Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/46—Polymerisation initiated by wave energy or particle radiation
  • C08F2/48—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light
  • C08F2/50—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light with sensitising agents
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F255/00—Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00

Definitions

• the present invention relates in particular to a composition comprising a linear olefin polymer, a photoinitiator and a co-additive containing one or more double bonds, as well as to the modified olefin polymer resin obtainable by the reaction thereof.
• a composition comprising a linear olefin polymer, a photoinitiator and a co-additive containing one or more double bonds, as well as to the modified olefin polymer resin obtainable by the reaction thereof.
• PP cross-link polypropylene
• the modified olefin polymers of the present invention have High Melt Strength (HMS) through an addition of photoinitiators and co-additives containing one or more double bonds and through the action of UV radiation.
• HMS High Melt Strength
• Melt Strength is understood as the maximal “tension” that can be applied to the polymer melt without rupture and this "tension” is proportional to a product of the maximal possible stretching force and the maximal possible melt stretching speed. Stretching force correlates with the melt stiffness and stretching speed corresponds to the melt extensibility, or toughness.
• these two properties - stiffness and toughness in either molten or solid state - tend to be inversely proportional, i.e., stiffness decreases dramatically with increasing toughness/extensibility.
• the current invention provides a simple and economical method for the manufacture of modified olefin polymer melt which has an improved balance of stiffness and extensibility. More broadly, the invention relates to the process of producing a polymer melt with any desired stiffness-extensibility balance.
• Polypropylene (PP) as a versatile polymer is constantly subjected to further developments aiming at higher levels of mechanical properties.
• its application is limited in several processing technologies, where the polymeric melts are stretched, e.g., in thermoforming, extrusion coating, film blowing, foam extrusion, blow moulding and fibre/filament spinning.
• the narrow processing window and/or reduced output/operation speed results from weakness of polypropylene melt that readily tears under tension, as linear molecules slide along each other without much restriction.
• melt strength of PP by an alternative pathway, e.g., via Molecular Weight Distribution (MWD) broadening.
• MWD Molecular Weight Distribution
• CRPP Controlled Rheology Polypropylene
• MFI Melt Flow Index
• MW Low Molecular Weight
• MWD narrow Molecular Weight Distribution
• High energy radiation process implies (relies on) the use of electron-beam accelerators or gamma-ray generators and requires expensive means for radiation control and protection.
• some polymer degradation cannot be prevented; the irradiated grades often have an impaired colour and reduced extensibility of the melt.
• Peroxide assisted reactive processing in the molten or solid states requires thorough peroxides de-activation afterwards. Unavoidably, small peroxide residues still remain in the polymer after the de-activation and may react with some co-additives and/or colorants, which might be introduced in the formulation in further processing steps. It is also known, that the final morphologies of reactively processed polymers are not stable, which, in turn, affects properties of the final articles.
• the present invention relates to a composition
• a composition comprising the Components
• Polymers of monoolefins and diolefins for example polypropylene, polyisobutylene, po- lybut-1-ene, poly-4-methylpent-1-ene, polyvinylcyclohexane, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene, for example high density polyethylene (HDPE), high density and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene (HDPE-UHMW), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE).
• HDPE high density polyethylene
• HDPE-HMW high density and high molecular weight polyethylene
• HDPE-UHMW high density and ultrahigh molecular weight polyethylene
• MDPE medium density polyethylene
• LLDPE linear low density polyethylene
• Polyolefins i.e. the polymers of monoolefins exemplified in the preceding paragraph, preferably polyethylene and polypropylene, can be prepared by different, and especially by the following, methods:
• metals usually have one or more than one ligand, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either ⁇ - or ⁇ -coordinated.
• ligand typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either ⁇ - or ⁇ -coordinated.
• ligand typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either ⁇ - or ⁇ -coordinated.
• catalysts may be soluble or insoluble in the polymerisation medium.
• the catalysts can be used by themselves in the polymerisation or further activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyloxanes, said metals being elements of groups Ia, Na and/or Ilia of the Periodic Table.
• the activators may be modified conveniently with further ester, ether, amine or silyl ether groups.
• These catalyst systems are usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).
• Mixtures of the polymers mentioned under 1 for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of different types of polyethylene (for example HDPE/LDPE).
• Copolymers of monoolefins and diolefins with each other or with other vinyl monomers for example ethylene/propylene copolymers, linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylene/but-1-ene copolymers, propylene/isobutylene copolymers, ethylene/but-1-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin copolymers (e.g.
• ethylene/norbornene like COC ethylene/1 -olefins copolymers, where the 1 -olefin is generated in-situ; propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethylene/vi- nylcyclohexene copolymers, ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers or ethylene/acrylic acid copolymers and their salts (ionomers) as well as terpolymers of ethylene with propylene and a diene such as hexadiene, dicyclopentadiene or ethylidene-norbornene; and mixtures of such copolymers with one another and with polymers mentioned in 1 ) above, for example polypropylene/ethy- lene-propylene copolymers, LLD
• Homopolymers and copolymers from 1.) - 3.) may have any stereostructure including syndio- tactic, isotactic, hemi-isotactic or atactic; where isotactic polymers are preferred. Stereoblock polymers are also included.
• Component (A) is at least one linear olefin polymer selected from the group consisting of a polyethylene homopolymer, a polypropylene homopolymer, a polyethylene copolymer and a polypropylene copolymer.
• Component (A) may also be a blend of e.g. two linear olefin polymers (such as e.g. a blend of polypropylene homopolymer and polypropylene random copolymer) in a weight ratio of e.g. 20:1 to 1 :20.
• two linear olefin polymers such as e.g. a blend of polypropylene homopolymer and polypropylene random copolymer
• the photoinitiators may be any of benzoin and benzoin ether derivatives; benzyl ketal derivatives; ⁇ , ⁇ -dialkyloxyacetophenone derivatives; ⁇ - aminoalkyphenone derivatives; ⁇ -hydroxyalkylphenone derivatives; ⁇ - sulphonylalkylphenones, mono- or bis acylphosphine oxides; acylphosphine sulfides; phenylglyoxylate derivatives; O-acyl-2-oximino ketone derivatives; benzophenone and its derivatives; Michler's ketone and its derivatives; thioxanthone and its derivatives; camphorquinone, anthraquinone and its derivatives; 2-ketocumarine and its derivatives; trihalomethyltriazine derivatives, especially trichloromethyl triazine derivatives; ⁇ - bromoketone derivatives; mixtures of all before mentioned compounds; and
• the preferred photoinitiators have to be able to subtract liable hydrogen atoms from linear olefin polymers (present Component (A)) and/or co-additives containing one or more double bonds (present Component (C)) and, preferably, in addition, provide free radicals required for initiation of radical reactions.
• the photoinitiator is a bifunctional unimolecular photoinitiator capable of hydrogen abstraction and of cleavage into free radicals.
• photoinitiators are compounds of the phenylglyoxylate type as e.g. described in WO-A-2004/108,799, WO-A-08/040,650 and US-A-6,048,660. The following two compounds are of interest:
• the photoinitiator is a mixture of one or more photoinitiators undergoing ⁇ -cleavage and one or more photoinitiators belonging to the group of bimolecular hydrogen abstractors.
• An example of such a system is a mixture of a benzophenone and a monoacylphosphine oxide (MAPO) and/or a bisacylphosphine oxide (BAPO).
• MAPO examples include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6- trimethylbenzoyl-phenylphosphinic acid ethyl ester, (2,4,6-trimethylbenzoy)l-(2'- hydroxybiphenyl-2-yl) phosphinic acid potassium salt and a copolymer of 4-acryloyloxy-2,6- dimethylbenzoyl-diphenylphosphine oxide and n-butylacrylate.
• BAPO bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)- phenylphosphine oxide and 1 ,10-bis[bis(2,4,6-trimethylbenzoyl- diphenylphosphine oxide]-decane.
• benzophenone which is commercially available as IRGACURE 819 (RTM), optionally in combination with a substituted or unsubstituted benzophenone is preferred.
• RTM IRGACURE 819
• a particularly preferred benzophenone is 4-dodecylbenzoylbenzene of the formula
• Blends of benzophenone and BAPO show a synergistic melt strength increase.
• An excess of benzophenone results in the rapid gain of melt stiffness, whereas an excess of acylphospine oxide derivatives leads to the build-up in both, melt stiffness and extensibility.
• An increase in melt extensibility alone happening without any significant change in melt stiffness is also possible.
• the ratio between benzophenone and BAPO varies depending on the intended application and may be for example 1 :10 to 10:1.
• An advantageous "stiffness/extensibility" balance of the final olefin polymer resin is achieved when benzophenone to BAPO ratio is e.g. 1 :1 to 1 :5.
• the photoinitiator is any type of bimolecular hydrogen abstractor such as benzophenone, Michler's ketone, thioxanthone or a mixture thereof.
• camphor quinone camphor quinone
• benzophenone benzophenone derivatives, such as 2,4,6- trimethylbenzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methyl- benzophenone, 2-methoxycarbonylbenzophenone 4,4'-bis(chloromethyl)benzophenone, 4- chlorobenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxy-benzophenone, [4- (4-methylphenylthio)phenyl]-phenylmethanone, methyl-2-benzoylbenzoate, 3-methyl-4'- phenylbenzophenone, 2,4,6-trimethyl-4'-phenylbenzophenone, 4,4'-bis(dimethylamino)- benzophenone, 4,4'-bis(diethylamino)benzophenone; ketal compounds, as for example benzildimethylketal; acetophenone,
• phenylglyoxalic esters and derivatives thereof e.g. oxo- phenyl-acetic acid 2-(2-hydroxy-ethoxy)-ethyl ester, dimeric phenylglyoxalic esters, e.g. oxo- phenyl-acetic acid 1-methyl-2-[2-(2-oxo-2-phenyl-acetoxy)-propoxy]-ethyl ester; oximeesters, e.g.
• ortho-chlorohexaphenyl-bisimidazole combined with 2-mercaptobenzthiazole, ferrocenium compounds, or titanocenes, e.g. bis(cyclopentadienyl)-bis(2,6-difluoro-3-pyrryl-phenyl)titanium.
• Component (B) is at least one photoinitiator selected from the group consisting of phenylglyoxylate derivatives, acylphospine oxide derivatives and benzophenone derivatives; in particular the
• phenylglyoxylate derivative of the formula > the phenylglyoxylate derivative of the formula bis[2,4,6-trimethylbenzoyl]-
• the photoinitiators suitable as present Component (B) are known and can be prepared in analogy to known methods; some are commercially available.
• Suitable co-additives containing one or more double bonds are ethene derivatives, propene derivatives, acrylic acid derivatives, methacrylic acid derivatives and diene derivatives as well as appropriate mixtures thereof.
• co-additives include in particular diacrylates of ethylene glycol, propylene glycol, neopentyl glycol, hexamethylene glycol or bisphenol-A, or the corresponding dimethacrylates; trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate or the corresponding tetraacrylate; 4,4'-bis(2- acryloyloxyethoxy)diphenylpropane, vinyl acrylate, divinyl benzene, triallylcyanurate, triallylisocyanurate, diallyl bisphenol-A as well as olefinic hydrocarbons such as 1 ,7- octadiene, 1 ,9-decadiene and trivinylcyclohexane (TVCH).
• trimethylolpropane trimethacrylate of the formula are particularly preferred.
• compositions or the final olefin polymer resins according to the present invention may also contain e.g. 0.001 to 10 %, preferably 0.01 to 5 %, relative to the weight of Component (A), of at least one conventional additive, in particular a stabilizer for protection against degradation during mixing, compounding, any further processing and the intended end use application.
• the conventional additives may be added before and/or after irradiation.
• Alkylated monophenols for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-di- methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-bu- tyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-( ⁇ -methylcyclohexyl)-4,6-dimethyl- phenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-meth- oxymethylphenol, nonylphenols which are linear or branched in the side chains, for example, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1 '-methylunde
• Alkylthiomethylphenols for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctyl- thiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl-4- nonylphenol.
• Alkylthiomethylphenols for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctyl- thiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl-4- nonylphenol.
• Hydroquinones and alkylated hydroquinones for example 2,6-di-tert-butyl-4-methoxy- phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octade- cyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-bu- tyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis(3,5-di-tert-butyl-4-hy- droxyphenyl) adipate.
• Tocopherols for example ⁇ -tocopherol, ⁇ -tocopherol, ⁇ -tocopherol, ⁇ -tocopherol and mixtures thereof (vitamin E).
• Hydroxylated thiodiphenyl ethers for example 2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2- methylphenol), 4,4'-thiobis(3,6-di-sec-amylphenol), 4,4'-bis(2,6-dimethyl-4-hydroxyphenyl)- disulfide.
• 2,2'-thiobis(6-tert-butyl-4-methylphenol 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2- methylphenol), 4,4'-thiobis(3,6-di-sec-amylphenol), 4,4'-bis(2,6
• Alkylidenebisphenols for example 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'- methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-( ⁇ -methylcyclohexyl)- phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4- methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butyl- phenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis[6-( ⁇ -methylben- zyl)-4-nonylphenol], 2,2'-methylenebis[6-( ⁇ , ⁇ -dimethyl
• Hydroxybenzylated malonates for example dioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hy- droxybenzyl)malonate, di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate, di- dodecylmercaptoethyl-2,2-bis (3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis[4-(1 ,1 ,3,3-te- tramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.
• dioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hy- droxybenzyl)malonate di-octadecyl-2-(3-tert-butyl-4-
• Aromatic hydroxybenzyl compounds for example 1 ,3,5-tris(3,5-di-tert-butyl-4-hydroxy- benzyl)-2,4,6-trimethylbenzene, 1 ,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetrame- thylbenzene, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.
• Triazine compounds for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxy- anilino)-1 ,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1 ,3,5-tri- azine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1 ,3,5-triazine, 2,4,6-tris- (3,5-di-tert-butyl-4-hydroxyphenoxy)-1 ,2,3-triazine, 1 ,3,5-tris(3,5-di-tert-butyl-4-hydroxyben- zyl)isocyanurate, 1 ,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl
• Benzylphosphonat.es for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphospho- nate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl3,5-di-tert-butyl-4-hy- droxybenzylphosphonate, dioctadecyl- ⁇ -tert-butyl ⁇ -hydroxy-S-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.
• Acylaminophenols for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N- (3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.
• esters of ⁇ -(3,5-di-tert-butyl-4-hvdroxyphenyl)propionic acid with mono- or polyhydric alcohols e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1 ,6-hexanediol, 1 ,9- nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethy- lene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hy- droxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylol- propane, 4-hydroxy
• esters of ⁇ -(5-tert-butyl-4-hvdroxy-3-methylphenyl)propionic acid with mono- or poly- hydric alcohols e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1 ,6-hexanedi- ol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis- (hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethyl- olpropane, 4-hydroxymethyl-1
• esters of ⁇ -(3,5-dicvclohexyl-4-hvdroxyphenyl)propionic acid with mono- or polyhydric alcohols e.g. with methanol, ethanol, octanol, octadecanol, 1 ,6-hexanediol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)ox- amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy- droxymethyl-1-phospha-2,6,7-triox
• esters of 3,5-di-tert-butyl-4-hvdroxyphenyl acetic acid with mono- or polyhydric alcohols e.g. with methanol, ethanol, octanol, octadecanol, 1 ,6-hexanediol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)ox- amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy- droxymethyl-1 -phospha-2,6,7-trioxabicyclo
• antioxidants for example N,N'-di-isopropyl-p-phenylenediamine, N,N'-di-sec-bu- tyl-p-phenylenediamine, N,N'-bis(1 ,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3- methylpentyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-dicy- clohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-bis(2-naphthyl)-p- phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenyl
• Sterically hindered amines for example : carbonic acid bis(1-undecyloxy-2,2,6,6-tetramethyl- 4-piperidyl)ester, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4- piperidyl)succinate, bis(1 ,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1 -octyloxy-2, 2,6,6- tetramethyl-4-piperidyl)sebacate, bis(1 ,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert- butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4- hydroxypiperidine and succinic acid, linear or cyclic condensates of N,N'-
• Metal deactivators for example N,N'-diphenyloxamide, N-salicylal-N'-salicyloyl hydrazine, N,N'-bis(salicyloyl)hydrazine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, 3-salicyloylamino-1 ,2,4-triazole, bis(benzylidene)oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N,N'-diacetyladipoyl dihydrazide, N,N'-bis(salicyl- oyl)oxalyl dihydrazide, N,N'-bis(salicyloyl)thiopropionyl dihydrazide.
• Phosphites and phosphonites for example triphenyl phosphite, diphenylalkyl phosphites, phenyldialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-di- cumylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphos
• Tris(2,4-di-tert-butylphenyl) phosphite (lrgafos ® 168, Ciba Specialty Chemicals Inc.), tris(no- nylphenyl) phosphite, 5.
• Hydroxylamines for example N,N-dibenzylhydroxylamine, N,N-diethylhydroxylamine, N, N- dioctylhydroxylamine, N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine, N, N- dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine, N-hexadecyl-N-octadecylhydrox- ylamine, N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derived from hydrogenated tallow amine.
• Nitrones for example, N-benzyl-alpha-phenylnitrone, N-ethyl-alpha-methylnitrone, N-octyl- alpha-heptylnitrone, N-lauryl-alpha-undecylnitrone, N-tetradecyl-alpha-tridecylnnitrone, N- hexadecyl-alpha-pentadecylnitrone, N-octadecyl-alpha-heptadecylnitrone, N-hexadecyl-al- pha-heptadecylnitrone, N-ocatadecyl-alpha-pentadecylnitrone, N-heptadecyl-alpha-hepta- decylnitrone, N-octadecyl-alpha-hexadecylnitrone, nitrone derived from N
• Thiosynergists for example dilauryl thiodipropionate, dimistryl thiodipropionate, distearyl thiodipropionate or distearyl disulfide.
• Peroxide scavengers for example esters of ⁇ -thiodipropionic acid, for example the lauryl, stearyl, myristyl or tridecyl esters, mercaptobenzimidazole or the zinc salt of 2-mercapto- benzimidazole, zinc dibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritol tetrakis( ⁇ - dodecylmercapto)propionate.
• esters of ⁇ -thiodipropionic acid for example the lauryl, stearyl, myristyl or tridecyl esters
• mercaptobenzimidazole or the zinc salt of 2-mercapto- benzimidazole zinc dibutyldithiocarbamate
• dioctadecyl disulfide pentaerythritol tetrakis( ⁇ - dodecyl
• Basic co-stabilizers for example melamine, polyvinylpyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids, for example calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate or zinc pyrocatecholate.
• Basic co-stabilizers for example melamine, polyvinylpyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids, for example calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium ric
• Nucleating agents for example inorganic substances, such as talcum, metal oxides, such as titanium dioxide or magnesium oxide, phosphates, carbonates or sulfates of, preferably, alkaline earth metals; organic compounds, such as mono- or polycarboxylic acids and the salts thereof, e.g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid, sodium succinate or sodium benzoate; polymeric compounds, such as ionic copolymers (ionomers).
• inorganic substances such as talcum
• metal oxides such as titanium dioxide or magnesium oxide
• phosphates carbonates or sulfates of, preferably, alkaline earth metals
• organic compounds such as mono- or polycarboxylic acids and the salts thereof, e.g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid, sodium succinate or sodium benzoate
• polymeric compounds such as ionic copolymers (
• Fillers and reinforcing agents for example calcium carbonate, silicates, glass fibres, glass beads, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, wood flour and flours or fibers of other natural products, synthetic fibers.
• additives for example plasticisers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow-control agents, optical brighteners, flameproofing agents, antistatic agents and blowing agents.
• the modified olefin polymer contains one or more of the following conventional additives: Processing aids, nucleating agents, antistatic agents, flame retardants, chemical blowing agents, colorants, pigments, fillers and combinations thereof.
• Particularly preferred conventional additives are phosphites or phosphonites as e.g. defined under item 4 above, antioxidants as e.g. defined under items 1.1 to 1.19 above, in particular phenolic antioxidants, and 2,2,6,6-tetramethylpiperidine derivatives as e.g. defined under item 2 above.
• the conventional additives can be added to the olefin polymer before or after modification at any stage.
• the invention also includes all moulded or extruded articles containing the olefin polymer modified according to the invention.
• Another embodiment of the present invention is a process for preparing a modified olefin polymer resin, which comprises preparing a solid polymer article made of a composition containing the Components (A), (B) and (C) as defined above, and having a thickness of equal or less than 3 mm, preferably 10 ⁇ m to 3 mm, in particular 100 ⁇ m to 2 mm; exposing the polymer article to light of 200 to 800 nm, preferably 200 to 600 nm, at a radiation doze of 0.5 to 10 J/cm 2 and at a temperature below the melting temperature of the initial polymer article.
• the polymer article of the above process is preferably in pellet form.
• Components (A), (B) and (C) are preferably compounded in a single or twin screw extruder at a temperature of 170 to 250 0 C and under inert gas.
• Gallium-doped gas discharge lamp is preferred for the light exposure.
• the radiation doze is preferably 0.5 to 10 J/cm 2 and the distance of the lamp to the article to be irradiated is conveniently 5 to 150 cm.
• the exposure is preferable done at room temperature, e.g. 20° to 25°C.
• the exposure may be carried out in the air atmosphere.
• the improvement of F break is preferably 15 to 150 %, for example 15 to 95 %, in particular 30 to 95 % or 40 to 95 %, relative to F break of the non UV irradiated composition.
• v break is preferably 15 to 100 %, for example 18 to 45 %, in particular 20 to 45 %, relative to v break of the non UV irradiated composition.
• the improvement of F break is preferably 15 to 150 %, for example 15 to 95 %, in particular 30 to 95 % or 40 to 95 %, relative to F break of Component (A).
• v break is preferably 15 to 100 %, for example 18 to 45 %, in particular 20 to 45 %, relative to v break of Component (A).
• Pellets preparation Polypropylene random copolymer is pre-mixed in a Henschel FM/A10 high speed mixer with 0.25 % of bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide, 0.25 % of 4-dodecylbenzoyl-benzene and 1 % of triallylcyanurate and compounded in a Berstorff ZE 25x32D twin screw extruder under nitrogen (flow rate: 25 ml/min).
• the barrel temperature is 180 0 C for all zones and the measured melt temperature is 185°C.
• a standard type of screw is used; the screw speed and the feeding rate are 180 revolutions per minutes (RPM) and 6 kg/hour, respectively.
• a single extruded stand is cooled by passing through a water bath and cut into pellets using a PRIMO 6OE type of granulator from Rieter Automatik.
• the resulted pellets have a cylindrical shape with the following average dimensions: the smaller diameter of the base oval is 1.8 mm, the larger diameter is 2.5 mm and the height of the cylinder is 1.8 mm.
• the material is kept either in black bags or/and in the closed cardboard containers to avoid premature (de)activation of the photoinitiators.
• UV-exposure procedure The UV-exposure is done with a statutory Gallium-doped ("G"-type; gas discharge lamp UVASPOT 400/T; Dr. Honle AG). UVASPOT lamps are specially designed for the large area exposures. Approximately 60 grams of pellets prepared as described above are placed into a shallow container of size 23 cm x 30 cm x 2 cm made of polished stainless steel and positioned directly under the lamp on the supporting plane parallel to the lamp bulb within 30 cm distance. Four different exposure times of 1 , 2, 3 and 4 minutes are used.
• G Gallium-doped
• Melt Flow Rate (MFR) measurements are done with Gottfert MF300 tester in accordance with ISO 1 133/ ASTM D1238 (230°C/2.16kg).
• Example 1 illustrates an increase in F break correlating with the melt stiffness with an increase in the exposure time/radiation doze.
• the observed increase in F break is mirrored by a decrease in MFR values.
• the example demonstrates that there is a certain radiation doze until which F break and v break (corresponding to the melt extensibility) raise in parallel. After this doze is exceeded, the melt stiffness increases at the expense of melt extensibility.
• Example 1 is repeated except that the loadings of bis[2,4,6-trimethylbenzoyl]- phenylphosphineoxide, 4-dodecylbenzoyl-benzene and triallylcyanurate are halved and the UV-exposure time is 2 and 4 minutes.
• Example 2 illustrates a surprising increase in F break and v break at the unchanged, as compared to initial, MFR values.
• Example 3 Foaming application. Foaming: 40 g of polypropylene random copolymer unmodified or modified as described in Example 1 , exposure time 4 min, are kneaded in the Brabender Plastogram PL 2000 with 2 % of a chemical foaming agent (Hydrocerol PEX 5008, available from Clariant) for 10 min at 170 0 C under nitrogen. After kneading, the polymers are pressed consecutively in two compression moulding machines, in the first, at 170 0 C with 50 bar for 3 min, and, in the second, at 220 0 C with 100 bar for another 3 min. Followinged that, the pressure is rapidly released and gases, formed in the course of the Hydrocerol decomposition, foamed the samples.
• Hydrocerol PEX 5008 available from Clariant
• Microscopy characterization of foams made of original and modified polypropylene random copolymer Appearance of the foamed samples in the cross-sectional plane is examined by an electron microscope ESEMTM FEI QUANTA 200. It is known that linear polymers are difficult to foam as their chains have a reduced ability to hold voids growing in the polymer matrix. In accordance with this, original polypropylene random copolymer is hardly foamed. The sample exhibits only a few holes formed in the result of the decomposition gases escape. Unlike the original polymer, the modified material demonstrates a "bubbled", that is, in the foaming jargon, a closed-cell structure been characteristic of the foamed high melt strength grades.
• Example 1 and Example 2 are repeated except that instead of triallylcyanurate, trimethylolpropane trimethacrylate is used as the co-additive containing double bonds and the exposure time is 1 and 3 min. Results are summarized in Tables 4 and 5.
• Example 4 confirms the trends for F bre ak and (/break seen in Examples 1 and 2. It also shows that a methacrylic acid derivative (trimethylolpropane trimethacrylate) can be used as a co- additive instead of an ethane derivative (triallylcyanurate) and that the former is more effective than the latter as, at the same loadings, shorter exposure times are required for trimethylolpropane trimethacrylate containing formulations to reach the same values of F bre a k -
• Example 5 Example 5:
• Example 1 is repeated except that instead of triallylcyanurate, trimethylolpropane trimethacrylate (TMPTMA) is used as the co-additive containing double bonds and instead of the combination of "bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide and 4-dodecylbenzoyl- benzene", a phenylglyoxylate derivative (PG) as indicated in Table 6 is used as the photoinitiator. The exposure time is 2 min. Results from the measurements are summarized in Table 6 below.
• TMPTMA trimethylolpropane trimethacrylate
• PG phenylglyoxylate derivative
• Pellets preparation Pellets of five formulations listed below are prepared and handled as described in Example 1 , except that not polypropylene random copolymer but linear low density polyethylene is used as the base polymer and the screw speed is 100-120 revolutions per minutes (RPM).
• UV-exposure is conducted as described in Example 1. The exposure time is 2 min.
• Melt Flow Index (MFI) measurements are conducted in accordance with ISO 1 133/ ASTM D1238 (190°C/2.16 kg).
• Melt Strength measurements are done as described in Example 1 , except that the temperature of the melt is 150 0 C and the acceleration rate of the Rheotens rollers is 15 mm/s 2 .
• TMPTMA Trimethylolpropanetrimethylacrylate
• Table 7 above illustrates a pronounced increase in F br ea k , correlating with the melt stiffness, at a higher loading of photoinitiators accompanied though by some decrease in the melt extensibility ⁇ v break ). At a lower loading, at the same radiation doze, a concurrent increase in both parameters is possible.
• Example 1 is repeated without bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide and triallylcyanurate being optionally present. Results are summarized in Tables 8 and 9.
• Example 1 is repeated except that the ratio of loadings of bis[2,4,6-trimethylbenzoyl]- phenylphosphineoxide and 4-dodecylbenzoyl-benzene is varied.
• Table 12 Effect of exposure time on properties of polypropylene random copolymer modified with 0.1% of bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide, 0.5% of 4-dodecylbenzoyl-benzene and 1 % of triallylcyanurate.
• Example 1 is repeated except that polypropylene homopolymer is used as the initial material for modification. Compounding is done at 200-210 0 C. The screw speed and the feeding rate are 150 revolutions per minutes (RPM) and 8 kg/hour, respectively. Melt strength measurements are conducted at 220 0 C. The results are summarized in the Table 13 below along with the MFR results.
• Example 9 is repeated except that a 1 :1 blend of polypropylene homopolymer and polypropylene random copolymer is used as the initial material for modification.
• Table 14 summarizes the results. Table 14:
• Polypropylene copolymer is pre-mixed in a Henschel FM/A10 high speed mixer with 0.25 % of bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide, 0.25 % of 4-dodecylbenzoyl-benzene, 1 % of triallylcyanurate and 0.25 % (one of each) HALS-1 , HALS-2 or HALS-3. Pellets of these formulations are prepared and exposed as described in Example 1 , exposure time being 4 min.
• MFR Melt Flow Rate
• HALS-1 , HALS-2 or HALS-3 Effect of the presence of HALS-1 , HALS-2 or HALS-3 on MFR of polypropylene copolymer modified with 0.25 % of bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide, 0.25 % of 4- dodecylbenzoyl-benzene and 1 % of triallylcyanurate before and after UV-light exposure.
• Table 15 illustrates that HALS-1 , HALS-2 or HALS-3 does not interfere with modification reactions initiated by UV-light.
• Table 16 illustrates that the light stability of polypropylene copolymer modified with 0.25 % of bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide, 0.25 % of 4-dodecylbenzoyl-benzene, 1 % of triallylcyanurate and 0.25% HALS-1 , HALS-2 or HALS-3 is excellent.
• Example 1 The procedure of Example 1 is repeated with fixed loadings of 0.25% of bis[2,4,6- trimethylbenzoyl]-phenylphosphineoxide and 0.125% of 4-dodecylbenzoyl-benzene in the presence of the co-additives 1 % of TAC, 1 % of TMPTMA or the blend 0.5% of TAC and 0.5% of TMPTMA, respectively.
• the exposure time is 4 min. Results from the measurements are summarized in Tables 17 and 18.
• TMPTMA Trimethylolpropanetrimethylacrylate
• Table 17 Effect of the co-additives composition on properties of polypropylene random copolymer modified with 0.25% of bis[2,4,6-trimethylbenzoyl]-phenylphosphineoxide and 0.125% of 4- dodecylbenzoyl-benzene after 4 min of UV-exposure.

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