AU732342B2 - Process for increasing the melt strength of polypropylene - Google Patents

Description

WO 99/36466 PCT/AU99/00036 -1-

PROCESS

FOR INCREASING THE MELT STRENGTH OF POLYPROPYLENE The present invention relates to polypropylene homopolymers and copolymers. In particular, the present invention relates to a process for increasing the melt strength and/or the extensional melt viscosity of said polymers by melt phase processing.

The melt strength and extensional viscosity of linear or straight chain polymers, such as polypropylene, decreases rapidly with temperature. By contrast, polymers such as low density polyethylene which are highly branched retain relatively high melt strengths and extensional viscosities. It is generally understood that the difference in melt strengths and extensional viscosities is attributable to the presence of long chain branching in polymers such as low density polyethylene. Long chain branching allows a greater degree of chain entanglement.

A number of methods for increasing the melt strength/extensional viscosity of polypropylene and related polymers through the introduction of branching or a limited degree of crosslinking in a process involving reactive extrusion have been proposed and are summarised in a recent paper by Wang et al. (Wang, Tzoganakis, and Rempel, J. Appl. Polym. Sci., 1996, 61, 1395). One such process involves the reactive extrusion of polypropylene with a polyfunctional monomer/initiator combination. For example, the use of pentaerythritol triacrylate in combination with 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (DHBP).

White (US 5578682) has disclosed the use of various polyunsaturated crosslinking agents (for example, bismeleimide derivatives) in combination with free radical initiators to achieve an increase in the melt strength various polymers.

It is well known that the melt phase processing of polypropylene leads to mechanochemical degradation. The processing of polypropylene in the presence of free radical initiators SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -2provides an increased rate of degradation. This controlled degradation of polypropylene is used commercially for the production of controlled rheology resins having reduced polydispersity and reduced die swell (Lambla, M. in Comprehensive Polymer Science, Pergamon, New York 1992, vol Suppl. 1, p 619; Hogt, Meijer, Jelinic, J. in Reactive Modifiers for Polymers, Al-Malaika, S. Ed., Chapman Hall, London, 1996, p The degradation of polypropylene as described therein results in a lowering of melt strength.

The batch modification of polypropylene to produce crosslinked (insoluble) polypropylene by treatment with peroxides is described by Borsig et al. (Borsig, Fiedlerova, Lazar, M.

Macromol. Sci, Chem., 1981, A16, 513). Initiators which produce benzoyloxy radicals or phenyl radicals are described as being more efficient in inducing crosslinking or grafting than those which produce t-butoxy or alkyl radicals. The process requires the use of high levels of peroxide. The use of polyfunctional monomers as coagents to retard degradation and enhance crosslinking is described by Chodak, Fabianova, Borsig, Lazar, M.

Agnew. Makromol. Chem., 1978, 69, 107.

DeNicola (EP 384331A2) has disclosed a means to produce a branched propylene polymer material showing a nett increase in the weight average molecular weight by solid state modification of predominantly isotactic semi-crystalline linear polypropylene. The process described in EP384331A2 involves blending peroxides with short half lives (eg peroxy dicarbonates) with linear propylene polymer in a mixing vessel at temperatures from 23°C to 120 0 C in an inert atmosphere and continuing to mix for a period of time until the peroxide decomposes and polymer fragmentation and branching occurs without significant gelation of the polymer. DeNicola states that at temperatures greater than 120 0 C no branching or melt strength enhancement is achieved.

U.S. 5,464,907 teaches that certain unsaturated maleate or itaconate derived peroxides may be used to induce grafting in polypropylene and a-olefin copolymers. They report that use SUBSTITUTE SHEET (Rule 26) (RO/AU) PCT/AU99/00036 Received 13 August 1999 CRCCOMP.019 -3of other peroxides generally results in chain degradation.

Polypropylene is also known to undergo substantial degradation during melt phase grafting of monofunctional monomers, for example maleic anhydride and glycidyl methacrylate. It has also been reported that the degradation that accompanies grafting of these monomers to polypropylene may be reduced by the addition of relatively high concentrations of certain comonomers including styrene (see, for example Sun, Hu, and Lambla, M., Angew. Makromol. Chem, 1995, 229, 1; Chen, Wong, B. and Baker, W.E. Polym.

Eng. Sci. 1996, 36, 1594.) Sun et al. report that there is degradation (as indicated by an overall decrease in molecular weight) when styrene alone is grafted onto polypropylene even when a relatively high concentration is used (4 moles/100g PP). Either 2,5-dimethyl-2,5-(tbutylperoxy)hex-3-yne or 2,5-dimethyl-2,5(t-butylperoxy-hexane(DHBP) was used as the initiator in these experiments.

We have found that melt mixing polypropylene homopolymer or ethylene-polypropylene copolymer in the presence of a suitable initiator provides one or more of the following: increased melt strength; increased extensional viscosity; increased molecular weight; and broadened molecular weight distribution.

According to the present invention there is provided a process for modifying a polypropylene (co)polymer wherein said process comprises melt mixing the polypropylene (co)polymer in the presence of an initiator wherein said initiator is selected from the group defined by formula 1:

SRAHEE

r AMENDED SHEET

IPEA/AU

PCT/AU99/00036 Received 13 August 1999 CRCCOMP.019 -4- -0-R U V Formula 1 wherein R is selected from the group consisting of optionally substituted C 1 to C~acyl, optionally substituted C 1 to C 1 alkyl, aroyl defined by formula 2, Formula 2 and groups of formula 3, AMENDED

SHEET

IPENAU

Y X' 'U

V

Formula 3 wherein U, V, X, Y, Z, Y' and Z' are independently selected from the group consisting hydrogen, halogen, C1-C18 alkyl, C1-C18 alkoxy, aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, aryloxycarbonyl, trialkyl silyl, hydroxy, or a moiety of formula 4, 0 Formula 4 and wherein T is alkylene.

o• Advantageously the thus formed modified polypropylene may be obtained without the 1 associated production of significant and detrimental amounts of gels.

Polymers suitable for use in the present invention include a wide variety of polypropylene homopolymers, copolymers and blends containing one or more polypropylene homopolymers and/or copolymers.

20 Suitable polypropylene homopolymers include isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene. Commercial isotactic polypropylene having a proportion of WO 99/36466 PCT/AU99/00036 -6meso/dyads of greater than 90% is preferably used in the process of the present invention.

Isotactic polypropylene is a semi-crystalline polymer having a number of properties which have made it one of the most widely used commercial polymers. These properties include heat resistance, stress cracking resistance, chemical resistance, toughness, and low manufacturing costs. However, the melt strength of isotactic polypropylene as measured directly by extensional viscosity or use of a commercial melt strength tester or indirectly by more qualitative measures such as drop time or die swell ratio is relatively low. This relatively low melt strength limits the use of polypropylene in applications such as foam extrusion, thermoforming and film blowing. In order to use polypropylene in such applications it is necessary to employ sophisticated processing equipment. The present invention now permits this already widely used commercial polymer to be used in an even wider range of applications.

Polypropylene copolymers include copolymers of propylene and other monomers with such other monomers being present preferably in amounts of up to 10%wt/wt. A preferred comonomer is ethylene.

The present invention is also applicable to other polymers comprising a-olefin monomers.

It is preferable that any such a-olefins are present in the polymer to be modified in amounts in excess of 90%wt/wt. a-olefins include propene, 1-butene, 1-pentene and 1-hexene.

The initiators for use in the present invention may be selected from the group defined by formula 1.

SUBSTITUTE SHEET (Rule 26) (RO/AU) PCT/AU99/00036 Received 13 August 1999 CRCCOMP.019 -7- O0-0-R U V Formula 1 wherein R is selected from the group consisting of optionally substituted C 1 to q. acyl, optionally substituted C 1 to C, 8 alkyl, aroyl defined by formula 2, VU

V

Formula 2 and groups of formula 3, AMENDED SHEET O06

IPENIAU

PCT/AU99/00036 Received 13 August 1999 CRCCOMP.019

O--T

Formula 3 wherein U, V, X, Y, Z, Y' and Z' are independently selected from the group consisting hydrogen, halogen, C1-C18 alkyl, C1-C18 alkoxy, aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, aryloxycarbonyl, trialkyl silyl, hydroxy, or a moiety of formula 4,

O

-0-0-R Formula 4 and wherein T is alkylene.

The alkyl, including acyl and alkoxy, groups included in the initiators of formula 1 may include hetero atoms within the carbon chain (eg polyalkylene oxide) and may be branched or unbranched and may be substituted with one or more groups such as with alkyl, aryl, alkoxy or halogen substituents.

Without wishing to be bound by theory, it is believed that the aroyloxy radical of formula AMENDED

SHEET

IPEA/AU

WO 99/36466 PCT/AU99/00036 -9- Formula ,where U, V, X, Y and Z are as hereinabove defined, provide the surprising increase in melt strength. Other compounds which generate these aroyloxy radicals may also be used in the present invention.

A preferred class of initiators of formula 1 are diaroyl peroxides of formula 6.

Y. X 'X .Y' U V 'V U' Formula 6 where X, Y, Z, U, V, V' are independently selected from the group consisting of hydrogen and Ci alkyl where at least one of X, Y, Z, U, V and Y', V' are not hydrogen.

Diaryl peroxides of formula 6 include Dibenzoyl peroxide, o,o'-Bis(methylbenzoyl) peroxide, p,p'-Bis(methylbenzoyl) peroxide, M,M'-Bis(methylbenzoyl) peroxide, o,m'-Bis(methylbenzoyl) SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 WO 9936466PCT/AU99/00036 10 peroxide, o,p'-Bis(methylbenzoyl) peroxide, mp'-Bis(methylbenzoyl) peroxide, Bis(ethylbenzoyl) peroxide (all isomers), Bis(propylbenzoyl) peroxide (all isomers), Bis(butylbenzoyl) peroxide (all isomers), Bis(pentylbenzoyl) peroxide (all isomers), Bis(hexylbenzoyl) peroxide (all isomers), Bis(heptylbenzoyl) peroxide (all isomers), Bis(octylbenzoyl) peroxide (all isomers), Bis(nonylbenzoyl) peroxide (all isomers), Bis(methoxybenzoyl) peroxide (all isomers), Bis(ethoxybenzoyl) peroxide (all isomers), Bis(propoxybenzoyl) peroxide (all isomers), Bis(butoxybenzoyl) peroxide (all isomers), Bis(pentoxybenz 'oyl) peroxide (all isomers), Bis(hexyloxybenzoyl) peroxide (all isomers), Bis(heptyloxybenzoyl) peroxide (all isomers), Bis(octyloxybenzoyl) peroxide (all isomers), -Bis(nonyloxybenzoyl) peroxide (all isomers), Bis(chlorobenzoyl) peroxide (all isomers), Bis(fluorobenzoyl) peroxide (all isomers), Bis(bromobenzoyl) peroxide (all isomers), Bis(dimethylbenzoyl) peroxide (all isomers), Bis(tnimethylbenzoyl) peroxide (all isomers), Bis(tert-butylbenzoyl)peroxide (all isomers), Bis(ditert-butylbenzoyl)peroxide (all isomers), Bis(ter-tbutoxybenzoyl)peroxide (all isomers), Bis(ditrimethylsilylbenzoyl) peroxide (a isomers), Bis(heptafluoropropylbenzoyl) peroxide (all isomers), Bis(2,6-dimethy.4- trimethylsilyl benzoyl) peroxide and isomers, 2,2'(dioxydicarbonyl) his Benzoic acid dibutyl ester where the term "all isomers" -refers to any variation in the position of the ring substituent as well as the structure of the substituent itself i.e. for propyl; n-propyl and isopropyl.

Examples of aromatic peresters of formula 1 include the following: tert-butyl perbenzoate, tertbutyl (methyl)perbenzoate (all isomers), tert-butyl (ethyl)perbenzoate (all isomers), tert-butyl (octyl)perbenzoate (all isomers), tert-butyl (nonyl)perbenzoate (all isomers), tert-amyl perbenzoate, tert-amyl (methyl)perbenzoate (all isomers), tert-amyl (ethyl)perbenzoate (all isomers), tert-amyl (octyl)perbenzoate (all isomers), tert-amyl (nonyl)perbenzoate (all isomers), tert-ainyl (methoxy)perbenzoate (all isomers), tert-amyl (octyloxy)perbenzoate (all isomers),,tertamyl (nonyloxy)perbenzoate (all isomers), 2-ethyhexyl perbenzoate, 2-ethylhexyl (methyl)perbenzoate (all isomers), 2-ethylhexyl (ethyl)perbenzoate (all isomers), 2-ethylhexyl (octyl)perbenzoate (all isomers), 2-ethyihexyl (nonyl)perbenzoate (all isomers), 2-ethyihexyl (methoxy)perbenzoate (all isomers), 2-ethyihexyl (ethoxy)perbenzoate (all isomers), 2ethylhexyl (octyloxy)perbenzoate (all isomers), 2-ethyihexyl (nonyloxy)perbenzoate (all isomers) SUBSTITUTE SHEET (Rule 26) (RO/AU) -11- The initiators for use in the present invention also include compounds of formula 1 where at least one of U, V, X, Y, Z, X' Y' and Z' is a moiety of formula 4 where R is as defined above. Preferably there is no more than one moiety of formula 4 per aromatic ring.

Such initiators are di or higher functional peroxides and may include polymeric peroxides such as Bis (tertbutylmonoperoxy phthaloyl) diperoxy terephthalate, Bis (tertamylmonoperoxy phthaloyl) diperoxy terephthalate diacetyl phthaloyl diperoxide, dibenzoyl phthaloyl diperoxide, bis(4 methylbenzoyl) phthaloyl diperoxide, diacetyl terephthaloyl di peroxide, dibenzoyl terephthaloyl diperoxide, and Poly[dioxycarbonyldioxy(1,1,4,4-tetramethyl-1,4butanediyl)]peroxide.

It is described that the initiators are selected such that it has an appropriate decomposition temperature (half life), solubility, and reactivity and such that the groups R, T, X, Y, Z, U, V, V give no adverse reaction under the conditions of the process. Preferred peroxides will have a 0.1 hour half life in the range 100 170°C.

The amount of initiator used in the process of the present invention should be an effective amount to achieve the desired increase in melt strength. Melt strength is considered in the art to be an indication of long-chain branching in polyolefins. It is preferable in the process 20 of the present invention that long-chain branching predominates over crosslinking in the reaction between the initiator and the polypropylene (co)polymer. Crosslinking of the *polypropylene (co)polymer may result in the formation of gels which disrupt the appearance of the polypropylene (co)polymer. In the process of the present invention it is desirable to control the degree and distribution of crosslinking and keep the level of crosslinking as 25 uniform and as low as necessary to produce the desired effects. The amount of crosslinking which occurs in the polypropylene (co)polymer is dependant upon the amount of initiator melt mixed with the polypropylene (co)polymer. The amount of crosslinking is also dependent upon the degree of mixing as any regions high in initiator concentration will result in excessive localised crosslinking and the formation of gels. It is desirable that good Sdistributive and dispersive mixing be employed to promote even distribution of the initiator WO 99/36466 PCT/AU99/00036 -12in the polypropylene (co)polymer so as to minimise the variation in initiator concentration throughout the polypropylene (co)polymer and reduce the likelihood of the formation of gels.

Preferably the initiator will be present in the range of from 0.004 to 0.25 moles of initiator per kg of the polypropylene homopolymer or copolymer (polypropylene (co)polymer). The more preferred range being from 0.006 to 0.10 moles of initiator per kg. of the polypropylene (co)polymer and even more preferred range being from 0.01 to 0.05 moles of initiator per kg of the polypropylene (co)polymer.

The initiator is preferably introduced into the polymer melt directly, either neat (as a powder or a liquid), dispersed or dissolved in a suitable medium (for example, dissolved in 2butanone) or adsorbed on polymer pellets or powder which are added as a masterbatch. It is desirable that the initiator is rapidly mixed with the polymer melt at a rate in keeping with the half life of the initiator at the processing temperature of the polypropylene (co)polymer.

The initiator may be added either alone, or along with the polypropylene (co)polymer, or with any other polymer, additive or filler, so that the polymer melts and mixes with the initiator as it is decomposing. When the initiator is fed to the main feed throat of the extruder it is preferred to have a barrel temperature which is relatively low in the region adjacent to the main feed throat and increases towards the die to prevent premature decomposition of the peroxide.

Preferably the initiators for use in the present invention are selected from the group consisting of Dibenzoyl peroxide, o,o'-Bis(methylbenzoyl) peroxide, p,p'-Bis(methylbenzoyl) peroxide, o,o'- Bis(methylbenzoyl) peroxide, o,m'-Bis(methylbenzoyl) peroxide, o,p'-Bis(methylbenzoyl) peroxide, m,p'-Bis(methylbenzoyl) peroxide, Bis(ethylbenzoyl) peroxide (all isomers), Bis(propylbenzoyl) peroxide (all isomers), Bis(butylbenzoyl) peroxide (all isomers), Bis(pentylbenzoyl) peroxide (all isomers), Bis(hexylbenzoyl) peroxide (all isomers), Bis(heptylbenzoyl) peroxide (all isomers), Bis(octylbenzoyl) peroxide (all isomers), Bis(nonylbenzoyl) peroxide (all isomers), Bis(methoxybenzoyl) peroxide (all isomers), SUBSTITUTE SHEET (Rule 26) (RO/AU) -13 Bis(ethoxybenzoyl) peroxide (all isomers), Bis(propoxybenzoyl) peroxide (all isomers), Bis(butoxybenzoyl) peroxide (all isomers), Bis(pentoxybenzoyl) peroxide (all isomers), Bis(hexyloxybenzoyl) peroxide (all isomers), Bis(heptyloxybenzoyl) peroxide (all isomers), Bis(octyloxybenzoyl) peroxide (all isomers), Bis(nonyloxybenzoyl) peroxide (all isomers), Bis(chlorobenzoyl) peroxide (all isomers), Bis(fluorobenzoyl) peroxide (all isomers), Bis(bromobenzoyl) peroxide (all isomers), Bis(dimethylbenzoyl) peroxide (all isomers), Bis(trimethylbenzoyl) peroxide (all isomers), Bis(tert-butylbenzoyl)peroxide (all isomers), Bis(ditert-butylbenzoyl)peroxide (all isomers), Bis(tertbutoxybenzoyl)peroxide (all isomers), Bis(ditrimethylsilylbenzoyl) peroxide (all isomers), Bis(heptafluoropropylbenzoyl) peroxide (all isomers), Bis(2,4-dimethyl-6- trimethylsilyl benzoyl) peroxide and isomers tert-amyl perbenzoate, tert-amyl (methyl)perbenzoate (all isomers), tert-amyl (ethyl)perbenzoate (all isomers), tert-amyl (octyl)perbenzoate (all isomers), tert-amyl (nonyl)perbenzoate (all isomers), tert-amyl (methoxy)perbenzoate (all isomers), tert-amyl (octyloxy)perbenzoate (all isomers), tert-amyl (nonyloxy)perbenzoate (all isomers), Bis (tertamylmonoperoxy phthaloyl) diperoxy terephthalate, diacetyl phthaloyl diperoxide, dibenzoyl phthaloyl diperoxide, bis(4-methylbenzoyl) phthaloyl diperoxide, diacetyl terephthaloyl di peroxide and dibenzoyl terephthaloyl diperoxide.

More preferably the initiators are selected from the group consisting of dibenzoyl peroxide, o,o'- Bis(methylbenzoyl) peroxide, p,p'-Bis(methylbenzoyl) peroxide, M,M'-Bis(methylbenzoyl) 20 peroxide, o,m'-Bis(methylbenzoyl) peroxide, o,p'-Bis(methylbenzoyl) peroxide, and m,p'- Bis(methylbenzoyl) peroxide.

*The initiators may optionally be used in combination with one or more monomers.

Preferably the one or more monomers are selected from the group consisting of monene monomer. It will be understood by those skilled in the art that by the term "monoene monomer" it is meant a monomer having a single reactive double bond.

The preferred monoene monomer(s) or mixtures thereof include vinyl monomers of structure RAL\ CH 2 CHX where X is chosen so as to confer the desired reactivity and solubility.

WO 99/36466 PCT/AU99/00036 14- More preferred monomers include styrene. The amount of monomer will preferably be up to 5 times the total moles of initiator added to the polypropylene (co)polymer. The most preferred range being 1 to 4 times the total moles of initiator added to the polypropylene (co)polymer.

The monomer may be added with the polypropylene (co)polymer or it can be added prior to the initiator, with the initiator or subsequent to the initiator. However it is preferred to have the monomer mixed and dispersed into the polymer melt before the initiator has substantially decomposed. The monomer is preferably introduced into the polymer melt directly, either neat (as a powder or a liquid), dispersed or dissolved in a suitable medium (for example, dissolved in 2-butanone) or adsorbed on polymer pellets or powder which are added as a masterbatch.

Preferred initiators for use in combination with monomers include Dibenzoyl peroxide, o,o'- Bis(methylbenzoyl) peroxide, p,p'-Bis(methylbenzoyl) peroxide, M,M'-Bis(methylbenzoyl) peroxide, o,m'-Bis(methylbenzoyl) peroxide, o,p'-Bis(methylbenzoyl) peroxide, m,p'- Bis(methylbenzoyl) peroxide, Bis(ethylbenzoyl) peroxide (all isomers), Bis(propylbenzoyl) peroxide (all isomers), Bis(butylbenzoyl) peroxide (all isomers), Bis(pentylbenzoyl) peroxide (all isomers), Bis(hexylbenzoyl) peroxide (all isomers), Bis(heptylbenzoyl) peroxide (all isomers), Bis(octylbenzoyl) peroxide (all isomers), Bis(nonylbenzoyl) peroxide (all isomers), Bis(methoxybenzoyl) peroxide (all isomers), Bis(ethoxybenzoyl) peroxide (all isomers), Bis(propoxybenzoyl) peroxide (all isomers), Bis(butoxybenzoyl) peroxide (all isomers), Bis(pentoxybenzoyl) peroxide (all isomers), Bis(hexyloxybenzoyl) peroxide (all isomers), Bis(heptyloxybenzoyl) peroxide (all isomers), Bis(octyloxybenzoyl) peroxide (all isomers), Bis(nonyloxybenzoyl) peroxide (all isomers), Bis(chlorobenzoyl) peroxide (all isomers), Bis(fluorobenzoyl) peroxide (all isomers), Bis(bromobenzoyl) peroxide (all isomers), Bis(dimethylbenzoyl) peroxide (all isomers), Bis(trimethylbenzoyl) peroxide (all isomers), Bis(tert-butylbenzoyl)peroxide (all isomers), Bis(di-tert-butylbenzoyl)peroxide (all isomers), Bis(tert-butoxybenzoyl)peroxide (all isomers), Bis(ditrimethylsilylbenzoyl) peroxide (all isomers), Bis(heptafluoropropylbenzoyl) peroxide (all isomers), Bis(2,4-dimethyl-6- trimethylsilyl benzoyl) SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 15 peroxide and isomers, 2,2'(dioxydicarbonyl) bis Benzoic acid dibutyl ester, tert-butyl perbenzoate, tert-butyl (methyl)perbenzoate (all isomers), tert-butyl (ethyl)perbenzoate (all isomers), tert-butyl (octyl)perbenzoate (all isomers), tert-butyl (nonyl)perbenzoate (all isomers), tert-amyl perbenzoate, tert-amyl (methyl)perbenzoate (all isomers), tert-amyl (ethyl)perbenzoate (all isomers), tert-amyl (octyl)perbenzoate (all isomers), tert-amyl (nonyl)perbenzoate (all isomers), tert-amyl (methoxy)perbenzoate (all isomers), tert-amyl (octyloxy)perbenzoate (all isomers), tert-amyl (nonyloxy)perbenzoate (all isomers), 2-ethylhexyl perbenzoate, 2-ethylhexyl (methyl)perbenzoate (all isomers), 2-ethylhexyl (ethyl)perbenzoate (all isomers), 2-ethylhexyl (octyl)perbenzoate (all isomers), 2-ethylhexyl (nonyl)perbenzoate (all isomers), 2-ethyihexyl (methoxy)perbenzoate (all isomers), 2-ethylhexyl (ethoxy)perbenzoate (all isomers), 2ethylhexyl (octyloxy)perbenzoate (all isomers), 2-ethyhexyl (nonyloxy)perbenzoate (all isomers), Bis (tertbutylmonoperoxy phthaloyl) diperoxy terephthalate, Bis (tertamylmonoperoxy phthaloyl) diperoxy terephthalate diacetyl phthaloyl diperoxide, dibenzoyl phthaloyl diperoxide, bis(4 methylbenzoyl) phthaloyl diperoxide, diacetyl terephthaloyl di peroxide, dibenzoyl terephthaloyl diperoxide and Poly[ dioxycarbonyldioxy(1,1,4,4-tetramethyl-1,4-butanediyl)] peroxide.

Advantageously initiators may be selected to avoid undesirable by-products. In certain applications, it may be desirable to avoid the use of initiators which generate benzene. For example di toluoyl peroxides (bis methyl benzoyl peroxides) may be used in preference to dibenzoyl peroxide.

The processability and other properties of the product may be improved by a chain scission step following the initial polymer modification step. This may be carried out by: a) adding one or more additional initiators with or subsequent to the first initiator addition; b) the use of high shear mixing; c) the use of high temperatures; d) the use combination is of one or more of above.

This additional step in the production of a polymer enables tailoring the properties of the product to meet the requirements of the desired application, For example, by this two stage SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 16process it is possible to produce materials with similar melt viscosity to the base polymer but a substantially increased melt strength. Use of the single stage process generally provides both an increase in melt strength and an increase in melt viscosity (see examples) One or more additional initiators may be added to the polypropylene (co)polymer during the modification process either with or subsequent to the initiator and monomer addition. The additional initiator is typically added to give chain scission of the polypropylene (co)polymer so as, to decrease the melt viscosity and improve the processability of the modified polypropylene (co)polymer. The additional initiator should be introduced to the polymer melt after the first initiator or have a sufficiently long half-life relative to the first initiator such that its decomposition can be staged to occur after the initial polymer modification process. In some instances a polypropylene (co)polymer modified in accordance with the present invention may have a MFI 1 g/10 min. With use of the additional initiator an MFI 1 min may be achieved. The additional initiator may be selected from the group consisting of 2 ,5-dimethyl-2,5-di(t-butylperoxy)hexane (DHBP), dicumyl peroxide (DCP), t-butyl peroxy- 2-ethylhexonate(TBEH), and dilauryl peroxide (DLP) or any other peroxide which may result in the overall chain scission of the polypropylene (co)polymer during melt processing. For example in the absence of the monoene monomers, t-butyl peroxybenzoate or other nonpreferred initiators for use in the presence of the monomer may be preferably added as the additional initiator. While the improvement in processability through chain scission normally results in some decrease in the melt strength/extensional viscosity of the modified polypropylene (co)polymer, the melt strength/extensional viscosity may still be acceptable, and improved over the unmodified polypropylene (co)polymer.

It is possible to combine the process of the present invention with other processes of polymer modification or with, for example, the addition of fillers, additives or stabilisers, or blending with other polymers. [which do not substantially interfere with the improved properties afforded by the process of the present invention].

SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -17- In the process of the present invention the polypropylene (co)polymer is melt mixed in the presence of initiator and monomer. Melt mixing may be carried out by any convenient means capable of mixing the polypropylene (co)polymer at temperatures above the melting point of the polypropylene (co)polymer.

Suitable apparatus for melt mixing the polypropylene (co)polymer include continuous and batch mixers. Suitable mixing equipment includes extruders such as single screw and twin screw extruders, static mixers, cavity transfer mixers and combinations of two or more thereof. It is preferred that the melt mixing is conducted in either a co- or counter- rotating twin screw extruder.

The barrel set temperatures are preferably in the range 80-280 Typical melt temperatures are in the range 170-290 'C.

In order to optimise the melt strength/extensional viscosity, the preferred melt temperatures are in the range 160 °C to 220 This range provides optimal properties whilst minimising the amount of chain scission which occurs during processing. However, in some cases it may be desirable to use higher temperatures such as in the venting/discharge sections of single screw or twin screw extruders or to induce some chain scission in order to decrease the molecular weight of the modified polypropylene (co)polymer and improve the processability of the modified polypropylene (co)polymer.

Typically, the die temperatures are in the range 180-290 °C.

Preferably the extrusion conditions are adjusted so that the polypropylene (co)polymer, initiator/monomer mixture are conveyed as quickly as possible into the melting/mixing zone to maximise the melt phase reaction (eg for twin screw extruders high throughput rates, higher screw speeds under starve fed conditions). It is more preferred that the additives are added to and mixed with molten polypropylene (co)polymer to further enhance the melt phase SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 18reaction. Preferably residence times in the range of from 10 seconds to 5 minutes are selected depending upon the temperature profile, throughput rate and initiator levels. More preferred residence times are in the range of from 15 seconds to 120 seconds.

Vacuum venting can be applied to remove volatile by-products, solvents and/or excess monomer.

While not wishing to be limited by theory, it is believed that the effectiveness of the present invention is determined by three factors: The rate and specificity of the reaction of the aroyloxy or the derived phenyl radicals or substituted phenyl radicals with polypropylene, and the monomer if present. It is believed that the aroyloxy, phenyl or substituted aroyloxy or phenyl radicals show less specificity for abstraction of tertiary vs. secondary or primary hydrogens than do, for example, alkoxy or alkyl radicals.

The initiator half-life. Use of an initiator with a short initiator half-life will generate a locally high concentration of radicals thus increasing the likelihood of radical combination events.

The solubility characteristics of the initiator in the polymer melt.

Without wishing to be bound by theory, peroxides that generate aroyloxy or aryl radicals (for example benzoyloxy, p-toluouloxy) are preferred over those that generate alkoxy radicals (for example, t-butoxy radical, cumyloxy radical). It is believed and supported in the literature that the latter class of peroxides promote chain scission under the melt mixing conditions.

While not wishing to be bound by the mechanism, it is believed that this effect is due to the specificity shown by the alkoxy radicals as opposed to the aroyloxy or aryl radicals generated by the peroxides of structure 1. Furthermore we believe that peroxides which generate both SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -19alkoxy and aroyloxy or aryl radicals (for example, t-butyl perbenzoate) show intermediate behaviour. It is believed that they promote less chain scission than peroxides which generate only alkoxy radicals (for example, dialkyl peroxides) when used alone and can be used to advantage in systems where a monomer coagent is employed. Preferred peresters are thus those which generate alkoxy radicals which are not active in hydrogen abstraction (for example t-amyl perbenzoate).

Similarly, it is believed, without wishing to be bound by theory, that the effectiveness of the monomer is determined by: The solubility of the monomer in the polymer melt. For example, styrene is known to be soluble in molten polypropylene.

The reactivity of the monomer towards polypropylene derived radicals.

The propensity for the radical formed by addition of monomer to give combination or addition (which leads to branch or crosslink formation) vs. disproportionation or hydrogen abstraction. It is known that the benzylic radicals give predominantly combination and have low (with relation to other radicals) tendency to abstract hydrogen.

Other initiators and monomers that meet the above criteria may also be used to advantage in the present invention.

Surprisingly, the process of the present invention results in a polypropylene (co)polymer with substantially increased melt strength. We have found that it is possible with the present invention to obtain a polypropylene (co)polymer which has a melt strength at least greater than the melt strength of the base polymer. We have also found that it is possible to obtain an increase in melt strength of greater than 100% for a number of the polypropylene (co)polymers produced in accordance with the process of the present invention. Increases in SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 melt strength were assessed using a Gottfert-Rheotens melt strength tester operated with a roller acceleration of 1.2 cm/sec 2 measuring the melt strength of a 2 mm strand of molten polypropylene (co)polymer (melt temperature of 210oC) which is fed to the Gottfert tester at -4 g/min.

In a further aspect of the present invention there is provided a modified polypropylene (co)polymer produced according to the process described herein, wherein said modified polypropylene (co)polymer preferably has a melt strength at least 25 and more preferably at least 100%, greater than the unmodified polypropylene (co)polymer.

The polypropylene (co)polymers produced according to the process of the present invention also may provide a significant increase in long-chain branching. Long-chain branching may be assessed by the Dow Rheology Index. Advantageously, the modified polypropylene (co)polymers may demonstrate a Dow Rheology Index (DRI) of greater than 1, preferably at least 2 and most preferably greater than The process of the present invention may also be used to increase the melt elasticity of a polypropylene (co)polymer.

Advantageously, the process of the present invention also provides a means to alter the molecular weight, molecular weight distribution and/or degree and length of branching of polypropylene, ethylene-propylene copolymers, and analogous a-olefin copolymers with or without altering the melt strength of said polymers by melt processing.

The process of the present invention may provide a means to generally increase the molecular weight and broaden the molecular weight distribution and/or introduce branching of the polypropylene (co)polymer. This will not always equate to significant increases in the melt strength or extensional viscosity of the polymer that is being modified eg modification of a lower molecular weight polymer to broaden the molecular weight and/or induce shorter SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -21branches. Such a product may not necessarily demonstrate a high melt strength, but may demonstrate other desirable properties, for example improved filler uptake, mechanical properties, surface properties, thermal and morphological properties.

The modified polypropylene (co)polymer produced by the process of the present invention may be used either neat or blended with another polymer or other additives to provide the desired balance of properties in the polymer blend.

The modified polypropylene (co)polymers and blends may be used in a wide variety of applications including thermoforming, blow moulding, tube or pipe extrusion, blown films, foams and extrusion coating.

The present invention may also be used in the recycling of waste polypropylene or materials containing waste polypropylene.

The increased melt strength of the modified polypropylene (co)polymers renders these (co)polymers more suitable for use in thermoforming applications. The modified polypropylene (co)polymers may be used to thermoform containers such as margarine tubs.

The benefits of this invention include that the polypropylene (co)polymers and blends containing same provide a wider temperature processing window than conventional isotactic polypropylene. The modified polypropylene (co)polymers may also be used in large part thermoforming such as in the production of refrigerator liners and the like where conventional isotactic polypropylene is unsuitable.

The modified polypropylene (co)polymers produced in accordance with the present invention are suitable for blow moulding and we have found that they can be more readily blow moulded into containers. Furthermore, the increased melt strength makes it possible to produce large blow moulded parts through the use of the high melt strength modified polypropylene (co)polymer. Thus components currently made by rotational moulding may SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -22now be produced by blow moulding using the modified polypropylene (co)polymer of the present invention.

Profile extrusion for example tube or pipe extrusion, using the modified polypropylene (co)polymer has been found to produce a more consistent product than conventional isotactic polypropylene.

Blown films made of polypropylene are generally blown downwards using relatively expensive equipment. The modified polypropylene (co)polymers of the present invention have sufficient melt strength for them to be able them to be blown upwardly using conventional polyethylene type film blowing equipment which is less expensive and generally more convenient to operate. Advantageously the modified polypropylene (co)polymers of the present invention may be used in the production of blown films.

The modified polypropylene (co)polymers of the present invention may also be foamed with a wider processing window than for conventional polypropylene. Either a physical or chemical blowing agent may be used. It is preferred to use carbon dioxide as a physical blowing agent to produce foams having a fine closed cell structure. Foamed pellets may be subsequently moulded to form components for use in a variety of applications such as automotive door trims, rooflinings, dash boards, bumpers and the like. Applications such as in foamed packaging are also possible, including thermoformed containers, insulating cups and the like.

Waste polypropylene or waste streams containing a significant proportion of polypropylene are presently difficult to recycle as conventionally a high degree of chain scission results from the recycling process. The process of the present invention may be used to upgrade recycled streams containing polypropylene by increasing the overall mechanical properties of the recycied polypropylene by the addition of initiator and monomer in accordance with the present invention.

SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -23- The present invention will now be described with reference to the following non-limiting examples. Described hereunder are the measurement techniques used in the examples and a full description of the process conditions employed. Comparative Examples are labelled CEn.

Melt Strength Measurement Melt strengths were measured on a "Rheotens" Melt Strength Tester, Type 010.1, supplied by Gottfert Werkstoff-Prufmaschinen Gmbh of Buchen, Germany. This test involves drawing an extruded strand of polymer vertically into the nip between two counter-rotating nip rollers.

The strand was extruded using a Brabender Plasticord single screw extruder of screw diameter 19mm and length to diameter ratio of 25. The extrudate exited via a right angle capillary die (2mm diameter). The temperature profile used was uniform along the length of the barrel of the extruder and the die and was set at 190 0 C. The nip rollers are mounted on a balance arm which allows the force in the drawing strand to be measured. The velocity of the nip rolls is increased at a uniform acceleration rate. As the test proceeds, the force increases until eventually the strand breaks. The force at breakage is termed the "melt strength".

While there is no interationally-established standard set of test requirements for melt strength testing, comparative melt strength values obtained under the given set of test conditions provide a quantitative determination of the increase in melt strength used in the patent. The test conditions used were: die temperature 190°C, extruder output rate -4 g/min, acceleration rate 1.2 cm/sec 2 draw distance 210 mm, matt finish steel rollers.

Dow Rheology Index The Dow Rheology Index (DRI) is believed in the art to be a measure of the long chain branching in a polymer. It is expressed as the deviation of a viscosity parameter obtained SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -24from shear rheology measurements on a "branched" polymer compared with that for a linear polymer. The branched polymers have lower values of the viscosity parameter than the linear polymers (for a given relaxation parameter). The parameters are obtained by fitting the Cross model to the shear viscosity flow curves. The DRI method has been described by Lai, Plumley, Butler, Knight and Kao in a paper in SPE ANTEC '94 Conference Proceedings (pp 1 8 1 4-1818) "Dow Rheology Index (DRI) for Insite Technology Polyolefins (ITP): Unique Structure-Processing Relationships".

Dynamic Rheology Tests The dynamic rheology tests were performed on a Rheometrics Dynamic Stress Rheometer SR200. Test conditions were: parallel plates, temperature 190°C, frequency range 0.01 to 100 rad/sec, and 3-4% strain, in a nitrogen atmosphere to prevent degradation. G' is the storage modulus representing the elasticity of the polymer melt, G" is the loss modulus which represents the viscous component of the deformation. The polydispersity index is 10 to power 5 divided by the crossover modulus, which is the value of G' G" when the G' and G" curves crossover it is believed to be a measure of MWD. The higher the greater elasticity in the polymer and the higher the MW.

MFI

Melt flow indexes (MFI) were measured a 230°C with a 2.16 kg load according to ASTM 1238.

Drop Times The drop times were determined by measuring the time taken for the polypropylene strand (cut at the die face) to drop from the die of the extruder to the floor. The die of the JSW twin screw extruder was 1140 mm above the floor. The drop time test combines the effects of SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 melt viscosity, extensional viscosity, chain entanglement (as shown by die swell), and elasticity (as shown by the tendency resist neck formation). Higher melt viscosity polypropylene polymers had drop times which incorporated some additional effect due to prolonged cooling of the slower moving (falling) molten strand.

GPC

GPC molecular weights were determined using a Waters 150C high temperature GPC unit.

1,2,4-trichlorobenzene was used as the solvent, eluting through two Styragel HT6E linear columns. The oven temperature was set at 140°C and the pump flow rate was Calibration was performed using narrow polydispersity polystyrene standards. All molecular weights quoted as polystyrene equivalents.

Mn= number average molecular weight Mw= weight average molecular weight Mz= viscosity average molecular weight Mp= peak molecular weight Twin Screw Extruder The twin screw extruder used in the examples was a JSW TEX-30 with a 30 mm screw diameter and an overall L/D of 42 [comprising ten temperature controlled barrel sections (L/D 3.5, temperatures between 120 and 2 3 0 0C as specified in Table three unheated sampling/monitoring blocks (L/D 1.167) and a cooled feed block (L/D equipped with two JSW TTF20 gravimetric feeders, one K-Tron KQx gravimetric additives feeder and a volumetric liquid addition pump (Fuji Techno Industries model HYM-03-08)]. The extruder was operated in either co-rotating (intermeshing self wiping) or counter rotating (intermeshing non-self wiping) modes with a throughput rate of between 5 and 20 kg/hr and screw speeds of between 100 and 400 rpm as specified in Table 1. The melt temperature and SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 WO 9936466PCT/AU99/00036 26 pressures were monitored at three points along the barrel and in the die.

Table 1 Operating conditions Conditions Screw Speed (rpm) 265 265 150 265 265 400 265 150 265 250 Feed Rate (kg/hr) 20 20 Temperature Profile

(OC)

150 0 C, 175'C (by 180'C, 200'C (by 2200'C (by 7) 5 1200C, 1300C (by 180*C (by 6) 20 140-C, 20 180-C, 250-C, 20 180-C, 20 80-C, 180-C, 5 800C, 180-C, 20 80-C, 180-C, 20 150-C, 1500C (by 200'C (by 230'C, 2400C, 260-C, 270-C, 280-C.

220 0C (by 120-C, 140-C, 160-C, 170-C, 200-C (by 1200C, 1400C, 1600C, 170-C, 190 -C (by 200 -C (by 2) 1200C, 1400C, 160-C, 170-C, 190-C (by 200-C (by 2) 1700C 180-C, 200-C, 220-C (by *The temperatures in the table refer to sections of the barrel of the extruder that are capable of independent temperature control. The first ten temperatures are barrel section temperatures and the last temperature indicates the temperature of the die.

SUBSTITUTE SHEET (Rule 26) (ROIAU) WO 99/36466 PCT/AU99/00036 -27- Table 2 Die configuration Condition Die Description 1 Large 3 hole strand die 6 mm holes 2 Small 3 hole strand die 4 mm holes 3 Large 2 hole strand die 6 mm holes 4 Single hole Brabender die- 10mm hole Table 3 Means of modifier addition Condition Die Description a Modifier added at block 4 in 2-butanone carrier solvent P Modifier added at block 4 in xylene carrier solvent Y Modifier coated onto PP powder pre tumble blended 6 Modifier coated onto PP powder masterbatch The overall extruder configuration and modifier conditions may be recited, for example, as condition: A16.

Solvent Addition of Modifiers The initiator, and monomer if present, was introduced as a solution in 2-butanone or xylene.

The concentration of the initiator varied from 5.6% wt/wt to 8.5% wt/wt. The benzoyl peroxide and the di-toluol peroxides were both powders wetted with 25 (wt/wt) water. The monomer was present in an amount between 4 to 10% wt/wt solvent.

Increased levels of initiator were generally added by increasing the amount of solution added to the polymer melt. The additional peroxides (if any) were added with the initiator in the carrier solvent.

Solventless Addition of Modifiers t-Butyl peroxybenzoate is a liquid. The solventless modification of the polymer was achieved by absorbing the initiator onto powdered polymer or blending it with powdered polymer at SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -28concentrations ranging from 5% wt/wt to 10% wt/wt to form a masterbatch. The masterbatch was added to the extruder in varying feed rates to alter the amount of additives. The amount of polymer feed was adjusted accordingly to give constant overall feed rate.

The stabilisers were also added as a masterbatch. The amount of stabiliser was generally kept constant at 0.33%wt/wt Irganox 1010 and 0.17%wt/wt Irgaphos 168 in the total composition.

The main polymer feed was added as either powder or pellets.

Single Screw Extruders Killion The Killion single screw extruder used in the examples was a segmented single screw extruder of L/D=40 (11 barrel sections 10 heated) and screw diameter of 31.75 mm.

Polypropylene powder, stabilisers (0.33%wt/wt Irganox 1010, 0.17%wt/wt Irgaphos 168 in total) and initiator were added to the feed throat of the single screw extruder via a twin screw K-Tron volumetric feeder.

Alternatively, the polypropylene powder and stabilisers were added via the K-Tron feeder and polypropylene powder, stabilisers and the modifiers were added as a master batch via a single screw APV Accurate volumetric feeder. The masterbatch contained 7.5%wt/wt benzoyl peroxide (prepared using a dispersion of benzoyl peroxide containing 25 %wt/wt water).

The output of the extruder was 1.5 kg/hr using a screw speed of 30rpm. The set barrel temperature was either a flat 220 0 C with each barrel section and the die set at a temperature of 220*C or (ii) 230 0 C/190 0 C with the first six melting sections of the barrel set at 230 0 C and the next four metering sections of the barrel and the die set at 190°C. The melt SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -29temperature varied from 220 to 260°C.

Brabender The Brabender single screw extruder used was a single screw extruder of L/D =25 (4 Barrel sections), compression ratio 2.5:1 and screw diameter of 19 mm. The die was a 4 mm rod die.

The screw speed of the extruder was 20 rpm. The set barrel temperature was 140°C, 170°C, 180°C, 1800C. Residences time: Start 3 min 40 sec; Middle 4 min 35 sec; and End 7 min sec.

Polypropylene powder either as cryoground pellets or ex-reactor powder was mixed with the modifiers and added to the feed throat, either flood feed or by a Brabender single screw volumetric feeder.

The following commercial polypropylene (co)polymers were used in the examples. The properties of the (co)polymers are shown in Table 4 below.

Table 4: Comparative data for a grade of high melt strength PP and conventional PP grades.

Example Polymer Polymer MFI Melt Strength Description 2.16kg cN 230°C Control 1 Montell High melt strength 3 18 PF814 polypropylene homopolymer Control 2 Montell Extrusion grade 3 3 JE6100 polypropylene homopolymer SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 Control 3 ICI Australia GYM 45 Control 4 ICI Australia GWM 22 Control 5 ICI Australia PXCA 6152 Control 6 Control 7

ICI

Australia LYM 120 Montell 6501 Injection moulding grade of polypropylene homopolymer Extrusion grade of polypropylene homopolymer Thermoforming grade of polypropylene homopolymer Injection moulding grade of propylene/ethylene copolymer Ex-reactor grade of injection moulding polypropylene homopolymer Extrusion grade of polypropylene homopolymer Extrusion grade of polypropylene homopolymer Ex-reactor grade of polypropylene powder homopolymerunstabalized Control 8 Montell KM6100 Control 9 Montell KMT6100 Control 10 Montell KM6100 SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -31 Melt strength and MFI were measured for a particular batch and we have found actual values vary up to 20% of these values.

Examples 1 to was modified in accordance with Table 5 below. GYM45 is a low molecular weight/higher MFI injection moulding grade of polypropylene homopolymer.

Table Example Conditions BPO Styrene Motor Die Drop MFI Melt Strength Current Temp. Time 2.16kg (cN) (amps) (oC) (secs.) 2300C Control 0 14 1.8 3 CE 1 Bla 0 0 13 231 8 12.2 1 Bla 0.36 0 13 229 9.7 14.4 1.9 2 Bla 0.7 0 13 229 13.5 14.4 2.3 3 Bla 0.95 0 13 230 17.1 12.5 3 4 D3a 1.0 0 19 197 23 9.7 4 D4a 0.34 0.45 21 179 22.9 9.1 6.9 Examples 6 to 18 GWM22 was modified in accordance with Table 6. GWM22 is an intermediate molecular weight/medium MFI extrusion grade of polypropylene homopolymer.

SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -32- Table 6: Example Conditions BPO Styrene Motor Die Drop MFI Melt Current Temp. Time 2.16kg Strength (amps) (OC) (secs.) 230°C (cN) Control 4 4.5 2.8 CE2 Bla 0 0 16 239 11.3 6 Bla 0.36 0 16 234 15.2 6.3 3 7 Bla 0.75 0 17 238 21.8 5.9 4.7 8 Bla 1 0 16 239 25.4 5 6.9 9 Bla 1.3 0 20 236 25.3 5.6 7.1 Bla 0.12 0.16 16 237 8.0 4.15 11 Bla 0.23 0.31 17 237 11.2 2.8 12 Bla 0.46 0.61 21 238 14 1.11 13 Bla 0.69 0.92 21 241 14.2 0.69 18.6 14 Bla 1.22 1.63 21 248 18.6 Ela 0.33 0.44 17 281 20 3.6 8.2 16 C2a 0.81 4.2 18 203 60 0.69 18.8 17 Ela 0.31 0.40 20 275 23 3.1 18 Ela 0.30 0.53 17 277 24 3.4 9.1 The increase in complex viscosity of examples been plotted against frequency in Figure 2.

14, 16, 17 and 18 is shown in Figure 1.G' has The modified polypropylene's of examples 14, 16, 17 and 18 were tested for additional physical properties and it was found that the modified polypropylene's had: 14 16 17 i) Elasticity 1200 680 40 rad/s (Pa) ii) 1/Relaxation -0.0013 0.085 15 Time Control 4 10 0.01 rad/s (pa) Crossover Frequency(rad/sec) 18 23 SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -33 iii) Polydispersity 222 Index iv) Dow 192 Rheology Index 39 4.4 4.7 3.7 86 2.0 5.6 0 LongChain Branching Examples 19 to 26 PXCA6152 was modified in accordance with Table 7 below. PXCA6152 is a high molecular weight/low MFI thermoforming grade of polypropylene homopolymer.

Table 7: Example Conditions BPO Styrene Motor Die Drop MFI Melt Current Temp. Time 2.16kg Strength (amps) (secs.) 230°C (cN) Control 5 0.8 6 CE 3 Fla 0 0 17 251 14.6 1.1 19 Bla 0.34 0 22 244 25.9 1.3 7.4 20 Bla 0.68 0 23 250 22.8 1.1 11.1 21 Bla 0.8 0 24 246 30.5 0.8 14 22 Bla 1.04 0 24 247 25.3 0.65 17.7 23 Fla 0.31 0.41 21 256 24.4 0.42 17.5 24 Fla 0.47 0.63 21 264 25 0.31 25 Fla 0.55 0.73 23 269 0.40 26 Fla 0.71 0.95 22 259 25 0.35 21.3 The modified polypropylene of example 22 was tested for additional physical properties and it was found that the modified polypropylene had: Elasticity 1/Relaxation Time 200 G' @0.01 rad/s (Pa) 7.1 Crossover frequency (rad/sec) SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -34iii) Polydispersity Index iv) Dow Rheology Index 3.9

M,/M,

10 Long Chain Branching The DRI of the base polypropylene material, PXCA 6152 (an unbranched polypropylene) was expected to be 0. The DRI of the modified polypropylene demonstrates a significant degree of long chain branching.

Examples 27 to 33 LYM120 was modified in accordance with Table 8 below. LYM120 is a low molecular weight/higher MFI injection moulding grade of PP copolymer.

Table 8: Example Conditions BPO Styrene Motor Die Drop MFI Melt Current Temp. Time 2.16kg Strength (amps) (secs.) @230°C (cN) Control 6 12.2 1.4 27 D2a 0.68 0 13 182 19.3 13.1 2.3 28 A4a 1.08 0 19.5 200 31 9 4.2 29 A2a 0.33 0.44 18 202 28 5.8 7.4 D2a 0.32 0.42 23 185 46.5 3.8 31 A4a 0.42 0.55 19.5 204 31.1 6.5 11.2 32 A4a 0.62 0.83 20 201 36.8 11.9 33 A4P 0.34 0.45 16 199 25.1 4.3 Examples 34 to 42 Ex-reactor GYM45 powder was modified according to Table 9 below. GYM45 is a low molecular weight/higher MFI injection moulding grade of polypropylene homopolymer. The polypropylene was stabilized with Irganox 1010 (0.33 wt%) and Irgaphos (0.17 The modifiers and stabilizers were added to the twin-screw extruder at the feed throat.

SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99136466 WO 9936466PCT/AU99/00036 Table 9: Example Conditions BPO Styrene Motor Die Drop MFI Melt Current Temp. Time 2.16kg Strength (ap) (secs.) t0 230*C (cN) Control 14 1.8 3 CE 4 H38 0 0 7 209 21.5 11.3 1.7 34 138 0.38 0 14 209 12.1 13.6 1.9 36 138 0.75 0 15 210 15.0 11.8 2.6 37 136 1.5 0 15 214 20.6 10.3 5.7 38 H36 0.75 0 6 209 35.5 17.6 2.1 39 H38 1.13 0 8 208 39.5 13.3 2.9 H36 1.5 0 8 208 43.3 9.8 4.4 41 136 0.15 0.2 18 215 16.6 9.6 42 138 0.23 0.3 16 214 20.5 6.5 Examples 43 to 49 was modified in accordance with Table 10 below. GYM45 is a low molecular weight/higher MFI injection moulding grade of polypropylene homopolymer.

Table Example Conditions Initiator Initiator Styrene Motor Die Drop MFI Current Temp. Time 2.16kg (amps) (OC) (secs) a 230'C CE 5 43 44 46 CE-6 CE-7 A~t M~a A3ax M~a A3a M~a A~ct

BPO

BPO

BPO

BPO

DHBP

DHBP

0 0.12 0.21 0.41 0.62 0.33 0.60 0 0.16 0.28 0.55 0.83 0.09 0.17 18 16 17 20 22 14.5 16 192 197 200 206 208 191 190 11.8 14 18.8 27.6 32.2 4.6 4 12.8 14.4 9.8 5.6 3.6 117 SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 WO 9936466PCT/AU99/00036 36 CE-8 CE-9 CE-li 47 48 49 CE-12 CE-13 CE-14 CE-16 CE-17 M~a M~a M~a M~a A3a M~a A3a M~a A3a M~a M~a A3a M~a

DHBP

TBEH

TBEH

TBEH

TBPB

TBPB

TBPB

DCP

DCP

DCP

DLP

DLP

DLP

0.90 0.33 0.60 0.90 0.30 0.68 0.89 0.08 0.17 0.25 0.33 0.63 0.92 0.28 0.34 0.62 0.93 0.30 0.70 0.91 0.09 0.17 0.25 0.33 0.64 0.93 14.5 16 17 17 15 17 19 14.5 15 15 15 15 15 190 191 192 193 194 198 199 192 191 191 190 190 190 3.9 9.9 10 10.6 7.8 14 15.6 4.3 3.9 3.7 11.2 132 18.3 19.5 17.2 58.3 47.3 38.5 48.5 64.7 90.3 16.5 15.1 18.0 Examples 50 to 54 LYM 120 was modified in accordance with Table 11 below. LYM 120 is a low molecular weight/higher MFL injection moulding grade of polypropylene copolymer.

Table 11: Example Conditions BPQ Motor Current Die Drop MFI Melt Strength (amps) Temp Time 2.16kg (cN) 0 C) (secs.) 230 0

C

Control 6 12.2 1.4 CE 18 H38 0 7 209 18.4 11.3 1.2 52 H38 0.75 8 210 50.5 6.9 2.6 53 H38 1.13 8 210 47.0 6.6 3.3 54 136 1.5 14 217 18.5 3.8 6.1 Examples 55 to 61 SUBSTITUTE SHEET (Rule 26) (ROIAU) WO 99/36466 PCT/AU99/00036 -37- LYM120 was modified in accordance with Table 12 below. LYM120 is a low molecular weight/higher MFI injection moulding grade of polypropylene copolymer.

Table 12: Example Conditions Initiator Initiator Styrene Motor Die Drop MFI Melt Current Temp. Time 2.16kg Strength (amps) (sees) 230°C (cN) CE-19 A3a BPO 0.00 0.00 16 195 9.9 12.8 1.1 A3a BPO 0.12 0.16 15 197 13.9 10.9 56 A3a BPO 0.21 0.28 17.5 201 17.7 7.50 57 A3a BPO 0.41 0.55 20 208 25.8 4.4 11.5 58 A3a BPO 0.62 0.83 21 209 26.5 2.9 A3a DHB 0.08 0.09 13.5 191 4.9 52

P

CE-21 A3a DHB 0.16 0.17 14 190 5.3 79

P

CE-22 A3a DHB 0.28 0.30 14.5 190 5.6 114

P

CE-23 A3a TBEH 0.31 0.32 14 192 8.6 17.8 CE-24 A3a TBEH 0.62 0.64 14 192 9 17.4 A3a TBEH 0.98 1.01 14 192 9.6 15.4 59 A3a TBPB 0.30 0.31 14 196 4.6 33.8 A3a TBPB 0.61 0.62 17 200 14.6 32.9 61 A3a TBPB 0.93 0.95 17 202 15.6 23.1 CE-26 A3a DCP 0.08 0.09 13 192 5 38.6 CE-27 A3a DCP 0.17 0.17 13.5 190 5.5 57.6 CE-28 A3a DCP 0.27 0.28 14 190 6.2 65.9 CE-29 A3a DLP 0.31 0.31 15 191 9.9 15.7 A3a DLP 0.64 0.65 13.5 190 9.8 14.8 CE-31 A3a DLP 1.00 1.01 13 190 14.8 Examples 62 to 73 LYM120 was modified in accordance with Table 13 below. LYM120 is a low molecular weight/higher MFI injection moulding grade of polypropylene copolymer.

SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 WO 9936466PCT/AU99/00036 38 Table 13: Example Conditions Intiator Initiator Styrene Motor Die Drop MFI Melt Current T emp. Time 2.16kg Strength (amps) (secs) (cN) 230'C2 CE-32 62 63 64 66 CE-33 CE.-34 CE-36 CE-37 CE-38 CE-39 67 68 69 70 CE-41 CE-.42 71 72 73 A38 A38 A38 A38 A36 A38 A38 A38 A36 A38 A38 A38 A38 A38 A36 A38 A38 A38 A38 A38 A38 A38 A36

BPO

BPO

BPO

BPO

BPO

DLP

DLP

DLP

TBPB

TBPB

TBPB

TBPB

BPO

BPO

BPO

BPO

DLP

DLP

DLP

TBPB

TBPB

TBPB

0 0.11 0.23 0.45 0.68 1.13 0.31 0.59 0.89 0.07 0.15 0.29 0.59 0.11 0.23 0.45 0.90 0.30 0.59 0.89 0.29 0.59 1.18 0 0 0 0 0 0 0 0 0 0 0 0 0.15 0.30 0.6 1.2 0.3 0.-6 0.9 0.3 0.6 1.2 14.5 14 16.5 16.5 17.5 18 13.5 14 13 12 12 10.5 11 17.5.

19.5 21.5 23.5 14.5 13 13 13.5 16.5 17 10 10 15.1 20.6 20.6 18.6 9.3 8.8 8.9 5.1 5.3 6.3 11.2 19.1 25 27.8 26.8 9.4 9.3 9.8 11.4 20.2 18.8 12.4 11.5 9.0 6.6 5.4 5.7 13.6 14.4 15.0 28.7 31.0 92.0 102.0 5.7 4.3 2.1 1.3 14.1 17.2 16.1 20.4 12.9 13.9 1.2 1.7 4.1 3.9 2.4 6.3 10.4 12.2 3.7 Examples 74 to 77 was modified in accordance with Table 13 below. GYM45 is a low molecular weight/higher MRI injection moulding grade of polypropylene homopolymer.

SUBSTITUTE SH[EET (Rule 26) (RO/AU) WO 99/36466 WO 9936466PCT/AU99/00036 -39- Table 13 Example Conditions Initiator Initiator Motor Die Drop MFI Current Temp. Time 2.16kg (amps) 0 Q) (secs) 230 0

C

CE 43 AMa -0 18 192 11.8 12.8 74 M~a BPO 0.23 16.5 196 10.35 17.0 Ma~ BPO 0.45 17 199 11.8 17.3 76 M~a BPO 0.73 17 200 15.9 15.4 77 M~a BPO 0.96 18 202 17.3 14.9 CE-44 AMa DHBP 0.08 15 191 3.6 96 CE-45 AMa DHBP 0.17 14.5 190 3.1 169 CE-46 AMa DHBP 0.29 13 188 2.3 100 CE-47 AMa DHBP 0.30 13 188 2.2 200 CE-48 M~a DHBP 0.50 13.5 186 1.9 200 CE-49 AMa DHBP 0.57 12 186 1.9 100 CE-5O AMa TBEH 0.30 17 197 8.8 12.0 AMa TBEH 0.64 14 188 7.2 24.4 CE-52 AMa TBEH 0.98 14 189 6.8 25.6 CE-53 AMa TBPB 0.31 13 186 2.6 CE-54 M~a TBPB 0.64 13 184 2.1 238 CE-55 AMa TBPB 1.03 12 184 1.9 250 CE-56 AMa DCP 0.08 16 192 3.8 47.1 CE-57 M~a DCP 0.17 14 189 2.9 121.3 CE-58 AMa DLP 0.32 16 191 10.9 14.5 CE-59 AMa DLP 0.64 16 190 10.6 17.9 CE-60 AMa DLP 0.95 16 189 10.4 16.6 Examples 78 to'82 LYM120 was modified in accordance with Table 14 below. LYM120 is a low molecular weight/higher MFI injection moulding grade of polyprooylene copolymer.

SUBSTIUT SHEET (Rule 26) (RO/AU) WO 99/36466 WO 9936466PCT/AU99/00036 40 Table 14: Example Conditions Initiator Initiator Motor Die Drop MFI Current Temp. Time 2.16kg (amps) (OC) (secs) 230 0

C

Control 24 A3a BPO 0 16 195 9.9 12.8 78 A3a BPO 0.25 15 196 10.3 13.4 7§ A3a BPO 0.47 14 198 13.2 13.1 M~a BPO 0.64 16 198 13.9 12.9 81 M~a BPO 0.70 17 201 13.6 11.9 82 Ma~ BPO 0.94 18 198 13.5 10.6 CE-61 M~a DI-BP 0.09 14 190 3.6 CE-62 M~a DHBP 0.16 13 188 3.1 160 CE -63 Ma~ DHBP 0.26 13 187 2.8 250 CE-64 A3a TBEH 0.29 15 193 7 A3a TBEH 0.60 13 192 6.7 19.4 CE-66 M~a TBEH 1.02 12 191 6 22.6 CE-67 Ma~ TBPB 0.30 13 186 3.6 CE-68 Mu. TBPB 0.61 12 184 3.8 173 CE-69 M~a TBPB 0.92 12 184 3.4 250 M~a DCP 0.08 16 192 4.5 14.6 CE-71 M~a DCP 0.17 13 190 3 107 CE-72 M~a DCP 0.25 13 188 3 131 CE-73 A3a DLP 0.32 14.5 191 9.5 14.3 CE-74 Ace DLP 0.68 15 191 9.4 15.8 M~a DLP 0.98 14.5 193 8.7 21.0 Examples 83 to 92 LYM 120 was modified in accordance with Table 15 below. LYM 120 is a low molecular weight/higher MFI injection moulding grade of polypropylene copolymer.

SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -41 Table Example Conditions Initiator Initiator Styrene Mole Motor Die Drop MFI Melt Ratio Current Temp. Time 2.16kg Strength Sty/Init (amps) (sees) (cN) 230"C CE-76 83 84 86 87 88 89 91 92 CE-77 A3a A3a A3a A3a A3a A3a A3a A3a A3a A3a A3a A3a 0

BPO

BPO

BPO

BPO

BPO

TBPB

TBPB

TBPB

TBPB

TBPB

DHB

0 0.43 0.41 0.41 0.43 0.45 0.56 0.55 0.61 0.54 0.58 0.27 0 0.19 0.37 0.55 0.76 0.99 0.19 0.37 0.62 0.73 0.97 0.1 1.04 2.07 3.11 4.14 5.18 0.78 1.57 1.91 3.14 3.92 0.84 195 207 207 208 210 205 192 196 200 201 204 190 9.9 18.5 22.5 25.8 25.4 28.3 8.9 11.0 14.6 16.0 16.2 4.4 12.8 6.9 4.9 4.4 3.9 4.4 71 38 33 19.2 15.7 187 1.1 11.6

P

CE-78 A3a DHB 0.25 0.18 1.69 14 191 5.3 125 CE-79 A3a DHB 0.28 0.30 3.04 14.5 190 5.6 114

P

A3a DHB 0.27 0.40 3.38 15 193 6.2 116

P

CE-81 A3a DHB 0.28 0.50 4.22 14 192 6.1 118 Examples 93 to 97 was modified in accordance with Table 16 below. GYM45 is a low molecular weight/higher MFI injection moulding grade of polypropylene homopolymer.

SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 WO 9936466PCT/AU99/00036 42 Table 16: Example Conditions Initiator Initiator Styrene Mole Motor Die Drop MFI Ratio Current Temp Time 2.16kg Sty/Init (amps) (secs) 230' C CE-82 AMa 0.00 0.00 0.00 18 192 11.8 12.75 93 AMa BPO 0.36 0.16 1.04 18 202 18.1 11.17 94 AMa BPO 0.41 0.37 2.07 18 209 23.5 6.38 AMa BPO 0.41 0.55 3.11 20 206 27.6 5.62 96 AMa BPO 0.43 0.76 4.14 22 209 25.7 4.05 97 AMa BPO 0.40 0.89 5.18 21 207 31.2 4.27 Example 98 to 105 LYM120 was modified in accordance with Table 17 below. LYM120 is a low molecular weight/higher MFI injection moulding grade of polypropylene copolymer.

SUBSTITUTE SHEET (Rule 26) (RQ/AU) Table 17: Example Conditions Initiator #1 wt% Initiator #2 wt% Mole ratio Init#1/Init Monomer wt% Initiator#1 =BPO, Initiator #2=DHBP, Monomer= Styrene 98 A36 0.43 0.06 9.08 99 A36 0.43 0.11 4.54 100 A36 0.43 0.17 3.03 Initiator #1 =BPO, Initiator#2 =TBPB, Monomer=Styrene 101 A36 0.43 0.11 3.07 102 A36 0.43 0.22 1.53 103 A36 0.43 0.34 1.02 104 A36 0.43 0.45 0.77 105 A38 0.43 0.34 1.02 0.57 0.58 0.58 0.58 0.58 0.59 0.60 0.94 Mole ratio Monomer /tot init 2.81 2.57 2.37 2.36 1.92 1.62 1.40 2.59 Motor Current (amps) Drop Die MFI time Te sees mp

°C

17 204 6.9 14.8 203 10.5 14 201 16.9 Melt strength (cN) 18.7 14.2 14 11.8 17 208 204 204 201 207 9.3 11.6 19.5 7.5

C

o 6.3 8 WO 99/36466 PCT/AU99/00036 -44- Example 108 and 109 Montell 6501 was modified in accordance with Table 19 below on the Killion screw extruder described above.

Sample Barrel Extruder BPO Temp Output wt% (kg/hr) Styrene Motor Die wt% Current Temp (amps) (OC) Drop Time

MFI

(secs) min) Control CE 84 220 flat 108 220 flat 109 220 flat 0.25 6 256 260 263 17 4.1 35 2.2 33 0.40 Examples 40. 41. 7. 12. 28. 29. 31 and 14 GPC molecular weights were determined using a Waters 150C high temperature GPC unit.

1,2,4-trichlorobenzene was used as the solvent, eluting through two Ultrastyragel linear columns. The oven temperature was set at 140°C and the pump[ flow rate was 1.0 ml/min.

Calibration was performed using narrow polydispersity polystyrene standards. All molecular weights quoted as linear polystyrene equivalents.

Mn=number average molecular weight Mw=weight average molecular weight Mz=viscosity average molecular weight SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 Mp=peak molecular weight Error are quoted as two times the standard deviation between duplicate injections.

Table Exam Cond. BPO Sty MFI Melt Mn Mw pie (g/10 str (g/mo (g/mo No. min) (cN) 1) x 1) x 3 10- 3 Mz Mp (g/mo (g/mo 1) x 1) x 10- 3 Intermediate Molecular Weight PP Homopolymer (GWM 22) Contr 4.5 2.8 55 295 1200 105 8 Bla 1.0 5.0 6.9 Bla 0.12 0.16 4.15 11 Bla 0.23 0.31 2.80 5.0 12 Bla 0.46 0.61 1.11 13 Bla 0.69 0.92 0.69 18.6 110 C2a 1.50 3.8 111 C2a 2.23 3.2 112 Cla 0.37 0.49 2.22 113 Cla 0.60 0.80 1.00 19.4 114 Cla 0.32 1.65 4.50 115 Cla 0.47 2.45 1.58 116 Cla 0.81 4.19 0.69 18.8 Low Molecular Weight PP Copolymer (PXCA 6152) 425 405 415 555 575 430 430 565 690 505 605 675 1415 200 1200 235 1400 195 2200 205 2200 180 1560 160 1700 150 2035 215 2575 170 1835 170 2160 205 2610 185 Contr 12.4 1.4 45 230 720 130 SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -46- 22 Bla 1.04 0.65 17.7 110 485 1615 195 27 61 62 28 78 79 80 27 A2a A2a A2a D2a D2a A3a A3a A3a D3a 0.33 0.41 0.62 0.28 0.32 0.25 0.47 0.64 0.68 0.44 0.55 0.83 0.38 0.44 7.4 -11.5 4.4 2.9 65 60 70 80 120 70 65 65 70 325 325 460 555 640 315 320 360 445 1045 1315 2435 2875 4130 1330 1380 1975 1865 140 125 135 160 140 135 130 130 140 13.4 13.1 12.9 13.1 *Errors in the molecular weight are generally less than 30% of the quoted value, as is usual in high temperature GPC under the conditions employed.

Examples 110 to 114 GWM22 and KM6100 were modified in accordance with Table 20 below.

Table 20: Effect of feed throat addition of BPO on the modification of prestabilised PP homopolymer KM6100 or GWM22] a Example Conditions Powder BPO Motor Drop Die MFI Melt wt% Current Time (sec) Temp (g/lO min.) Str.

a (amps) °C (cN) Prestabilised PP homopolymer GWM 22 Control -A o 4 110 J38 8.8 0.92 25 111 J38 13.3 1.40 30 Prestabilised PP Homopolymer KM6100 244 3.9 248 2.6 11.0 SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 -47- Control 8 112 113 114 J36 J36 J38 J36 0 0.41 0.81 1.28 a: BPO added to pellet feed in PP powder derived from cryoground prestabilised PP pellets Examples 115 to 117 KMT6100 was modified in accordance with Table 22 below. KMT6100 is a prestabilised PP copolymer.

Table 22: Effect of feed throat addition of BPO on the modification of prestabilised PP copolymer KMT6100 Example Conditions Powder BPO Motor Drop Die MFI Melt Str.

wt% Current Time Temp (g/10 min.) (cN) a (amps) (sec) *C Control -3.5 9 CE-86 J36 0 0 24 8 231 4.4 115 J36 1.9 0.40 25 10 233 5.4 1.9 116 J38 3.0 0.81 24 13 235 4.4 3.1 117 J36 5.9 1.22 29 15 237 3.0 a: BPO added to pellet feed in PP powder derived from cryoground prestabilised PP pellets SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PTA9/03 PCT/AU99/00036 48 Examples 118 to 121 KM6100u was modified with para-toluoyl peroxide (PTP) and BPO in accordance with Table 23 below. The KM6100u was stabilized with Irganox 1010 (0.33wt%) and Irgaphos 168 (0.17 wt%) which were added to the main feed throat of the extruder.

Table 23: Example Conditions Peroxide Peroxide Motor Drop Die MFI Melt Current Time Temp (gl 10 nudn.) Str.

(amps) (see) 0C -(cN) Control -3.5 CE-87 J38 0 22 9 240 5.2 2.7 118 J38 BPO 1.0 22 17 252 5.2 7.2 119 J38 PTP 1.0 21 16 240 5.2 6.8 120 J38 PTP 1.5 22 18 239 3.9 14.2 121 J38 PTP 2.0 24 243 3.4 14.0 SUBSTITUTE SHEET (Rule 26) (RQIAU) 0 t-.

Examples 122 to 128 PXCA6152 was modified with mixed initiator systems in accordance with Table 24 below.

Table 24: Example Conditions Init #1 Init 2 Mole Motor Drop Die MFI Melt Str.

wt% wt% ratio Current Time Temp (g/10 (cN) Init#1/In (amps) (sec) 0 C min.) it #2 Control 0.8 6 CE-88 122 B3a B3a 0 0.87 255 257 0.9 1.28 5.1 14.2 Initiator #1 BPO, Initiator 2 DHBP B3a B3a 0.87 0.87 0.045 0.064 23.2 16.3 251 250 B3a 0.87 0.084 12.4 Initiator #1 BPO, Initiator 2 TBPB B3a B3a B3a 0.87 0.87 0.87 0.006 0.012 0.019 129.4 64.7 40.9 254 249 249 Examples 129 to 132 Cryoground PXCA6152 in the form in the form of a powder was modified with mixed initiator systems according to Table 25 below.

Table 25: Effect of Mixed Initiators on the Modification of PXCA6152 Powder a (cryoground pellets) Example Conditions it #1 Init 2 Mole ratio Motor Drop Die NEI Melt Str.

wt% wt% Init#1I/Init #2 Current Time Temp (g/10 (cN) (amps) (sec) 0 C min.) Control 0.8 6 CE-89 B36 0 0 25 13 256 1.0 Initiator #1 BPO, Initiator 2 =DHBP 129 B38 0.86 0 -23 17 253 1.8 10.8 130 B38 0.87 0.004 23 17 254 2.1 8.8 Initiator #1 BPO, Initiator 2 TBPB 131 B36 0.87 0.016 24 18 253 2.6 8.2 132 B38 0.87 0.026 23 17 253 3.6 7.7 Examples 79 and LYM120 was modified in accordance with Table 26 below.

Table 26: Example Conditions BPO Monomer/ Monom Motor Current Drop Die MFI Melt Str.

wt% Coagent er wt% (amps) Time (sec) Temp (g/10 (cN) OC min.) Control 6 CE-76 79 0 0.47 0.41 none none Styrene 0 0 0.54 10 13 25.8 195 198 208 12.2 12.8 13.2 4.4 1.1 11.6 Examples 133 GYM 22 was modified in accordance with Table 27 below.

Table 27: Example Conditions BPO Monomer! Coagent Monomer Motor Drop Die NEI Melt Str.

awt% Wt% Current Time Temp (g/l 0 min.) (cN) (amps) (sec) O Control 4.5 2.8 4 CE-2 Blci 0 none -16 11 239 5 6 Bla 0. 36 none -16 15 234 6.3 3 133 Bla 0.34 Styrene 0.45 21 29 250 1.72 WO 99/36466 PCT/AU99/00036 -54- Examples 134 to 137 Cryoground KM6100 in the form of a powder was modified on a Brabender single screw extruder in accordance with the general description of the Brabender SSE above and Table 28 below. The initiator was added at the feed throat of the SSE along with the stabilizers (0.33 wt% Irganox 1010 and 0.17 wt% Irgaphos 168).

Table 28: Example Control 8 134 135 136 137 Peroxide Type

BPO

PTP

PTP

PTP

Peroxide (wt%) 0 1 0.5 1 2

MFI

(g/10 min.) 2.9 3.8 3.3 PTP- Paratoluol Peroxide (bis paramethyl benzoyl peroxide) Example 138 PXCA6152 was modified in accordance with Table 29: Modification ofPXCA6152 Pellets Example Conditions BPO Styrene Motor wt% wt% Current (amps) Table 29 below.

Drop Die MFI Melt Time Temp (g/10 min.) Str.

(sec) °C (cN) Control CE-94 138 B3a B3a 0 0.51 22 0.68 24 255 0.9 279 0.6 5.1 21.0 SUBSTITUTE SHEET (Rule 26) (RO/AU) Examples 139 to 143 The modified PXCA6152 produced according to Example 138 was melt mixed with GYM45 in accordance with Table Table 30: Blends of the Modified PP with other PP Homopolymers Example Conditions PP#1 PP#1 Motor Current Drop time Die Temp MFI Melt Strength (amps) (seconds) 0

C

A3 Control 5 Control 3 (95) 18 11 206 9.9 CE-96 A3 Control 5 (10) Control 3 (90) 19 12 202 7.8 CE-97 A3 Control 5 (15) Control 3 (95) 19 13 202 CE-98 A3 Control 5 (20) Control 3 (80) 19 14 202 CE-99 A3 Control (25) Control 3 (75) 19 15 202 4.7 2.6 139 A3 138 Control 3 (95) 19 15 199 9.3 140 A3 138 (10) Control 3 (90) 19 16 201 7.4.

141 A3 138 (15) Control 3 (85) 19 18 203 6.6 142 A3 138 (20) Control 3 (80) 20 19 204 143 A3 138 (25) Control 3 (75) 19 20 207 4.7 5.2 CE-100 A3 Control 4 (100) 20 15 208 5.3 144 A3 138 Control 4 (95) 21 18 207 3.7 145 A3 138 (10) Control 4 (90) 21 19 206 146 A3 138 (15) Control 4 (85) 22 21 210 2.3 147 A3 138 (20) Control 4 (80) 22 21 212 2.6 148 A3 138 (25) Control 4 (75) 23 23 213 2.4 7.7

C,'

0, 0 0o

L.J

0% WO 99/36466 PCT/AU99/00036 -56- Examples of Carbon Dioxide Foaming of Modified PP The equipment used for foaming the polypropylene (from earlier examples) was a tandem extrusion line made up of an Leitritz twin screw extruder (34 mm screw diameter, corotating, with 11 barrel sections) connected via a melt pipe to a single screw extruder (43 mm screw diameter). CO 2 was introduced into barrel six of the twin screw extruder. The gassed polymer was then cooled slowly in the single screw extruder.

Example Control 1 MFI (g/10 min) 3 Melt Strength (cN) 18 Foaming Temp 166 to 159 169 to 159 167 to 161 Av Foam Density (g/cc) 0.058 0.044 0.051 Av Cell Size (Aim) 550 300 280 11.2 Non high melt strength grades of polypropylene have foam of less than 1lC.

temperature processing windows Foamed examples 13 and 17 both has a fine closed cell structure.

Examples of thermoforming The modified polypropylene produced in Example 69 was extruded on a Welex single screw extruder through a sheet die to produce a sheet 78cm wide and -1.25 mm thick. The sheet was fed to a Gabler F702 continuous thermoformer to produce margarine tubs. Tubs produced from the modified PP sample had a crush strength of 25 kg after 1 hour. No appreciable sag was noticed of the PP sheet during the process.

Blow Moulding SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 99/36466 PCT/AU99/00036 57- The modified polypropylene of Example 5 was blow moulded on Bekum blow moulder fitted with a general purpose polyolefin screw using a 750 ml screw top bottle mould, (radially non symmetrical bottle with waist). The mould temperature was 0C.

The blow mouldability of the modified injection moulding grade of PP was compared against that of a commercial low melt flow index PP homopolymer (ICI GWM110 of MFI It was found that the modified PP homopolymer (MFI 9.1 and Melt Strength 6.9 cN) could be easily blow moulded into 750 ml bottles. Conventional PP of similar MFI could not be successfully blow moulded. The modified PP gave similar performance to an extrusion grade PP of low MFI.

The results are very promising where a higher MFI PP could be used to blow bottles. This possibly opens up the opportunity to produce large blow moulded parts through use of a high melt strength modified PP which has been tailored to have an MFI acceptable to blow moulding (ie 1-2 MFI) Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within its spirit and scope. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

SUBSTITUTE SHEET (Rule 26) (RO/AU) Doaumcl7-0y2OMI -57A- Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims (1)

1. 58- TH -I.AIMS DEFINING THEINVENTION ARE AS FOLLOWS: 1. A process for increasing the melt strength and/or the extensional melt viscosity of a polypropylene (co)polymer wherein said process comprises melt mixing the polypropylene (co)polymer in the presence of an initiator wherein said initiator is selected from the group defined by formula 1. y x 0 tU v Formula 1 wherein R is selected from the group consisting of optionally substituted C 1 to q 8 acyl, optionally substituted C 1 to C 18 alkyl, aroyl defined by formula 2, *o -59- and groups of formula 3, O0-0-T 'U v Formula 3 wherein U, V, X, Y, Z, Y' and Z' are independently selected from the group consisting hydrogen, halogen, Cl-C18 ailkyl, C1-C18 alkoxy, aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, axyloxycarbonyl, trialkyl silyl, hydroxy, or a moiety of formula 4, 100 Formula 4 and wherein T is alkylene. 2. A process according to claim 1 wherein the initiator is selected from compounds of 15 formula 6: S .5 S S S S *SSS *SSS 0 S WO 99/36466 PTA9/03 PCT/AU99/00036 60 Formula 6 where X, Y, Z, U, V, VT are independently selected from the group consisting of hydrogen and C 1 C, 8 alkyl where at least one of X, Y, Z, U, V and Yin, V' are not hydrogen. 3. A process according to claim 2 wherein the initiator is selected from the group* consisting of Dibenzoyl peroxide, o,o'-Bis(methylbenzoyl) peroxide, p,p'-Bis(methylbenzoyl) peroxide, M,M'-Bis(methylbenzoyl) peroxide, o,m'-Bis(methylbenzoyl) peroxide, o,p'- Bis(methylbenzoyl) peroxide, mp'-Bis(methylbenzoyl) peroxide, Bis(ethylbenzoyl) peroxide (all isomers), Bis(propylbenzoyl) peroxide (all isomers), Bis(butylbenzoyl) peroxide (all isomers), Bis(pentylbenzoyl) peroxide (all isomers), Bis(hexylbenzoyl) peroxide (all isomers), Bis(heptylbenzoyl) peroxide (all isomers), Bis(octylbenzoyl) peroxide (all isomers), Bis(nonylbenzoyl) peroxide (all isomers), Bis(methoxybenzoyl) peroxide (all isomers), Bis(ethoxybenzoyl) peroxide (all isomers), Bis(propoxybenzoyl) peroxide (all isomers), Bis(butoxybenzoyl) peroxide (all isomers), Bis(pentoxybenzoyl) peroxide (all isomers), Bis(hexyloxybenzoyl) peroxide (all isomers), Bis(heptyloxybenzoyl) peroxide (all isomers), Bis(octyloxybenzoyl) peroxide (all isomers), Bis(nonyloxybenzoyl) peroxide (all isomers), B is(chlorobenzoyl) peroxide (all isomers), Bis(fluorobenzoyl) peroxide (all isomers), Bis(bromobenzoyl) peroxide (a isomers), Bis(dimethylbenzoyl) peroxide (all isomers), Bis(timethylbenzoyl) peroxide (all isomers), Bis(tert-butylbenzoyl)peroxide (all isomers), Bis(di- SUBSTITUTE SHEET (Rule 26) (RQIAU) -61 tert-butylbenzoyl)peroxide (all isomers), Bis(tertbutoxybenzoyl)peroxide (all isomers), Bis(ditnmethylsilylbenzoyl) peroxide (all isomers), Bis(heptafluoropropylbenzoyl) peroxide (all isomrs),Bis(2,6-dOimethyl-4-trimethylsilyl benzoyl) peroxide and isomers, and 2;,2'(dioxydicArbonyl) bis-Benzoic acid dibutyl ester. 4. A process according to claim 1 wherein the initiator is selected from the group consisting of tert-butyl perbenzoate, tert-butyl (methyl)perbenzoate (all isomers), tert-butyl (ethyl)perbenzoate (all isomers), tert-butyl (octyl)perbenzoate (all isomers), tert-butyl (nonyl)perbenzoate (all isomers), tert-amyl perbenzoate, tert-amyl (methyl)perbenzoate (all isomers), tert-amyl (ethyl)perbenzoate (all isomers), tert-amyl (octyl)perbenzoate (all isomers), tert-amyl (nonyl)perbenzoate (all isomers), tert-amyl (methoxy)perbenzoate (all isomers), tert- amyl (octyloxy)perbenzoate (all isomers), tert-amyl (nonyloxy)perbenzoate (all isomers), 2- ethythexyl perbenzoate, 2-ethyihexyl (methyl)perbenzoate (all isomers), 2-ethyihexyl (ethyl)perbenzoate (all isomers), 2-ethyihexyl (octyl)perbenzoate (all isomers), 2-ethylhexyl (nonyl)perbenzoate (all isomers), 2-ethylbexyl (methoxy)perbenzoate (all isomers), 2-ethylhexyl (ethoxy)perbenzoate (all isomers), 2-ethylhexyl (octyloxy)perbenzoate (all isomers), 2- ethylhexyl (nonyloxy)perbenzoate (all isomers). A process according to claim 1 wherein the initiator is selected from the group consisting of Bis (tertbutylmonoperoxy phthaloyl) diperoxy terephthalate, Bis (tertamylmonoperoxy phthaloyl) diperoxy terephithalate, diacetyl phthaloyl diperoxide, dibenzoyl phthaloyl diperoxide, Bis(4 methylbenzoyl) phthaloyl diperoxide, diacetyl 25 tercphthaloyl di peroxide, dibenzoyl terephthaloyl diperoxide, ixcrbnlioy11,4,4-tetrametvl-1,4-butanediyl)] peroxide. 6. A process according to any one of claims i to 5 wherein the initiator has a 0. 1 hour half life in the range 100 170 *C. 62 7. A process according to any one of claims 1 to 5 wherein the initiator is present in the range of from 0.004 to 0.25 moles of initiator per kg of the polypropylene homopolymer or copolymer. 8. A process according to any one of claims 1 to 5 wherein the initiator is present in the range of from 0.006 to 0.10 moles of initiator per kg of the polypropylene homhopolyrner or copolymer. A process according to claim I wherein the initiator is present in the range of from 0.01 to 0.05 moles of initiator per kg of the polypropylene homopolymer or copolymer. 10. A process according to claim 1 wherein there is no added monomer and the initiator is selected from the group consisting of Dibenzoyl peroxide, o,o'-Bis(methylbenzoyl) peroxide, p,p'-Bis(methylbenzoyl) peroxide, o, o'-Bis(methylbenzoyl) peroxide, o,m'-Bis(methylbenzoyl) peroxide, o,p'-Bis(methylbenzoyl) peroxide, mnp'-Bis(methylbenzoyl) peroxide, Bis(ethylbenzoyl) peroxide (all isomers), Bis(propylbenzoyl) peroxide (all isomers), Bis(butylbenzoyl) peroxide (all isomers), Bis(pentylbenzoyl) peroxide (all isomers), Bis(hexylbenzoyl) peroxide (all isomers), Bis(heptylbenzoyl) peroxide (all isomers), Bis(octylbenzoyl) peroxide (all isomers), Bis(nonylbenzoyl) peroxide (all isomers), Bis(methoxybenzoyl) peroxide (all isomers), Bis(ethoxybenzoyl) peroxide (all isomers), Bis(propoxybenzoyl) peroxide (all isomers), :Bis(butoxybenzoyl) peroxide (all isomers), Bis(pentoxybenzoyl) peroxide (all isomers), 0 .0 Bis(hexyloxybenzoyl) peroxide (all isomers), Bis(heptyloxybenzoyl) peroxide (all isomers), Bi*cyoxbnol peoie(l smr) i*oyoxbnol eoie(l smr) Bis(ctloxbenzoyl) peroxide (all isomers), Bis(oloxbenzoyl) peroxide (all isomers), Bis(chlorobenzoyl) peroxide (all isomers), Bis(fluoroybenzoyl) peroxide (all isomers), Bis(romotybenzoyl) prxd (all isomers), Bis(dimebtylbenzoyl) peroxide (all isomers), d- tr-uybnolperoxide (l smr) i~etuoyezy~eoie(l smr) Bis(trimethyfylbenzoyl) peroxide (all isomers), Bis(btafrpoylbenzoyl) peroxide (allismr)Bsd- *2tert-amylb(ezoyl)perbode (all isomers), Bis-ay(tetutoxybenzolproe (all isomers), tay 0000 (ttayehyl)perbenzoate (all isomers), tert-amyl (etyl)perbenzoate (all isomers), tert-amyl (all isomers), tert-amyl (onylo)perbezoate (all isomers), tert-amyl 11 63 (methoxy)perbenzoate (all isomers), tert-amyl (octyloxy)perbenzoate (all isomers), tert-amyl (nonyloxy)perbenzoate (all isomers), Bis (tertamylmonoperoxy phthaloyl) diperoxy terephithalate, diacetyl phthaloyl diperoxide, dibenzoyl phthaloyl diperoxide, bis(4- methylbenzoyl) phthaloyl diperoxide, diacetyl terephthaloyl di peroxide and dibenzoyl 5 ereh~tb~y1dijioxide.' 11. A process according to claim 10 wherein the initiator is selected from the group consisting of dibe zoyt peroxide, o *o'Bis(metliylbenzoyl) peroxide, p,p'- Bis(methylbenzoyl) peroxide, M,M'-Bis(methylbenzoyl) peroxide, Bis(methylbenzoyl) peroxide, o,p'-Bis(methylbenzoyl) peroxide, m,p'-Bis(methylbenzoyl) peroxide. 12. A process according to any one of claims 1 to I11 wherein the initiator is used in -combination with a monomer. 13. A process according to claim 12 wherein the amount of monomer is up to 5 times the total moles of initiator. 14. A process according to claim 12 or claim 13 wherein the monomer is a monoene monomer. 15. A process according to claim 12 or claim 13 wherein the monomer is styrene. 16. A process according to claim 12 wherein the initiator is selected from the group consisting of Dibenzoyl peroxide, o,o'-Bis(methylbenzoyl) peroxide, p,p'-Bis(methylbenzoyl) 25 peroxide, M,M'-Bis(methylbenzoyl) peroxide, o,m'-Bis(methylbenzoyl) peroxide, o,p'- :Bis(methylbenzoyl) peroxide, m,p'-Bis(methylbenzoyl) peroxide, Bis(ethylbenzoyl) peroxide (al ismr).i~rplezy)prxd al smr) i~uybno eoie(l aisomers), Bis(prpylbenzoyl) peroxide (all isomers), Bis( butylbenzoyl) peroxide (allismr) ismr),Bis( pentylbenzoyl) peroxide (all isomers), Bis(hxylbenzoyl) peroxide (all isomers), 0Bis(heptylbenzoyl) peroxide (all isomers), Bis(toybenzoyl) peroxide (all isomers), 64 Bis(ethoxybenzoyl) peroxide (all isomers), Bis(propoxybenzoyl) peroxide (all isomers), Bis(butoxybenzoyl) peroxide (all isomers), Bis(pentoxybenzoyl) peroxide (all isomers), Bis(hexyloxybenzoyl) peroxide (all isomers), Bis(heptyloxybenzoyl) peroxide (all isomers), Bis(octyloxybenzoyl) peroxide (all isomers), Bis(nonyloxybenzoyl) peroxide (all isomers), Bis(chlorobenzoyl) peroxide (all isomers), Bis(fluorobenzoyl) peroxide (all isomers), Bis(bromobenzoyl) peroxide (all isomers), Bis(dimethylbenzoyl) peroxide (all isomers), Bis(trimethylbenzoyl) peroxide (all isomers), Bis(tert-butylbenzoyl)peroxide (all isomers), Bis(di-tert-butylbenzoyl)peroxide (all isomers), Bis(tert-butoxybenzoyl)peroxide (all isomers), Bis(ditrimethylsilylbenzoyl) peroxide (all isomers), Bis(heptafluoropropylbenzoyl) peroxide (all isomers), Bis(2,4-dimethyl-6- trimethylsilyl benzoyl) peroxide and isomers, 2,2'(dioxydicarbonyl) bis Benzoic acid dibutyl ester, tert-butyl perbenzoate, tert-butyl (methyl)perberizoate (all isomers), tert-butyl (ethyl)perbenzoate (all isomers), tert-butyl (octyl)perbenzoate (all isomers), tert-butyl (nonyl)perbenzoate (all isomers), tert-amyl perbenzoate, tert-amyl (methyl)perbenzoate (all isomers), tert-amnyl (ethyl)perbenzoate (all isomers), tert-amyl (octyl)perbenzoate (all isomers), tert-amyl (nonyl)perbenzoate (all isomers), tert-amyl (methoxy)perbenzoate (all isomers), tert-amyl (octyloxy)perbenzoate (all isomers), tert-amyl (nonyloxy)perbenzoate (all isomers), 2-ethyihexyl perbeazoate, 2-ethylhexyl (methyl)perbenzoate (all isomers), 2-ethyihexyl (ethyl)perbenzoate (all isomers), 2-ethylhexyl 20(octyl)perbenzoate (all isomers), 2-ethylhexyl (nonyl)perbenzoate (all isomers), 2-ethyihexyl (methoxy)perbenzoate (all isomers), 2-ethyihexyl (ethoxy)perbenzoate (all isomers), 2- ethyihexyl (octyloxy)perbenzoate (all isomers), 2-ethylhexyl (nonyloxy)perbenzoate (all isomers), Bis (tertbutylmonoperoxy phthaloyl) diperoxy terephtbalate, Bis (tertamyhuonoperoxy phthaloyl) diperoxy terephthalate diacetyl. phtbaloyl diperoxide, dibeuzoyl phtbaoyl diperoxide, bis(4 methylbenzoyl) phthaloyl diperoxide, diacetyl terephthaloyl di peroxide, dibenzoyl terephthaloyl diperoxide and Poly[ dioxycarbonyldioxy(1,1,4,4-tetmethyl-1,4-butalediyl)] peroxide. :17. A modified polypropylene produced according to the process of any one of claims I to 16. PCT/AU99/00036 cRCcOMP.019 Received 26 November 1999 18. A process wherein the modified polypropylene of claim 17 is melt mixed with an unmodified polypropylene to produce a modified polypropylene. 19. A process for modifying an a-olefin polymer wherein said process comprises melt mixing the a-olefin polymer in the presence of an initiator and optionally a monoene monomer wherein said initiator is selected from the group defined by formula 1. -0-R U V Formula 1 wherein R is selected from the group consisting of optionally substituted C 1 to Cg acyl, optionally substituted C 1 to C 1 s alkyl, aroyl defined by formula 2, X' Formula 2 AMENDED SHEET iPFeA