WO2015095443A1 - Thermoplastics having improved barrier properties - Google Patents

Abstract

Provided are thermoplastics that are imparted with improved barrier properties to resist penetration by contaminants as oxygen or carbon dioxide, flavorants, solvents such as gasoline or toluene, and moisture. Thermoplastic is infused with a barrier material capable of reducing the permeability of the thermoplastic material to a gas or a liquid relative to a thermoplastic material that is not infused with a barrier material. The infused material provides barrier properties without the need for a barrier coating thereby providing robust, and long-lifetime barrier properties to the resulting thermoplastics.

Description

THERMOPLASTICS HAVING IMPROVED BARRIER PROPERTIES

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application depends from and claims priority to U.S. Provisional Application No: 61/917,572 filed December 18, 2013, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The invention relates to reducing the permeability of plastic materials. Embodiments of the invention include methods for adding barrier compositions to thermoplastic materials to prevent permeation of liquids and gasses. Specific methods are provided for the infusion of barrier forming compounds into the surface of thermoplastic materials.

BACKGROUND

[0003] Thermoplastics are used on a large scale for the manufacture of bottles such as those extensively used to package beverages including carbonated soft drinks, beer, or mineral water. In both food and non-food applications, however, thermoplastic materials are often lacking in their barrier properties towards gasses such as oxygen or carbon dioxide, flavorants, solvents such as gasoline or toluene, and moisture.

[0004] Preventing the transport of gases through a thermoplastic material is a significant challenge in the food and beverage industry. The penetration of oxygen into a food container can lead to food or beverage discoloration, rancidity, changes in taste or smell, or promote mold formation. This could potentially lead to serious consequences. With respect to beer and soft drinks, the permeation of carbon dioxide will lead to reduced carbonation of the contained product resulting in a flat, undesirable drink.

[0005] As such, there is a long felt need for processes of imparting improved barrier properties to thermoplastics.

SUMMARY

[0006] The following summary is provided to facilitate an understanding of some of the innovative features unique to the present inventions and is not intended to be a full description. A full appreciation of the various aspects of the inventions can be gained by taking the entire specification, claims, drawings, and abstract as a whole.

[0007] Provided are thermoplastic materials and processes for the formation thereof, that include a barrier material to prevent transfer of a liquid or gas through the thermoplastic where the barrier material is infused into the surface of the thermoplastic thereby providing excellent, and optionally long term barrier properties.

[0008] Processes of forming a barrier infused thermoplastic material are provided that include: providing a thermoplastic material in solid form; mixing, immersing, or coating said thermoplastic material with an infusion agent solution at an infusion temperature below the melting temperature of said thermoplastic for an infusion time, said infusion agent solution comprising one or more barrier materials and one or more infusion agents, said one or more barrier materials capable of reducing the permeability of said thermoplastic material to a gas or a liquid relative to a thermoplastic material that is not infused with said barrier material, said one or more infusion agents operable to promote penetration of said barrier material into the surface of said thermoplastic material; and infusing said barrier material into said thermoplastic material by said mixing, immersing, or coating step thereby forming a barrier infused thermoplastic material such that said one or more barrier materials reduces the permeability of said thermoplastic material to a gas or a liquid. An infusion temperature is optionally below the glass transition temperature (Tg) of the thermoplastic, optionally below the melting temperature of the thermoplastic. In some aspects, an infusion temperature is from 60 degrees Celsius to 98 degrees Celsius, optionally 81 degrees Celsius to 91 degrees Celsius. A thermoplastic is infused for an infusion time. An infusion time is optionally 15 minutes or less, optionally at or between 1 second to 5 minutes. A thermoplastic used in the processes is optionally a polyester, optionally polyethylene terephthalate, or polycarbonate. The barrier material following infusion optionally penetrates the thermoplastic to a depth of less than 2 millimeters, optionally to less than 1 millimeter. In some aspects, a barrier material is infused to a final depth of less than 200 microns. In any of the aspects of the invention, a barrier material is optionally a fatty acid amide, a low molecular weight silicone, an isocyanate, an ethyoylate, terephthalic acid, oxidized polyethylene, or combinations thereof. In some aspect, the thermoplastic is preheated to the infusion temperature prior to contact with an infusion agent solution and/or barrier material. Optionally, the infusion agent solution and/or barrier material is heated to the infusion temperature and an unheated thermoplastic is immersed, mixed, or otherwise contacted with the infusion agent solution.

[0009] In any of the aspects of the invention, an infusion agent optionally has a structure of Formula I: Ri— [(0(CH2)_m)n— ]OR2 (I) where R² and R¹ are each independently H or a Ci-is alkyl, benzyl, benzoyl, or phenyl; n is 1, 2 or 3; and m is any value from 1 to 35. R¹ is optionally an ethyl, propyl or butyl, optionally a C₄ alkyl. In some aspects, m is 2, 3, or 4. Optionally, n is 2 or 3. Optionally, the benzyl, benzoyl, or phenyl is substituted in the aromatic ring by alkyl and/or halogen. In some aspects the infusion agent is 2-butoxyethanol, bis(2-ethylhexyl) phthalate, butyl benzyl phthalate, diisodecyl phthalate, di-n-octyl phthalate, diisooctyl phthalate, diisobutyl phthalate, di-n-hexyl phthalate, or combinations thereof. In some aspects, the infusion agent is 2-butoxyethanol, the thermoplastic is PET, and the barrier is a blocked isocyanate or oleamide. An infusion agent optionally as a structure of Formula II: H— [(0(CH2)m)n— ]OH (II) where n is 1, 2 or 3; and m is any value from 1 to 35. Optionally, m is 2, 3, or 4. Optionally, n is 2 or 3. Optionally a first infusion agent is an agent of Formula I and a second infusion agent is of Formula II and a first and second infusion agents are included in an infusion agent solution.

[0010] In any aspect of the provided processes, a thermoplastic may be in the form of a preform or in the form of a final consumer product such as a bottle. Optionally, a preform is infused with a barrier material and then the final barrier material depth is achieved by blow molding or otherwise forming a final shape to the thermoplastic such as a bottle.

[0011] Also provided are infused thermoplastics including: a thermoplastic material having a thickness and a barrier material capable of reducing the permeability of said thermoplastic material to a gas or a liquid relative to a thermoplastic material that is not infused with said barrier material, the barrier material penetrating said thermoplastic material to an infusion depth of 2 millimeters or less but not coating said thermoplastic material, and said thermoplastic material having a thickness greater than said infusion depth. In any aspect, a thermoplastic is optionally polyester, optionally polyethylene terephthalate. A barrier material infused into the thermoplastic is optionally covalently associated with the thermoplastic. A barrier material is optionally a fatty acid amide, low molecular weight silicone, blocked isocyanate, an ethoxylate, terephthalic acid, an oxidized polyethylene, or any combination thereof. The infused thermoplastic is optionally free of any coating, optionally free of a coating of any barrier material. In any aspect, the thermoplastic is optionally a biphasic material. [0012] The resulting barrier infused thermoplastic materials address the long felt need for thermoplastics with improved barrier properties without requiring a coating thereby providing a robust, and optionally permanent barrier to transport of unwanted gasses such as oxygen or carbon dioxide, flavorants, solvents such as gasoline or toluene, or moisture. DETAILED DESCRIPTION

[0013] The following description of particular embodiment(s) is merely exemplary in nature and is in no way intended to limit the scope of the invention, its application, or uses, which may, of course, vary. The invention is described with relation to the non-limiting definitions and terminology included herein. These definitions and terminology are not designed to function as a limitation on the scope or practice of the invention but are presented for illustrative and descriptive purposes only. While the processes are described as an order of individual steps or using specific materials, it is appreciated that described steps or materials may be interchangeable such that the description of the invention includes multiple parts or steps arranged in many ways as is readily appreciated by one of skill in the art.

[0014] It will be understood that, although the terms "first," "second," "third" etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, "a first element," "component," "region," "layer," or "section" discussed below could be termed a second (or other) element, component, region, layer, or section without departing from the teachings herein.

[0015] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms, including "at least one," unless the content clearly indicates otherwise. "Or" means "and/or." As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and/or "comprising," or "includes" and/or "including" when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. The term "or a combination thereof means a combination including at least one of the foregoing elements.

[0016] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0017] The processes provided are useful for imparting barrier properties to thermoplastics such as PET, as one example. Currently, methods improving the resistance of a thermoplastic material to penetration by gasses, solvent, or moisture rely on coating the thermoplastic material with a barrier promoting composition or incorporating an inner barrier layer of a known barrier material to produce a multilayer PET container. The present invention does not require a coating, although in some embodiments a coating may optionally be added. A "coating" as used herein is defined as a continuous or discontinuous layer of material that adds thickness to the overall thermoplastic material structure. The infused thermoplastic materials are substantially of equivalent thickness to the uninfused thermoplastic material as a barrier material penetrates the surface of the thermoplastic material thereby not adding thickness thereto.

[0018] The infused thermoplastic materials provide herein include a barrier material infused into the surface of a thermoplastic thereby not requiring adhesion to the surface of a thermoplastic. Optionally, a thermoplastic is not coated with a barrier promoting composition. As such, the invention has utility as a method for imparting barrier properties to thermoplastic materials. Although many of the following aspects are described with respect to polyethylene terephthalate (PET), many aspects are similarly useful for other thermoplastic types.

[0019] A process of infusing a barrier material into the surface of a thermoplastic material is provided including optionally providing or otherwise obtaining a thermoplastic material in solid form, infusing the thermoplastic material with one or more barrier materials to form a barrier infused thermoplastic material. A barrier infused thermoplastic material is optionally at least a portion of post-consumer material. Optionally, a barrier infused thermoplastic material is entirely post consumer material.

[0020] A process includes obtaining or providing a thermoplastic material. A thermoplastic material is optionally one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate, polyethylene (PE), polylactic acid (PLA), nylon, PET copolymers, acrylics, Surlyn™, polyethylene naphthalate (PEN), polyamides, polycarbonate co-polymers, elastomeric polymers - thermoplastic elastomers, thermoplastic urethanes, polyurethanes, acrylic co-polymers, acrylonitrile butadiene styrene, or other thermoplastics. In particular embodiments, a thermoplastic is polyethylene terephthalate (PET).

[0021] A barrier infused thermoplastic is optionally formed combining an infusion solvent, a barrier material, and a thermoplastic material for an infusion time and at an infusion temperature. The barrier material penetrates the surface of the thermoplastic to impart excellent barrier properties to the thermoplastic material itself without the need for an additional barrier coating.

[0022] A barrier material is a material suitable to decrease the permeability of the thermoplastic material to a gas or liquid. A barrier material can include any suitable low molecular weight organic species or inorganic species of such size and polarity that it will be preferentially infusible into the polymer of choice. Barrier materials optionally include any number of individual or combinations of low molecular weight organic molecules such as terephthalic acid, terephthalic acid esters and the like, ionomers (e.g. SURLYN), fatty acid amides, low molecular weight silicones, free or blocked isocyanates, oxidized polyethylenes (e.g. from Baker Huges), or materials such as an ethoxylate (e.g. Baker Hughes UNITHOX).

[0023] In some aspects, a barrier material includes one or more organic, inorganic, or composite nanoparticles such as but not limited to cellulose, montmorillonite and hectorite clays, silicas, silica oxides, silicates, silicon nitrides, ceramics, graphene, metal oxides. Optionally, more than one barrier material is used. Optionally, 1, 2, 3, 4, 5, or more barrier materials are used. Optionally, 1 and no more barrier materials are used.

[0024] A barrier material is optionally a low molecular weight silicone. Exemplary low molecular weight silicones have fewer than 6 silicon atoms. Illustrative examples of low molecular weight silicones include the siloxanes. Siloxanes are illustratively cyclic organosiloxanes or non-cyclic organosiloxanes. Examples of cyclic organosiloxanes illustratively include cyclic polydiorganosiloxanes, cyclotetradimethicones and cyclopentadimethicones. Linear organopolysiloxanes are illustratively alkyl-, alkoxy- or phenyldimethicones, and alkyl-, alkoxy- or phenyltrimethicones. Optionally, a carrier is an aliphatic volatile organosiloxane. Aliphatic volatile organosiloxanes optionally have from two to six silicon atoms. Optionally, an aliphatic volatile organosiloxane is a linear polyorganosiloxane such as a polyorganosiloxane with 2 to 6 silicon atoms, optionally, an organo- trisiloxane, disiloxane, or combinations thereof.

[0025] A barrier material is optionally a fatty acid amide. A fatty acid amide is a primary fatty acid amide, a bis-fatty acid amide, or combinations thereof. Fatty acid amides are based on fatty saturated and unsaturated straight-chain, monobasic acids optionally derived from naturally occurring feedstocks. Predominant chain lengths range from eighteen to twenty-two carbon atoms. The primary amides are optionally waxy solids with melting points in the range of 68-108 °C. Illustrative, non-limiting examples of fatty acid amides include oleamide and erucamide. Oleamide fatty acid amides include an unsaturated fatty primary amide derived from oleic acid wherein the major component is:

Erucamide fatty acid amides include unsaturated fatty primary amide derived from erucic acid wherein the major component is:

[0026] A barrier material is optionally a free or blocked isocyanate. Blocked isocyanates are typically formed by the reaction of an isocyanate with either an active hydrogen or methylene compound such as malonic esters. A blocked isocyanate is optionally an active hydrogen blocked isocyanate or an active methylene blocked isocyanate. More specifically, an isocyanate is blocked with an alcohol, caprolactam, phenol, oxime, pyrazole, or malonate. Specific illustrative examples of a blocked isocyanate include 3,5-dimethyl pyrazole (DMP), diisopropyl amine (DIP A), and t-butyl benzyl amine (BEBA). In some embodiments, an isocyanate is sold as Bayhydrol XP 2637.

[0027] When a barrier material includes a blocked isocyanate, the resulting infused thermoplastic is optionally subjected to an additional crosslinking step capitalizing on the isocyanate to form urethane linkages with one or more additional reactants that may be used to form a coating, to crosslink to the thermoplastic material itself forming a more robust thermoplastic material, or combinations thereof thereby forming a biphasic barrier infused thermoplastic material. Optionally, the blocked isocyanate heated to its reaction temperature which allows formation of covalent cross links to elements present in the thermoplastic material itself. Upon cure, the result is a barrier protected thermoplastic with two phases with a first phase being a more rigid region, and a second phase being a less rigid region. The more rigid region is to a depth of infusion of the original blocked isocyanate, or a portion thereof. [0028] A barrier material is optionally one or more ethoxylate. An ethoxylate is a non-ionic ethoxylated linear alcohol with surface activity. An illustrative example of an ethoxylate is U ITHOX from Baker Hughes.

[0029] A barrier material optionally forms an active barrier, a passive barrier, or combinations thereof. An active barrier is formed of a barrier material with the capability to chemically react with a gas or liquid that with the exception of the barrier material, would be capable of penetrating the thermoplastic such that the barrier material sequesters, alters, chemically modifies, or otherwise prevents the gas or liquid from penetrating the thermoplastic.

[0030] In some aspects, a barrier material forms a passive barrier whereby the passive barrier substantially acts as a physical or chemical barrier to penetration of a gas or liquid into or through the infused thermoplastic material. In some aspects, a barrier material serves to fill or partially fill free volume or pores existing in a polymeric material. The filling of free volume or pores in the material may aid in creation of a barrier to penetration by a liquid or gas into or through the thermoplastic material.

[0031] A barrier material reduces the permeability of a thermoplastic material to a gas or a liquid relative to a thermoplastic material that is not infused with the barrier material. A gas is optionally oxygen or carbon dioxide. A liquid is optionally water. A barrier infused thermoplastic material has a barrier lifetime. A barrier lifetime is a time for which the barrier infused thermoplastic material has a barrier function 90% or greater relative to a freshly infused thermoplastic material. Optionally, a barrier lifetime is less than 90 days, optionally less than 60 days, optionally less than 30 days, optionally less than 14 days. A barrier lifetime is optionally not in excess of 90 days. In some aspects, a barrier lifetime is up to two years, optionally up to one year. As one example, when a barrier material is an oxygen scavenging compound, the barrier lifetime may be 1 to 2 years in some aspects. In some aspects, a barrier lifetime is 1 year or more, optionally 2 years or more. Optionally, a barrier lifetime is 1, 2, 3, 4, 5, 6 or more years. Optionally, a barrier lifetime is substantially equal to the lifetime of the thermoplastic material itself. In some aspects, a barrier lifetime is limited only by the physical integrity lifetime of the thermoplastic material itself.

[0032] In some aspects of a process, a thermoplastic material is mixed or otherwise contacted with an infusion agent solution including one or more infusion agents. An infusion agent is a chemical composition operable to promote penetration of a barrier material into the surface of a thermoplastic. An infusion agent solution is optionally an aqueous solution, or a solution of one or more organic solvents or solutes. An infusion agent solution is optionally entirely formed of an infusion agent. In some embodiments, an infusion agent solution includes water, an infusion agent, and optionally one or more additives. An additive is illustratively one more surfactants or emulsifiers. An infusion agent solution is optionally free of a dye prior to mixing with a thermoplastic. Optionally, an infusion agent solution includes one or more dyes.

[0033] An infusion agent solution is optionally an aqueous solution wherein water is present in an amount of less than or equal to 98 percent by weight, optionally less than or equal to 80 percent by weight, optionally less than or equal to 75 percent by weight. In some embodiments, water is present in an infusion agent solution in an amount of at least 50 or 51 percent by weight, optionally at least 60 percent by weight, and optionally at least 65 percent by weight. Water may be present in the infusion agent solution in an amount ranging from 50 to 85 percent by weight or any value or range therebetween, with particular ranges being preferred. For example, water may be present in the infusion agent solution in an amount from 50 (or 51) to 85 percent by weight, optionally 60 to 87 percent by weight, optionally in an amount of from 65 to 75 percent by weight, optionally 70 percent by weight. In some embodiments, water is present from 85 to 99 percent by weight, optionally 90 to 98 percent, optionally 95 to 98 percent by weight, optionally 98 percent by weight. The percent weights being based on the total weight of the infusion agent solution. In some embodiments, water is present in an amount from 50 to 90, preferably 62.5 to 85, most preferably 70 to 77.5 pbw (percent by weight relative to the weight of the infusion agent solution mixture). The water used is optionally deionized water or distilled water the preparation of each of which is well known in the art.

[0034] An infusion agent is optionally an oxidizing agent, a free radical precursor, or a compound having the formula of Formula I:

R¹ [(0(CH₂)m)n— ]OR² (I)

wherein R² and R¹ are each independently H or a Ci-is alkyl, benzyl, benzoyl, or phenyl; n is 1, 2 or 3; and m is any value from 1 to 35. In some embodiments, m is 1 to 12. In some embodiments, m is 1. Optionally, R¹ denotes H. Optionally, R¹ denotes butyl and R² denotes H.

[0035] An aromatic R¹ or R² group of Formula I is optionally substituted with 1 to 5 groups selected from halo groups (e.g., chloro, bromo and fluoro), linear or branched C 1-C9 alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and nonyl), and aromatic groups

(e.g., phenyl). [0036] Specific examples of an infusion agent solution according to Formula I include 2- methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2- phenoxyethanol, 2-benzyloxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, 2-(2-butoxyethoxy)ethanol, dimethoxyethane, diethoxyethane, and dibutoxyethane, ethylene glycol butyl ether, diethylene glycol ethylether, diethylene glycol butylether, propylene glycol propylether, dipropylene glycol propyl ether and tripropylene glycol propylether, or combinations thereof.

[0037] The infusion agent is typically present in the infusion agent solution in an amount of less than or equal to 30 percent by weight, optionally less than or equal to 25 percent by weight, optionally less than or equal to 20 percent by weight. The infusion agent is optionally present in the solution in an amount of at least 10 percent by weight, optionally at least 15 percent by weight, optionally at least 17 percent by weight. The infusion agent may be present in the solution in an amount ranging from 10 to 30 percent by weight or any value or range therebetween. For example, the infusion agent is optionally present in the solution in an amount from 10 to 30 percent by weight, optionally from 15 to 25 percent by weight, optionally in an amount of from 17 to 20 percent by weight. The percent weights being based on the total weight of the infusion agent solution.

[0038] An infusion agent solution optionally includes one or more infusion agents.

Optionally, an infusion agent solution includes 1, 2, 3, 4, 5, 6, or more infusion agents. In some embodiments, when more than one infusion agent is present in an infusion agent solution, there may be infusion agents of more than one type. In some embodiments, a first infusion agent is an agent of Formula I, and a second infusion agent is a diol of Formula II:

H— [(0(CH₂)m)n— ]OH (II)

[0039] wherein n is 1, 2 or 3; and m is any value from 1 to 35. In some embodiments, m is 1 to 12. In some embodiments, m is any value from 2 to 4. Optionally, m is any value from 2 to

4 and n is 1, 2, or 3. Illustrative agents of Formula II include diethylene glycol, triethylene glycol and 1,4 butanediol.

[0040] An infusion agent is optionally present in an infusion agent solution at a concentration of 2.5 to 20, optionally 5 to 12.5, optionally 7.5 to 10 pbw. A second infusion agent is optionally present in an amount identical to a first infusion agent. Optionally, a second infusion agent is present in an amount of 5 to 30, preferably 10 to 25, most preferably 15 to 20 pbw. [0041] An infusion agent solution optionally includes one or more emulsifiers. Illustrative examples of an emulsifier include ionic or non-ionic emulsifiers, or mixtures thereof. Illustrative examples of an anionic emulsifier include: amine salts or alkali salts of carboxylic, sulfamic or phosphoric acids, for example, sodium lauryl sulfate, ammonium lauryl sulfate, lignosulfonic acid salts, ethylene diamine tetra acetic acid (EDTA) sodium salts, and acid salts of amines, such as, laurylamine hydrochloride or poly(oxy- 1 ,2-ethanediyl), a-sulfo-omega-hydroxy ether with phenol 1 -(methylphenyl)ethyl derivative ammonium salts. An emulsifier is optionally an amphoteric emulsifier illustratively: lauryl sulfobetaine; dihydroxy ethylalkyl betaine; amido betaine based on coconut acids; disodium N-lauryl amino propionate; or the sodium salts of dicarboxylic acid coconut derivatives. Typical non-ionic emulsifiers include ethoxylated or propoxylated alkyl or aryl phenolic compounds, such as octylphenoxypolyethyleneoxyethanol. A specific emulsifier used is diethylene glycol.

[0042] An emulsifier is optionally present in an infusion agent solution in an amount from 0 to 15 weight percent, optionally 7 to 15 weight percent, optionally 10 to 15 weight percent, optionally 0.5 to 5 weight percent, optionally 3 to 4 weight percent.

[0043] An infusion agent solution optionally includes one or more surfactants.

[0044] An infusion agent solution is optionally at ambient temperature (approximately 25°C) or heated above ambient temperature. In some embodiments, an infusion process includes heating a thermoplastic alone or in the presence of an infusion agent solution where heating is to a temperature below the melting temperature of the thermoplastic material. Optionally, an infusion agent solution is preheated or heated in the presence of a thermoplastic, optionally to any infusion temperature less than 100 °C.

[0045] A process includes an infusing a thermoplastic at an infusion temperature. Optionally, an infusion temperature is between 81°C and 91°C. The infusion temperature is appreciated to be below the melting temperature of the thermoplastic material. Illustratively, for a polycarbonate thermoplastic material an infusion temperature may be 90°C to 99°C. It is appreciated that thermoplastics that may have a lower heat distortion temperature may be infused at a lower temperature. As one example, an infusion temperature of a polyurethane may be about 60°C. An infusion time is optionally less than one hour, preferably from 1 second to 15 minutes, or any value or range therebetween.

[0046] A process for forming a barrier infused thermoplastic material optionally includes mixing a thermoplastic material with an infusion agent solution for an infusion time. Mixing is optionally immersing a thermoplastic material in an infusion agent solution, spraying an infusion agent solution on a thermoplastic, or other mixing recognized by one of skill in the art. An infusion time is optionally any time from <1 second to 120 minutes, or more. In some aspects, an infusion time is optionally from <1 second to 30 minutes, optionally from <1 second to 20 minutes, optionally from 1 second to 10 minutes, optionally from 5 seconds to 1 minute, optionally from 5 seconds to 30 seconds, optionally from 10 seconds to 20 seconds. An infusion time is optionally 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 or 60 seconds. An infusion time is optionally 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, or 30 minutes.

[0047] Upon forming a container using infused thermoplastic such as by compression molding, thermoforming, injection molding, rotational molding, extrusion, inject/blow, injection reheat stretch blown and extrusion blow molding, or casting of the thermoplastic into a final shape, the barrier material is present to a depth of 0.001 to 1 mm. As such, the process provided are used to infuse a barrier material that is from 0.01 to 2 mm in depth or more, or any value or range therebetween. Optionally, a barrier material depth is from 0.01 to 0.5 mm. Optionally, a barrier material depth is from 0.05 to 0.2 mm.

[0048] Optionally, a barrier material is subsequently subjected to a chemical reaction to alter the barrier material to provide improved barrier properties, to covalently combine a barrier material with one or more components within a thermoplastic or a subsequently applied coating material, or to otherwise alter the barrier material.

[0049] Following an infusion time, or optionally during an infusion time, an infusion agent solution is optionally subjected to a renewal process to remove contaminant material(s) from the solution. The purification of the infusion agent solution is optionally achieved by contacting the infusion agent solution with a filtration media such as activated carbon, mechanical filtering, skimming, irradiation, or combinations thereof. The filtration media may be in the form of a column, a bed, or any other configuration that will allow the adequate contact of the used infusion agent solution resulting in a reduction of contaminant, optionally contaminant free infusion agent solution suitable for reuse.

[0050] In some aspects, additional barrier material, infusion agent, or other is supplemented into an infusion agent solution during the infusion time. Supplementation of additional infusion agent, barrier material, or a second infusion agent or second barrier material into an infusion agent solution serves to drive the infusion into the thermoplastic material by renewing the equilibrium between the barrier material in the thermoplastic and the infusion agent solution thereby driving the reaction toward infusion.

[0051] The inventive processes are used to form a barrier infused thermoplastic material. As such, barrier infused thermoplastic materials are also provided. A barrier infused thermoplastic material includes a thermoplastic material that includes one or more barrier materials penetrating the surface of the thermoplastic material, optionally not penetrating the entire thermoplastic material. An infused thermoplastic material is distinguished from a coated thermoplastic material as the coated thermoplastic material does not include the coating material penetrating the surface. A coated material is merely adhered to the surface of the thermoplastic material. In contrast, a barrier infused thermoplastic material includes a barrier material penetrating the surface of the thermoplastic material to a depth of 0.1 to 2 mm, or any value or range therebetween, optionally as elsewhere described herein. A barrier infused thermoplastic material is distinguished from a fully homogenous or heterogeneous barrier material containing thermoplastic material on the basis that the infused thermoplastic material is free of barrier material in a region extending across the area of the thermoplastic material adjacent to the region including the infused barrier material. As such, a barrier infused thermoplastic material is optionally not a coated thermoplastic material (absent infused barrier material), or a fully barrier material containing thermoplastic material.

[0052] The barrier infused thermoplastic made according to the invention may be used in making containers, bottles, closures, films, thermoforms, food packaging, or other material. Optionally, the thermoplastic includes a total recycled material content that may be quite low (less than or equal to 20%), relatively high (greater than 20%), or entirely containing recycled material, depending upon the application. Thus, some embodiments involve the manufacture of an article using at least some content that is recycled thermoplastic that has been substantially barrier infused by one or more processes provided. Illustrative examples of an article include bottles, food packaging, computer face-plates, keyboards, bezels and cellular phones, color coded packaging and containers of all types including ones for industrial components, residential and commercial lighting fixtures, components in building and in construction, tableware including plates, cups and eating utensils, small appliances and their components, optical and sun-wear lenses, as well as decorative films including such films that are intended for use in film insert molding. In particular embodiments, and article is a bottle made of at least a portion or entirely of recycled PET. Methods of forming bottles are well known in the art. [0053] Various aspects of the present invention are illustrated by the following non-limiting examples. The examples are for illustrative purposes and are not a limitation on any practice of the present invention. It will be understood that variations and modifications can be made without departing from the spirit and scope of the invention. Reagents illustrated herein are commonly commercially available, and a person of ordinary skill in the art readily understands where such reagents may be obtained.

EXAMPLES

Example 1: Infusion of barrier material into PET.

[0054] For PET, hot preforms are infused with oleamide (C18H35NO) (Licowax C and Licolub FA1 from Clariant) or an isocyante (Bayhydrol XP 2637; Bayer Material Science, Pittsburg, PA). For infusion, an infusion solvent including water (70% w/w), infusion agent (2- butoxyethanol) (20% w/w) and emulsifier (diethylene glycol) (10% w/w) containing either oleamide or isocyanate is heated to a temperature of 96°C. Both cold and very hot PET preforms are treated in individual batches. In some tests, preforms taken immediately off the injection press can be infused. The infusion time can range while submersed in the infusion solvent for 1, 5, 8, 10, 20, or 30 seconds.

[0055] Following the infusion time, the test samples are rinsed twice in water to remove residual infusion agent solution and then allowed to dry at room temperature overnight. Infused preforms are blow molded into bottles such that the final infusion depth of the isocyanate or oleamide is 1 mm to 0.05 mm.

[0056] To test for the presence of infusion agent or for permeation tests, blown bottles are cut into single wall sections. A cut section approximately 6" diameter of each of the test samples is used for testing by standard permeation test methods. In some aspects, whole blown bottles are tested.

Examples 2-12:

[0057] PET thermoplastic material is to be infused with other barrier materials using the methods as exemplified in Example 1. Briefly, infusion solvent including water (70% w/w), infusion agent (2-butoxyethanol) (20% w/w) and emulsifier (diethylene glycol) (10% w/w) containing a barrier material as presented in Table 1 is heated to a temperature of 96°C. PET preforms are treated by immersion in the infusion solvent for an infusion time of between 10 to 20 seconds. The test samples are then removed from the infusion agent solution, rinsed twice in water, and then allowed to dry at room temperature overnight. In some examples infused preforms are blow molded into bottles.

Table 1 :

Example Barrier Material

2 terephthalic acid

3 poly(ethylene-co-methacrylic acid) sodium

4 1,3-dibenzyltetramethyldisiloxane

5 tetradecamethylhexasiloxane

6 docosatetraenoylethanolamide

7 oleoylethanolamide

8 palmitoylethanolamide

9 erucamide

10 3,5-dimethyl pyrazole

11 diisopropyl amine

12 t-butyl benzyl amine

[0058] Similar infusion results are expected with all barrier materials tested.

Examples 13-19:

[0059] The barrier materials oleamide, isocyanate, or those presented in Table 1 infused into a thermoplastic of Table 2.

Table 2:

Example Thermoplastic

13 polycarbonate

14 polybutylene terephthalate

15 polyethylene

16 polylactic acid

17 nylon

18 polyethylene naphthalate

19 acrylonitrile butadiene styrene [0060] Briefly, infusion solvent including water (70% w/w), infusion agent (2- butoxyethanol) (20% w/w) and emulsifier (di ethylene glycol) (10% w/w) containing the barrier material is heated to a temperature of 96°C. PET preforms are treated by immersion in the infusion solvent for an infusion time of between 10 to 20 seconds. The test samples are then removed from the infusion agent solution, rinsed twice in water, and then allowed to dry at room temperature overnight. In some examples infused preforms are blow molded into bottles.

[0061] Similar infusion results are expected with all thermoplastics tested.

[0062] Various modifications of the present invention, in addition to those shown and described herein, will be apparent to those skilled in the art of the above description. Such modifications are also intended to fall within the scope of the appended claims.

[0063] It is appreciated that all reagents are obtainable by sources known in the art unless otherwise specified.

REFERENCES

[0064] U.S. Patent Nos: 6,733,543; 6,749,646; 7, 175,675; 7,504,054; 6,959,666; 6,949, 127; 6,994,735; 7,094,263; 8,206,463; and 7,921,680

[0065] U.S. Patent Application Publication Nos: 2008/0067124; 2009/0297830; and 2009/0089942.

[0066] Patents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These patents and publications are incorporated herein by reference to the same extent as if each individual application or publication was specifically and individually incorporated herein by reference.

[0067] The foregoing description is illustrative of particular embodiments of the invention, but is not meant to be a limitation upon the practice thereof. The following claims, including all equivalents thereof, are intended to define the scope of the invention.

Claims

1. A process of forming a barrier infused thermoplastic material comprising:

providing a thermoplastic material in solid form;

mixing, immersing, or coating said thermoplastic material with an infusion agent solution at an infusion temperature below the melting temperature of said thermoplastic for an infusion time, said infusion agent solution comprising one or more barrier materials and one or more infusion agents, said one or more barrier materials capable of reducing the permeability of said thermoplastic material to a gas or a liquid relative to a thermoplastic material that is not infused with said barrier material, said one or more infusion agents operable to promote penetration of said barrier material into the surface of said thermoplastic material; and

infusing said barrier material into said thermoplastic material by said mixing, immersing, or coating step thereby forming a barrier infused thermoplastic material such that said one or more barrier materials reduces the permeability of said thermoplastic material to a gas or a liquid.

2. The process of claim 1 wherein said infusion temperature is from 60 degrees Celsius to 98 degrees Celsius.

3. The process of claim 1 wherein said infusion temperature is from 81 degrees Celsius to 91 degrees Celsius.

4. The process of claim 1 wherein said infusion time is 15 minutes or less.

5. The process of claim 1 wherein said infusion time is 10 minutes or less.

6. The process of claim 1 wherein said infusion time is at or between 1 second to 5 minutes.

7. The process of any one of claims 1-6 wherein said thermoplastic is a polyester, optionally polyethylene terephthalate, or polycarbonate.

8. The process of any one of claims 1-6 wherein said barrier material penetrates said thermoplastic to a depth of less than 2 millimeters, optionally to less than 1 millimeter.

9. The process of any one of claims 1-6 wherein said barrier material is a fatty acid amide.

10. The process of any one of claims 1-6 wherein said barrier material is a low molecular weight silicone. 11. The process of any one of claims 1-6 wherein said barrier material is a blocked isocyanate.

12. The process of any one of claims 1-6 wherein said barrier material is an ethoxylate.

13. The process of any one of claims 1 -6 wherein said barrier material is terephthalic acid.

14. The process of any one of claims 1 -6 wherein said barrier material is an oxidized polyethylene.

15. The process of any one of claims 1 -6 further comprising heating said

thermoplastic material to said infusion temperature for said infusion time subsequent to or simultaneous with said step of mixing.

16. The process of any one of claims 1-6 wherein said infusion agent has a structure of Formula I:

R¹— [(0(CH₂)m)n— ]OR² (I)

wherein R² and R¹ are each independently H or a Ci-is alkyl, benzyl, benzoyl, or phenyl; n is 1, 2 or 3; and m is any value from 1 to 35.

17. The process of claim 16 wherein said infusion agent includes an R¹ that is an ethyl, propyl or butyl.

18. The process of claim 16 wherein m is 2, 3 or 4.

19. The process of claim 16 wherein n is 2 or 3.

20. The process of claim 16 wherein said benzyl, benzoyl, or phenyl is substituted in the aromatic ring by alkyl and/or halogen.

21. The process of claim 16 wherein said R¹ is a C₄ alkyl.

23. The process of any one of claims 1 -6 wherein said infusion agent is 2- butoxyethanol.

24. The process of any one of claims 1-6 wherein said infusion agent is in an aqueous infusion agent solution.

25. The process of any one of claims 1-6 wherein said thermoplastic is polyethylene terephthalate.

26. The process of claim 23 wherein said infusion temperature is at or between 81 to 91 degrees Celsius. 27. The process of any one of claims 1-6 wherein said infusion agent is selected from the group consisting of bis(2-ethylhexyl) phthalate, butyl benzyl phthalate, diisodecyl phthalate, di-n-octyl phthalate, diisooctyl phthalate, diisobutyl phthalate, and di-n-hexyl phthalate.

28. The process of claim 16 wherein said infusion agent solution further comprises a second infusion agent has a structure of Formula II:

H— [(0(CH₂)m)n— ] OH (II)

n is 1, 2 or 3; and m is any value from 1 to 35.

29. The process of claim 28 wherein m is 2, 3 or 4.

30. The process of claim 28 wherein n is 2 or 3.

31. The process of any one of claims 1 -6 wherein said solid form is a preform.

32. The process of any one of claims 1 -6 wherein said solid form is a bottle. 33. A barrier infused thermoplastic material comprising:

a thermoplastic material having a thickness; and

a barrier material capable of reducing the permeability of said thermoplastic material to a gas or a liquid relative to a thermoplastic material that is not infused with said barrier material; said barrier material penetrating said thermoplastic material to an infusion depth of 2 millimeters or less but not coating said thermoplastic material, and said thermoplastic material having a thickness greater than said infusion depth.

34. The barrier infused thermoplastic material of claim 33 wherein said thermoplastic material is a polyester, optionally polyethylene terephthalate.

35. The barrier infused thermoplastic material of claim 35 wherein said barrier material is a fatty acid amide.

36. The barrier infused thermoplastic material of claim 33 wherein said barrier material is a low molecular weight silicone.

37. The barrier infused thermoplastic material of claim 33 wherein said barrier material is a blocked isocyanate. 38. The barrier infused thermoplastic material of claim 33 wherein said barrier material is an ethoxylate.

39. The barrier infused thermoplastic material of claim 33 wherein said barrier material is terephthalic acid.

40. The barrier infused thermoplastic material of claim 33 wherein said barrier material is an oxidized polyethylene.

41. The barrier infused thermoplastic material of any one of claims 33-40 wherein said barrier infused thermoplastic material is free from a coating. 42. The barrier infused thermoplastic material of any one of claims 33-40 wherein said thermoplastic material is a biphasic material.