WO1998013266A1 - Article desoxygenant transparent comprenant un polyester biaxialement oriente - Google Patents

Article desoxygenant transparent comprenant un polyester biaxialement oriente Download PDF

Info

Publication number
WO1998013266A1
WO1998013266A1 PCT/US1997/016826 US9716826W WO9813266A1 WO 1998013266 A1 WO1998013266 A1 WO 1998013266A1 US 9716826 W US9716826 W US 9716826W WO 9813266 A1 WO9813266 A1 WO 9813266A1
Authority
WO
WIPO (PCT)
Prior art keywords
article
scavenging
polymer
oxygen
aromatic
Prior art date
Application number
PCT/US1997/016826
Other languages
English (en)
Other versions
WO1998013266A9 (fr
Inventor
Steven L. Schmidt
Amit S. Agrawal
Ernest A. Coleman
Original Assignee
Continental Pet Technologies, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Continental Pet Technologies, Inc. filed Critical Continental Pet Technologies, Inc.
Priority to CA002266503A priority Critical patent/CA2266503A1/fr
Priority to BR9713221-7A priority patent/BR9713221A/pt
Priority to JP51577398A priority patent/JP2001504399A/ja
Priority to AU44911/97A priority patent/AU710677C/en
Priority to EP97943437A priority patent/EP0934201A1/fr
Publication of WO1998013266A1 publication Critical patent/WO1998013266A1/fr
Publication of WO1998013266A9 publication Critical patent/WO1998013266A9/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
    • C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/42—Component parts, details or accessories; Auxiliary operations
    • B29C49/78—Measuring, controlling or regulating
    • B29C2049/7879—Stretching, e.g. stretch rod
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/08—Biaxial stretching during blow-moulding
    • B29C49/087—Means for providing controlled or limited stretch ratio
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037—Other properties
    • B29K2995/004—Semi-crystalline
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/412—Transparent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/514—Oriented
    • B32B2307/518—Oriented bi-axially
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/724—Permeability to gases, adsorption
    • B32B2307/7242—Non-permeable
    • B32B2307/7244—Oxygen barrier
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/74—Oxygen absorber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2367/00—Polyesters, e.g. PET, i.e. polyethylene terephthalate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00—Containers; Receptacles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2553/00—Packaging equipment or accessories not otherwise provided for
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
    • C08L67/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones

Definitions

  • the present invention is directed to oxygen-scavenging materials and packages for holding oxygen-sensitive products, and more particularly to a transparent article incorporating an oxygen-scavenging aromatic ester polymer and a biaxially-oriented polyester, the article being useful for protecting oxygen-sensitive products from deterioration.
  • Plastic packaging has certain inherent benefits over glass and metal packaging, such as light weighting, variability in package design, non-breakability, and reduced cost of manufacture.
  • plastic packaging may have greater permeability to certain gases (oxygen and carbon dioxide) and liquids (water) than glass or metal; these gases/liquids permeate through the plastic and reduce the shelf life of the product contained therein.
  • gases oxygen and carbon dioxide
  • liquids water
  • Various specialty plastics and layer structures have been developed to provide commercially-acceptable plastic barrier packages with an acceptable shelf life for certain oxygen-sensitive products, such as juice and ketchup.
  • a "passive" barrier prevents oxygen permeation into the package.
  • PVDC polyvinylidene chloride copolymer
  • EVOH ethylene vinyl alcohol copolymer
  • metal films thin layers of metal films
  • PVC polyvinylidene chloride copolymer
  • PET polyethylene terephthalate
  • an oxygen “scavenger” is incorporated into a single or multilayer plastic structure to consume the oxygen initially present and/or generated from the inside of the package, as well as to prevent exterior oxygen from reaching the interior of the package.
  • oxygen scavengers both remove oxygen from inside the package and prevent its ingress into the package.
  • Another important design parameter for oxygen-barrier packaging is thermal resistance.
  • the product e.g., juice
  • the container is then sealed (capped), and the juice/container allowed to cool.
  • the container must withstand both the hot-filling temperature and the vacuum generated in the sealed container as the product cools, without distortion.
  • Commercially successful hot-fill juice containers have been developed by Continental PET Technologies, Inc.
  • multilayer juice containers include two very thin intermediate barrier layers of EVOH positioned between inner and outer layers of virgin PET, and a core layer of either virgin or recycled PET.
  • C0 2 carbon dioxide
  • PEN polyethylene naphthalate
  • PET polyethylene terephthalate
  • the present invention is directed to a transparent oxygen-scavenging article, which includes a biaxially-oriented aromatic polyester polymer and an aromatic ester scavenging polymer.
  • the scavenging polymer has alpha-hydrogen carbonyl groups:
  • n 2 or more, which provide the oxygen-scavenging function.
  • the relative weight percentages of the alpha-hydrogen carbonyl groups and aromatic groups are selected to provide a desired rate of oxygen scavenging and a T G which allows biaxial orientation of the polyester polymer without substantial loss of transparency.
  • the aromatic groups provide single or multiple aromatic rings in the backbone or sidechain of the scavenging polymer, and preferably include, in the backbone:
  • the article may be a film or package, or a portion thereof; examples include a film stretched in transverse directions and a blow-molded container which has undergone axial and hoop expansion.
  • the article may be a single layer or multiple layers.
  • the scavenging polymer may be provided in a separate layer from the polyester, or it may be blended with or copolymerized with the polyester.
  • the object of the present invention is to provide a scavenging polymer which is compatible with aromatic polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) , such that the polyester can be biaxially-oriented without loss of transparency.
  • Transparency may be defined as the percent haze for transmitted light through the article wall or film thickness H ⁇ (as hereinafter defined), measured in accordance with ASTM Method D1003 using a standard color difference meter.
  • the article preferably has a percent haze of less than 10 percent, and more preferably less than 5 percent.
  • the process compatibility of the scavenging polymer and polyester is indicated by the glass transition temperatures (T G ) of the two polymers, whereby either a blend, copolymer, or separate layers of the polymers can be processed in the same temperature range without loss of transparency, i.e., held at a temperature above T G and stretched in transverse directions to biaxially orient the polyester.
  • T G glass transition temperatures
  • the average biaxial stretch ratio is from 9:1 to 15:1.
  • the T G of the scavenging polyester may be adjusted by varying the percentage of aromatic groups in the polymer — with increasing amounts of aromaticity increasing the T G .
  • the T G of a polymer used in a commercial plastic container must be at least 5 °C above the ambient use temperature, e.g., if a carbonated beverage bottle will be used in an environment where the temperature may reach 35 °C, the polymer should have a T G of at least 40 °C or the polymer may melt (no longer be a solid article).
  • the T G also determines the temperature above which an aromatic polyester must be heated to enable biaxial stretching, which orients and partially crystallizes the polymer to provide structural strength.
  • PET has a T G of about 70°C
  • PEN has a T G of about 120°C
  • the polymers are typically stretched in an orientation temperature range of at least 20 °C above T G (e.g., at least 90°C for PET, at least 140°C for PEN, and varying with the copolymer content).
  • T G the orientation temperature of the polyester which is to be biaxially oriented (e.g., PET or PEN), but not so far below that the scavenging polymer will crystallize (become nontransparent or opaque) during the orientation process.
  • the T G of the scavenging polymer should be at least 10°C below the orientation temperature used to biaxially orient the polyester.
  • a preferred range of T G for a scavenging polymer having an amorphous nature is 0-15°C below the T G of the polyester, more preferably 3-7°C below, and most preferably about 5°C below.
  • a preferred range of T 0 for a crystallizable scavenging polymer is 0-15°C above the T G of the polyester, more preferably 3-7°C above, and most preferably about 5°C above.
  • the scavenging polymer should have a T G of at least 40 °C, preferably at least 48 °C, and more preferably in the range of 70-135°C.
  • the scavenging polymer preferably has a T G of 70-85 °C, and for ease of processing with PEN polymers a T G of 120-135°C.
  • a lower T G of 90-100°C for use with PEN polymers is acceptable.
  • the relative molar or weight percentages of the various groups in the scavenging polymer are selected to optimize the desired scavenging and compatibility characteristics.
  • increasing the alpha-hydrogen carbonyl groups will increase the oxygen- scavenging rate.
  • the ester groups (COO) provide compatibility with the polyester.
  • Increasing the aromatic groups increases the T G .
  • Increasing the aliphatic chain length may increase the oxygen-scavenging capacity (scavenging performance over the shelf life of the container) as described below.
  • oxygen-scavenging properties of these polymers result from the presence of the carbonyl groups which provide a non-uniformity, such as a kink, in the backbone molecular structure at or near the location of the carbonyl group. It is believed that this non-uniformity decreases the chemical stability of the hydrogen atoms bonded to the atoms alpha to the carbonyl carbon. As a result, these hydrogen atoms have a significantly reduced bond strength which is then much more easily disassociated by diatomic gaseous oxygen, and thus have a relatively high propensity to react with oxygen, resulting in the oxygen-scavenging property.
  • a non-uniformity such as a kink
  • oxygen-scavenging polymers of the present invention need not include any carbon-carbon double bonds in the backbone to achieve scavenging.
  • the aliphatic chain (e.g., (CH 2 ) n ) adjacent the carbonyl carbon is believed to provide continuing (cascading) sites for oxygen consumption, as illustrated in the steps of Figs. 13A-13K.
  • the oxygen molecule has liberated an alpha hydrogen to form a radical on the alpha carbon and radicalize the oxygen molecule as: -O — O — H.
  • the radical of the alpha carbon is satisfied, at least temporarily, by attachment of the radical O — O — H.
  • Another oxygen molecule is added to further the reaction and eventually be consumed.
  • Fig. 13F the final stable reactants are shown.
  • the new carbonyl is in the position of the previous alpha hydrogen, a water molecule is formed, and an oxygen molecule is now free.
  • the radicalized oxygen molecule O — O — H attaches itself to the second alpha carbon temporarily satisfying the radicals. Another oxygen molecule is added to be consumed. The water molecule resulting from the previous steps is not shown for it is no longer involved in any reactivity.
  • Fig. 13K the final form of the molecular structure is shown with all the alpha hydrogens liberated to produce water, and all the alpha carbons have become carbonyls. Also shown is the recently de-radicalized oxygen molecule coming from the *O — O — H radical. This illustrates the continuing (cascading) scavenging function of the aliphatic chain, wherein the larger the chain the greater the number of potential scavenging sites. It is understood that this extends the scavenging potential over time, i.e., extends the shelf life of the package. Compatibility of the scavenging polymer and polyester is generally indicated by a substantial match of solubility parameters.
  • the Van Krevelen solubility parameters for the scavenging polymer and the polyester are preferably within 3 units and more preferably within 1 unit.
  • the solubility match enhances blending and adhesion of the polymers.
  • the compatibility of the scavenging polymer and polyester may be further indicated by crystallization rate, with the crystallization rate of the scavenging polymer less than or equal to that of the polyester. This provides process compatibility to enable biaxial orientation of the PET, in either a blend, copolymer or a separate layer, without loss of transparency.
  • the aromatic ester scavenging polymer may be a homopolymer, a random copolymer, an alternating copolymer, or a block copolymer.
  • the scavenging polymer must include alpha-hydrogen carbonyl groups to provide the oxygen-scavenging functionality, and aromatic and ester groups for compatibility with the polyester.
  • the polymer may include other functional groups, so long as the compatibility with the polyester is maintained.
  • a preferred scavenging homopolymer has the single-repeating unit set forth below and is referred to as EVPET: . g _
  • the REVPET repeating unit has the same amount of aromaticity (a single backbone ring) and 5 number of ester groups (two) as PET, and the same 2-carbon (ethyl) group in the backbone. It provides an exact match of solubility parameter.
  • Modified REVPET has a very close match of solubility parameter. There is an extra carbon atom in the aliphatic carbon chain which reduces the T G . Depending on the application, it may be desirable to form a copolymer (e.g., add additional groups which modify T G or the 15 crystallization rate). Various other scavenging polymers are described in the detailed description.
  • a preferred transparent oxygen-scavenging article is a multilayer package, such as a blow-molded container, having one or more layers of a biaxially-oriented PET polymer and one or more layers of a scavenging polymer such as REVPET.
  • the thickness of the REVPET 0 layer(s) may range from relatively thin (e.g., about 2% by weight of the container) to relatively thick (e.g., about 40% by weight of the container).
  • an aromatic ester scavenging condensation polymer may be prepared from a dicarboxylic aliphatic acid having the formula:
  • n 2 or more, and preferably 2-10, or a derivative of the acid (e.g., dimethyl ester, acid 0 chlorides, acid anliydrides, diacyl chlorides), to provide the alpha-hydrogen carbonyl groups.
  • the dicarboxylic aliphatic acid (or derivative) is reacted with one or more aromatic glycols or diacetates, having the general formula: O O
  • n and m are the same or different integers from 0 to 6, and R' and R" are the same or different previously described aromatic backbone or side chain groups (see pages 4-5).
  • These glycols and diacetates provide the aromatic rings and adjacent oxygens (the backbone oxygen in the ester group of the aromatic ester polymer).
  • the molar ratio of aromatic groups : ester groups : alpha hydrogen carbonyl groups is 1 :2:2 for polycondensation homopolymers. Copolymers often have different ratios to optimize the T G of the scavenging polymer.
  • cobalt will enhance the oxygen-scavenging rate of the aromatic ester scavenging polymers of this invention.
  • 50-500 micrograms of cobalt is added per gram of scavenging polymer.
  • the cobalt is added in the form of cobalt neodeconoate or cobalt acetate.
  • Alternative enhancers include magnesium and manganese acetates.
  • Figs. 1 A-l K show methods for making various polymers including a prior art two-step method for preparing PET (Fig. 1 A), and in Figs. 1 B-l K methods for making various oxygen-scavenging polymers useful in the present invention;
  • Fig. 2 is a vertical cross-section of a multilayer preform useful in making a beverage container according to one embodiment of the present invention
  • Fig. 3 is a side elevational view of a multilayer pressurized container made from the preform of Fig. 2;
  • Fig. 4 is a horizontal cross-section taken along line 4-4 of Fig. 3, showing the multilayer sidewall of the container;
  • Fig. 5 is a vertical cross-section of a blow-molding apparatus for making the container of Fig. 3;
  • Fig. 6 is a vertical cross-section taken along line 6-6 of Fig. 3, showing one foot of the container base;
  • Fig. 7A is an enlarged fragmentary cross-section of a crystallized neck finish and cap, according to one embodiment
  • Fig. 7B is an enlarged fragmentary cross-section of an amorphous neck finish and cap, according to another embodiment
  • Figs. 8A and 8B are side elevational views of a multilayer preform and resulting container according to another embodiment of the present invention.
  • Fig. 9 is a schematic sectional view through a preform for making a can according to an alternative embodiment
  • Fig. 10 is a schematic sectional view of an intermediate article made from the preform of Fig. 9, including as a lower portion a can which is biaxially oriented up through the finish, and an upper portion which is removed and discarded;
  • Fig. 1 1 is a schematic sectional view through a preform according to another embodiment having a neck finish insert and multilayer body- and base-forming portions;
  • Fig. 12 is a graph illustrating changes in internal temperature and pressure over a typical pasteurization cycle, for a prior art 12-oz glass container filled with a juice product carbonated at 2.5 volumes;
  • Figs. 13A-13K are a series of steps showing oxygen consumption by the aliphatic chain of the alpha-hydrogen carbonyl group.
  • the present invention relates to aromatic ester scavenging polymers, having alpha-hydrogen carbonyl oxygen-scavenging groups, which can be blended or copolymerized (includes transesterification) with an aromatic polyester polymer, or used in a layer structure with the polyester polymer, to form a transparent article for the storage of oxygen-sensitive products.
  • the scavenging polymer is used for injection molding substantially transparent preforms, and blow molding of those preforms to form substantially transparent containers for beer, juice, ketchup and other oxygen-sensitive products.
  • the particular materials, wall thicknesses, layer structures and container design will depend upon the particular product application and conditions of filling, sterilization and use, but the common goal is to provide active barrier protection in a cost-effective manner for use with commercially-available aromatic polyester resins (e.g., PET and PEN), such that the final container provides substantial transparency, is lightweighted and has the structural integrity required of a commercially-acceptable polyester container.
  • aromatic polyester resins e.g., PET and PEN
  • the aromatic ester oxygen-scavenging polymer should have chemical and physical properties that allow substantially transparent preforms and packaging structures to be formed partially or entirely therefrom.
  • the scavenging polymer should be substantially chemically inert under the conditions used to make preforms and packaging structures, and under the unfilled storage conditions of such preforms and packaging structures.
  • the end groups of the polymer may be desirable that the end groups of the polymer have reduced chemical reactivity.
  • the oxygen-scavenging polymer should not substantially deletcriously affect the transparency, melting temperature, viscosity or other processing parameters of the polymer composition.
  • the oxygen-scavenging polymer should be substantially chemically inert towards foods and/or beverages intended to be stored within the packaging structure.
  • a diacid may be condensed with a glycol, or a hydroxy acid self-condensed, in order to form a linear polyester such as PET.
  • Fig. 1 A (taken from K. Wissermal and H J. Arpe, Industrial Organic Chemistry, Section 14.4, Applications of Terephthalic Acid and Dimethyl Terephthalate, Veriag Chemical Press, pages 349-351 (1978)), describes a two-step process for PET manufacture.
  • dimethyl terephthalate DMT
  • TPA terephthalic acid
  • This first step is carried out at a temperature on the order of 100-150°C and a pressure of 10-70 bar, in the presence of for example copper, cobalt or zinc acetate catalysts.
  • the resulting intermediate product is bis(2-hydroxyethyl) terephthalate.
  • the intermediate product undergoes catalytic polycondensation to produce PET; this is typically done at a temperature of approximately 10-20°C above the melting point of PET (246°C), under vacuum, and usually with a catalyst, such as Sb 2 O 3 .
  • a catalyst such as Sb 2 O 3 .
  • ethylene glycol is removed.
  • the resulting PET melt is then cooled and granulated.
  • Fig. 1A and subsequent figures the atoms/groups being removed are shown in a box with an arrow, for ease of identifying the reaction sites.
  • PET is a thermoplastic polyester, used in strain-oriented form as both a packaging film and as blow-molded soft-drink containers.
  • PET PET homopolymer
  • PET copolymers which include varying amounts, normally up to about 10 mole percent of other monomers, which are compatible with the PET and do not substantially detract from the desired PET structural properties or processing parameters. These may also be used in the context of the present invention.
  • PET is meant to include PET homopolymer and copolymers.
  • Fig. I B illustrates a method of making an oxygen-scavenging polymer referred to herein as "REVPET".
  • the repeating unit for REVPET (shown in Fig. IB) has the same numbers of carbon, oxygen and hydrogen atoms, and thus the same molecular weight, as the repeating unit for PET (shown in Fig. 1A).
  • REVPET has a high level of compatibility with PET which enables it to be blended and/or copolymerized with PET, or used in a layer structure with PET, wherein the PET can be biaxially oriented and remain substantially transparent.
  • transparent is meant to include substantially transparent in that it is commercially acceptable to have some reduction in light transmission caused by crystallization or the like in what is generally referred to as a transparent container.
  • a definition of transparency is set forth hereinafter with regard to ASTM Method D1003.
  • REVPET The structural difference between REVPET and PET (as illustrated in Figs. 1 ⁇ - 1 B), is that in REVPET the backbone oxygen in each ester (COO) group is adjacent to the aromatic ring, and thus the CH 2 group (adjacent to the C of the ester group) provides an alpha- hydrogen carbonyl functional group for oxygen scavenging.
  • REVPET has two alpha-hydrogen carbonyl groups per repeating unit, which provides a relatively high degree of oxygen scavenging.
  • the two ester groups, single aromatic ring and two methyl groups in the backbone provide a match of solubility parameters with PET, permitting use in blends, copolymers, and layer structures with good adhesion between layers and transparency.
  • the first column, T G is an important parameter as previously discussed.
  • the scavenging polymer should have a T G at least 10°C below the orientation temperature of the polyester polymer with which it is combined (in the transparent article).
  • REVPET has a T G of 43 °C, well below the typical orientation temperature of PET (e.g., 90°C and above).
  • the second column, T m shows that REVPET has a melting temperature of 214°C.
  • the third column, the solubility parameter shows that REVPET has the exact same solubility parameter (20.53) as PET.
  • the fourth and fifth columns, the densities of the amorphous and crystalline polymers, are identical for REVPET and PET. Also, the solubility to nitrogen (PERM) is identical.
  • AROM the weight percentage of the aromatic rings
  • T G the percentage of aromaticity
  • REVPET has a rather low T G compared to later described scavenging polymers. ⁇ higher T G would provide a higher use temperature, and reduce the potential that the scavenging polymer will crystalline (or opacify) during the orientation process.
  • CARB the weight percentage of the carbonyl (CO)
  • ALPHA the weight percentage of aliphatic chain
  • AROM 30 to 70
  • CARB 5 to 30
  • ALPHA 5 to 30
  • Fig. IB The reaction illustrated in Fig. IB may be implemented in accordance with various well-known processes as follows: PREPARATION OF POLY HYDROQUINONE SUCCINATE, REVPET, BY
  • Bisphenol A can be substituted for hydroquinone to make a higher T G polymer (see Fig. U below).
  • SUCCINATE (REVPET)(see British Patent 636,429 to Eric R. Wallsgrove and Frank Reeder, issued April 26, 1950): 10 parts hydroquinone diacetate is combined with 9.5 parts succinic acid and .1 parts p-Me-C 6 H 4 SO 3 H. They are heated at 180°C for 45 minutes, then 200-220°C for 1 hour, then 280°C for 3 hours all at atmospheric pressure, and finally 280°C for 3 hours at 1 mm Hg while nitrogen is bubbled through the molten mix.
  • REVPET SUCCINATE
  • isomers of the aforementioned monomers to make small adjustments in T G and larger adjustments in crystallinity levels.
  • Fig. 1 C Modified REVPET
  • Fig. 1C illustrates a method of making a second oxygen-scavenging polymer referred to herein as modified REVPET.
  • modified REVPET has a solubility parameter (SOL) of 20.18, compared to 20.53 for PET.
  • SOL solubility parameter
  • the extra carbon atom (in the aliphatic carbon chain) also reduces the T G , compared to the T G of REVPET. It may be desirable to add additional functional groups which would increase the T G . Examples of such modifications to the T G are described below for the methods/polymers of Figs. ID- IK.
  • Fig. ID shows a method of making another aromatic ester oxygen-scavenging polymer useful in the present invention, and referred to herein as polymer- ID.
  • the repeating unit shown in Fig. 1 D) includes two alpha-hydrogen carbonyl groups, two ester groups, six aromatic rings (two in the backbone and four on side chains), and one 3-carbon aliphatic group. The six aromatic rings increase the T G (compared to PET), however the extra carbon atom in the aliphatic chain (3CH 2 ) decreases the T G (compared to the 2-carbon chain in PET).
  • Fig. IE Polvmer- IE
  • Fig. IE shows another aromatic ester oxygen-scavenging polymer for use in the present invention.
  • the repeating unit (shown in Fig. IE) includes two alpha-hydrogen carbonyl groups, two esters, a 4-carbon atom aliphatic chain, and one aromatic structure (including two rings) in the backbone. While the 4-carbon aliphatic chain would reduce the T G (compared to the 2-carbon chain in PET), the extra aromatic ring (compared to a single ring in PET) would increase the T G .
  • Polymer-IE has an estimated T G of 71 °C (see Appendix C on page 49) which is just above that of PET (70°C) and in the preferred range. Polymer- IE is commercially available from Dow Chemical, Midland, Michigan US ⁇ .
  • the relative proportions of components may be adjusted for a specific application. Generally, to increase the level of oxygen-scavenging, one would increase the level of alpha- hydrogen carbonyl groups by substituting more adipic acid and reducing the amount of diglycidyl ether of bis-phenol A.
  • a modified version of polymer- IE made with succinic acid has a T G of 70°C.
  • Fig. IF Polymer- I F Fig. IF shows a further alternative aromatic ester oxygen-scavenging polymer referred to herein as polymer- IF.
  • the repeating unit includes two alpha-hydrogen carbonyl groups, two ester groups, a 4-carbon aliphatic chain in the backbone, and one aromatic side chain.
  • succinic acid — instead of adipic — would have a higher T G (see Table in Appendix C on page 49). Further increases in T G are possible by using distyrene oxide (instead of styrene oxide) with adipic acid, or distyrene glycol (instead of styrene oxide) with succinic acid.
  • Fig. 1G illustrates the process of making a further scavenging polymer, referred to herein as REVPEN.
  • REVPEN This is similar to REVPET (Fig. IB), but is based upon naphthalene rather than benzene.
  • REVPEN is prepared by condensing 1 ,2 or 2,6 naphthalene diacetate and dimethyl ester of succinic acid. The reaction conditions are similar to those for making REVPET, but at a higher temperature (e.g., 300°C) in the final stage.
  • a modified version of REVPEN is shown below, having an additional CH 2 group at each side of the aromatic ring:
  • Fig. Ill shows a random polymer of groups A, B, and C, where A is provided by naphthalene dicarboxylate (NDC), B is provided by adipic acid, and C is provided by ethylene glycol (where the atoms/molecules lost are shown in a box with an arrow).
  • the resulting polymer- 1H is basically a random copolymer of PEN and aliphatic acid. For every two naphthalene components, there is one aliphatic component (molar parts). This is a solid, highly crystalline polymer, which is stable at higher temperatures. This enables the polymer to be easily dried and solid stated to build up the molecular weight. Polycondensation polyesters, having highly crystalline structures and high melt temperatures, can be solid stated to increase the molecular weight.
  • Transparent multilayer blow-molded bottles have been made from preforms, including layers of virgin PET and layers of polymer- I II. There is good adhesion between the layers, which prevents delamination.
  • Fig. I I there is shown a substituted hydroxy acid monomer with an acetate on one end and an ethyl, methyl ester on the other end; this monomer reacts with itself to produce another oxygen-scavenging polymer having the repeating unit shown.
  • Polymer II has one aromatic ring, one ester group, one alpha hydrogen carbonyl group, and a 2-carbon aliphatic chain.
  • Fig. 1 J shows condensation of bisphenol-A diacetate and adipic acid to make the polymer- IJ, having two alpha-hydrogen carbonyl groups, two esters, one aromatic backbone structure (with two rings), and a 4-carbon chain aliphatic group.
  • polymer- IJ has relatively high T G of 91 °C.
  • a modified polymer listed just below polymer- IJ in the Table, identified as "Bis A Acetate/Suberic Acid" has a lower T G of 79°C, which is in the preferred range for use with PET orientation temperatures.
  • diacetate of bisphenol A is prepared by dissolving 1 l g (grams) of bisphenol A in a solution of 9g (.22 mole) sodium hydroxide in 45ml water in a 250ml Erlenmeyer flask. The mixture is cooled in an ice bath and a small quantity of ice is added to the flask. Then, 22.4g (.22 mole) acetic anhydride is added and the flask is shaken vigorously in an ice bath for 10 minutes. The white solid is filtered, washed with water, and recrystallized from ethanol.
  • a mixture of bisphenol A diacetate 312g (1 mole), suberic acid 174g (1 mole), 0.60g tolunenesulfonic acid (monohydrate) is placed in a 2-liter, 2-neck flask with agitator. The flask is purged with nitrogen while agitating for 20 minutes. The temperature is then raised to 180°C while agitating and purging with nitrogen at ambient pressure. Acetic acid distills as the temperature is slowly raised from 180°C to 250 °C while the pressure is slowly reduced to about 1 torr. The melt is maintained at 250°C and 1 torr for 1 hour.
  • pyridine be substituted for sodium hydroxide and water in the above reaction.
  • Fig. I K Polvmer-IK
  • Fig. IK shows a ring opening polymerization of a cyclic ester.
  • polymer- I K (cyclic) is combined with a cyclic carbonate ester, to produce polymer- I K.
  • the resulting polymer has two alpha-hydrogen carbonyl groups, a two-ring aromatic structure in the backbone (bisphenol A) and a five-carbon aliphatic chain.
  • polymer- IK has a T G of 85 °C, in the preferred range for use with PET polymers.
  • Polymer- 1K has a good match of solubility parameter with PET (20 vs. 20.53).
  • oxygen-scavenging polymers may be used alone, or blended or copolymerized with an aromatic polyester polymer, preferably a PET or PEN polymer, to provide an oxygen-scavenging material. This material may then be incorporated in a packaged container structure to provide a desired level of oxygen scavenging property, as described below.
  • Figs. 2-6 illustrate a method of making a transparent one-liter pasteurizable beer container utilizing a multilayer structure and oxygen-scavenging polymer of this invention.
  • An injection-molded multilayer preform 30 is shown in Fig. 2.
  • the preform is substantially cylindrical, as defined by vertical centerline 32, and includes an upper neck portion or finish 34 integral with a lower body-forming portion 36.
  • the neck portion has a top sealing surface 31 which defines the open top end of the preform, and a generally cylindrical exterior surface with threads 33 and a lowermost flange 35.
  • the body-forming portion 36 which includes an upper cylindrical portion 41 , a flared shoulder-forming portion 37 which increases radially inwardly in wall thickness from top to bottom, a cylindrical panel- forming section 38 having a substantially uniform wall thickness, and a thickened base-forming section 39 which is thicker than the panel-forming section 38.
  • the closed bottom end of the preform 40 is substantially hemispherical and may be thinner than the base-forming portion 39.
  • Preform 30 has a three-material, five-layer (3M, 5L) structure and is substantially amorphous and transparent.
  • the multiple preform layers comprise, in serial order: outer layer 42 of virgin PET, outer intermediate layer 43 of EVOH, central core layer 44 of oxygen-scavenging material, inner intermediate layer 45 of EVOH, and inner layer 46 of virgin PET.
  • the virgin PET may be any commercially available, bottle-grade PET homopolymer or copolymer having an intrinsic viscosity of about 0.90 dl/g.
  • the EVOH is commercially available with a 32 mole % ethylene content from Evalca, Omaha, Kansas, USA, or Kuraray Co. Ltd., Osaka, Japan.
  • the core layer is REVPET as previously described (Fig.
  • the REVPET polymer includes 150 micrograms of cobalt per gram of REVPET polymer, added as cobalt neodeconoate.
  • the preform 30 is adapted for making the 1.0 liter pasteurizable pressurized container for beer, shown in Fig. 3.
  • the preform 30 has a height of about 150mm, and an outer diameter in the panel-forming section 38 of about 23.8mm.
  • the total wall thickness of the panel- forming section 38 is about 4.1mm; the thickness of the various sidewall layers are: outer and inner layers each about 1.1 mm thick; inner and outer intermediate layers each about 0.1 mm thick; and core layer about 1.7mm thick.
  • the preform panel-forming section 38 preferably undergoes an average planar stretch ratio of about 13.0 to 14.5.
  • the planar stretch ratio is the ratio of the average thickness of the preform panel-forming portion 38 to the average thickness of the container panel 86 (as shown in Fig. 3); the average is taken along the length of the respective preform and container portions.
  • the average panel hoop-stretch is preferably about 4.0 to 4.5, and the average panel axial stretch is about 3.0 to 3.2. This produces a container panel 86 with the desired biaxial orientation and visual transparency.
  • the specific panel thickness and stretch ratio selected depend on the dimensions of the bottle, the internal pressure, and the processing characteristics (as determined for example by the intrinsic viscosity of the particular materials employed).
  • the preform shown in Fig. 2 may be injection molded by a sequential metered process described in U.S. Patent Nos. 4,550,043; 4,609,516; 4,710,1 18; 4,781 ,954; 4,990,301 ; 5,049,345; 5,098,274; and 5,582,788, owned by Continental PET Technologies, Inc. of Bedford, New Hampshire.
  • predetermined amounts of the various materials are introduced into the gate of the preform mold as follows: a first shot of virgin PET which forms partially- solidified inner and outer preform layers as it moves up the cool outer mold and core walls; a second shot of EVOH which will form the inner and outer intermediate layers; and a third shot of the oxygen-scavenging material which pushes the EVOH up the sidewall (to form thin barrier layers) and forms a central core layer of oxygen-scavenging material.
  • a final shot of virgin PET may be used to clear the nozzle and finish the bottom of the preform with virgin PET. After the mold is filled, the pressure is increased to pack the mold against shrinkage of the preform. After packing, the mold pressure is partially reduced and held while the preform cools.
  • each of the polymer melts are injected into the mold at a rate of about 10-12 grams per second, a packing pressure of about 7500 psi (50 X 10 6 N-m "2 ) is applied for about 4 seconds, and the pressure is then dropped to about 4500 psi (30 X 10 6 N-m "2 ) for the next 15 seconds, after which the pressure is released and the preform is ejected from the mold.
  • a packing pressure of about 7500 psi (50 X 10 6 N-m "2 ) is applied for about 4 seconds, and the pressure is then dropped to about 4500 psi (30 X 10 6 N-m "2 ) for the next 15 seconds, after which the pressure is released and the preform is ejected from the mold.
  • Increasing the pressure above these levels may force higher levels of interlayer bonding, which may include chain entanglement, hydrogen bonding, low-level interlayer crystallization and layer penetration; these may be useful in particular applications to increase the resistance to layer separation in both the
  • increased pressure holds the preform against the cold mold walls to solidify the preform without haze, i.e., loss of transparency, at the minimum possible cycle time.
  • faster injection rates may yield higher melt temperatures within the injection cavity, resulting in increased polymer mobility which improves migration and entanglement during the enhanced pressure portion of the injection cycle, and thus increases the delamination resistance.
  • increasing the average preform temperature and/or decreasing the temperature gradient through the preform wall may further reduce layer separation by minimizing shear at the layer boundaries during preform expansion.
  • Fig. 5 illustrates a stretch blow-molding apparatus 70 for making the container 80 from the preform 30. More specifically, the substantially amorphous and transparent preform body-forming section 36 is reheated to a temperature above the glass transition temperatures of the inner/outer PET and core oxygen-scavenging layers, and the heated preform then positioned in a blow mold 71.
  • a stretch rod 72 axially elongates (stretches) the preform within the blow mold to insure complete axial elongation and centering of the preform.
  • the thickened base- forming region 39 of the preform resists axial deformation compared to the panel- and shoulder- forming portions 38 and 37. This produces greater axial elongation in the resulting panel and shoulder portions of the container.
  • a blowing gas (shown by arrow 73) is introduced to radially inflate the preform to match the configuration of an inner molding surface 74 of the blow mold.
  • the formed container remains substantially transparent but has undergone strain-induced biaxial orientation to provide the increased strength necessary to withstand carbonation and the increased temperature and pressure of pasteurization.
  • Fig. 3 shows the 1.0 liter pasteurizable multilayer beverage bottle 80 made from the preform of Fig. 2.
  • the preform body-forming portion 36 has been expanded to form a transparent biaxially-oriented container body 81.
  • the upper thread finish 34 has not been expanded, but is of sufficient thickness or material construction to provide the required strength.
  • the bottle has an open top end 82 and receives a screw-on cap (see Figs. 7A-7B).
  • the expanded container body 81 includes:
  • the substantially cylindrical panel section 86 preferably has a relatively tall and slender configuration, i.e., a height to diameter ratio on the order of 2.0 to 3.0, in order to minimize the stress in the sidewall (and minimize creep); relatively shallow transition regions 87 and 88 are provided at the upper and lower ends of the panel 86, respectively; larger transition areas would be more likely to expand (straighten) during pasteurization and cause a volume increase (fill level drop); for the same reason, preferably no ribs (which may creep) are provided in the panel section 86;
  • a footed base 90 has a substantially hemispherical bottom wall 92 and for example, five legs 91 which extend downwardly from the bottom wall to form five foot pads 93 on which the container rests; the legs 91 are symmetrically disposed around the container circumference; in addition, it is preferable to provide a high depth base, i.e., close to a hemispherical base, in order to maximize strength and resistance against creep; it is also preferable to provide an angled foot pad which can move outwardly under creep and yet remain within the diameter of the container.
  • the panel-forming section 38 of the preform may be stretched at an average planar stretch ratio on the order of 13.0 to 14.5; the virgin PET layers of the resulting panel section 86 have an average strain-induced crystallinity on the order of 20% to 30%, and preferably on the order of 25% to 29%).
  • the shoulder 83 undergoes an average planar stretch ratio of about 10.0 to 12.0; the virgin PET layers of the resulting shoulder 83 have an average crystallinity of about 20% to 25%.
  • the hemispherical bottom wall 92 in the base undergoes an average planar stretch of about 5.0 to 7.0, and the virgin PET layers have about 5% to 15% average crystallinity; the legs and feet undergo an average planar stretch of about 13.0 to 14.0, and the virgin PET layers have about 20% to 26%) average crystallinity.
  • the core oxygen- scavenging layer has an average level of crystallinity of about 2% less than the virgin PET layers in each respective area of the container, e.g., 18-28% in the panel, 18-23% in the shoulder, 3- 12% in the hemispherical bottom wall, and 18-24% in the legs and feet.
  • Fig. 4 shows a cross-section of the panel wall 86, including inner layer 95 of virgin PET, core layer 96 of oxygen-scavenging material, outer layer 97 of virgin PET, and inner and outer intermediate layers 98, 99 of EVOH.
  • the relative percent by total weight of the various layers in the panel section are about 30% for inner layer 95, about 40% for core layer 96, and about 30% for outer layer 97 (the EVOH layers 98, 99 together are less than 2 weight percent).
  • the EVOH inner intermediate layer 98 will become permeable to oxygen when water vapor from the product permeates through the inner PET layer 95; this will enable oxygen in the container to permeate layers 95 and 98 and reach core layer 96 where it is consumed.
  • outer intermediate layer 99 remains relatively dry and resists exterior oxygen from entering the container.
  • a known five-foot PET disposable carbonated beverage container (non-pasteurizable) has a relatively low base profile ( ⁇ of about 45°).
  • the present base preferably has a relatively high base profile on the order of 60° or better.
  • the relative heights of the base are illustrated as H ⁇ for the full hemi, and H B for the truncated hemi. It is preferable to provide a base height between H B and I I A , and more preferably where ⁇ is greater than 65°.
  • the foot pad is preferably spaced a distance Lp from the vertical centerline CL to a point G which is vertically aligned with a center point of radius R Q .
  • Radius R forms the outer edge of the foot pad.
  • the foot pad forms an acute angle ⁇ with a horizontal surface 102 on which the base rests.
  • Lp is on the order of 0.32R to 0.38R
  • ⁇ is on the order of 5° to 10°, to allow each foot pad and leg to move out under creep, and yet remain within the diameter of the container.
  • FIG. 7A is an enlarged cross-section of an opacified neck finish enclosure according to one embodiment. More specifically, the unoriented neck finish 1 10 has been thermally crystallized (opacified) by for example, high-temperature exposure; this increases the strength and enhances its resistance to the increased temperature and pressure of pasteurization. The heat-treated area may extend just below the flange 1 1 1.
  • a cap 1 16 has an annular ring 1 17 of a resilient material (e.g., plastisol or other thermoplastic elastomer) which seals the top sealing surface 1 12 of the neck finish. If there is any deformation of the neck finish during pasteurization, the liner 1 17 deforms to ensure a tight seal and prevent leakage.
  • a resilient material e.g., plastisol or other thermoplastic elastomer
  • a substantially amorphous and unoriented neck finish 120 is provided, i.e., it has not been crystallized.
  • the amorphous neck finish is provided with a laminated foil liner 124, which lies within an inner surface of a cap 126, and which may, for example, be heat sealed or adhesively sealed to the top sealing surface 122 of the neck finish. Again, if there is any deformation of the neck finish, the liner 124 ensures a tight seal to prevent leakage.
  • Fig. 8 shows another embodiment comprising a ' ⁇ -liter non-pastcurizable beer container.
  • the bottler extensively filters the beer, so that the bottle need not be subjected to heat treatment.
  • a preform 200 for making the bottle is shown in Fig. 8A, including thread finish 201, flared shoulder portion 202, cylindrical body portion 203, and closed bottom 204.
  • the preform 200 and resulting blow-molded container 210 (Fig. 8B) have a five-layer structure (not shown), including inner and outer layers of virgin PET (62 weight percent by total weight), a core layer of post consumer PET (35 weight percent), and 2 thin intermediate layers of REVPET homopolymer, as the oxygen-scavenging polymer (3 weight percent).
  • the REVPET has an intrinsic viscosity of 0.70 dl/g, a T G of 43°C and a melting point of 214°C.
  • the virgin PET is Shell 8006, having a 0.80 IV nominal, and including 4 molar percentage isothalic acid copolymer (available from Shell Oil Company, Houston, Texas, U.S.A.).
  • this beer bottle has a champagne base 212, including a standing ring 214 which surrounds a central push-up dome 216. This container provides a shelf life for beer of about 16 weeks.
  • FIG. 9 shows a preform 142 (from the Beck patent) which includes a support flange 144, a thin upper body portion 145 which flares into a thick generally cylindrical main body portion 146, and a generally hemispherical bottom portion 148.
  • the Beck process enables a high degree of biaxial orientation to be obtained in all portions of the resulting container, so that the container has economical thin walls and the desired strength characteristics.
  • the preform is expanded to form an intermediate article 150, which includes a lower portion 152 in the form of the desired container, and an upper portion 154.
  • the lower portion includes a cylindrical body 132, concave bottom 134, tapered shoulder 136, mouth 138, and annular flange 130.
  • the upper portion is severed from the flange 130 at point 164 (as by cutting or laser trimming), and may be discarded, or ground and the material reused. It is generally not necessary to thermally crystallize or otherwise reinforce the upper end of the container, because the biaxial orientation provides the necessary strength.
  • a method of trimming the expanded preform to remove the upper unoriented portion is described in U.S. Patent No. 4,539,463 to Piccioli et al., which issued September 3, 1985, and is hereby inco ⁇ orated by reference in its entirety.
  • first molding station In the first set of cavities (first molding station), a high T G amo ⁇ hous or crystallized neck portion is formed on one set of cores, while in the other set of cavities (second molding station) a plurality of amo ⁇ hous body-forming portions are formed on the other set of cores.
  • the cores are sequentially positioned in each of the first and second molding stations.
  • a polyester preform for making a hot-fillable container
  • CPET is a terephthalic polyester with nucleating agents which render the polymer rapidly crystallizable during injection molding.
  • CPET is sold by Eastman Chemical Company, Kingsport, Tennessee, USA.
  • the body-forming portion 181 is a two-material, three- layer (2M, 3L) structure, including inner and outer layers of virgin polyethylene terephthalate (PET), and a core layer of the oxygen-scavenging polymer of this invention.
  • the base-forming portion 182 is similar to the body-forming portion, but may include a core layer 183 of virgin PET in at least the bottom part and possibly extending through to the exterior of the preform.
  • the core layer 183 in the base may be of a higher T G polymer to enhance the thermal stability of the resulting container base; this is particularly useful with champagne-type container bases.
  • the higher T G polymer may be injected via a third extruder.
  • Numerous alternative high-glass transition (T G ) polymers may be used in place of CPET, such as: acrylate polymers; polyethylene naphthalate (PEN) homopolymers, copolymers or blends; polycarbonates; polyarylates; etc.
  • PEN polyethylene naphthalate
  • PEN polyethylene naphthalate
  • polycarbonates polycarbonates
  • polyarylates etc.
  • numerous alternative polymers and layer structures are possible, inco ⁇ orating PEN, ethylene/vinyl alcohol (EVOH) or MXD-6 nylon barrier layers, etc.
  • the container is useful in a variety of applications, including refillable, pasteurizable, and hot-fillable containers.
  • the material could be provided as an insert which can be added to a container.
  • the insert may consist of an oxygen-scavenging material coated with a polymer which is impermeable to oxygen when dry, and permeable when wet. The moisture in the product then permeates the coating, allowing oxygen to permeate to the oxygen- scavenging core layer.
  • the PET polymer as used herein includes homopolymers, copolymers, and blends of PET with other known compatible polymers, including other polyesters such as polybutylene terephthalate (PBT), polypropylene terephthalate (PPT), polyethylene naphthalate (PEN), and a cyclohexane dimethanol substituted PET copolymer known as PETG (available from Eastman Chemical Company, Kingsport, Tennessee USA).
  • PETG cyclohexane dimethanol substituted PET copolymer known as PETG (available from Eastman Chemical Company, Kingsport, Tennessee USA).
  • PETG cyclohexane dimethanol substituted PET copolymer
  • at least 90 mole % will be terephthalic acid and at least 90 mole % an aliphatic glycol or glycols, especially ethylene glycol.
  • PC-PET Post-consumer PET
  • I.V. intrinsic viscosity
  • moisture content a substance that is removed by consumers for a recycling operation
  • contaminants a certain level of contaminants.
  • typical PC-PET having a flake size of one-half inch maximum
  • I.V. average about 0.66dl/g
  • moisture content a moisture content of less than 0.25%
  • PVC ⁇ 100 ppm aluminum: ⁇ 50 ppm olefin polymers (HDPE, LDPE, PP): ⁇ 500 ppm paper and labels: ⁇ 250 ppm colored PET: ⁇ 2000 ppm other contaminants: ⁇ 500 ppm
  • PC-PET may be used alone or in one or more layers for reducing the cost or for other benefits.
  • Another useful aromatic polyester is polyethylene naphthalate (PEN).
  • PEN provides a 3-5X improvement in oxygen and carbon dioxide barrier properties and enhanced thermal resistance, at some additional expense, compared to PET.
  • Polyethylene naphthalate (PEN) is a polyester produced when dimethyl 2,6-naphthalene decarboxylate (NDC) is reacted with ethylene glycol.
  • the PEN polymer comprises repeating units of ethylene 2,6 naphthalate.
  • PEN resin is available having an inherent viscosity of 0.67dl/g and a molecular weight of about
  • PEN has a glass transition temperature T Q of about 120°C, and a melting temperature T m of about 267°C. PET and PEN may be blended or copolymerized in various amounts. In the ranges of about 0-20% PEN and
  • the material is crystalline, while from about 20-80% PEN the material is substantially amo ⁇ hous.
  • biaxially-orientable aromatic polyesters include: polypropylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, polycyclohexanedimethanol terephthalate, polypropylene naphthalate, polybutylene naphthalate, polycyclohexanedimethanol naphthalate.
  • the multilayer preform/container may also include one or more layers of an oxygen/carbon dioxide/moisture barrier material such as ethylene/vinyl alcohol (EVOH), PEN, polyvinyl alcohol (PVOH), polyvinyldene chloride (PVDC), nylon 6, crystallizable nylon (MXD-6), LCP (liquid crystal polymer), amo ⁇ hous nylon, polyacrylonitrile (PAN) and styrene acrylonitrile (SAN).
  • an oxygen/carbon dioxide/moisture barrier material such as ethylene/vinyl alcohol (EVOH), PEN, polyvinyl alcohol (PVOH), polyvinyldene chloride (PVDC), nylon 6, crystallizable nylon (MXD-6), LCP (liquid crystal polymer), amo ⁇ hous nylon, polyacrylonitrile (PAN) and styrene acrylonitrile (SAN).
  • EVOH ethylene/vinyl alcohol
  • PVOH polyvinyl alcohol
  • PVDC polyvinyldene chlor
  • an oxygen-scavenging catalyst compounds such as cobalt, manganese, or magnesium with organic ligands.
  • examples include cobalt neodecanoatc, cobalt acetate, magnesium acetate, and manganese acetate. It is believed that the cobalt may reduce the bond energy at the alpha-hydrogen carbonyl site, to provide increased reactivity with oxygen.
  • the organic ligands are believed to promote ingress of the oxygen into the polymer, and facilitate movement of oxidation gases (see Figs. 13 ⁇ -K).
  • the intrinsic viscosity (I.V.) effects the processability of the resins.
  • Polyethylene terephthalate having an intrinsic viscosity of about 0.8 is widely used in the carbonated soft drink (CSD) industry.
  • Polyester resins for various applications may range from about 0.55 to about 1.04, and more particularly from about 0.65 to 0.85dl/g.
  • Intrinsic viscosity measurements of polyester resins are made according to the procedure of ASTM D-2857, by employing 0.0050 ⁇ 0.0002 g/ml of the polymer in a solvent comprising o-chlorophenol (melting point 0°C), respectively, at 30°C.
  • n is the viscosity of the solution in any units
  • is the viscosity of the solvent in the same units.
  • C is the concentration in grams of polymer per 100 mis of solution.
  • the polymers as used herein are high polymers, having a molecular weight of at least about 50,000, for which the melt viscocity is an important process parameter. If the melt viscocity is too high, it is not possible push the polymer through the injection manifold fast enough to produce commercial preforms. Another important parameter is melt strength; if the melt strength is too low, it is not possible to maintain layer integrity in a multilayer structure having one or more relatively thin layers. Generally, as the molecular weight of the polymer increases, both the melt viscocity and melt strength increase.
  • melt viscocity is generally represented as a melt index, measured according to ASTM 1238B.
  • Shell 8006 virgin PET has a melt index of 29g/10 minutes. It has been found that an adjacent scavenging layer should preferably have a melt index of from 50-100g/10 minutes.
  • the blown container body should be substantially transparent.
  • the diffuse and specular light transmission values are measured in accordance with ASTM Method D 1003, using any standard color difference meter such as model D25D3P manufactured by Hunterlab, Inc., Reston, Virginia, U.S.A.
  • the container body should have a percent haze (through the panel wall) of less than about 10%, and more preferably less than about 5%.
  • the preform body-forming portion should also be substantially amo ⁇ hous and transparent, having a percent haze across the wall of no more than about 10%), and more preferably no more than about 5%.
  • the container will have varying levels of crystallinity at various positions along the height of the bottle from the neck finish to the base. The percent crystallinity may be determined according to ASTM 1505 as follows:
  • ds sample density in g/cm
  • da density of an amo ⁇ hous polymer of zero percent crystallinity
  • dc density of the crystal calculated from unit cell parameters.
  • the panel portion of the container is stretched the greatest and preferably has an average percent crystallinity of at least about 15%, and more preferably at least about 20%. Generally, a 25 to 29% crystallinity range is useful in the panel region.
  • Crystallinity can be achieved by heat setting to provide a combination of strain-induced and thermal-induced crystallization.
  • Thermal-induced crystallinity is achieved at low temperatures to preserve transparency, e.g., holding the container in contact with a low temperature blow mold. In some applications, a high level of crystallinity at the surface of the sidewall alone is sufficient.
  • the oxygen-scavenging material of this invention may be made by a masterbatch process, wherein the oxygen-scavenging polymer is prepared first, and then blended or copolymerized with the PET polymer.
  • a masterbatch process for combining an oxygen- scavenging polymer with PET is described in copending and commonly-owned U.S. Serial No. 08/355,703, filed December 14, 1994, entitled OXYGEN-SCAVENGING COMPOSITIONS FOR MULTILAYER PREFORM AND CONTAINER (docket no. 7180), which was published as WO 96/18685 on June 20, 1996, and is hereby inco ⁇ orated by reference in its entirety.
  • the average molecular weight of the oxygen-scavenging polymer may be selected, for various pu ⁇ oses.
  • One such pu ⁇ ose is to improve the blendability with the PET polymer, and for this pu ⁇ ose the average molecular weight of the oxygen-scavenging polymer is preferably in the range of 70,000-100,000, and more preferably 78,000-94,000.
  • the compatibility of the oxygen-scavenging polymer with the PET polymer may be determined by preparing and combining (blending or copolymerizing) samples thereof. Alternatively, it may be determined based on various known compatibility indicators. For example, it has been found that REVPET has a solubility parameter, determined according to a known Van Krevelen method, which is substantially identical to that of unmodified PET. There is a commercially-available software program known as Polymer-CAD, Version 1.6, published by Novel Advanced Systems For Engineering And Research, P.O. Box 130304, Ann Arbor, Michigan 481 13-0304, USA, which allows one to calculate several fundamental properties of a polymer from its structure based on different Additive Group Contribution methods. For example, utilizing the following structure for REVPET:
  • the cohesive energy and solubility parameter are determined using direct and molar attraction constant contribution methods.
  • a molar volume of 144.24 c Vmole is used, at 298°K. See Van Krevelen, D.W. and Hoftyzer, P.J., J. Appl. Polymer Sci., 13, page 871 (1969); and Van Krevelen, D.W., Properties Of Polymers, 3rd Edition, Elsevier Science Publishers ( 1990).
  • the method utilizes the group contribution to the molar volume of the amo ⁇ hous polymer, followed by that for the crystalline polymer in cm 3 /mole (gram basis).
  • the output includes the: volumetric properties; calorimetric properties; transition temperatures; cohesive energy and solubility; molar refraction and refractive index; electrical properties; magnetic properties; mechanical properties; acoustic properties; permachor and permeability; and thermal decomposition temperatures.
  • volumetric properties calorimetric properties; transition temperatures; cohesive energy and solubility; molar refraction and refractive index; electrical properties; magnetic properties; mechanical properties; acoustic properties; permachor and permeability; and thermal decomposition temperatures.
  • solubility parameter within 3 units, and more preferably within 1 unit, as determined by the above software program (Van Krevelen 1 ).
  • Appendix C is a list of the solubility parameters (SOL) and other properties of various polymers.
  • SOL solubility parameters
  • PET and REVPET have the same value of solubility parameter (20.53).
  • Modified REVPET has a value of 20.18.
  • MXD-6 nylon has a much higher value of 26.8, which is well outside the 3 unit preferred range and shows that this polymer is much less compatible with PET.
  • REVPET Falling within the preferred range of 3 units are: REVPET (Fig. IB); modified REVPET (Fig. 1C);
  • Distyrene glycol/diphenic acid/glutaric acid (Fig. ID); Bis A Epoxy/Adipic Acid (Fig. IE); Styrene Oxide/Adipic Acid (Fig. IF);
  • Bis A Acetate/ Adipic Acid (Fig. IJ); Bis A Acetate/Suberic Acid (see text re Fig. 1 J); Styrene Oxide/Succinic Acid (see text re Fig. 1 J); Distyrene Oxide/Adipic Acid (see text re Fig. 1 J); Distyrene Glycol/Succinic Acid (see text re Fig. IJ); and
  • oxygen-scavenging rate it is herein meant to refer to the amount of oxygen a packaging structure scavenges in units of nanograms (ng) of oxygen per square centimeter (cm 2 ) of package surface area, per day (i.e., units of ng/cm 2 /day).
  • ng nanograms
  • cm 2 centimeter
  • ng/cm 2 oxygen-scavenging capacity
  • the package should have an oxygen scavenging rate of at least 5ng/cm 2 /day, and more preferably at least 30ng/cm 2 /day.
  • a "scavenging performance ratio" as used herein refers to the ratio of the oxygen permeability of a control package formed of the aromatic polyester only, to the permeability of a package including both the polyester and an aromatic ester oxygen-scavenging polymer of this invention, where the two packages have the same dimensions.
  • a single-use (e.g., 8- 12 ounce) beer container should have a scavenging performance ratio of at least about 4, and more preferably about 10 or greater.
  • a single-use (e.g., 8-12 ounce) fruit juice container should have a scavenging performance ratio of at least about 1.5, more preferably at least about 4, and most preferably at least about 8.
  • a package is designed to have a shelf life of several weeks or months. For example, a typical requirement for beer is 1 part per million (ppm) of oxygen over a 1 12-day shelf life.
  • ppm part per million
  • a control container was made from a monolayer of virgin bottle-grade PET, having a thickness of 13 mils, a diameter of 2.6 inches, and a height of 4.75 inches.
  • the estimated surface area of the container was about 60 inches squared.
  • the container is filled with deoxygenated water.
  • the rate at which oxygen passes from the exterior to the interior of this control container was measured using an oxygen analyzer (model LC700F, Serial No. 695935, available from Mocon Inc., Minneapolis, Minnesota USA), according to ASTM SI 307-90.
  • the oxygen ingress rate for this control bottle was 30,000 ng/package/day. Dividing the oxygen ingress rate by the surface area produces an oxygen ingress rate per square area of 77 ng/cm 2 /day.
  • a container of the same dimensions made from a monolayer of REVPET has an oxygen ingress rate per square area of 1 or less ng/cm 2 /day.
  • lng/cm 2 /day is equal to 70 ppb of total accumulated oxygen over 1 12 days. This is a 77 times improvement over the control container.
  • control bottle will have an oxygen ingress rate of 6000 ng/package/day, or 18.6 ng/cm 2 /day.
  • various catalysts may be used to increase the oxygen-scavenging rate of the oxygen-scavenging material.
  • Eastman 9921 is a PET polymer having residual cobalt; the cobalt acts as a catalyst during preparation of the PET.
  • the residual cobalt has been found to act as a catalyst for oxygen-scavenging when the PET polymer is blended or copolymerized with various oxygen-scavenging compositions.
  • Eastman 9921 is available from Eastman Chemical, Kingsport, Tennessee, USA.
  • the presence of water has been found to enhance the oxygen- scavenging rate. In an expected use of the container for a liquid product containing water, this enhancement would inherently occur. For example, it has been observed that wet samples will scavenge at a rate as much as 4 times that of dry samples.
  • FIG. 12 illustrates graphically, as a function of time, the increasing internal temperature and pressure during a known wet process pasteurization cycle for a 16- ounce glass container, which has been filled with a juice product carbonated at 2.5 volumes; "2.5 volumes” means that the volume of carbon dioxide at 0°C under 1 atmosphere is 2.5 times the volume of the liquid.
  • the typical pasteurization cycle as shown in Fig.
  • the temperature curve 12 shows that the container and contents remain above 70°C for roughly 10 minutes (in bath 3), during which time the internal pressure increases significantly to about 1 10 psi (1 x 10 N-m " ).
  • This 10-minute hold period at a temperature of about 70 to 75°C provides effective sterilization for most carbonated beverage products, including those containing 100% fruit juice.
  • a glass container can withstand these temperatures and pressures without deformation.
  • a plastic container including the oxygen-scavenging polymer of this invention can be made to withstand the temperatures/pressures of pasteurization by one or more of: using a higher T G (more thermal resistant) polyester; adjustments to the package design; use of thermal- induced crystallinity; use of crystallized neck finish; etc.

Abstract

Article désoxygénant transparent, destiné à emballer des produits sensibles à l'oxygène, tels que bière, jus, ketchup, etc. L'article comprend un polyester aromatique biaxialement orienté, tel que le polyéthylène téréphtalate (PET) ou le polyéthylène naphtalate (PEN), et un polymère d'un ester aromatique désoxygénant compatible avec le polymère de polyester. Ce dernier contient des groupes aromatiques et des groupes alpha-hydrogène carbonyles de formule (I). Les polyesters sont par exemple les acides succinique, glutarique, adipique et subérique, avec l'hydroquinone, le bisphénol A, le styrène oxyde ou le distyrène glycol, ou un acide dicarboxylique aliphatique contenant du copolyéthylène naphtalate. Les deux polymères peuvent constituer un polymère, un mélange ou, de préférence, différentes couches de l'article. Le polymère désoxygénant peut être incorporé à un emballage barrière à un prix compétitif, et donne les propriétés désirées de transparence, résistance à la chaleur et résistance à la pression.
PCT/US1997/016826 1996-09-25 1997-09-24 Article desoxygenant transparent comprenant un polyester biaxialement oriente WO1998013266A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CA002266503A CA2266503A1 (fr) 1996-09-25 1997-09-24 Article desoxygenant transparent comprenant un polyester biaxialement oriente
BR9713221-7A BR9713221A (pt) 1996-09-25 1997-09-24 Artigo de eliminação de oxigênio transparente incluindo poliéster bi-axialmente orientado
JP51577398A JP2001504399A (ja) 1996-09-25 1997-09-24 二軸延伸ポリエステルを含む透明な脱酸素性物品
AU44911/97A AU710677C (en) 1996-09-25 1997-09-24 Transparent oxygen-scavenging article including biaxially-oriented polyester
EP97943437A EP0934201A1 (fr) 1996-09-25 1997-09-24 Article desoxygenant transparent comprenant un polyester biaxialement oriente

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US71954396A 1996-09-25 1996-09-25
US71962296A 1996-09-25 1996-09-25
US08/719,622 1996-09-25
US08/719,543 1996-09-25

Publications (2)

Publication Number Publication Date
WO1998013266A1 true WO1998013266A1 (fr) 1998-04-02
WO1998013266A9 WO1998013266A9 (fr) 1998-05-22

Family

ID=27110095

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1997/016826 WO1998013266A1 (fr) 1996-09-25 1997-09-24 Article desoxygenant transparent comprenant un polyester biaxialement oriente

Country Status (8)

Country Link
EP (1) EP0934201A1 (fr)
JP (1) JP2001504399A (fr)
CN (1) CN1237936A (fr)
AR (1) AR009368A1 (fr)
BR (1) BR9713221A (fr)
CA (1) CA2266503A1 (fr)
HU (1) HUP0200350A2 (fr)
WO (1) WO1998013266A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001034479A1 (fr) 1999-11-11 2001-05-17 Crown Cork & Seal Technologies Corporation Recipients reutilisables en polyester comportant une substance desoxygenante
EP1146068A1 (fr) * 1998-07-03 2001-10-17 Teijin Limited Film (co)polymere de trimethylene-2,6-naphtalenedicarboxylate, copolymere de sulfanate de phosphonium quatrenaire et compositions renfermant ces composes
US6607795B1 (en) * 2001-12-19 2003-08-19 Chevron Phillips Chemical Company Lp Oxygen scavenging compositions comprising polymers derived from aromatic difunctional monomers
US7214415B2 (en) * 2000-10-26 2007-05-08 Bp Corporation North America Inc. Oxygen scavenging monolayer bottles
US8337968B2 (en) 2002-09-11 2012-12-25 Boston Scientific Scimed, Inc. Radiation sterilized medical devices comprising radiation sensitive polymers

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2533550C2 (ru) * 2009-04-09 2014-11-20 Колорматрикс Холдингс, Инк. Поглощение кислорода
DK2784120T3 (en) * 2011-11-25 2017-08-21 Mitsubishi Gas Chemical Co OXYGEN-ABSORBING RESIN COMPOSITION, OXYGEN-ABSORBING FORMED USE OF THE SAME, AND MULTIPLE BODIES, CONTAINERS, INJECTED BODIES AND MEDICINAL CONTAINERS, WHICH USES OXYGEN ORGANESE MEDICINE ORMS, OXYGEN ABOUT
CN103407257B (zh) * 2013-08-16 2016-08-10 汕头可逸塑胶有限公司 高阻隔性bopet包装薄膜及其生产方法
JP7028790B2 (ja) * 2016-04-11 2022-03-02 ディーエーケー アメリカス，リミティド ライアビリティ カンパニー 低減したガス透過性を備えるポリエステル容器及びフィルム

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4401805A (en) * 1982-03-01 1983-08-30 Eastman Kodak Company Modified poly(ethylene terephthalate) having improved gas barrier properties
JPS6215222A (ja) * 1985-07-15 1987-01-23 Mitsui Petrochem Ind Ltd ポリヒドロキシポリエステル、その製法およびその用途
EP0394751A2 (fr) * 1989-04-10 1990-10-31 Mitsui Petrochemical Industries, Ltd. Polyester de cocondensation, procédé pour sa préparation et son utilisation
JPH04168148A (ja) * 1990-10-31 1992-06-16 Mitsui Petrochem Ind Ltd ポリエステル樹脂組成物およびその用途
US5506014A (en) * 1995-09-01 1996-04-09 Eastman Chemical Company Pet copolyesters containing succinic and naphthalenedicarboxylic acid moieties having improved barrier properties
WO1996018685A1 (fr) * 1994-12-14 1996-06-20 Continental Pet Technologies, Inc. Composition pour absorber l'oxygene pour une preforme et un recipient a couches multiples
WO1996018686A1 (fr) * 1994-12-14 1996-06-20 Continental Pet Technologies, Inc. Emballage transparent contenant un agent de suppression d'oxygene de polycetone aliphatique

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4401805A (en) * 1982-03-01 1983-08-30 Eastman Kodak Company Modified poly(ethylene terephthalate) having improved gas barrier properties
JPS6215222A (ja) * 1985-07-15 1987-01-23 Mitsui Petrochem Ind Ltd ポリヒドロキシポリエステル、その製法およびその用途
EP0394751A2 (fr) * 1989-04-10 1990-10-31 Mitsui Petrochemical Industries, Ltd. Polyester de cocondensation, procédé pour sa préparation et son utilisation
JPH04168148A (ja) * 1990-10-31 1992-06-16 Mitsui Petrochem Ind Ltd ポリエステル樹脂組成物およびその用途
WO1996018685A1 (fr) * 1994-12-14 1996-06-20 Continental Pet Technologies, Inc. Composition pour absorber l'oxygene pour une preforme et un recipient a couches multiples
WO1996018686A1 (fr) * 1994-12-14 1996-06-20 Continental Pet Technologies, Inc. Emballage transparent contenant un agent de suppression d'oxygene de polycetone aliphatique
US5506014A (en) * 1995-09-01 1996-04-09 Eastman Chemical Company Pet copolyesters containing succinic and naphthalenedicarboxylic acid moieties having improved barrier properties

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, vol. 107, no. 10, 7 September 1987, Columbus, Ohio, US; abstract no. 78465, XP002051091 *
CHEMICAL ABSTRACTS, vol. 118, no. 4, 25 January 1993, Columbus, Ohio, US; abstract no. 23225, XP002051090 *
W.M. EARECKSON, III, JOURNAL OF POLYMER SCIENCE, vol. 40, 1959, pages 399 - 406, XP002051089 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1146068A1 (fr) * 1998-07-03 2001-10-17 Teijin Limited Film (co)polymere de trimethylene-2,6-naphtalenedicarboxylate, copolymere de sulfanate de phosphonium quatrenaire et compositions renfermant ces composes
EP1146068A4 (fr) * 1998-07-03 2003-04-23 Teijin Ltd Film (co)polymere de trimethylene-2,6-naphtalenedicarboxylate, copolymere de sulfanate de phosphonium quatrenaire et compositions renfermant ces composes
WO2001034479A1 (fr) 1999-11-11 2001-05-17 Crown Cork & Seal Technologies Corporation Recipients reutilisables en polyester comportant une substance desoxygenante
US7214415B2 (en) * 2000-10-26 2007-05-08 Bp Corporation North America Inc. Oxygen scavenging monolayer bottles
US6607795B1 (en) * 2001-12-19 2003-08-19 Chevron Phillips Chemical Company Lp Oxygen scavenging compositions comprising polymers derived from aromatic difunctional monomers
US8337968B2 (en) 2002-09-11 2012-12-25 Boston Scientific Scimed, Inc. Radiation sterilized medical devices comprising radiation sensitive polymers

Also Published As

Publication number Publication date
JP2001504399A (ja) 2001-04-03
CA2266503A1 (fr) 1998-04-02
EP0934201A1 (fr) 1999-08-11
CN1237936A (zh) 1999-12-08
AU710677B2 (en) 1999-09-30
HUP0200350A2 (en) 2002-08-28
AR009368A1 (es) 2000-04-12
AU4491197A (en) 1998-04-17
BR9713221A (pt) 2000-04-04

Similar Documents

Publication Publication Date Title
US7713464B2 (en) Multilayer container of polyglycolic acid and polyester and blow molding production process
US6749785B2 (en) Multilayer structures of poly(1,3-propylene 2,6 napthalate) and poly (ethylene terephthalate)
EP0109305B1 (fr) Laminés et leur utilisation pour la fabrication de récipients
US6548133B2 (en) Multilayer container resistant to elevated temperatures and pressures, and method of making the same
US6355738B2 (en) Polyester and process for preparing polyester
US6485804B1 (en) Polyester compositions and laminates and processes for producing biaxially stretched polyester bottles
JPH11314335A (ja) 高強度の曇りのない透明物品を形成するための同時加工可能な多層積層体及びそれを製造する方法
EP1651527B1 (fr) Composition servant a produire un article d'emballage ayant des proprietes desoxygenantes et un faible trouble
EP0934201A1 (fr) Article desoxygenant transparent comprenant un polyester biaxialement oriente
WO1998013266A9 (fr) Article desoxygenant transparent comprenant un polyester biaxialement oriente
US20070232763A1 (en) Naphthalate based polyester resin compositions
US20110101573A1 (en) Hollow container and process for producing the same
WO2003099562A1 (fr) Produit étiré multicouche
WO2017180629A1 (fr) Récipients et films en polyester présentant une perméabilité aux gaz réduite
JP2010247497A (ja) プラスチック多層構造体
JPH11310629A (ja) 新規なポリエステルおよびポリエステルの製造方法
US20050214489A1 (en) Multilayer stretched product
JPS6172051A (ja) ポリエステル組成物
JPS6279258A (ja) ポリエステルボトル
MXPA99002736A (en) Transparent oxygen-scavenging article including biaxially-oriented polyester
US20220288900A1 (en) Resin layered body
JP3742644B2 (ja) ポリエステル
JPS6251442A (ja) 多層容器
KR20000048570A (ko) 이축 연신 폴리에스테르를 포함하는 투명한 산소-제거 물품

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 97199860.4

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZW AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH KE LS MW SD SZ UG ZW AT BE CH DE DK ES FI FR GB GR IE IT LU MC

COP Corrected version of pamphlet

Free format text: PAGES 1/20-20/20, DRAWINGS, REPLACED BY NEW PAGES 1/18-18/18; DUE TO LATE TRANSMITTAL BY THE RECEIVING OFFICE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase

Ref document number: 2266503

Country of ref document: CA

Ref document number: 2266503

Country of ref document: CA

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 334770

Country of ref document: NZ

WWE Wipo information: entry into national phase

Ref document number: PA/a/1999/002736

Country of ref document: MX

WWE Wipo information: entry into national phase

Ref document number: 1019997002494

Country of ref document: KR

ENP Entry into the national phase

Ref document number: 1998 515773

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1997943437

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWP Wipo information: published in national office

Ref document number: 1997943437

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 09402335

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 1019997002494

Country of ref document: KR

WWW Wipo information: withdrawn in national office

Ref document number: 1997943437

Country of ref document: EP

WWR Wipo information: refused in national office

Ref document number: 1019997002494

Country of ref document: KR