WO2009120211A1 - Polymeric compositions for plastic strapping - Google Patents

Abstract

A polymeric composition for use in plastic strapping includes a chain extender, a impact modifier; and a condensation polymer, where the chain extender is a polymerization product of: (i) a, epoxy-functional (meth)acrylic monomer; and (ii) a styrenic and/or (meth)acrylic monomer; the chain extender has an epoxy equivalent weight of from about 180 to about 2800, a number-average epoxy functionality (Efn) value of less than about 30, a weight-average epoxy functionality (Efw) value of up to about 140, and a number-average molecular weight (Mn) value of less than 6000 and wherein at least a portion of the chain extender has reacted with at least a portion of the condensation polymer to produce a chain-extended condensation polymer.

Description

POLYMERIC COMPOSITIONS FOR PLASTIC STRAPPING

FIELD

[0001 ] The invention is generally directed to polymeric compositions.

BACKGROUND

[0002] Many condensation or step-growth polymers, including polyesters, polyamides, polycarbonates, and polyurethanes are widely used to make plastic products such as films, bottles, and other molded products. The mechanical and physical properties of these polymers are highly dependent on their molecular weights.

[0003] In a life cycle, these materials may experience a synthesis process, followed by an extrusion step, and a final processing step which may be another compounding/extrusion operation followed by profile or sheet forming, thermoforming, blow molding, or fiber spinning, or they can be injection or otherwise molded in the molten state. Typically, all of these steps occur under high temperature conditions. In addition, in recent years, increased attention has been focused on improved methods of reclaiming and recycling the plastics made from these polymers, with an eye toward resource conservation and environmental protection. The processing steps involved in recycling these polymers also involve high temperatures.

[0004] In each one of these high temperature steps, particularly during the compounding/processing and reclaiming/recycling processes, some degree of polymer molecular weight degradation occurs. This molecular weight degradation may occur via high temperature hydrolysis, alcoholysis or other depolymerization mechanisms well know for these polycondensates. It is known that molecular weight degradation negatively affects the mechanical, thermal, and rheological properties of materials, thus preventing them from being used in demanding applications or from being recycled in large proportions for their original applications. Today, recycled or reprocessed polycondensates with deteriorated molecular weights can only be used in very low proportions in demanding applications or in larger proportions in less demanding applications. For instance, due to molecular weight Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

degradation, recycled bottle grade polyethylene terephthalate (PET) is mostly employed exclusively in fiber and other low end applications. Similarly, reclaimed polycarbonate from compact disks (CD), electronics' housings, and automotive parts, mostly goes to low end applications. For these reasons, the current recycling technologies are limited to a narrow range of applications, which limits considerably the total volumes of these plastics that can be recycled, thus increasing the tremendous amounts of these plastics being disoposed of in landfills.

[0005] Today, there exist a considerable number of processes in the art employed to minimize loss in molecular weight and to maintain or even increase the molecular weight of the polycondensates for processing or recycling. Most of these routes employ as main processing equipment either an extruder, a solid state polycondensation reactor, or both in sequence, or similar equipment designed for melt or high viscosity material processing. As an instrumental part of any of these processes, chemical reactants known in the art as "chain extenders" are employed. Chain extenders are, for the most part, multi-functional molecules that are included as additives in the reactor or extruder during any or all of the described processing steps with the purpose of "re-coupling" polycondensate chains that have depolymerized to some degree. Normally the chain extender has two or more chemical groups that are reactive with the chemical groups formed during the molecular weight degradation process. By reacting the chain extender molecule with two or more polycondensate fragments it is possible to re-couple them (by bridging them), thus decreasing or even reverting the molecular weight degradation process. In the art there are numerous chain extender types and compositions, polycondensate formulations, and processing conditions described to this end.

[0006] Bi- or poly- functional epoxides, epoxy resins or other chemicals having two or more epoxy groups per molecule, are an example of chain extending modifiers that have been used to increase the molecular weight of recycled polymers. These bi- or poly-functional epoxides are generally made using conventional methods by reacting a epichlorohydrin with a molecule having two or more terminal active hydrogen groups. Examples of such chain extenders include bis-phenol type epoxy compounds prepared by the reaction of bisphenol-A with epichlorohydrin, novolak type epoxy compounds prepared by reacting novolak resins Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

with epichlorohydrin, polyglycidyl esters formed by reacting carboxylic acids with epichlorohydrin, and glycidyl ethers prepared from aliphatic alcohols and epichlorohydrin. Other forms of epoxidation of molecules not including epichlorohydrin can be also used to prepare these and other compounds bearing labile epoxy groups, such as epoxidized soy-bean oil, and a variety of epoxidized hydrocarbons. Additionally, various acrylic copolymers have been used as polymer additives to improve the melt strength and melt viscosity of polyesters and polycarbonates. These additives generally include copolymers derived from various epoxy containing compounds and olefins, such as ethylene. However, these chain extenders have met with limited success in solving the problem of molecular weight degradation in reprocessed polymers. The shortcomings of these copolymer chain extenders can be attributed, at least in part, to the fact that they are produced by conventional polymerization techniques which produce copolymers of very high molecular weight, which when coupled with a polycondensate can dramatically increase the molecular weight leading to localized gelation and other defects with physical characteristics which limit their capacity to act as chain extenders. More recently, acrylic and styrene-acrylic copolymers bearing high epoxy functionality per chain have proven capable of effectively increasing the molecular weight of a variety of polycondensates.

SUMMARY

[0007] In a first aspect, a polymeric composition for use in plastic strapping is provided. In one embodiment, the composition includes from about 0.05 wt% to about 2 wt% of a chain extender, from about 0.05 wt% to about 5 wt% of a impact modifier; and from about 90 wt% to about 99 wt% of a condensation polymer. The chain extender may be a polymerization product of: (i) an epoxy-functional (meth)acrylic monomer; and (ii) a styrenic and/or (meth)acrylic monomer. The chain extender may also have an epoxy equivalent weight of from about 180 to about 2800, a number-average epoxy functionality (Efh) value of less than about 30, a weight-average epoxy functionality (Efw) value of up to about 140, and a number-average molecular weight (Mn) value of less than 6000 and wherein at least a portion of the chain extender has reacted with at least a portion of the condensation polymer to produce a chain-extended condensation polymer. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

[0008] In some embodiments, the polymeric composition may also have an antioxidant.

[0009] In some embodiments, the chain extender has a polydispersity index of from about 1.5 to about 5.

[0010] In some embodiments, the epoxy-functional (meth)acrylic monomer is present from about 50 wt% to about 80 wt% and the styrenic and/or (meth)acrylic monomer is present from about 20 wt% to about 50 wt%. In other embodiments, the chain extender comprises about 25 to about 50 wt% of the epoxy-functional (meth)acrylic monomer and about 50 wt% to about 75 wt% of the styrenic and/or (meth)acrylic monomer. In other embodiments, the chain extender comprises about 5 wt% to about 25 wt% of the epoxy- functional (meth)acrylic monomer and about 75 wt% to about 95 wt% of styrenic and/or (meth)acrylic monomer. The chain extender may have a weight average molecular weight of less than about 25,000 g/mol.

[0011] In some embodiments, condensation polymer is selected from polyesters, polyamides, polycarbonates, polyurethanes, polyacetals, polysulfones, polyphenylene ethers, polyether sulfones, polyimides, polyether imides, polyether ketones, polyether-ether ketones, polyarylether ketones, polyarylates, polyphenylene sulfides, or polyalkyls. The condensation polymer may be a condensation polymer that has been recycled or reprocessed.

[0012] In some embodiments, the impact modifier is selected acrylic rubbers, ASA rubbers, diene rubbers, organosiloxane rubbers, EPDM rubbers, SBS or SEBS rubbers, ABS rubbers, MBS rubbers, glycidyl esters, polystyrene-polybutadiene, polystyrene- poly(ethylene-ρropylene), polystyrene-polyisoprene, poly(α-methylstyrene)-polybutadiene, polystyrene-polybutadiene-polystyrene, polystyrene-poly(ethylene-propylene)-polystyrene, polystyrene-polyisoprene-polystyrene, poly(α-methylstyrene)-polybutadiene-poly(θ!- methylstyrene), methylmethacrylate-butadiene-styrene (MBS) and methylmethacrylate- butylacrylate, polyalkylacrylates grafted with polymethylmethacrylate, polyalkylacrylates grafted with styrene-acrylonitrile co-polymer, polyolefins grafted with poly ethylmethacrylate, polyolefins grafted with styrene-acrylonitrile co-polymer, butadiene core-shell polymers, polyphenylene ether-polyamide, polyamides, styrene- Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

acrylonitrile co-polymer, styrene-acrylonitrile co-polymer grafted onto polybutadiene, or a combination of any two or more.

[0013] In some embodiments, the impact modifier comprises a first component and a second component, wherein the first component is a co-polymer of ethylene and an unsaturated epoxides, and the second component is a co-polymer of ethylene and an alkyl (meth)acrylate. The unsaturated epoxide is typically selected from allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and itaconate, glycidyl (meth)acrylate, 2-cyclohexene-l- glycidyl ether, cyclohexene-4,5-diglycidyl carboxylate, cyclohexane-4-glycidyl carboxylate, 5- norbornene-2-methyl-2-glycidyl carboxylate, or endo-cis-bicyclo-(2,2,l)-5-heptene-2,3- diglycidyl dicarboxylate. The alkyl (meth)acrylate is typically selected from methyl (meth)acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate , n-octyl acrylate, or 2- ethylhexyl acrylate.

[0014] In some embodiments, the antioxidant is a compound selected from di- substituted phenols, phenyl phosphites, hydroperoxide decomposers, sterically hindered phenols, or a combination of any two or more.

[0015] In another aspect, a plastic article made from the polymeric compositions is provided, where the plastic article is plastic strapping. Articles such as blown film, thermoformed packaging such as clam shells, blister paks, shrinkable film, plastic sheet for signage, and thermoformed parts, and injection molded parts such as electrical housing automotive parts may also be prepared from the polymeric compositions.

[0016] In another aspect, a use of the polymeric compositions in the preparation of plastic strapping is provided.

DESCRIPTION

[0017] A polymeric composition may include a chain extender, an impact modifier, a polymeric host, and optionally an antioxidant, UV absorber, or other additives. Such polymeric compositions may find use in the production of plastic parts from polycondensation polymers, from recycling materials, and in a variety of plastic part applications. One particular such use is as plastic strapping. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

[0018] For the purposes of this disclosure and unless otherwise specified, "a" or "an" means "at least one."

[0019] As used herein, "about" will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, "about" will mean up to plus or minus 10% of the particular term.

[0020] As used herein, wt% refers to weight percent or percent by weight.

Chain Extender

[0021] The chain extenders are capable of reverting the post-processing molecular weight decrease in different polycondensates from the minimum value reached without chain extension, back to the initial molecular weight values or even larger than the original molecular weight values, without the incidence of gel and without substantially adverse effects on mechanical, thermal, or rheological properties at a target polycondensate molecular weight. This is accomplished through the proper design of the chain extenders which make it possible to increase the molecular weight of polycondensates such as polyesters, polyamides, polycarbonates and others, in a controlled manner. In one embodiment, chain extenders are prepared from the polymerization of at least one epoxy-functional (meth)acrylic monomer and at least one non-functional styrenic and/or (meth)acrylic monomer. The chain extenders are characterized by relatively low epoxy equivalent weight (EEW) values and relatively low molecular weights.

[0022] Chain extenders may include epoxy-functional styrene (meth)acrylic copolymers produced from monomers of at least one epoxy-functional (meth)acrylic monomer and at least one non-functional styrenic and/or (meth)acrylic monomer. As used herein, the term (meth)acrylic includes both acrylic and methacrylic monomers. Examples of epoxy-functional (meth)acrylic monomers for use in the present invention include both acrylates and methacrylates. Examples of these monomers include, but are not limited to, those containing 1 ,2-epoxy groups such as glycidyl acrylate and glycidyl methacrylate. Other Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

suitable epoxy-functional monomers include allyl glycidyl ether, glycidyl ethacrylate, and glycidyl itoconate.

[0023] Suitable acrylate and methacrylate monomers for use in the chain extenders include, but are not limited to, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, s-butyl acrylate, i-butyl acrylate, t-butyl acrylate, n-amyl acrylate, i-amyl acrylate, isobornyl acrylate, n-hexyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate, methylcyclohexyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, i-propyl methacrylate, i-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, i-amyl methacrylate, s-butyl-methacrylate, t-butyl methacrylate, 2-ethylbutyl methacrylate, methylcyclohexyl methacrylate, cinnamyl methacrylate, crotyl methacrylate, cyclohexyl methacrylate, cyclopentyl methacrylate, 2-ethoxyethyl methacrylate, and isobornyl methacrylate. Non-functional acrylate and non-functional methacrylate monomers include butyl acrylate, butyl methacrylate, methyl methacrylate, iso-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate and isobornyl methacrylate and combinations thereof are particularly suitable.

[0024] Styrenic monomers for use in the present invention include, but are not limited to, styrene, alpha-methyl styrene, vinyl toluene, p-methyl styrene, t-butyl styrene, o- chlorostyrene, vinyl pyridine, and mixtures of these species. In certain embodiments the styrenic monomers for use in the present invention are styrene and alpha-methyl styrene.

[0025] In one embodiment, the chain extenders contain about 50 wt% to about 80 wt%, based on the total weight of the monomers, of at least one epoxy-functional (meth)acrylic monomer and between about 20 wt% and about 50 wt% of at least one styrenic monomer. In other embodiments, the chain extenders contain between about 25 wt% and about 50 wt% of at least one epoxy-functional (meth)acrylic monomer, between about 15 wt% to about 30 wt% of at least one styrenic monomer, and between about 20 wt% and about 60 wt% of at least one non-functional acrylate and/or methacrylate monomer. In yet another embodiment, the chain extenders contain about 50 wt% to about 80 wt%, based on the total weight of the monomers, of at least one epoxy-functional (meth)acrylic monomer Any. Dkt. No. 018894-0254 (BASF No. IN-6423)

and between about 15 wt% and about 45 wt% of at least one styrenic monomer and between about 0 wt% to about 5 wt% of at least one non-functional acrylate and/or methacrylate monomer. In still another embodiment, the chain extenders contain between about 5 wt% and about 25 wt% of at least one epoxy- functional (meth)acrylic monomer, between about 50 wt% to about 95 wt% of at least one styrenic monomer, and between about 0 wt% and about 25 wt% of at least one non-functional acrylate and/or methacrylate monomer.

[0026] It is surprising that styrene (meth)acrylic chain extenders having certain physical properties produce superior results at lower loadings than conventional chain extenders. Specifically, by combining low molecular weights with low EEW values, the chain extenders are able to achieve a high degree of chain binding without inducing gelation. This allows the present chain extenders to be more effective at lower loadings than other chain extenders and produce chain extended condensation polymers that are substantially free from gel particles. In addition, these properties lead to a variety of processing advantages which will be discussed in more detail below. As used herein, the phrase "substantially free from gel particles" means the chain extension reaction takes place in such a manner that gel particle formation is avoided to any extent that is detectable, or that has a significant negative impact on the polymeric product.

[0027] Without wishing or intending to be bound to any particular theory, it is believed that the surprising advantages of the epoxy- functional chain extenders result from favorable combinations of certain number average epoxy functionality (Efh), polydispersity index (PDI), and EEW values possessed by these oligomers and low molecular weight polymers. These characteristics are believed to allow for the maximization of polycondensate molecular weight increase at a given chain extender load, without the incidence of gel and without adverse effects on the mechanical, thermal, or rheological properties at a target polycondensate molecular weight. Specifically, the present invention provides novel chain extenders having the following characteristics: 1) very high Efh: Efh values of up to about 30, and, in some cases, even higher than 30, including Efh values ranging from 2 to 20, and further including Efh values ranging from 3 to 10; 2) controlled PDI values ranging from about 1.5 to about 5, including ranges from about 1.75 to about 4, and further including ranges from about 2 to about 3.5; 3) low EEW: from about 2800 to Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

about 180, including from about 1,400 to about 190, and further including from about 700 to about 200; 4) very low molecular weights (number average molecular weight (Mn)<6,000, weight average molecular weight (Mw)<25,000) allowing for high molecular mobility and fast incorporation of the chain extender into the polycondensate melt. The molecular weight ranges above include various embodiments wherein Mn ranges from 1000 to about 5000, including from 1500 to 4000, and further including from 2000 to 3000. The molecular weight ranges above also include various embodiments wherein Mw ranges from 1500 to about 18000, including from 3000 to 13000, and further including from 4000 to 8500. In addition, the chain extenders possess a wide range of solubility parameters tailored for high solubility in polycondensates. In various exemplary embodiments, the chain extenders have an EEW of from about 180 to about 300, an Em value from about 4 to about 12 and a PDI of from about 1.5 to about 2.8. In other exemplary embodiments, the chain extenders have an EEW of from about 300 to about 500, an Em value of from about 4 to about 12 and a PDI of from about 2.8 to about 3.2. In still other exemplary embodiments, the chain extenders have an EEW of from about 500 to about 700, an Em value of from about 4 to about 12 and a PDI of from about 3.2 to about 4.5.

[0028] The desired EEW is fixed by the desired content of the epoxy-functional monomer employed (GMA or other). Additionally, at a given EEW, the Em per chain can be tailored from very low to very high (e.g. > 30) by controlling the Mn of the oligomer. Moreover, for a given EEW the Efw can be designed by altering the polydispersity index of the oligomer (PDI=Mw/Mn=Efw/Efh) through changes in composition, processing conditions, and molecular weight. Suitable values of Efw include values of up to about 140, or even higher than 140, including Efw values ranging from 3 to 65, and further including values ranging from 6 to 45.

[0029] The chain extenders may be produced according to standard techniques well known in the art. Such techniques include, but are not limited to, continuous bulk polymerization processes, batch, and semi-batch polymerization processes. Production techniques that are well suited for the chain extenders are described in U.S. Patent No. 6,552,144. Briefly, these processes involve continuously charging into a reactor at least one epoxy-functional (meth)acrylic monomer, at least one styrenic and/or (meth)acrylic Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

monomer, and optionally one or more other monomers that are polymerizable with the epoxy-functional monomer, the styrenic monomer, and/or the (meth)acrylic monomer. This process surprisingly produces oligomeric or low molecular weight copolymer compositions having epoxy equivalent weights, Efh, weight average epoxy functionalities (Efw), and PDI (PDI=E fw/Efn) which dramatically increase the molecular weight of reprocessed plastics without gelation when used in small quantities in the absence of any pretreatment or additional catalysts.

[0030] The proportion of monomers charged into the reactor may be the same as those proportions that go into the chain extenders discussed above. Thus, in some embodiments, the reactor may be charged with about 50 wt% to about 80 wt% of at least one epoxy-functional (meth)acrylic monomer and with about 20 wt% to about 50 wt% of at least one styrenic and/or (meth)acrylic monomer. Alternatively, the reactor may be charged with from about 25 wt% to about 50 wt% of at least one epoxy-functional (meth)acrylic monomer and with about 50 wt% to about 75 wt% of at least one styrenic and/or (meth)acrylic monomer. In other embodiments the reactor may be charged with from about 5 wt% to about 25 wt% of at least one epoxy-functional (meth)acrylic monomer and with about 75 wt% to about 95 wt% of at least one styrenic and/or (meth)acrylic monomer.

[0031 ] The reactor may also optionally be charged with at least one free radical polymerization initiator and/or one or more solvents. Suitable initiators and solvents are provided in U.S. Patent No. 6,552,144. Briefly, the initiators suitable for carrying out the process according to the present invention are compounds which decompose thermally into radicals in a first order reaction, although this is not a critical factor. Suitable initiators include those with half-life periods in the radical decomposition process of about 1 hour at temperatures greater or equal to 90⁰C and further include those with half-life periods in the radical decomposition process of about 10 hours at temperatures greater or equal to 100⁰C. Others with about 10 hour half-lives at temperatures significantly lower than 100⁰C may also be used. Suitable initiators are, for example, aliphatic azo compounds such as 1-t-amylazo-l- cyanocyclohexane, azo-bis-isobutyronitrile and 1 -t-butylazo-cyanocyclohexane, 2,2'-azo-bis- (2-methyl)butyronitrile and peroxides and hydroperoxides, such as t-butylperoctoate, t-butyl perbenzoate, dicumyl peroxide, di-t-butyl peroxide, t-butyl hydroperoxide, cumene Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

hydroperoxide, di-t-amyl peroxide and the like. Additionally, di-peroxide initiators may be used alone or in combination with other initiators. Such di-peroxide initiators include, but are not limited to, l,4-bis-(t-butyl peroxycarbo)cyclohexane, 1 ,2-di(t-butyl peroxy)cyclohexane, and 2,5-di(t-butyl peroxy)hexyne-3, and other similar initiators well known in the art. The initiators di-t-butyl peroxide and di-t-amyl peroxide are particularly suited for use in the invention.

[0032] The initiator may be added with the monomers. The initiators may be added in any appropriate amount, but preferably the total initiators are added in an amount of about 0.0005 to about 0.06 moles initiator(s) per mole of monomers in the feed. For this purpose initiator is either admixed with the monomer feed or added to the process as a separate feed.

[0033] The solvent may be fed into the reactor together with the monomers, or in a separate feed. The solvent may be any solvent well known in the art, including those that do not react with the epoxy functionality on the epoxy-functional (meth)acrylic monomer(s) at the high temperatures of the continuous process described herein. The proper selection of solvent may help decrease or eliminate the gel particle formation during the continuous, high temperature reaction of the present invention. Such solvents include, but are not limited to, xylene, toluene, ethyl-benzene, Aromatic- 100®, Aromatic 150®, Aromatic 200® (all Aromatics are available from Exxon), acetone, methylethyl ketone, methyl amyl ketone, methyl-isobutyl ketone, n-methyl pyrrolidinone, and combinations thereof. When used, the solvents are present in any amount desired, taking into account reactor conditions and monomer feed. In one embodiment, one or more solvents are present in an amount of up to 40 wt%, up to 15 wt% in a certain embodiment, based on the total weight of the monomers.

[0034] The reactor is maintained at an effective temperature for an effective period of time to cause polymerization of the monomers to produce a oligomeric or low molecular weight chain extender from the monomers.

[0035] A continuous polymerization process allows for a short residence time within the reactor. The residence time is generally less than one hour, and may be less than 15 minutes. In some embodiments, the residence time is generally less than 30 minutes, and maybe less than 20 minutes. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

[0036] The process for producing the chain extenders may be conducted using any type of reactor well-known in the art, and may be set up in a continuous configuration. Such reactors include, but are not limited to, continuous stirred tank reactors ("CSTRs"), tube reactors, loop reactors, extruder reactors, or any reactor suitable for continuous operation.

[0037] A form of CSTR which has been found suitable for producing the chain extenders is a tank reactor provided with cooling coils and/or cooling jackets sufficient to remove any heat of polymerization not taken up by raising the temperature of the continuously charged monomer composition so as to maintain a preselected temperature for polymerization therein. Such a CSTR may be provided with at least one, and usually more, agitators to provide a well-mixed reaction zone. Such CSTR may be operated at varying filling levels from 20 to 100 % full (liquid full reactor LFR). In one embodiment the reactor is more than 50 % full but less than 100 % full. Li another embodiment the reactor is 100 % liquid full.

[0038] The continuous polymerization is carried out at high temperatures. In one embodiment, the polymerization temperatures range from about 180⁰C to about 35O°C, this includes embodiments where the temperatures range from about 190⁰C to about 325⁰C, and more further includes embodiment where the temperatures range from about 200⁰C to about 300⁰C In another embodiment, the temperature may range from about 200⁰C to about 275°C Due to their high temperature synthesis the chain extenders of this invention show high thermal stability when used later in chain extending applications in condensation polymer compositions processed at similar temperature ranges. In contrast other chain extenders presently available undergo degradation and gas evolution under these conditions.

Impact Modifier

[0039] Impact modifiers are materials that are added to a polymer to improve the impact resistance that polymer. Impact modifiers, as used herein, include materials effective to improve the impact properties of the composition, for example the ductility and/or the notched Izod impact strength of the composition. The present impact modified compositions preferably have a notched Izod impact strength of at least about 40 kJ/m at -20° C. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

[0040] In one embodiment, useful impact modifiers are substantially amorphous copolymer resins, including but not limited to acrylic rubbers, ASA rubbers, diene rubbers, organosiloxane rubbers, EPDM rubbers, SBS or SEBS rubbers, ABS rubbers, MBS rubbers and glycidyl ester impact modifiers.

[0041] Acrylic rubbers are multi-stage, core-shell, interpolymer compositions having a cross-linked or partially cross linked (meth)acrylate rubbery core phase, preferably butyl acrylate. Associated with this cross-linked acrylic ester core is an outer shell of an acrylic or styrenic resin, preferably methyl methacrylate or styrene, which interpenetrates the rubbery core phase. Incorporation of small amounts of other monomers such as acrylonitrile or (meth)acrylonitrile within the resin shell also provides suitable impact modifiers. The interpenetrating network is provided when the monomers forming the resin phase are polymerized and cross-linked in the presence of the previously polymerized and cross-linked (meth)acrylate rubbery phase.

[0042] In another embodiment, block co-polymers and rubbery impact modifiers are provided. For example, A— B--A triblock co-polymers and A-B diblock co-polymers. The A-B and A--B--A type block co-polymer rubber additives which may be used as impact modifiers include thermoplastic rubbers comprised of one or two alkenyl aromatic blocks which are typically styrene blocks and a rubber block, e.g., a butadiene block which may be partially hydrogenated. Mixtures of these triblock co-polymers and diblock co-polymers are especially useful.

[0043] Suitable A-B and A-B-A type block co-polymers are disclosed in, for example, U.S. Pat. Nos. 3,078,254; 3,402,159; 3,297,793; 3,265,765; and 3,594,452 and U.K. Patent 1,264,741. Examples of typical species of A-B and A— B-A block co-polymers include polystyrene-polybutadiene (SBR), polystyrene-poly(ethylene-propylene), polystyrene-polyisoprene, poly(α-methylstyrene)-polybutadiene, polystyrene-polybutadiene- polystyrene (SBR), polystyrene-poly(ethylene-propylene)-polystyrene, polystyrene- polyisoprene-polystyrene and poly(o>methylstyrene)-polybutadiene-poly(o;-methylstyrene), as well as the selectively hydrogenated versions thereof, and the like. Mixtures comprising at least one of the aforementioned block co-polymers are also useful. Such A-B and A--B--A Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

block co-polymers are available commercially from a number of sources, including Phillips Petroleum under the trademark SOLPRENE, Shell Chemical Co., under the trademark KRATON, Dexco under the trade name VECTOR, and Kuraray under the trademark SEPTON.

[0044] Other rubbers useful as impact modifiers include graft and/or core shell structures having a rubbery component with a Tg (glass transition temperature) below 0° C, preferably between about-40°C to about -80°C, which comprise polyalkylacrylates or polyolefins grafted with polymethylmethacrylate or styrene-acrylonitrile co-polymer. The rubber content is at least about 40 wt% in some embodiments, at least about 60 wt% in other embodiments, and from about 60 wt% to about 90 wt%, in yet other embodiments.

[0045] Other suitable rubbers for use as impact modifiers are the butadiene core-shell polymers of the type available from Rohm & Haas under the trade name P ARALO ID® EXL2600. Most preferably, the impact modifier will comprise a two stage polymer having a butadiene based rubbery core, and a second stage polymerized from methylmethacrylate alone or in combination with styrene. Impact modifiers of the type also include those that comprise acrylonitrile and styrene grafted onto cross-linked butadiene polymer, which are disclosed in U.S. Pat. No. 4,292,233.

[0046] Other impact modifiers useful herein include those which comprise polyphenylene ether, a polyamide or a combination of polyphenylene ether and a polyamide. The composition may also comprise a vinyl aromatic-vinyl cyanide co-polymer. Suitable vinyl cyanide compounds include acrylonitrile and substituted vinyl cyanides such a methacrylonitrile. Preferably the impact modifier comprises styrene-acrylonitrile co-polymer (hereinafter SAN). The preferred SAN composition comprises at least 10 wt% acrylonitrile (AN), in some embodiments, and from about 25 wt% to about 28 wt% AN, in other embodiments, with the remainder styrene, p-methyl styrene, or alpha methyl styrene. Another example of SANs useful herein include those modified by grafting SAN to a rubbery substrate such as, for example, 1 ,4-polybutadiene, to produce a rubber graft polymeric impact modifier. High rubber content (greater than 50 wt %) resin of this type (HRG-ABS) may be especially useful for impact modification of polyester resins and their polycarbonate blends. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

[0047] In some embodiments, the impact modifier is a high rubber graft ABS modifier, comprise greater than or equal to 90 wt% SAN grafted onto polybutadiene, the remainder being free SAN. Some exemplary embodiments include compositions of about 8 wt% acrylonitrile, 43 wt% butadiene and 49 wt% styrene, and about 7 wt% acrylonitrile, 50 wt% butadiene and 43 wt% styrene. These materials are commercially available under the trade names BLENDEX 336 and BLENDEX 415 respectively (G.E. Plastics, Pittsfield, Mass.).

[0048] Other suitable impact modifiers may be mixtures comprising core shell impact modifiers made via emulsion polymerization using alkyl acrylate, styrene and butadiene. These include, for example, methylmethacrylate-butadiene-styrene (MBS) and methylmethacrylate-butylacrylate core shell rubbers.

[0049] Other suitable impact modifiers include those having at least a first component that is a co-polymer of ethylene and an unsaturated epoxide that can be obtained by co- polymerization of ethylene and an unsaturated epoxides, or by grafting the unsaturated epoxide onto polyethylene, and at least a second component that is a co-polymer of ethylene and an alkyl (meth)acrylate.

[0050] The first component is typically a co-polymer of ethylene and an unsaturated epoxide that can be obtained by co-polymerization of ethylene and an unsaturated epoxides, or by grafting the unsaturated epoxide onto polyethylene. Such grafting may be carried out in the solvent phase, or on molten polyethylene, in the presence of a peroxide. Co- polymerization of ethylene and an unsaturated epoxides may be carried out by as free-radical polymerization methods. The free-radical polymerization may be performed at pressures from about 200 bar to about 2500 bar.

[0051] Unsaturated epoxides that are suitable for use in the first component include, but are not limited to, aliphatic glycidyl esters and ethers such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and itaconate, glycidyl (meth)acrylate; and alicyclic esters and ethers such as 2-cyclohexene-l -glycidyl ether, cyclohe-xene-4,5-diglycidyl carboxylate, cyclohexane-4-glycidyl carboxylate, 5-norbornene-2-methyl-2-glycidyl carboxylate and endo- Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

cis-bicyclo-(2,2,l)-5-heptene-2,3-diglycidyl dicarboxylate. In some embodiments, the epoxide is glycidyl (meth)acrylate.

[0052] Other monomers that may be incorporated into the first component include, but are not limited to, α-olefins such as propylene, 1-butene, and hexane; vinyl esters of saturated carboxylic acids such as vinyl acetate or vinyl propionate; and esters of saturated carboxylic acids such as alkyl (meth)acrylates having from 2 to 24 carbon atoms.

[0053] In grafting unsaturated epoxides to other polymers, suitable other polymers include, but are not limited to, polyethylene (PE); co-polymers of ethylene and an alpha- olefin; co-polymers of ethylene and at least one vinyl ester of a saturated carboxylic acid, such as vinyl acetate or vinyl propionate; co-polymers of ethylene and at least one ester of an unsaturated carboxylic acid, such as an alkyl (meth)acrylate with an alkyl group having from 2 to 24 carbon atoms; ethylene/propylene rubber (EPR) elastomers; ethylene/propylene/diene (EPDM) elastomers; and mixtures of any two or more such polymers. For example, materials such as VLDPE (PE of very low density), ULDPE (PE of ultra-low density), or PE metallocene polymers, may be used. As used herein, PE metallocene polymers are polyethylene polymers produced with metallocene catalysts such as early transition metal metallocenes. Titanocene dichloride and zirconocene dichloride are but two such examples known to those of skill in the art.

[0054] In some embodiments, the first component is an ethylene/alkyl

(meth)acrylate/unsaτurated epoxide co-polymer containing up to 40 wt% of alkyl (meth)acrylate.

[0055] Suitable the alkyl (meth)acrylate for use in the impact modifiers include, but are not limited to those of having from 2 to 24 carbon atoms. For example, methyl (meth)acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate , n-octyl acrylate and 2- ethylhexyl acrylate, are several that may be used. The quantity of alkyl (meth)acrylate may range from about 20 wt% to about 35 wt%.

[0056] As noted, carboxylic acid anhydride functionality may be incorporated into the first component. Suitable examples of the co-polymers of ethylene, an alkyl (meth)acrylate, Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

and an anhydride of an unsaturated carboxylic acid and co-polymers of ethylene, a vinyl ester of a saturated carboxylic acid and an anhydride of an unsaturated carboxylic acid. In some embodiments the anhydride functionality is the anhydride of an unsaturated dicarboxylic acid. For example, maleic anhydride, itaconic anhydride, citraconic anhydride and tetrahydrophthalic anhydride are some examples. The quantity of unsaturated carboxylic anhydride can be up to 15 wt% of the co-polymer, and the quantity of ethylene at least 50 wt%.

[0057] In some embodiments, the fluidity index (MFI), of the first component is from about 0.1 to about 50 g/10 min at 190⁰C under 2.16 kg; from about 2 to about 40 g/10 min at 190⁰C under 2.16 kg, in other embodiments; and from about 5 to about 20 g/10 min at 19O⁰C under 2.16 kg, in yet other embodiments.

[0058] The second component is typically a co-polymer of ethylene and an alkyl

(meth)acrylate. Suitable alkyl (methacrylates) include those as described above, including, but not limited to, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate and 2- ethylhexyl acrylate. The quantity of alkyl (meth)acrylate in the second component ranges from about 20 wt% to about 40 wt%.

[0059] In forming the impact modifier, the wt% ratio of the first component in the mixture ranges from about 10 wt% to about 50 wt%, in some embodiments, from about 15 wt% to about 40 wt%, in some other embodiments, and from about 20 wt% to about 30 wt%, in some further embodiments. Impact modifiers that are rich in ethylene - alkyl (meth)acrylate co-polymer show improved impact resistance at room temperature and lower. Such impact resistance is higher than that of compositions which are rich in ethylene-alkyl (meth)acrylate-glycidyl acrylate co-polymer.

Condensation Polymers

[0060] The chain extenders may be reacted with condensation polymers to form a substantially gel free chain extended condensation polymer composition. Suitable condensation polymers include, but are not limited to, polyesters (PEs), polyamides (PAs), polycarbonates (PCs), polyurethanes (PUs), polyacetals, polysulfones, polyphenylene ethers (PPEs), polyether sulfones, polyimides, polyether imides, polyether ketones, polyether-ether Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

ketones, polyarylether ketones, polyarylates, polyphenylene sulfides and polyalkyls. In one embodiment of the invention the condensation polymer is a polyester selected from the family of polyethylene terephthalates (PETs), polypropylene terephthalates (PPTs), and polybutylene terephthalates (PBTs). In another embodiment the condensation polymer is a reprocessed or recycled condensation polymer. As used herein, the term reprocessed means a polymer reclaimed from a production facility originally scrapped for not meeting quality control or specification targets. Amongst these can be included products out of specification from compounding, extrusion, or molding start-up and shut down production and/or products from general production out of specification or otherwise not meeting product quality specifications. Also included in the definition of reprocessed products are products processed to final use form but not meeting product specifications, such as product out of caliber or dimensions, color, shape, etc., or waste process material such as injection runners, edges, trim and flashes, etc. As used herein the term recycled condensation polymer means a condensation plastic reclaimed a posteriori from its final use from diverse sources, this include but is not limited to scrap from soda bottles, detergent bottles, plastic toys, engine components, assembled plastic components, films, fibers, CDs, DVDs, and the like.

[0061] The polyesters may be homo- or copolyesters that are derived from aliphatic, cycloaliphatic or aromatic dicarboxylic acids and diols or hydroxycarboxylic acids. In addition, mixtures of these polyesters or of polyesters with further plastics are also suitable, for example blends of PBT/PC, PBT/acrylonitrile-butadiene-styrene (ABS), PET/PA, and the like. Their composition will depend essentially on the desired properties for a specific end use. Such polyesters are well known in the art. Particularly suitable polyesters are PET, PBT and corresponding copolymers and blends, as exemplified by PBT/PC, PBT/ASA, PBT/ ABS, PET/ABS, PET/PC or also PBT/PET/PC, which predominantly contain the indicated polyesters; PET and its copolymers as well as PBT blends being the preferred choice in certain embodiments.

[0062] As used herein, the term polyamide includes various well known polyamide resins. These include polyamides produced by polycondensing a dicarboxylic acid with a diamine, polyamides produced by polymerizing a cyclic lactam, and polyamides produced by co-polymerizing a cyclic lactam with a dicarboxylic acid/diamine salt. The polyamides Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

useful for this invention also include polyamide elastomer resins. Polyamide resins that are particularly suitable for use in the present invention include nylon 6, nylon 6-6, nylon 6-10, nylon 11, nylon 12, and co-polymers and blends thereof.

[0063] As used herein, the term polycarbonate includes various well known polycarbonate resins. These include aromatic polycarbonates produced by reactions of bisphenols with carbonic acid derivatives such as those made from bis-phenol A (2,2-bis(4- hydroxyphenyl)propane) and phosgene or diphenyl carbonate. Various modified polycarbonates and copolycarbonates made from other types of bisphenols such as those where phenolic radicals in the para position are bridged via C, O, S or alkylene are also included. Polyester carbonates made from one or more aromatic dicarboxylic acids or hydroxycarboxylic acids, bisphenols and carbonic acid derivatives are also included. Polycarbonate resins made from bis-phenol A and carbonic acid derivatives are particularly suitable for this invention.

[0064] The thermoplastic polyurethanes of the present invention may be made by any conventional process, as known in the art. Typical polyurethanes are made from a polyol intermediate and generally an equivalent amount of a polyisocyanate. The polyol intermediate is generally a liquid polyether polyol or a polyester polyol or combinations thereof.

[0065] Polyether polyols that are use to produce the polyurethanes are generally made by reacting an alkylene oxide, such as propylene oxide, with a strong base such as potassium hydroxide, optionally in the presence of water, glycols and the like. Other polyethers which can be utilized include, but are not limited to, those which are produced by polymerization of tetrahydrofuran or epoxides such as epichlorohydrin, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, for example in the presence of Lewis catalysts such as boron trifiuoride, or by the addition of epoxides, optionally mixed or in succession, onto starter components with reactive hydrogen atoms such as water, alcohols, ammonia, or amines.

[0066] The polyester polyols that may be used to form the thermoplastic polyurethanes may be formed from the condensation of one or more polyhydric alcohols with one or more polycarboxylic acids. Examples of suitable polyhydric alcohols include the Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

following: ethylene glycol, propylene glycol such as 1 ,2 -propylene glycol and 1,3 -propylene glycol, glycerol; pentaerythritol; trimethylolpropane; 1,4,6-octanetriol; butanediol; pentanediol; hexanediol; dodecanediol; octanediol; chloropentanediol, glycerol monoallyl ether; glycerol monoethyl ether, diethylene glycol; 2-ethylhexanediol-l,4; cyclohexanediol- 1,4; 1,2,6-hexanetriol; 1,3,5-hexanetriol; 1, 3 -bis-(2-hydroxyethoxy) propane, 1,4- and 2,3- butylene glycol, neopentyl glycol, l,4-bis-(hydroxymethyl)cyclohexane, trimethylolethane, together with di-, tri-, tetra-, and higher polyethylene glycols, di- and higher polypropylene glycols, together with di- and higher polybutylene glycols, and the like. Examples of polycarboxylic acids include the following: phthalic acid; isophthalic acid; terephthalic acid; tetrachlorophthalic acid; maleic acid; dodecylmaleic acid; octadecenylmaleic acid; fumaric acid; aconitic acid; trimellitic acid; tricarballylic acid; 3,3'-thiodipropionic acid; succinic acid; adipic acid; malonic acid, glutaric acid, pimelic acid, sebacic acid, cyclohexane-1,2- dicarboxylic acid; l,4-cyclohexadiene-l,2-dicarboxylic acid; 3-methyl-3,5-cyclohexadiene- 1 ,2-dicarboxylic acid and the corresponding acid anhydrides such as tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, acid chlorides and acid esters such as phthalic anhydride, phthaloyl chloride and the dimethyl ester of phthalic acid, dimerized and trimerized unsaturated fatty acids, optionally mixed with monomelic unsaturated fatty acids, terephthalic acid monomethyl ester and terephthalic acid monoglycol ester.

[0067] The polyacetals usable in the present thermoplastic resin compositions are crystalline thermoplastic resins, sometimes called polyoxymethylene (POM). Suitable polyacetals are, for example, the compounds obtainable from the reaction of glycols, such as diethylene glycol, triethylene glycol, 4,4'-dioxethoxy diphenyl dimethyl methane and hexane diol, with formaldehyde. Polyacetals suitable for use in accordance with the present invention may also be obtained by the polymerization of cyclic acetals. Other specific examples of polyacetals include formaldehyde homopolymers and copolymers of trioxane (i.e., trimer of formaldehyde) and a small amount of cyclic ethers such as ethylene oxide and 1,3-dioxane. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

Chain Extension of Condensation Polymers

[0068] Chain extension of the polycondensates may be accomplished through any conventional mean, many of which are known in the art. For example, chain extension of the polycondensates may be accomplished through dry tumbling together or co-feeding a chain extender with a desired polycondensate. The chain extender may then be melt or solution blended with the polycondensate by methods well known in the art, such as by reactive extrusion. In addition, other suitable formulation ingredients such as pigments, fillers, reinforceants, or additives such as stabilizers, antioxidants, lubricants, and/or any other additives known in the art needed for specific applications may be added to the formula in typical amounts. Examples of suitable reactors for reactive extrusion include single and twin screw extruders systems, of different screw designs, configurations, L/D and compression ratios, operating at suitable RPM's to provide the prescribed average residence times at known feed rates. Other suitable reactors include Banbury mixers, Farrell continuous mixers, Buss co-kneaders, and roll mills. These systems may operate at temperatures above the Tg of the chain extender and above the Tg and/or Tm of the polycondensate in what is known in the art as reactive extrusion. The average residence time in the reactor may vary, but the chain extenders of the present invention need only short residence times compared to other presently available chain extenders. Typically, the residence times will range from about 0.5 minutes to about 15 minutes. This includes embodiments where the residence time is from about 1 minute to about 10 minutes and further includes embodiments where the residence time is from about 2 minutes to about 7 minutes.

[0069] The chain extending operations can be followed by plastic forming operations such as extrusion, molding and fiber spinning. The reactive extrusion can also take place within primary processing equipment without pre-compounding. Alternatively, the compounding may be followed by a finishing step such as solid state polymerization and may be processed in any reactor system and configuration operating at temperatures above the Tg of the chain extender and between the Tg and Tm of the polycondensate for an average residence time between 1 and 24 hours, including from 2 to 18 hours, and further including 3 to 12 hours. Examples of suitable reactors for solid state polymerization are well know in the art, and operational modes of the same include batch, semi-batch and continuous solid state Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

polymerization. In one embodiment, the blend, co-feed, or separate-feed is processed in a combination process comprising suitable arrays of reactive extrusion and solid state polymerization processes known in the art, operating within the ranges given above, and in which chain extender may be added to either or both stages.

[0070] Processing may be followed by a polymer recovery and a pelletization stage to obtain pellets or granules of the chain extended polycondensates suitable for further processing.

[0071] Because the chain extenders provide low EEWs they are effective even in very small quantities. In some embodiments of the invention, the chain extender is present in an amount of up to 5 wt%, up to 3 wt%, in other embodiments, up to 2 wt%, in yet other embodiments, up to 1 wt%, in further embodiments, and up to 0.5 wt%, in yet additional embodiments, based on the total weight of the mixture. This includes embodiments where the chain extender is present in an amount of from about 0.01 wt% to about 5 wt%, based on total weight of the mixture, and further includes embodiments where the chain extender is present in an amount of from about 0.03 wt% to about 4 wt%, or from about 0.05 wt% to about 2.5 wt% based on the total weight of the mixture. It follows that the condensation polymer maybe present in an amount of up to 99.99 wt%, 99.95 wt%, 99.5 wt%, 99 wt%, 98 wt%, 97 wt%, or 95 wt%, based on the total weight of the mixture.

[0072] The chain extenders provide a number of processing advantages compared to other chain extenders. For example, pre-drying of the polycondensate is not required prior to chain extension. This is of particular commercial advantage as pre-drying adds cost and complexity to the process of recycling by requiring another process step as well as more time. In addition, unlike many of the chain extenders currently available, the chain extenders of the present invention do not require the addition of a catalyst or high vacuum operation in order to drive the reaction to the desired extent. This significantly reduces processing costs. Thus, in various embodiments of the invention, the chain-extended condensation polymers are substantially free of gel particles, are produced without pre-drying the condensation polymer, and are produced by reacting the chain extenders and the condensation polymers in a single stage of conventional equipment in the absence of additional catalyst and/or without vacuum Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

operation. Furthermore, in some of these embodiments, the chain extended polycondensates obtained have molecular weights that are similar to or higher than those obtained through solid state polymerization, and have properties that are similar or even better than those obtained through solid state polymerization, thus allowing for the replacement of expensive and cumbersome solid state polymerization processes by simpler reactive extrusion processes.

[0073] The chain extenders have demonstrated enhanced ability to restore or even improve the properties of reprocessed or recycled condensation polymers or of lower grade virgin, condensation polymers. The improvements provided by the chain extenders can be seen directly in the physical properties of the chain extended condensation polymers compared to the same properties in the unmodified low grade virgin condensation polymers or reprocessed or recycled condensation polymers. The efficacy of chain extension and molecular weight increase can be assessed in a number of different ways. Some common methods for the assessment of chain extension are change in melt viscosity, which maybe measured by capillary rheometry, melt flow index (MFI), cone-and-plate or parallel plate rheometry. Other common methods are based on changes in solution viscosity, which may be measured for example by Ostwall-Fenske or Ubbelohde capillary viscometers as changes in relative, inherent, or intrinsic viscosity (LV.) .

[0074] The chain extenders are very effective at increasing the molecular weight of reprocessed or recycled condensation polymers. This is evidenced by the increase in the intrinsic viscosity of the condensation polymers following chain extension. For example, in some instances the chain extenders may increase the intrinsic viscosity of the chain extended condensation polymer back to within 15% of the intrinsic viscosity of the condensation polymer prior to recycling or reprocessing, where intrinsic viscosity is measured according to ASTM D-2857. This includes embodiments where the intrinsic viscosity of the chain extended condensation polymer may increase back to within 10% of the intrinsic viscosity of the condensation polymer prior to recycling or reprocessing, and further includes embodiments where the intrinsic viscosity of the chain extended condensation polymer may increase back to within 5% of the intrinsic viscosity of the condensation polymer prior to recycling or reprocessing. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

[0075] In some cases, the intrinsic viscosity of the chain extended condensation polymers is actually higher than the initial intrinsic viscosity of the condensation polymers before they underwent recycling or reprocessing. This includes embodiments where the intrinsic viscosity of the chain extended condensation polymer is increased by at least 2%, at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, and even at least 50% with respect to the condensation polymer from which the recycled or reprocessed condensation polymer was produced. In some instances the chain extenders may increase the intrinsic viscosity of the chain extended condensation polymers, as described above, without any need from pre-drying the condensation polymer, catalyst, vacuum operation, or solid state polymerization steps.

[0076] The increase in the viscosity of the condensation polymers following chain extension may also be measured by melt viscosity as measured by capillary rheometry. For example, in some instances the chain extenders may increase the melt viscosity of the chain extended condensation polymer as measured by capillary rheometry at 100^"1, by up to 300 % relative to the initial post-processing melt viscosity of the condensation polymer. This includes embodiments where this increase in melt viscosity is realized without the need for any pre-drying of the condensation polymer, catalyst, vacuum operation, or solid state polymerization steps.

[0077] The increase in the molecular weight of the condensation polymers following chain extension is also demonstrated by the decrease in the melt flow index (MFI) of the condensation polymer after chain extension has occurred. For example, in some instances the melt flow index (MFI) of the chain extended condensation polymer, as measured by ASTM- D-1238, may be only about 60% or less of the MFI of the reprocessed or recycled condensation polymer or of the initial MFI of a low grade condensation polymer. This includes embodiments where this decrease in MFI is realized in a melt blending process without the need for any pre-drying of the condensation polymer, catalyst, vacuum operation, or solid state polymerization steps.

[0078] Due to their ability to provide recycled or processed materials with properties equivalent to those of the un-recycled or un-processed materials, the chain extenders have the Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

advantage that more of the recycled or reprocessed material can be incorporated into the final product. The chain extenders have the further advantage that the mechanical, thermal and impact properties of chain extended polycondensates are not negatively impacted and in many instances are enhanced with respect to those of the un-recycled or un-processed polycondensates.

[0079] The chain extenders may be used with lower grade virgin polycondensates in order to make such polycondensates suitable for uses which they otherwise would not be. For example, a chain extended lower grade condensation polymer, such as a polyester, according to the invention, may have an intrinsic viscosity that permits the polymer to be used in more demanding application. This includes embodiments where the intrinsic viscosity of the chain extended lower grade condensation polymer is increased by at least 2%, at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, and even at least 50% by reaction with a chain extender. "Lower grade" polycondensate, as used herein, means a resin grade with comparatively lower molecular weight with respect to other grades in the same chemical family, exhibited as lower I.V., or lower melt viscosity at given conditions, which also results in lower physical properties than the other grades in the same family.

Antioxidant

[0080] The polymeric chain extended compositions may also include an antioxidant.

The polymeric compositions may contain from about 0 wt% to about 5 wt% antioxidant, in some embodiments, from about 0.1 wt% to about 5 wt% antioxidant, in other embodiments, and from about 0 wt% to about 3 wt% in yet other embodiments. Exemplary antioxidants include those such as di-substituted phenols, phenyl phosphites, and hydroperoxide decomposers. Useful antioxidants include tetrakis[methylene(3,5-di-tert-butylhydroxy hydrocinnamate)]methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, tris(2,4-di- tert-butylphenyl) phosphite, l,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-l,3,5-triazine- 2,4,6(1H,3H,- 5H)-trione and benzenepropanoic acid, 3,5-bis(l,l-dimethyl-ethyl)-4-hydroxy- C₇ C₉ branched alkyl esters, 4,4'-thiobis-(6-t-butyl-m-cresol), 2,2'-methylenebis-(4-methyl-6- t-butyl-butylphenol), bis-(2,4-di-t-butylphenyl) pentaerythritol diphosphite, Irganox® 1093 (1979)(((3,5-bis(l,l-dimethylethyl)-4-hydroxyphenyl)methyl)-dioctadecyl ester phosphonic Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

acid), Irganox® 1098 (N,N'-l,6-hexanediylbis(3,5-bis(l,l-dimethyl)-4-hydroxy- benzenepropanamide ), Naugaard®. 445 (aryl amine), Irganox® L 57 (alkylated diphenylamine), Irganox® L 115 (sulfur containing bisphenol), lrganox® LO 6 (alkylated phenyl-delta-napthylamine), 2,2'-ethylidenebis(4,6-di-t-butylphenyl)fluorophosnite.

[0081] Useful hydroperoxide decomposers include Sanko® HCA (9, 10-dihydro-9- oxa-10-phosphenanthrene-lO-oxide), triphenyl phosphate and other organo-phosphorous compounds, such as, Irgafos® TNPP from Ciba Specialty Chemicals, Irgafos® 168, from Ciba Specialty Chemicals, Ultranox® 626 from GE Specialty Chemicals, Mark PEP-6 from Asahi Denka, Mark HP-10 from Asahi Denka, Irgafos® P-EPQ from Ciba Specialty Chemicals, Ethanox 398 from Albemarle, Ethaphos 368 from Albemarle, Weston 618 from GE Specialty Chemicals, Irgafos® 12 from Ciba Specialty Chemicals, Irgafos® 38 from Ciba Specialty Chemicals, Ultranox® 641 from GE Specialty Chemicals and Doverphos® S-9228 from Dover Chemicals.

[0082] Another class of useful antioxidants are the sterically hindered phenols. Such materials include, butylated hydroxytoluene (BHT), Vitamin E (di-alpha-tocopherol), Irganox® 1425WL (calcium bis-(O-ethyl(3,5-di-t-butyl-4-hydroxybenzyl))phosphonate), Irganox® 1010 (tetrakis(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate))methane), Irganox® 1076 (octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate), Ethanox® 702 (hindered bis phenolic), Ethanox® 330 (high molecular weight hindered phenolic), and Ethanox® 703 (hindered phenolic amine).

UV Stabililizers

[0083] The polymeric compositions may further include a UV stabilizer. Suitable UV stabilizers include hindered amine light stabilizers (HALS), benzotriazole UV absorbers, hydroxyphenyl-triazine or -pyrimidine UV absorbers, and hydroxybenzophenone UV absorbers. Some such materials are described in U.S. 6,630,527. Such materials are commercially available.

[0084] Exemplary HALS absorbers include those sold under the tradenames such as

TINUVIN 622 (Ciba Specialty Chemicals, Inc.), UVINUL 5050H (BASF), and l-(l-acetyl- Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

2,2,6,6-tetramethyl-4-piperidyl)-3 -dodecyl-pyrrolidine-2,5-dione (SANDUVOR 3058, Clariant). Benzotriazole UV absorbers include materials such as, 2-(2'-hydroxy-5'- octylphenyl)-benzotriazole, 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(2-hydroxy- 3,5-di-ført-amyl-phenyl)-2H-benzotriazole, 2-[2-hydroxy-3,5-di(l,l-dimethylbenzyl)phenyl]- 2H-benzotriazole, the reaction product of 2-(2-hydroxy-3-tert-butyl-5-methyl propionate)- 2H-benzotriazole and polyethylene ether glycol having a weight average molecular weight of 300, and 2-(2-hydroxy-3-tert-butyl-5-iso-octyl propionate)-2H-benzotriazole.

[0085] Suitable hydroxyphenyl-triazine or -pyrimidine UV absorbers include compounds having a 2,4,6-trisaryl-l,3,5-triazine or 2,4, 6-trisaryl- 1,3 -pyrimidine group, and which further contain free hydroxyl groups. For example, 2-[4-((2,-hydroxy-3- dodecyloxy/tridecyloxypropyl)oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-l,3,5- triazine; 2-[4-(2-hydroxy-3-(2-ethylhexyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4- dimethylphenyl) 1 ,3,5-triazine; 2-(4-octyloxy-2-hydroxyphenyl)-4,6-bis(2,4- dimethylphenyl)-l,3,5-triazine; 2-(4,6-diphenyl-l,3,5-triazin-2-yl)-5-[(hexyl)oxy]phenol; and 2-(4,6-bis(2,4-dimethylphenyl)-l,3,5-triazin-2-yl]-5-(oxtyloxy)phenol.

[0086] Suitable hydroxybenzophenone UV absorbers, include for example, 2,4- dihydroxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, and 2-hydroxy-4- dodecyloxybenzophenone.

Applications and Uses

[0087] Applications of chain extended polycondensates include, but are not limited to, recycling of scrap plastics, such as polyesters, polycarbonates, polyamides, and blends and alloys of scrap plastics by either a reactive extrusion or a solid state polymerization process of this invention, and post-processing of the recycled material through extrusion/blow molding into various articles including, but not limited to, food or non-food contact containers and transparent colored applications, films, coatings, tapes, moldings, fibers, strapping and other consumer products. In one particular embodiment, the chain extended polycondensates, along with an impact modifier, are useful in plastic strapping applications for various packaging arrangements. Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

[0088] One skilled in the art will readily realize that all ranges and ratios discussed can and do necessarily also describe all subranges and subratios therein for all purposes and that all such subranges and subratios also form part and parcel of this invention. Any listed range or ratio can be easily recognized as sufficiently describing and enabling the same range or ratio being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range or ratio discussed herein can be readily broken down into a lower third, middle third and upper third, etc.

[0089] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

[0090] The present invention will be better understood by reference to the following examples which are intended for purposes of illustration and are not intended to nor are to be interpreted in any way as limiting the scope of the present invention, which is defined in the claims appended hereto.

Examples

Example 1

[0091] Polyethylene terephthalate (PET) strips were prepared according to the tables below. The samples were prepared in a four step process, the conditions of which are shown in Table 1. In the first step, the materials are oven dried. In the second step, the components are mixed in a high speed mixer. In the third step, the materials are compound with twin screw extruders, and in the final step, the materials are injection molded at elevated temperature. The chain extender used in the mixture was JONCRYL™ ADR 4300 (BASF), the A impact modifier was Rohm & Haas' PARALOID™ EXL-2314, and the B modifier was Arkema's LOTADER™ SX 8900. The PET used in the test is PET CB-602 available from Yuan Fang (copolymer with IV = 0.8 dl/g). Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

Table 1 : Processing: PET+ impact modifiers+ chain extender

Table 2: Concentration of the samples:

[0092] The mechanical test properties were based on tensile strength and impact strength. For the tensile strength test, the samples were subjected to a full load of 500 kfg as at tensile speed of 50 mm/min. For the impact strength, the samples were run in IZOD mode at a speed of 3.80 m/s, with a capacity of 10 J. All samples were 4 mm thick and 10 mm wide. The mechanical test results are presented in Table 3.

Table 3: Mechanical Strength Test Results

Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

Example 2

[0093] Polyethylene terephthalate (PET) strips were prepared according to the sample descriptions below in Table 4. The samples were prepared as above in Example 1, the conditions of which are shown in Table 5. The chain extender used in the mixture was JONCRYL™ ADR 4300 (BASF), the A impact modifier was Rohm & Haas' PARALOID™ EXL-2314, and the B modifier was Arkema's LOTADER™ SX 8900.

Table 4

Table 5; Processing: PET+ impact modifiers+ chain extender

[0094] The mechanical test properties were based on tensile strength and impact strength. For the tensile strength test, the samples were subjected to a full load of 500 kfg as at tensile speed of 50 mm/min. For the impact strength, the samples were run in IZOD mode Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

at a speed of 3.80 m/s, with a capacity of 10 J. All samples were 4 mm thick and 10 mm wide. The mechanical test results are presented in Table 6.

Table 6: Mechanical Strength Test Results

[0095] The tables show that increasing the impact modifier concentration increases the mechanical properties of the PET up to a given level. Increasing the modifier beyond the given level does not appear give additional mechanical benefits, at least with regard to the break strength in both tensile strength and elongation measurements. Impact modifier B in combination with the chain extender gives better mechanical strength properties than impact modifier A. A combination of 1% impact modifier B and 0.2% chain extender shows the best mechanical properties of PET.

[0096] While several, non-limiting examples have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the invention in its broader aspects as defined in the following claims.

Claims

Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)WHAT IS CLAIMED IS:

1. A polymeric composition for use in plastic strapping comprising from about 0.05 weight percent to about 2 weight percent of a chain extender, from about 0.05 weight percent to about 5 weight percent of a impact modifier; and from about 90 weight percent to about 99 weight percent of a condensation polymer; wherein, the chain extender comprises a polymerization product of: (i) a, epoxy- functional (meth)acrylic monomer; and (ii) a styrenic and/or (meth)acrylic monomer; the chain extender has an epoxy equivalent weight of from about 180 to about 2800, a number-average epoxy functionality (Efn) value of less than about 30, a weight-average epoxy functionality (Efw) value of up to about 140, and a number-average molecular weight (Mn) value of less than 6000 and wherein at least a portion of the chain extender has reacted with at least a portion of the condensation polymer to produce a chain-extended condensation polymer.

2. The polymeric composition of Claim 1, further comprising an antioxidant.

3. The polymeric composition of any one of Claims 1 or 2, wherein the chain extender has a polydispersity index of from about 1.5 to about 5.

4. The polymeric composition of any one of Claims 1, 2, or 3, wherein the epoxy- functional (meth)acrylic monomer is present from about 50 to about 80 weight percent and the styrenic and/or (meth)acrylic monomer is present from about 20 to about 50 weight percent.

5. The polymeric composition of any one of Claims 1 , 2, 3, or 4, wherein the chain extender comprises about 25 to about 50 weight percent of the epoxy-functional (meth)acrylic monomer and about 50 to about 75 weight percent of the styrenic and/or (meth)acrylic monomer.

6. The polymeric composition of any one of Claims 1 to 5, wherein the chain extender comprises about 5 to about 25 weight percent of the epoxy-functional (meth)acrylic Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

monomer and about 75 to about 95 weight percent of the styrenic and/or (meth)acrylic monomer.

7. The polymeric composition of any one of Claims 1 to 6, wherein the chain extender has a weight average molecular weight of less than about 25,000.

8. The polymeric composition of any one of Claims 1 to 7, wherein the condensation polymer is selected from the group consisting of polyesters, polyamides, polycarbonates, polyurethanes, polyacetals, polysulfones, polyphenylene ethers, polyether sulfones, polyimides, polyether imides, polyether ketones, polyether-ether ketones, polyarylether ketones, polyarylates, polyphenylene sulfides and polyalkyls.

9. The polymeric composition of any one of Claims 1 to 8, wherein the condensation polymer is a condensation polymer that has been recycled or reprocessed.

10. The polymeric composition of any one of Claims 1 or 9, wherein the impact modifier is selected from the group consisting of acrylic rubbers, ASA rubbers, diene rubbers, organosiloxane rubbers, EPDM rubbers, SBS or SEBS rubbers, ABS rubbers, MBS rubbers, glycidyl esters, polystyrene-polybutadiene, polystyrene-poly(ethylene- propylene), polystyrene-polyisoprene, poly(α;-methylstyrene)-polybutadiene, polystyrene-polybutadiene-polystyrene, polystyrene-poly(ethylene-propylene)- polystyrene, polystyrene-polyisoprene-polystyrene, poly(α-methylstyrene)- polybutadiene-poly(omethylstyrene), methylmethacrylate-butadiene-styrene (MBS) and methylmethacrylate-butylacrylate, polyalkylacrylates grafted with polymethylmethacrylate, polyalkylacrylates grafted with styrene-acrylonitrile copolymer, polyolefins grafted with poly ethylmethacrylate, polyolefins grafted with styrene-acrylonitrile co-polymer, butadiene core-shell polymers, polyphenylene ether- polyamide, polyamides, styrene-acrylonitrile co-polymer, styrene-acrylonitrile copolymer grafted onto polybutadiene, and a combination of any two or more thereof.

11. The polymeric composition of any one of Claims 1 to 9, wherein the impact modifier comprises a first component and a second component, wherein the first component is Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

a co-polymer of ethylene and an unsaturated epoxides, and the second component is a co-polymer of ethylene and an alkyl (meth)acrylate.

12. The polymeric composition of Claim 11, wherein the unsaturated epoxide is selected from the group consisting of allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and itaconate, glycidyl (meth)acrylate, 2-cyclohexene-l -glycidyl ether, cyclohexene-4,5-diglycidyl carboxylate, cyclohexane-4-glycidyl carboxylate, 5- norbornene-2-methyl-2-glycidyl carboxylate, and endo-cis-bicyclo-(2,2,l)-5-heptene- 2,3-diglycidyl dicarboxylate.

13. The polymeric composition of Claim 11 , wherein the alkyl (meth)acrylate is selected from the group consisting of methyl (meth)acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate , n-octyl acrylate, and 2-ethylhexyl acrylate.

14. The polymeric composition of Claim 2, wherein the antioxidant is a compound selected from the group consisting of di-substituted phenols, phenyl phosphites, hydroperoxide decomposers, sterically hindered phenols, and a combination of any two or more thereof.

15. The polymeric composition of Claim 2, wherein the antioxidant is a compound selected from the group consisting of tetrakis[methylene(3,5-di-tert-butylhydroxy hydrocinnamate)]methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, tris(2,4-di-tert-butylphenyl) phosphite, 1 ,3 ,5-tris(3 ,5-di-tert-butyl-4-hydroxybenzyl)- l,3,5-triazine-2,4,6-(lH,3H,5H)-trione and benzenepropanoic acid, 3,5-bis(l,l- dimethyl-ethyl)-4-hydroxy-C₇-C₉ branched alkyl esters, 4,4'-thiobis-(6-t-butyl-m- cresol), 2,2'-methylenebis-(4-methyl-6-t-butyl-butylphenol), bis-(2,4-di-t-butylphenyl) pentaerythritol diphosphite, ((3,5-bis(l,l-dimethylethyl)-4-hydroxyphenyl)methyl)- dioctadecyl ester phosphonic acid, N,N'-l,6-hexanediylbis(3,5-bis(l,l-dimethyl)-4- hydroxy-benzenepropanamide, Naugaard®. 445, Irganox® L 57, Irganox® L 115, alkylated phenyl-delta-napthylamine, 2,2'-ethylidenebis(4,6-di-t- butylphenyl)fluorophosnite, 9, 10-dihydro-9-oxa- 10-phosphenanthrene- 10-oxide, triphenyl phosphate, Irgafos® TNPP, Irgafos® 168, Ultranox® 626, Mark PEP-6, Mark HP-10, Irgafos® P-EPQ, Ethanox 398, Ethaphos 368, Weston 618, Irgafos® 12, Atty. Dkt. No. 018894-0254 (BASF No. IN-6423)

Irgafos® 38, Ultranox® 641, Doverphos® S-9228, butylated hydroxytoluene (BHT), Vitamin E, calcium bis-(O-ethyl(3,5-di-t-butyl-4-hydroxybenzyl))phosphonate, tetrakis(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate))methane, octadecyl 3,5- di-tert-butyl-4-hydroxyhydrocinnamate, Ethanox® 702, Ethanox® 330, Ethanox® 703, and a combination of any two or more thereof.

16. A plastic article made from the polymeric composition of any one of Claims 1-15, wherein the plastic article is plastic strapping.

17. Use of the polymeric composition of any one of Claims 1 -15 in the preparation of plastic strapping.