GB2132621A - Photodegradable polymer composition - Google Patents

Abstract

A photodegradable composition comprising a polymer such as polypropylene, polyethylene and copolymers and terpolymers thereof, zinc-oxide and a piperidine derivative ester or ether such as bis(2,2,6,6- tetramethyl-4-piperidyl) adipate.

Description

SPECIFICATION Photodegradable polymer composition The present invention relates to photodegradable polymer compositions, the articles made therefrom and new compositions which are usefully employed in combination with polymer materials in order to accelerate the photodegradability of said polymers.

The use of plastics as disposal or disposable items has been greatly increasing. For example, consumption of polyethylene and polypropylene plastic films, bags, bottles, films, ribbon yarn, styrofoam cups and blister packages, ropes and twine increases yearly.

The increasing use of plastics in packaging and binding applications has created a serious ecological problem because polymeric materials such as polyolefins, for example polypropylene and polyethylene, tend to remain substantially intact for relatively long periods of time. The burning of the plastic materials is unsatisfactory for while the plastic litter is being removed the air is seriously polluted by the gases given off during the burning process.

It would be desirable to produce a composition which would greatly accelerate the photodegradability of polymer articles such as thermoplastic polymeric articles on exposure to UV light, thereby alleviating the ecological problem.

The use of zinc oxide in combination with polymeric materials in order to provide an ultraviolet light stabilized article is well known.

U.S. 4,076,689 describes an ultraviolet light stabilizer combination for polymers, said combination comprising zinc oxide, a zinc dihydrocarbyldithiocarbamate and certain organo nickel compounds such as nickel dihydrocarbyldithiocarbamate.

In "Ultraviolet Stabilization of PP by Zinc Oxide", Modern Plastics, January, 1 969, 46(1)114- 1 6 R. D. Deanin descrbies the UV-stabilizing ability of zinc oxide. In "Zinc Oxide/Synergistic Systems Provide Improved UV Control", Modern Plastics, July, 1981, 58(7), 64--68, D. S. Carr describes the synergistic UV stabilization effects obtained by the combination of zinc oxide with other compounds in such as zinc dimethyl and diethyldithiocarbamates and tris(nonylphenyl) phosphite.

Mamanasso et al in Additives for Plastics, Vol. 2, New Developments, edited by Raymond B.

Seymour, Academic Press, New York (1978) describes the prevention of degradation of polymers upon exposure to ultraviolet radiation by the use of zinc oxides and zinc alkyldithiocarbamates.

Many materials have been suggested and employed as UV light photodegradation accelerators.

For example, photodegradable polymer compositions are described in U.S. Patents 4,028,480, 4,191,320, 3,903,064 and Canadian patent 1,073,581. The additives described in these patents have not proven entirely satisfactory in achieving an acceptable rate of outdoor degradation while retaining durability for packaging and wrapping purposes.

As will be apparent from the description following, the present invention provides a satisfactory additive package for enhancing and accelerating the photodegradability of polymers, and accordingly, represents an improvement over the prior art.

It is an object of the present invention to provide an ultraviolet light destabilizer composition for enhancing and accelerating the photodegradability of polymers and the articles manufactured therefrom.

It is another object of this invention to provide photodegradable polymer compositions and articles.

It has now been discovered that the composition comprising zinc oxide and certain piperidine derivatives imparts surprising and synergistic enhancement and acceleration of UV light degradation to polymeric materials. This is especially surprising since until the present invention the piperidine derivatives were known as UV light stabilizers.

In accordance with the present invention, there is provided an ultraviolet light destabilizer composition comprising a mixture of: a. Zinc oxide, and b. A piperidine derivative represented by the general formula

wherein R1 and R2, which may be the same or different, are each an alkyl group, or form together with the carbon atom to which they are attached, a saturated alicyclic group with 5 to 7 ring carbon atoms or a group of the formula:

n is an integer of 1 to 3; and when n is 1, R3 is an acyl group, an N-substituted carbamoyl group having as a substituent alkyl, cycloalkyl or aryl, an N-monosubstituted thiocarbamoyl group having as a substituent alkyl, cycloalkyl or aryl, a monovalent group obtained by removing a hydroxyl group from a sulfinic acid, a sulfonic acid, a phosphorus-containing acid or a boric acid, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group or a group of the general formula::

wherein R1 and R2 are as defined above, when n is 2, R3 is a diacyl group, derived from a dibasic aliphatic or aromatic carboxylic acid, a dicarbamoyl group in which two carbamoyl groups are connected by an aryl, alkyl, diarylalkane or diaryl ether, a carbonyl group, a divalent group obtained by removing two hydroxyl groups from a disulfonic acid, a phosphorus-containing acid or a boric acid, an alkylene group, an arylene group or arylene dialkylene group, and when n is 3, R3 is a triacyl group derived from an aromatic, cycloaliphatic orfurane tricarboxylic acid, a tricarbamoyl group in which three carbamoyl groups are attached to one aryl group, a trivalent group obtained by removing three hydroxyl groups from a trisulfonic acid, a phosphorus-containing acid or a boric acid, alkanetriyl, an arenetriyl group or an arenetriyltrialkylene group; or a salt thereof with phosphoric acid, carbonic acid, citric acid, stearic acid or benzoic acid.

Also provided is a photodegradable polymeric composition comprising the above ultraviolet light destabilizer composition or combination.

In a preferred embodiment of the invention the value for n in the formula for the piperidine derivative is 2, each of R1 and R2 are methyl groups and R3 is a diacyl group derived from a dibasic aliphatic or aromatic carboxylic acid having 1 to 24, preferably 1 to 12, more preferably 1 to 10 carbon atoms.

The invention will now be described in greater detail together with illustrative examples, which examples are not to be construed in any iimiting way.

As indicated above, the additive combination or composition for enhancing photodegradability of polymer comprises zinc oxide and the piperidine derivative as described above.

Component (a), zinc oxide, is a well known additive generally employed as a pigmenting additive or as described in the description of the prior art used in combination with ultraviolet light stabilizers to enhance ultraviolet light stability. In general, as employed in accordance with the instant invention, zinc oxide will be in a finely divided form having a particle size ranging from 0.10 to 0.25 microns.

The piperidine derivatives employed in accordance with this invention, are represented by the general formula:

wherein R1, R2, R3 and n have the values as described above.

Illustrative but nonlimiting examples of the piperidine derivatives which can be employed in accordance with this invention are: 4-acetoxy-2,2,6,6-tetramethylpiperidine; 4-stearoyloxy-2,2,6,6-tetra methylpiperidine; 4-acryloyloxy-2,2,6,6-tetramethylpiperidine; 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine; 4-(phenoxyacetoxy)-2,2,6,6-tetra methylpiperidine; 4-cyclohexanoyloxy-2,2,6,6-tetramethylpiperidine; 4-benzoyloxy-2,2,6,6-tetramethylpiperidine; 4-(p-chlorobenzoyloxy)-2,2,6,6-tetramethylpiperidine; 4-(m-chlorobenzoyloxy)-2,2,6,6-tetramethylpiperidine; 4-(o-chlorobenzoyloxy)-2,2-6,6-tetramethylpiperidine; 4-(o-toluoyloxy)-2,2,6,6-tetramethylpiperidine; 4-isonicotinoyloxy-2,2,6,6-tetramethylpiperidine; 4-(2-furoyloxy)-2,2,6,6-tetramethylpiperidine;; 4-(,B-naphthoyloxy)-2,2,6,6-tetramethylpiperidine; 4-methoxy-2,2,6,6-tetramethylpiperidine; 4-stearyloxy-2,2,6,6-tetramethylpiperidine; 4-cyclohexyloxy-2,2,6,6-tetra methylpiperidine; 4-benzyloxy-2,2,6,6-tetra methylpiperidine; 4-phenoxy-2,2,6,6-tetramethylpiperidine; 4-(ethylcarbamoyloxyl)-2,2,6,6-tetramethylpiperidine; 4-(cyclohexylcarbamoyloxy)-2,26,6-tetramethylpiperidine; 4-(phenylcarbamoyloxy)-2,26,6-tetramethylpiperidine; 4-(p-chlorophenylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine; 4-(o-tolylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine; 4-(α-naphthylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine; 4-(ethylthiocarbamoyloxy)-2,2,6,6-tetramethylpiperidine; 4-(cyclohexylthiocarbamoyloxy)-2,2,6,6-tetramethylpiperidine; 4-(phenylthiocarbamoyloxy)-2,2,6,6-tetramethylpiperidine;; 4-benzenesulfinyloxy-2,2,6,6-tetramethylpiperidine; 4-benzenesu Ifonyloxy-2,2,6,6-tetra methyipiperidine; 4-(p-toluenesulfonyloxy)-2,2,6,6-tetramethylpiperidine; 4-(p-n-dodecylbenzenesulfonyloxy)-2,2,6,6-tetramethylpiperidine; 4-methanesulfonyloxy-2,2,6,6-tetramethylpiperidine; bis(2,2,6,6-tetramethyl-4-piperidyl)carbonate; bis(2,2,6,6-tetramethyl-4-piperidyl)oxalate; bis(2,2,6,6-tetramethyl-4-pierpdiyl)malonate; bis(2,2,6,6-tetramethyl-4-piperidyl)adipate; bis(2,2,6,6-tetramethyl-4-piperidyl)fumarate; bis(2,2 ,6,6-tetramethyl-4-piperidyl)sebacate; bis (2,2,6,6-tetramethyl-4-piperidyl)hexahydroterephthalate; bis (2,2,6,6-tetramethyl-4-piperidyl)terephehanlate; 1 ,2-bis(2,2,6,6-tetramethyl-4-piperidyloxy)ethane; a,a,' -bis(2,2,6,6-tetramethyl-4-piperidyloxy)p-xylene;; bis(2,2,6,6-tetramethyl-4-piperidyl)tolylene-2,4-dicarbamate; bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylene-1,6-dicarbamate; bis(2,2,6,6-tetramethyl-4-piperidyl)diphenylmethane-p,p'-dicarbamate; bis(2,2,6,6-tetramethyl-4-piperidyl)diphenyl-ether-p,p'-dicarbamate; bis(2,2,6,6-tetramethyl-4-piperidyl)benzene-1,3-disulfonate; bis(2,2,6,6-tetramethyl-4-piperidyl)phenyl-phosphite; tris(2,2,6,6-tetra methyl-4-piperidyl)phosphite; tris(2,2,6,6-tetramethyl-4-piperidyl)phosphate; 6-aza-7,7-dimethyl-9-benzoyloxy-spiro[4,5]decane; 1-aza-2,2-dimethyl-4-benzoyloxy-spiro[5.5]undecane; 1 ,9-diaza-4-(benzoyloxy-2,2,8,8, 10,1 0-hexamethylspiro[5,5]undecane; 1,9-diaza-4-(cyclohexylcarbamoyloxy)-2,2,8,8,10,10-hexamethyl-spiro[5,5]undecane; bis(2,2,6,6-tetramethyl-4-piperidyl)ether;; tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene- 1 ,3,5-trica rboxylate; and tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene- 1 3,4-tricarboxylate.

Preferably, the piperidine derivatives which can be usefully employed in accordance with this invention are represented by the general formula above wherein R1 and R2 are each methyl, n is 2 and R3 is a diacyl group derived from a dibasic aliphatic or aromatic carboxylic acid having from 1 to 24 carbon atoms and preferably 1 to 12 carbon atoms.Illustrative but nonlimiting examples of such piperidine derivatives are: bis(2,2,6,6-tetramethyl-4-piperidyl)carbonate; bis(2,2,6,6-tetramethyl-4-piperidyl)oxalate; bis(2,2,6,6-tetramethyl-4-piperidyl)malonate; bis(2,2,6,6-tetramethyl-4-piperidyl)adipate; bis(2,2,6,6-tetramethyl-4-piperidyl)fumarate; bis(2,2,6,6-tetra m ethyl-4-piperidyl)sebacate; bis(2,2,6,6-tetramethyl-4-piperidyl)hexahydroterephthalate; and bis(2,2,6,6-tetramethyl-4-piperidyl)terephthalate.

In a most preferred embodiment of this invention, the piperidine derivative is bis(2,2,6,6tetramethyl-4-piperidyl)sebacate.

The preparation of the piperidine derivatives which may be usefully employed in accordance with this invention are well known and adequately described in U.S. Patent 3,640,928 issued February 10 1972.

The polymeric materials that can be employed in the practice of this invention are normally solid polymers derived from unsaturated monomers including homopolymers, copolymesr, terpolymers, blends of at least two (2) polymers selected from homopolymers, copolymers, and terpolymers and block copolymers, including polymers of aliphatic 1-olefins such as polyethylene, polyproyplene, poly(1-butene), olefins and poly(1-pentene), poly(1-hexene) and the like; poly(vinyl-substituted aromatic compounds) such as polystyrene; poly(vinyl halides) such as polyvinyl chloride; polyvinylidene chloride; polyvinyl acetate, and ethylene higher alpha-olefins, copolymers such as ethylene propylene, ethylene butene, ethylene hexene; propylene higher alpha-olefin copolymers, and terpolymer of alphaolefins including ethylene.Other polymers can also obtain acceleration and enhancement of photodegradability by incorporating the ultraviolet light destabilizer composition of zinc oxide and the piperidine derivatives described herein.

The preferred polymers usefully employed in the practice of this invention include homopolymers and copolymers derived from the mono-1-olefins having from 2 to 8 carbon atoms; most preferably, the mono-olefins and polymers of preference are ethylene and propylene homopolymers, copolymers of ethylene and propylene, copolymers of ethylene or propylene with minor amounts of another copolymer copolymerizable therewith such as propylene or ethylene with higher 1-olefins and copolymers of ethylene or propylene with vinyl acetate.

A preferred composition of the invention comprises polypropylene as the polymer, optionally with from 5 to 1 5 wt% ethylene vinyl acetate copolymer.

The ingredients, i.e., zinc oxide and the piperidine derivatives described above, comprising the ultraviolet light destabilizer package or composition can be incorporated in the polymers in any suitable manner. They can be incorporated separately or together. Preferably, the zinc oxide and piperidine derivative are reacted together and thereafter mixed with the polymeric materials. Generally, each ingredient is incorporated in small but effective amounts to enhance and accelerate the photodegradability of the polymer. In order to obtain the greatest benefit of the invention as described herein the ratio of zinc oxide to the piperidine derivative in the range of from 1:1 to 12:1; preferably, the ratio of zinc oxide to piperidine derivative is in the range of 2:1 to 8:1.The zinc oxide and piperidine derivative combination can be used in amounts ranging from 1.0 to 1 5.0 wt.% of the polymeric composition and preferably from 2.0 to 8.0%.

The novel photodegradabie polymeric compositions and articles of this invention can also contain additives such as chemical additives, for example, antioxidants, fillers, pigments, or reinforcements which are commonly used in plastic composition formulations and which will not materially interfere with the photodegradation process. For example, the compositions of this invention can contain additives and processing aids, viscosity modifiers, mold-release agents, emuisifiers and slip agents. The polymeric compositions and articles of this invention can also contain antioxidants, and anti-static agents which will not materially inhibit the photodegradation of the composition. The compositions can also contain fillers such as, for example, barium sulfate, calcium carbonate, calcium silicate, fumed silica, glass and clay.The polymeric compositions of this invention can also employ flame retardants, lubricants, plasticizers, adhesion promoters and stabilizers typically employed to prevent thermooxidative decomposition during, for example, high-temperature processing.

The zinc oxide and piperidine derivatives employed in accordance with this invention can be incorporated in the polymer in any suitable manner known in the art. The ultraviolet light destabilizer additives can be mixed with a polymer individually or in combination using any conventional manner known in the art. It is desirable that the ingredients be intimately dispersed in the polymer. Suitable mixing procedures include dry blending the various components, making solutions of one or more of the additives components and blending the resulting solutions with the polymer, melt blending the various components individually with the melted polymer and the like.

The polymeric materials of this invention can be usefully employed for producing films, bags, bottles, foam cups, melt blown webs, blister packages, ribbon yarn, and baling twine. The articles can be formed by methods well known in the art including injection molding, rational molding and blow molding. Typically films or ribbon yarns may have a thickness of from 0.3 to 50 mils (0.076 to 12.7 microns).

The following detailed examples of the invention are provided by way of illustration only.

Examples Dry blends of polypropylene powder and all additives were extruded on a 2 inch (5.08 cm) Prodex Extruder at 4250F to form pellets. The pellets were converted to 2x 100 mil (25.4 micron) ribbon yarn by extruding on a Ribbon Yarn Line equipped with a 2-1/2" (6.35 cm) Prodex Extruder at 5O00F (2600 C).

Samples of the ribbon yarns were exposed a) in an Atlas 6500 watt Xenon Weatherometer, Ci 65 emitting UV radiation at between 300 and 700 millimicrons, and b) to the direct sunlight using Test Services located in South Florida and Arizona. The samples were all in unstrained conditions. The outdoor exposures were initiated in the month of October.

in each case the initial tensile strength and % elongation were determined on each ribbon sample prior to exposure. Thereafter, the ribbon yarn was periodically examined for % tensile retention and elongation retention (ASTM D-1708 and 1708 respectively). The ingredients, denier and results are summarized in Tables I, II and III.

In Table I, various metal oxides in combination with bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate are compared for enhancement of photodegradability. In Tables II and Ill, various second compounds with ZnO are compared under different exposure conditions.

It is demonstratably clear from the Tables that the combination of zinc oxide and piperidine derivatives greatly enhances the photodegradability of polymer compositions.

Table I Xenon weatherometer exposures (hoursJ Weight % metal oxide % Tensile retention % Elong. retention Samples" Denier ZnO AL203 MgO CuO 222 500 721 222 500 721 -1 1525 - - - - 94 94 85 97 86 78 -2 1623 0.50 89 87 81 74 70 65 -3 1623 1.0 97 62 34 94 45 30 1 1492 2.0 82 26 0 61 38 0 -5 1492 4.0 31 0 28 0 -6 1590 4.0 90 82 73 75 72 61 -7 1295 4.0 96 91 87 76 66 66 -8 1558 4.0 86 72 69 68 33 55 (1) All samples contain 0.50 wt.% bis(2,2,6,6-4-tetramethyl piperidine)sebacate 0.05 wt% Irganox 1010 an organic stabilizer (M.P. of 230-257 F (110 -125 )) manufactured by Ciba Geigy 0.1 5 wt% distearyl thiodipropionate, a thioester, M.P. of 1 470F (650 C) manufactured by American Cyanamid Table II Xenon weatherometer exposure results1 Xenon weatherometer exposures (hours) Weight % additives, pigments % Tensile retention % Elongation retention Sample No. Denier NBC2 7703 10104 DSTP5 ZnO6 D.P.7 500 1000 1500 2000 2500 3000 3500 500 1000 1500 2000 2500 3000 3500 1 1082 1.0 .05 .15 99 99 97 95 93 90 89 98 97 95 95 50 50 48 2 1016 .70 .05 .10 99 99 98 97 68 56 0 95 94 94 82 45 40 0 3 1066 .70 .05 4.0 .10 10 0 12 0 4 1098 1.0 .05 .15 4.0 100 84 84 82 56 40 4 100 91 90 89 39 25 0 1 All samples contain 10 wt.% Elvax 360, an ethylene vinyl acetate copolymer (1.7 to 2.3 Ml) 2 Ni-n,n'-dibutyldithiocarbamate 3 bis(2,2,6,6-4-tetramethyl piperidine sebacate 4 Irganox 1010 5 Distearyl Thiodipropionate, 6 Zinc oxide, manufactured by St.Joe Minerals Corporation 7 DuPont Monastral Green G (Gt-829-0.75-94719) Table III Outdoor exposure results1 So. Florida (months)3 Arizone (months) Weight % additives, pigments % Tensile retention % Elongation ret. % Tensile ret. % Elong. ret.

Sample Denier NBC2 7703 10104 DSTP5 D.P.6 ZnO7 6 12 16 22 25 28 6 12 16 22 25 28 6 12 18 21 6 12 18 21 1 1082 1.0 .05 .15 92 90 89 70 64 31 98 95 93 79 67 51 97 96 95 98 98 96 96 100 2 1016 .70 .05 .10 91 89 87 90 82 91 92 90 80 78 80 85 91 89 89 89 81 79 78 79 3 1066 .70 .05 .10 4.0 98 0 - - - - 30 0 0 0 0 0 27 0 - - 24 0 - 4 1098 1.0 .05 .15 4.0 90 89 86 23 0 - 93 85 75 24 0 - 92 88 86 92 86 81 81 88 1 All samples contain 10 wt.% Elvax 360, an ethylene vinyl acetate copolymer of 1.7 to 2.3 Ml 2 Ni-N,N'-dibutyldithiocarbamate 3 bis(2,2,6,6-4-tetramethyl piperidine)sebacate 4 Irganox 1010 5 Distearyl Thiodipropionate, 6 DuPont Monastral Green G (GT-829-0,75-94719) 7 Zinc oxide, manufactured by St. Joe Minerals Corporation

Claims (11)

Claims

1. An ultraviolet light destabilizer composition comprising a mixture of: a. Zinc oxide, and b. A piperidine derivative represented by the general formula

wherein R and R2, which may be the same or different, are each an alkyl group, or form together with the carbon atom to which they are attached, a saturated alicyclic group with 5 to 7 ring carbon atoms or a group of the formula:

n is an integer of 1 to 3; and when n is 1, R3 is an acyl group, an N-substituted carbamoyl group having as a substituent alkyl, cycloalkyl or aryl, an N-monosubstituted thiocarbamoyl group having as a substituent alkyl, cycloalkyl or aryl, a monovalent group obtained by removing a hydroxyl group from a sulfinic acid, a sulfonic acid, a phosphorus-containing acid or a boric acid, an alkyl group, a cycloalkyl group, an aralkyl grouip, an aryl group or a group of the general formula::

wherein R1 and R2 are as defined above, when n is 2, R2 is a diacyl group, derived from a dibasic aliphatic or aromatic carboxylic acid, a dicarbamoyl group in which two carbamoyl groups are connected by an aryl, alkyl, diarylalkane or diaryl ether, a carbonyl group, a diva lent group obtained by removing two hydroxyl groups from a disulfonic acid, a phosphorus-containing acid or a boric acid, an alkylene group, an arylene group or arylene dialkylene group, and when n is 3, R3 is a triacyl group derived from an aromatic, cycloaliphatic or furane tricarboxylic acid, a tricarbamoyl group in which three carbamoyl groups are attached to one aryl group, a trivalent group obtained by removing three hydroxyi groups from a trisulfonic acid, a phosphorus-containing acid or a boric acid, alkanetriyl, an arenetriyl group or an arenetriyltrialkylene group; or a salt thereof with phosphoric acid, carbonic acid, citric acid, stearic acid or benzoic acid, the weight ratio of said zinc oxide to said piperidine derivative being in the range of from 1:1 to 12:1.

2. A composition according to Claim 1 wherein the weight ratio of said zinc oxide to said piperidine derivative is in the range of 2:1 to 8:1.

3. A composition according to Claim 1 or 2 wherein n is 2, each of R1 and R2 are methyl groups, and R3 is a diacyl group derived from a dibasic aliphatic or aromatic carboxylic acid having from 1 to 24 carbon atoms.

4. A composition according to Claim 3 wherein the piperidine derivative is bis(2,2,6,6 tetramethyl-4-piperidyl) carbonate, bis(2,2,6,6-tetramethyl-4-piperidyl) oxalate, bis(2,2,6,6tetramethyl-4-piperidyl) maionate, bis(2,2,6,6-tetramethyl-4-piperidyl) adipate, bis(2,2,6,6 tetramethyl-4-piperidyl) fumarate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl) hexahydroterephthalate, or bis (2,2,6,6-tetramethyl-4-piperidyl) terephthalate.

5. A composition according to Claim 4 wherein the piperidine derivative is bis(2,2,6,6tetramethyl-4-piperidyl) sebacate.

6. A photodegradable article comprising a polymer characterized in that it also comprises an ultraviolet light destabilizer composition as claimed in any of Claims 1 to 5.

7. An article according to Claim 6, in which the polymer is polyethylene, polypropylene, poly(1butene), polystyrene, polyvinylchloride, polyvinylidene, chloride, polyvinyl acetate, a copolymer or terpolymer thereof or a mixture thereof.

8. An article according to Claim 7, in which the -4mer is polypropylene, polyethylene or ethylene-vinyl acetate copolymer.

9. An article according to any of Claims 6 to 8, in the form of a film or ribbon yarn.

10. An article according to any of Claims 6 to 9 which comprises from 1.0 to 1 5.0 wt.% of the composition as claimed in any of Claims 1 to 5.

11. An article according to any of Claims 6 to 10, which comprises from 5 to 1 5 wt.% ethylenevinyl acetate copolymer.