polyolefin compositions to stabilize them against thermal and oxidative degradation.The various forms of [triethyl-tris- (3, 3 ', 5, 5'-tetra-tert.butyl-1, 1, 2-biphenyl-2, 2'-diyl) phosphite] 2, 2 ', 2"-nitrile are known. For example, U.S. Patent No. 5,326,802 describes a beta crystalline modification of [triethyl-tris- (3, 3 ', 5, 5'-tetra-tert.butyl-1, 1-biphenyl-2, 2'-diyl) phosphite] of 2, 2 •, 2"-nitrile Example 6 describes the stabilization of polypropylene which also contains calcium stearate.

D No. 5,331,031 and 5,405,893 describe a crystalline range modification of [triethyl-tris- (3, 3 ', 5, 5'-tetra-tert.butyl-1, 1-biphenyl-2, 2'-diyl) phosphite] of 2 , 2? , 2"-nitrile Example 4 illustrates the stabilization of polypropylene which also contains calcium stearate.A solid amorphous modification of [trityl-tris- (3, 3 ', 5, 5'-tetra-tert.butyl-1, 2, 2 ', 2"-nitrile 1-biphenyl-2,2'-diyl) phosphite] is disclosed in U.S. Patent No. 5,276,076. Example 3 illustrates the stabilization of polypropylene which also contains calcium stearate. The use of N / N-dialkylhydroxylamines to stabilize the polyolefins is also known. Thus, U.S. Patent No. 4,668,721 discloses that hydroxylamine derivatives can be used to stabilize polyolefin compositions against degradation due to extrusion, exposure to natural gas combustion products, gamma radiation or during storage. . The hydroxylamine derivative may have a chemical structure that conforms to one of the fourteen structural formulas. In Example 21, a combination of hydroxylamine and calcium stearate is considered to be much superior to hydroxylamine alone with respect to yellowing resistance of processed polypropylene at 260 ° C. U.S. Patent No. 4,876,300 discloses that the long chain N, N-dialkylhydroxylamine compounds to they can be used as process stabilizers for polyolefin compositions in order to minimize discoloration and increase in melt flow rate due to extrusion. The International Patent Publication No. WO 94/24344 discloses a stabilized polypropylene with an effective amount of a selected hindered amine, a selected N, N-dialkylhydroxylamine and a phosphite which may be [triethyl-tris- (3, 3 ', 5, 5'-tetra-tere. 2, 2 ', 2"-nitrile butyl-1/1-biphenyl-2, 2'-diyl) phosphite] The polypropylene composition is free or almost free of any traditionally used phenolic antioxidant and is said to possess better stability in the light, better long-term thermal stability and discoloration stability by specially improved gases All the formulations described in the Examples contain calcium stearate One object of the invention is to provide an olefin polymer composition that generates a minimal amount of smoke during extrusion into a fiber, film or sheet Another objective of the invention is to offer an olefin polymer composition that produces little smoke, which is stabilized against thermal and oxidative degradation, and the fiber, film or sheet prepared from it.

D Still another object of the invention is to provide a method for reducing, up to 9 ° C, the volatile organic compounds that are generated during the production of the polyolefin fiber, film or sheet. In one aspect, the present invention relates to a polymer composition containing: (i) a define polymer containing a neutralizing acid agent other than a metal salt of a saturated or unsaturated fatty acid, and (ii) a stabilizing system distributed throughout the polymer, wherein the stabilizing agent consists of: (a) a phosphite selected from the group consisting of [triethyl-tris- (3, 3 ', 5, 5'-tetra-tert.butyl, 2,2 ', 2"- nitrile and tris (2,4-di-tert-butylphenyl) -phosphite; and (b) an N, N-dialkylhydroxylamine, a phosphite-2-biphenyl-2,2'-diyl) phosphite] benzofuranone or mixtures thereof In another aspect, the present invention relates to a method for preparing an olefin polymer fiber, film or sheet, which consists of: i) incorporating a stabilizer system in and / or an olefin polymer Containing a neutralizing acid different from calcium stearate, the stabilizer system consists of: D (a) a phosphite selected from the group consisting of [triethyl-tris- (3, 3 *, 5, 5'-tetra-tere, butyl-1, 1-biphenyl-2,2'-diyl) phosphite] of 2 , 2 ', 2"- nitrile and tris (2,4-di-tert-butylphenyl) phosphite); and (b) an N, N-dialkylhydroxylamine, a benzofuranone or mixtures thereof by thereby producing a stabilized olefin polymer; and ii) extruding the stabilized olefin polymer through a nozzle, thereby producing an olefin polymer fiber, film or sheet. The inventor has unexpectedly discovered that the smoke production during fiber, film and sheet processing can be significantly reduced by using: (1) a combination of N, N-dialkylhydroxylamine and a specific phosphite stabilizer to stabilize the melt of the olefinic polymer to a controlled rheology, and (2) an acid neutralizing agent different from the metal salt of a saturated or unsaturated fatty acid. The olefinic controlled rheology polymers are prepared by polymerizing the olefinic monomers at a relatively high weighted average molecular weight, which are then treated ("viscosity reduced") with peroxide to reduce their molecular weight to an average D wanted. Otherwise, controlled rheology polymers can be prepared using a known Ziegler-Natta catalyst system to provide the desired weight average molecular weight and using a sufficient amount of a chain transfer agent, such as hydrogen, during the polymerization to achieve the desired flow rate of the melt. The olefinic polymer is obtained by polymerizing at least one mono-α-olefin, such as ethylene, propylene, isobutylene, butene-1,3-methyl-1-butene and 4-methyl-1-pentene. The polyethylene, both the homopolymer and the copolymer, can be, for example, medium density, high density or low density linear polyethylene. The copolymers of the mono-α-olefins can also be used in the present compositions, for example ethylene / propylene copolymers, propylene / butene-1 copolymers, propylene / octene-1 copolymers, ethylene / butene-1 copolymers, ethylene / octene-1 copolymers, as well as ethylene / vinyl acetate copolymers. Heterophasic or shock modified olefinic polymers can also be used in the compositions of this invention. Suitable heterophasic olefinic polymers include: D an olefinic polymer composition consisting of: (i) about 10 parts to about 60 parts by weight of a crystalline propylene homopolymer having a higher isotactic index of 80, or a crystalline copolymer selected from the group consisting of: (a) propylene and ethylene, (b) propylene, ethylene and a C4-C8 α-olefin and (c) propylene and a C4-C8 α-olefin, the copolymer having a propylene content of more than 85% by weight and an isotactic index greater than 85; (ii) about 5 parts to about 25 parts by weight of an ethylene-propylene copolymer or a C4-C8 α-olefin which is insoluble in xylene at room temperature; and (iii) about 30 parts to about 70 parts by weight of an elastomeric copolymer selected from the group consisting of: (a) ethylene and propylene, (b) ethylene, propylene and C4-C8 olefin and (c) ethylene and an α-olefin of C4-C8I the copolymer optionally having a content of about 0.5% to about 10% by weight of a diene, and having a content of less than 70% by weight of ethylene, being soluble in xylene at room temperature and with a viscosity OR x? intrinsic from about 1.5 to about 4.0 dl / g; being the total of (ii) and (iii), based on the total composition of the olefinic polymer from about 50o to about 90%, and the weight ratio of (i) / (iii) less than 0.4, wherein the composition it is prepared by polymerization in at least two stages and has a flexural modulus of less than 150 MPa; (b) an olefin polymer consisting of: (i) about 10 to about 60% of a propylene homopolymer having an isotactic index greater than 80, or a crystalline copolymer selected from the group consisting of (a) ethylene and propylene , (b) ethylene, propylene and a C4-C8 α-olefin / y (c) ethylene and a C4-C8 α-olefin, the copolymer having a propylene content greater than 85? and an isotactic index greater than 85 &;; (ii) about 20% to about 60% of an amorphous copolymer selected from the group consisting of: (a) ethylene and propylene, (b) ethylene, propylene and a C4-C8 α-olefin, and (c) ethylene and an α-olefin of C4-C8, the copolymer optionally with a content of about 0.5% to about 10 ¿of a diene and with a content or less than 70% ethylene and being soluble in xylene at room temperature; and (iii) about 3% to about 40% of an ethylene-propylene copolymer or a C4-C-olefin, which is insoluble in xylene at room temperature; where the composition has a greater flexural modulus than 150 but less than 1200 MPa, preferably 200 to 1100 MPa, more preferably 200 to 1000 MPa; and (c) an olefin polymer composition consisting of: (i) about 30% to about 98% of a polymeric material that is selected from the group consisting of a polypropylene homopolymer having an isotactic index greater than 90, and crystalline copolymer having an isotactic index greater than 85 of propylene and at least one α-olefin of the formula CH 2 = CHR, wherein R is H or an alkyl group of C 2 -Cg, the α-olefin being less than 10% of the copolymer when R is E and less than 20% when R is a C2-Cg alkyl group or a combination thereof with R = H, and (ii) about 2% to about 70% of an elastomeric propylene copolymer and an olefin of the formula CH2 = CHR, wherein R is H or a D C2-C8 alkyl group. the α-olefin being about 45% to about 75% of the elastomeric copolymer, and about 10% to about 40% of the elastomeric copolymer being insoluble in xylene at room temperature, or an elastomeric copolymer of ethylene and an α-olefin of C4- C with an olefin content of about 15% to about 60% When used in the present, room temperature, it is approximately 25 ° C. The total amount of the polymerized ethylene in (a) is preferably about 10 to about 40% by weight. The C4-8 α-olefins useful in the preparation of (a) and (b) include, for example, butene-1; pentene-1; hexene-1; 4-methyl-l-pentene and octene-1. The diene, when present, is usually a butadiene, 1,4-hexadiene; 1, 5-hexadiene or ethylidene norbornene. The propylene polymer materials (a) and (b) can be prepared by polymerization in at least two stages, wherein, in the first stage the propylene or propylene and ethylene or an α-olefin, or propylene, ethylene and an α-olefin are polymerized to form component (i) of (a) or (b), and in the following steps the mixtures of D ethylene and propylene or the α-olefin or ethylene, propylene and the α-olefin and optionally a diene, are polymerized to form the components (ii) and (iii) of (a) and (b). The polymerization of (a) and (b) can be carried out in liquid phase, gaseous phase or liquid-gas phase using separate reactors, all of which can be done batchwise or in continuous mode. For example, it is possible to carry out the polymerization of component (i) using liquid propylene as a diluent, and the polymerization of components (ii) and (iii) in the gas phase without intermediate steps, except partial degassing of propylene. The preferred method is gas phase. The preparation of the propylene polymer material (a) is described in greater detail in U.S. Patent Nos. 5,212,246 and 5,409,992, the preparation of which are incorporated herein by reference. The preparation of the propylene polymer material (b) is described in greater detail in U.S. Patent Nos. 3,302,454 and 5,409,992, the preparation of which is incorporated herein by reference. The composition of the polymer (c) can be obtained by sequential polymerization of the monomers in the presence of Ziegler-Natta catalysts or by mechanical mixing of the components (i) and (ii). This sequence polymerization is described in greater detail in the patent D United States 5,486,419, the preparation of which is incorporated herein by reference. The sequence polymerization can also be carried out with a mixture of Ziegler-Natta and metallocene catalysts or by using a Ziegler-Natta catalyst in a reactor, preferably the first reactor, and a metallocene catalyst in the other reactor (s), preferably the reactor (s) subsequent to the first reactor. Mixtures of the homopolymers or mixtures of the olefin copolymers or mixtures of both can be used. The olefin polymer is preferably a crystalline propylene polymer, more preferably a crystalline propylene homopolymer having an isotactic index greater than 90, more preferably greater than 93, or a crystalline, random copolymer of propylene and ethylene or a olefin of C4-C1Q, with an isotactic index greater than 85.

The propylene polymer is preferably reduced in its viscosity to a melt flow rate ("VFF") of -50 g / 10 minutes, more preferably 25-38 g / 10 minutes, measured in accordance with ASTM 1238, Condition L. These propylene polymers are available commercially from Montell USA Inc. The composition of the polymer of the present invention contains an acid neutralizing agent different from the metal salt of a saturated or unsaturated fatty acid, D specifically, metal stearates and especially calcium stearate. Commonly, fatty acids have from 4 to 22 carbon atoms with a terminal carboxyl group (COOH). The common metals are those of group la and II of the Periodic Table. Acidoneutralizing compounds suitable for use in the present invention include hydrotalcites, aluminum silicate and oxides and hydroxides of Group II metals. Calcium lactate, calcium hydroxide, calcium oxide or mixtures thereof are more preferred. Hydrotalcite with a calcium stearate content is not preferred. An effective amount of the neutralizing acidic agent will be in the range of 50 to 2000 ppm of the polymer, preferably 250 to 1,000 ppm of the polymer. In the case of polypropylene, a preferred amount of the acid neutralizing agent is in the range of 200 to 300 ppm of the polymer. The process of reducing the viscosity of a propylene polymer material is well known to those skilled in the art. In general, it is carried out as follows: the propylene polymer in particulate form, for example, "as obtained from the polymerization" in flakes or granules, has spraying thereon or combined therewith a prodegradant source or generator of free radicals, for example a peroxide in liquid or powder form or absorbed D on and / or in a carrier, for example polypropylene / peroxide concentrate. The propylene polymer and peroxide or propylene / peroxide polymer concentrate is then introduced into a means for plasticizing by thermal means or melting and transporting the mixture, for example, an extruder at elevated temperature. The residence time and temperature are controlled in relation to the specific peroxide selected (ie, based on the half-life of the peroxide at the extruder process temperature) to effect the desired degree of degradation of the polymer chain. The net result is to narrow the molecular weight distribution of the propylene polymer, as well as to reduce the overall molecular weight and thereby increase the VFF in relation to the polymer of propylene as obtained polymerized. For example, a propylene polymer with a fractional VFF (ie, less than 1), or a propylene polymer with a VFF of 0.5-10 g / 10 minutes, can be selectively reduced in viscosity to a VFF of 15-50 , preferably 25-38 g / 10 minutes, by selecting a type of peroxide, the temperature of the extruder and the residence time in the extruder without undue experimentation. Sufficient care must be exercised in the practice of the process to avoid crosslinking in the presence of a copolymer containing ethylene; Usually, it should be D avoid crosslinking where the ethylene content of the copolymer is sufficiently low. The phosphite stabilizer can be [triethyl-tris- (3, 3 ', 5, 5' -tetra-tere.butyl-1, l-biphenyl-2,2'-diyl) phosphite] of 2,2 ', 2" -nitrile or tris (2,4-di-tert-butylphenyl) phosphite Both compounds are commercially available The preparation of [triethyl-tris- (3, 3", 5, 5'-tetra-tert.butyl) 2, 2 ', 2"-nitrile-1, biphenyl-2, 2'-diyl) phosphite] is disclosed in U.S. Patent No. 4,318,845, the disclosure of which is incorporated herein by reference in its The N, N-dialkylhydroxylamine must have a hydroxyl group attached to the nitrogen atom, and preferably according to the formula: R R2NOH wherein R] _ and R2 are, independently, alkyl of cl-36 '- which is unsubstituted or substituted by hydroxyl Illustrative hydroxylamines falling within the above formula include N, N-distearylhydroxylamine and di (hydrogenated bait) amine.A common di (hydrogenated bait) amine has the following distribution of substituents I rent: D The origin of the di (hydrogenated bait) amine from animal sources may also vary somewhat in the specific distribution of the alkyl substituents, but the di (hydrogenated bait) amine contains significant amounts of N, N- dihexadecyla ina, N, N-dioctadecylamine and N-hexadecyl-N-octadecylamine. The individual components of the mixture can be separated by high vacuum distillation. However, for the purposes of this invention, it is not necessary to carry out this separation and the hydroxylamine which is prepared from di (hydrogenated bait) amine is a preferred embodiment of the present invention. The long chain N, N-dialkylhydroxylamines can be prepared by various methods. These include: D (a) oxidation of the corresponding secondary amine with aqueous hydrogen peroxide to form the desired N, N-dialkylhydroxyla directly; (b) adding the secondary amine to an alpha, beta-unsaturated compound, such as an alkyl acrylate, to form a Michael addition product, which in turn is oxidized to the corresponding tertiary amine oxide using hydrogen peroxide aqueous, and followed by removal of the alpha, beta-unsaturated compound by the Cope reaction to produce N, N-dialkylhydroxylamine; (c) the metathesis reaction between an alkyl halide and a hydroxylamine in the presence of alkali such as sodium amide; and (d) the reaction of an amine with a peroxy compound, such as benzoyl peroxide, followed by saponification of the intermediate formed to the desired hydroxylamine derivative. In another embodiment, benzofuran-2-ones may be used in place of the hydroxylamine derivative or mixed with the hydroxylamine derivatives. Suitable benzofuran-2-ones compounds and processes for making them are described in U.S. 4,325,863, 4,338,224, 5,175,312 and 5,344,860, the descriptions of which are incorporated by reference. Examples of these benzofuran-2-ones compounds of the formula: D wherein R j is phenyl or phenyl which is substituted by 1 to 3 alkyl radicals having together not more than 18 carbon atoms, alkoxy with 1 to 12 carbon atoms, alkoxycarbonyl with 2 to 18 carbon atoms or chlorine; R12 is hydrogen; R] _4 is hydrogen, alkyl having from 1 to 12 carbon atoms, cyclopentyl, cyclohexyl or chloro; R] _3 has a meaning of Rj_2 ° R14 ° is a radical of the formula: D \ (CHJViCi-ORw, - (CHj -e ií -N <R, 7; 2, oo li II - (- CHj-tj-C-O-A-O-C-- -CHí? -? - E, (C? T) "- üC- mu-k-NR" - íC- (CH!) -, < -E, (CH2) ".-- C? ¡-« ~ NNRR "1S-A-O- C- (CHj) .- E, -f-ChitipC-NN-CH-CHfh E.

-CHj-S-R ", --CHCC1H5) -CÍÍ-? Rl6 or -D-E, wherein: R] _6 is hydrogen, alkyl having 1 to 18 carbon atoms, alkyl having 2 to 18 carbon atoms which is interrupted by oxygen or sulfur, dialkylaminoalkyl having a total of 3 to 16 carbon atoms; carbon, cyclopentyl, cyclohexyl, phenyl or phenyl substituted by from 1 to 3 alkyl radicals having together not more than 18 carbon atoms; n is 0, 1 or 2; D the substituents 17, independently of one another, are hydrogen, alkyl having from 1 to 18 carbon atoms, cyclopentyl, cyclohexyl, phenyl, phenyl substituted by 1 or 2 alkyl radicals having together not more than 16 carbon atoms, a radical of the formula - C2H4OH, -C2H4-O-CmH2m +? or or together with the nitrogen atom, to which they are attached, form a piperidine or morpholine radical; m is from 1 to 18; R20 is hydrogen, alkyl having from 1 to 22 carbon atoms or cycloalkyl having from 5 to 12 carbon atoms; A is alkylene having from 2 to 22 carbon atoms which can be interrupted by nitrogen, oxygen or sulfur; R] _ is hydrogen, alkyl having from 1 to 18 carbon atoms, cyclopentyl, cyclohexyl, phenyl, phenyl substituted by 1 or 2 alkyl radicals having together no more than 16 carbon atoms, or is benzyl; R; _9 is alkyl having from 1 to 18 carbon atoms; D is -O-, -S-, -SO-, -SO2- or -C (R2i) 2 _ '* D the substituents 21 - independent of each other, are hydrogen, C? -C? alkyl, the two R21 together contain from 1 to 16 carbon atoms, R21 is also phenyl or a radical of the formula: in which n, R] _g and R 7 are as defined above; E is a radical of the formula in which R ??, R 2 and R14 are as defined; and R 5 is hydrogen, alkyl having 1 to 20 carbon atoms, cyclopentyl, cyclohexyl, chlorine or a radical of the formula: CHj-C i-OR16 or -CHa-C li-N (R, 7) " wherein R] _g and R] _7 are as defined, or R15 together with R? 4 form a tetramethylene radical.

D Preference is given to those benzofuran-2-ones in which R] _3 is hydrogen, alkyl having 1 to 12 carbon atoms, cyclopentyl, cyclohexyl, chlorine or a radical of the formula: O O - -CH2- -C II - ORl4? -f-CH # t- ICI-N < R | 7 > 2 or -D-E, in which n, Rig, 17- »D and E are as defined above, R] _g is, in particular, hydrogen, alkyl having 1 to 18 carbon atoms, cyclopentyl or cyclohexyl. Preference is furthermore given to those benzofuran-2-ones in which R ^ is phenyl or phenyl substituted by 1 or 2 alkyl radicals having together not more than 12 carbon atoms; R ^ 2 is hydrogen; R] _4 is hydrogen or alkyl having 1 to 12 carbon atoms; R] _3 is hydrogen, alkyl having 1 to 12 carbon atoms, fi -f-CH2ft-C-ORw / - (- CH2 -C-N (R17) 2 or -D-E; Rj_5 is hydrogen, alkyl having from 1 to 20 carbon atoms, -CH, -C-ORw or -CHa-C-N (R17) 2, D or R] _5 together with R14 form a tetramethylene radical, n, R ± Q, R17 D and E are as defined at the beginning. An effective amount of the stabilizing system will usually be in the range of from 250 to 2000 ppm of the polymer, with a preferred amount of 700 to 1500 ppm of the polymer. The stabilizer system may contain from 5 to 80% of N, N-dialkylhydroxylamine, benzofuranone or mixtures thereof and from 95 to 20% of phosphite, preferably from 5 to 45% and from 95 to 55%, and most preferably from 5 to 25% and 95 to 75% by weight. When a mixture of the hydroxylamine derivative and the benzofuran-2-one compound are used they may be in amounts of from 5 to 95% by weight. The stabilizer system of the present invention may also contain at least one other stabilizing compound. For example, another phosphite compound can be used in the partial replacement of the primary phosphite stabilizer compounds for economic reasons. However, the inventor has discovered that this substitution can only be partial (ie, approximately 50%); The complete replacement of the primary phosphite compounds will significantly increase the production of smoke. Suitable partial phosphite substitutions include tris (2,4-di-tert-butylphenyl) phosphite and 2,4,6-tri-tert-butylphenyl-2-butyl-2-ethyl-1,3-propanediol phosphite.

D The stabilizer system may also include conventional stabilizer compounds with little or no adverse effect on smoke production. For example, a light stabilizer of hindered amines (HALS) can be added to the stabilizer system. Suitable HALS includes poly [6- [(1,1,3,3-tetramethyl-butyl) amino-s-triazine 2,4-yl] 2,2,6,6-tetramethyl-4-piperindyl) imino] hexamethylene [(2, 2, 6, 6-tetramethyl-4-piperidyl) imino] and 1, 3, 5-triazin-2,4,6, -triamin-N, N "- [1,2-ethanedylbis [N-] (3- [4,6-bis- (butyl-1,2,2,6,6-pentamethyl-4-piperidinyl) aminajpropyl- [N, N-dibutyl-N, N-bis (1,2,2, 6, 6-pentamethyl-4-piperidinyl) In the same way, phenolic stabilizers such as octadecyl-3,5-di-tert.butyl-4-hydroxyhydrocinnamate and tetrakis [methylene 3- (3 ', 5'-di- tert-butyl-4 '-hydroxyphenyl) propionate] -methane can be added to increase thermal stability The stabilized polyolefin composition can contain other additives as is suitable for the proposed use of the composition.These additives include antistatic agents, flame retardant agents , anti-blocking agents, lubricants, pigments, optical brighteners, nucleators and clarifiers. can be incorporated into the olefin polymer in any conventional way, such as by dry blending the stabilizer system directly with polymer granules, D medium drum mixers and Henschel mixers. The solutions, emulsions or slurries of the stabilizing system can be sprayed on or mixed with the granular polymer. For example, the stabilizing components can be coated in granules of the olefin polymer in a fluidized bed according to the process of U.S. Patent No. 5,141,772, the description of which is incorporated herein in its completeness. The stabilizing components can also be mixed with the molten polymer by means of a Banbury mixer, Bradbender mixer, roller mill or propeller extruder. The stabilizer system can also be added to the olefin polymer in the form of a masterbatch according to the conventional techniques described in U.S. Patent No. 5,236,962, the description of which is incorporated herein by reference in its completeness . The stabilized polyolefin composition is especially suitable for manufacture in a fiber or film using conventional techniques and apparatus. More specifically, the stabilized olefin polymer can be extruded at conventional temperatures (i.e. from 210 to 280 ° C) by a nozzle, it can be tempered, partially or fully oriented and thermoset before being wound on a coil or being subjected to another prosecution, D such as yarn stuck in a coil of non-woven fabrics. A particularly preferred resin composition consists of 800 ppm of triethyl-tris (3,3 ', 5, 5'-tetra-tert.butyl-1, 1-biphenyl-2,2'-diyl) phosphite, 2,2'. , 2"-nitrile, 400 ppm of N, N-di (stearyl) hydroxylamine, 500 ppm of tetrakis [methylene (3, 5-di-tert.util-4-hydroxyhydrocinnamate)] methane, and 250 ppm of calcium lactate as an acid neutralizing agent.

EXAMPLES: These examples are presented for the purpose of illustration only, and in no way should they be considered as limiting the nature or scope of the invention described herein. The chemical identities of the products that are used in the following formulations are as follows: Polyfine Polymers PF-304 polypropylene polymer commercially available from Montell USA Inc. PF-305 polypropylene polymer available commercially from Montell USA Inc.

Phosphites D Irgafos 12 [triethyl-tris (3, 3 *, 5, 5 '-tetra-tert.butyl-l, l-biphenyl-2,2'-diyl) phosphite] of 2,2', 2"-nitrile, available in the trade of Ciba Specialty Chemicals Corporation Irgafos 168 tris (2,4-di-tert-butylphenyl) phosphite, commercially available from Ciba Specialty Chemicals Corporation Ultranox 626 bis (2,4-di-tert-butyl) bisphosphite butylphenyl) pentaerythritol, commercially available from GE Specialty Chemicals, Ultranox 641 2, 4,6-tri-tert-butylphenyl-2-butyl-2-ethyl-1,3-propanediol phosphite, commercially available from GE Specialty Chemicals Hydroxylamines FS-042 N, N-di (stearyl) hydroxylamine, commercially available from Ciba Specialty Chemicals Corporation.

Benzofuranones HP 136 5,7-di-t-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one, commercially available from Ciba Specialty Chemicals Corporation.

Phenolic Antioxidants Disabled: D Irganox 1010 tetrakis [methylene 3- (3 ', 5'-di-tert-butyl-4' -hydroxyphenyl) propionate] methane, available commercially from Ciba Specialty Chemicals Corporation. Irganox 1076 octadecyl-3, 5-di-tert-butyl-4-hydroxy hydrocinmate, commercially available from Ciba Specialty Chemicals Corporation.

Impaired Amines: Chimmassorb 119 1, 3, 5-triazin-2, 4, 6, -triamin-N, N "- [1,2-ethandylbis [N- (3- [4,6-bis- (butyl-1) , 2, 2, 6, 6-pentamethyl-4-piperidinyl) amine] propyl- [N, N-dibutyl-N, N-bis (1, 2, 2, 6, 6-pentamethyl-4-piperidinyl), available in the trade of Ciba? pecialty Chemicals Corporation Chimassorb 944 poly [6- [(1, 1, 3, 3-tetramethyl-butyl) amino-s-triazin 2,4-yl] 2, 2, 6, 6-tetramethyl -4-piperindyl) imino] examethylene [(2,2,6,6, -tetramethyl-4-piperidyl) imino], commercially available from Ciba Specialty Chemicals Corporation Tinuvin 622 poly- (N-β-hydroxyethyl) succinate -2, 2, 6, 6-tetramethyl-4-hydroxy-piperidyl), commercially available from Ciba Specialty Chemicals Corporation.Miscellaneous: Pationic 1240 calcium lactate commercially available from American Ingredients Company.

D DHT-4A hydrotalcite, commercially available from Kyowa Chemicals Industry Co., Ltd.

Mixtures: FS-601 is a 1: 1 mixture of F? -042 N, N-di (stearyl) idroxylamine and Irgafos 12 [triethyl-tris (3, 3 ', 5, 5'-tetra-tert.butyl-l) , l-biphenyl-2, 2'-diyl) phosphite] of 2, 2 ', 2"-nitrile FS-301 is a 1: 1 mixture of FS-042 N, N-di (stearyl) hydroxylamine and Irgafos 168 tris (2,4-di-tert-butylphenyl) phosphite Ultranox 627A is a mixture of Ultranox 626 Phosphite 93% and DHT4A 7% Hydrotalcite Irganox B-225, Stabilizer, is a mixture of a part of the product Irganox 1010 and a part of the Irgafos 168 product, as described above, available commercially from Ciba Specialty Chemicals Corporation.

EXAMPLE I Fifteen samples of the polypropylene resin composition were evaluated for their smoke production. All samples were based on a polypropylene material prepared from commercially produced polypropylene flakes with a xylene-soluble content at room temperature of 4.0% and an initial VFF of 1.5 g / 10. to "- minutes, measured in accordance with ASTM 1238, Condition L, and decrease in viscosity at a target VFF of 38 g / 10 minutes The sample formulations were then mixed together in a Kokneader extruder and granulated. measured by extruding 10-pound samples of each formulation at a rate of 10 pounds / hour at 260 ° C through a 1.25"(2.81 cm) fiber extruder and carrying out extinction under moderate conditions. The volatile organic compounds were measured and recorded from the evolved smoke sucked from the orifice of the nozzle through a vacuum system into a sample chamber where a laser particle counter measured the concentration of volatile particles in milligrams per cubic meter . The results were recorded in a recorder with recording tape. The formulations shown and the measurements of their smoke are listed below in Table 1: D TABLE. Sample D The examination of Table I illustrates the drastic reduction in the production of volatile organic compounds shown by the present invention. More specifically, samples 1-3 through 1-8, 1-11 and 1-13 through 1-15 of the invention all achieved a reduction of at least 90% in the production of volatile organic compounds compared to the control sample 1-1 that does not contain any stabilizer. The deleterious effect of a still small amount of calcium stearate on the production of volatile organic compounds is demonstrated in the comparison of samples 1-8 and 1-9. The presence of only 15 parts per million of calcium stearate causes almost twice as much smoke as that generated by an otherwise identical sample formulation. The comparison of samples 1-2 and 1-10 also show the deleterious effect of calcium stearate on the measured smoke.

EXAMPLE II Samples of the polypropylene resin composition and control samples were evaluated for smoke production. Two samples (II-1 and II-2) were based on a polypropylene material prepared from commercially produced polypropylene flakes with a D -i nri i "- -" "T-T1 T -i - ilU V X X -UjeLlVO Cie ¿y / lu illiuui.ua. uci? ucotxaú xca a tca \ J. A. -J to 11-14) were formulated using a devolatilized polypropylene material prepared from commercially produced polypropylene flakes with an initial VFF of 4/10 minutes, with reduction of viscosity to a VFF target of 38 g / 10 minutes. The samples were formulated and measured for smoke production using the methods and apparatuses described in Example 1, except for the use of premixed mixtures of N, N-dialkylhydroxylamine and phosphite.

The control samples were processed several times during the course of the evaluation due to a changing reading of the particle laser counter. The formulations shown and the measurements of your smoke are listed below in the Table 2: D TABLE Sample D c 3 Examination of Table 2 illustrates the reduction in the production of volatile organic compounds possible with the use of [triethyl-tris (3, 3 ', 5, 5'-tetra-tert.butyl-1, 1-biphenyl-2, 2 '-diyl) phosphite] 2, 2', 2"-nitrile or tris (2,4-di-tert-butylphenyl) phosphite as a phosphite stabilizer, as well as the use of premixed mixtures of N, N'-dialkylhydroxylamine and the phosphite stabilizer, and non-preferential hydrotalcite.

EXAMPLE III A heterophasic olefin polymer material available commercially from Montell USA Inc., which contains: (a) 35% propylene homopolymer having an isotactic index defined as the xylene insoluble fraction of 97.5, (b) 6.9 % of semicrystalline ethylene-propylene copolymer insoluble in xylene at room temperature, and (c) 58.1% of an ethylene-propylene copolymer insoluble in xylene at room temperature, was reduced in its viscosity to a target VFF of 30 g / 10 minutes . Three sample formulations were formulated according to the procedures of Example 1 and extruded by a Hills fiber apparatus through an orifice nozzle 40 at 260 ° C. Volatile organic compounds produced during extrusion were measured using a laser particle counter capable of expressing the concentration in milligrams per cubic meter.

D Table 3 refers to the formulations and the amount of volatile organic compounds produced during extrusion. The first control sample (sample III-1, with a calcium stearate content) generated a quantity of volatile organic compounds that exceeds the particle counter calibration parameters. By changing the acid-neutralizing agent of calcium stearate to hydrotalcite (with a lower content of calcium stearate) (control sample III-2) it reduced the production of volatile organic compounds up to the particle counter measurement scale. However, the concentrations of 260 milligrams per cubic meter is known as an unacceptable level for the extrusion of fibers, and it is considered that it is very likely to cause deposits in the nozzle during the manufacture of the film. On the contrary, sample III-3, which contained a stabilizing system of the invention, presented significantly lower production of volatile organic compounds.

TABLE 3 Sample Us D EXAMPLE IV I Three samples were formulated using the polypropylene material of Example I and according to the procedures and apparatuses of Example I. The sample formulations and measurements of their smoke are set forth in the Table. 4.

TABLE 4 Sample Nos.

Claims (20)

CLAIMS: 1. A polymer composition containing: (i) an olefin polymer containing an acid neutralizing agent different from a metal salt of a saturated or unsaturated fatty acid, and ii) a stabilizer system distributed throughout the polymer, the system stabilizer consists of: (a) a phosphite selected from the group consisting of [triethyl-tris (3, 3 ', 5, 5'-tetra- tert.butyl-1, l-biphenyl-2,2'-diyl) phosphite ] of 2,2 ', 2"-nitrile and tris (2,4-di-tert-butylphenyl) phosphite; and (b) an N, N-dialkylhydroxylamine, a benzofuranone or mixtures thereof. of the claim

1, wherein the acid neutralizing agent is at least one member selected from the group consisting of: hydrotalcites, aluminum silicate and oxides and hydroxides of Group II metals. 3. The polyolefin composition of claim 2, wherein the neutralizing acid agent is selected from the group consisting of calcium lactate, calcium hydroxide, calcium oxide and mixtures thereof. 4. The polyolefin composition of claim 1, wherein the phosphite is [triethyl- tris (3, 3 ', 5, 5' -tetra-tere.util-1, 1-bifeni1-2, 2'-diyl) phosphite] of 2, 2 ', 2"-nitrile 5. The polymer composition of claim 1, wherein the N, N-dialkylhydroxylamine forms the formula: R] _R2NOH wherein Rj_ and R2 are independently unsubstituted or substituted hydroxylic cl-36 'alkyl 6. The polymer composition of claim 5, wherein the N, N-dialkylhydroxylamine is N, distearylhydroxylamine. 7. The polymer composition of claim 5, wherein the N, N-dialkylhydroxylamine comprises di (hydrogenated bait) hydroxylamine. The polyolefin composition of claim 1, wherein the stabilizer system is present in an amount of 250 to 2000 ppm of the polymer. 9. The polyolefin composition of claim 8, wherein the stabilizing system is present in an amount from 700 to 1500 ppm of the polymer. The polyolefin composition of claim 1, wherein the stabilizing system comprises from 10 to 80% N, N-dialkylhydroxylamine and from 90 to 20% phosphite. 11. The polymer composition of claim 1, further comprises: (c) at least one other stabilizing compound, the other stabilizer comprising at least one member selected from the group consisting of a phenol, a hindered amine and a phosphite different from [triethyl-tris (3, 3 ', 5, 5'-tetra-tert.butyl-1, 1-biphenyl-2,2'-diyl) phosphite] of 2, 2', 2"-nitrile or trisphosphite (2,4-di-tert-butylphenyl) 12. The polyolefin composition of claim 11, wherein the other stabilizing compound is 2,4,6-tri-tert-butylphenyl-2-butyl-2-phosphite. ethyl-l, 3-propanediol 13. The polyolefin composition of claim 11, wherein the other stabilizing compound is a hindered amine which is selected from the group consisting of poly [6- [(1, 1, 3, 3 -tetramethyl-butyl) amino-s-triazin-2,4-yl] 2, 2, 6, 6-tetramethyl-4-piperindyl) imino] hexamethylene [(2, 2, 6, 6, -tetramethyl-4-piperidyl ) imino] and 1, 3, 5-triazin-2,, 6, -triamin-N, N "- [1,2-ethanedylbis [N- ( 3- [4,6-bis- (butyl-1,2,2,6,6-pentamethyl-4-piperidinyl) to in] propyl- [N, N-dibutyl-N, N-bis (1,2, 2,6,6-pentamethyl-4-piperidinyl). The polyolefin composition of claim 11, wherein the other stabilizing compound is a phenol selected from the group consisting of tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane and tetrakis [methylene 3- (3 ', 5'-di-tert-butyl-' -hydroxyphenyl) propionate] methane. 15. The polymer composition of claim 1, wherein the olefin polymer is a crystalline propylene homopolymer having an isotactic index greater than 90 or a random copolymer, crystalline propylene and ethylene or C4-C10 1-olefins. The polymer composition of claim 1, wherein the olefin polymer is a propylene to which the viscosity was reduced and which has a melt flow rate of 15 to 50 g / 10 minutes., measured in accordance with ASTM 1238, Condition L. 17. The polymer composition of claim 16, wherein the melt flow rate is 25 to 38 g / 10 minutes, measured in accordance with ASTM 1238, Condition L. 18. A method for preparing an olefin polymer fiber, film or sheet consisting of: i) incorporating a stabilizer system into an olefin polymer containing an acid neutralizing agent different from a metal salt of a saturated or unsaturated fatty acid , the stabilizing system consists of: (a) a phosphite selected from the group consisting of [triethyl-tris (3, 3 ', 5, 5'-tetra-

2.2, 2"-nitrile and tris (2,4-di-tert-butylphenyl) tert.-butyl-1, 1-biphenyl-2,2'-diyl) phosphite; and (b) a N, N-dialkylhydroxylamine, thereby producing a stabilized olefin polymer, and ii) extruding the stabilized olefin polymer through a nozzle, thereby producing a fiber, film or olefin polymer sheet. fiber produced according to the process of claim 18. 20. A film or sheet produced according to the process of claim 18.