Preparation method and application of master batch composition

Abstract

The present disclosure relates generally to methods of making high barrier polyolefin compositions and masterbatch compositions comprising a synergistic combination of a nucleating agent and a hydrocarbon resin for making barrier layers and barrier films having barrier properties suitable for packaging applications.

Description

Technical Field

[0001] The present disclosure broadly relates to methods for preparing high barrier polyolefin compositions and masterbatch compositions, wherein the high barrier polyolefin compositions and masterbatch compositions can be used to prepare barrier layers and barrier films having barrier properties suitable for packaging applications. Specific embodiments disclosed herein relate to methods for preparing masterbatch compositions, and the use of such masterbatch compositions for forming high barrier polyolefin layers in films.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to Australian Provisional Patent Application No. 2022900898 filed on April 6, 2022, Australian Provisional Patent Application No. 2023900832 filed on March 24, 2023, and Australian Provisional Patent Application No. 2023900833 filed on March 24, 2023, each of which is incorporated herein in its entirety by cross-reference as if fully set forth. Background Art

[0004] Polyolefins, such as polyethylene, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene linear low density polyethylene (mLLDPE), very low density linear polyethylene (VLLDPE), ethylene vinyl acetate (EVA), and plastomers have a variety of commercial uses.

[0005] Polyethylene is a versatile polymer with a unique combination of properties such as chemical inertness, toughness, low permeability to water vapor and oxygen, and moldability.

[0006] High density polyethylene (HDPE) is commonly used in blown film applications where high water vapor resistance and oxygen permeability are beneficial, for example, cereal box liners and packaging for dry foods.

[0007] Water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) are important properties of barrier films. These properties reflect the amount of water vapor and oxygen, respectively, that can pass through the film. Generally, for films used in many food packaging, it is desirable for the film to exhibit low WVTR and / or OTR values.

[0008] The best HDPE blown film grades have a density of about 3.0-3.6 g / m at 40 micron gauge. 2 / day water vapor transmission rate (WVTR). Since WVTR is also a function of film thickness, this is equivalent to about 2.4-2.9 g / m at 50 micron specifications. 2 / sky.

[0009] The WVTR at a particular specification is a property that is related not only to the intrinsic properties of HDPE, but also to how HDPE is processed into a film. The addition of hydrocarbon resins (HCRs) mixed into polyolefins such as polypropylene and polyethylene has been used to improve barrier properties. It is generally taught and accepted in the prior art that a relatively high concentration of HCR of at least about 10%-20% w / w is required to achieve suitable WVTR performance, i.e., a WVTR reduction of about 30% in a typical film. For example, EP 2520615, WO 2010 / 104628, and US2012 / 0107542 disclose that HCR concentrations greater than 10% w / w are necessary to provide the desired barrier and mechanical properties in the barrier layers exemplified therein. Due to the relatively high cost of HCR, the addition of high concentrations of HCR to barrier films significantly increases the overall production cost. Therefore, it would be advantageous and desirable if suitable barrier properties could be achieved using less HCR. Furthermore, high concentrations of HCR (eg, concentrations above 10% w / w) can significantly reduce useful film mechanical properties such as toughness and tear resistance and can adversely affect the suitability of the film for use in packaging or food contact applications.

[0010] Compared to WVTR, processability is a material / resin inherent property, not a film inherent property. Poor processability not only makes it difficult to make blown film from the resin, but also the film mechanical properties such as tear strength and puncture resistance will be adversely affected.

[0011] Nucleating agents help form crystals easily and extensively during processing. The end result is smaller crystals, and when they are well dispersed, the path of gas molecules through the resin is more tortuous. When a typical HDPE film is effectively nucleated, the WVTR can be reduced by about 25% to about 30%. However, there are difficulties in effectively introducing and homogenizing nucleating agents in HDPE due to poor compatibility and / or particle aggregation.

[0012] It is known that the combination of hydrocarbon resins and nucleating agents, when added together to a polymer composition (e.g., polyethylene), provides an additive or cumulative effect in improving the barrier properties of the resulting barrier layer. However, the prior art shows that significant improvements can only be achieved at relatively high hydrocarbon resin concentrations of greater than about 10% in the polymer composition. In addition, the improvements brought about by the combination of hydrocarbon resins and nucleating agents have been shown to be limited to additive or cumulative effects, rather than "synergistic" effects. This is consistent with the theory that hydrocarbon resins and nucleating agents improve the amorphous phase and crystalline phase of the polymer composition, respectively. In this regard, it is generally understood and accepted by those skilled in the art that hydrocarbon resins and nucleating agents essentially act independently of each other. Therefore, most progress in this field has focused on finding new forms of hydrocarbon resins, nucleating agents, introducing different additives, adjusting the physical properties of the polymer matrix and their blends, etc., and finding an effective balance of the above, aiming to reduce costs while maintaining reasonable barrier properties.

[0013] As described above, one approach to improving nucleation efficiency involves narrowing the molecular weight distribution of the polymer and limiting the extent of long chain branching. By changing the molecular weight distribution in the polymer so that the ultra-low molecular weight fraction is blended with the high molecular weight fraction in a specific ratio, the ability of the resin to effectively nucleate can be improved, reducing the WVTR by about 40%-50%. In another approach, blends of HDPE polymers with low melt flow index and high melt flow index with nucleating agents have been shown to be effective in reducing the WVTR by about 20%-40%. However, there is a limit to the extent to which barrier properties can be improved by adding higher melt index or low molecular weight polymers without adversely affecting processability and film mechanical properties, especially puncture resistance and tear resistance. It would be advantageous and desirable if suitable processability, mechanical properties and barrier properties could be achieved using a wider range of film components, such as lower melt index of polymers and a wider range of polymer molecular weights.

[0014] There are many other methods to improve the water vapor barrier of HDPE-based films. For example, a layer of HDPE can be laminated or coextruded with other layers of material to form a multilayer HDPE-based film with improved water vapor barrier properties. However, the formation of multilayer films typically involves higher costs, and such films are generally less recyclable. In particular, the use of different types of materials in multilayer films limits the ability to recycle the film, thereby adversely affecting the environment. Monolayer films of HDPE can also be prepared, and the water vapor barrier of monolayer films can be improved by increasing their thickness, but this has the significant disadvantage of increasing the weight and cost of packages formed with these films.

[0015] Improved methods of making barrier films having suitable barrier properties, such as high water vapor resistance and oxygen permeability balanced with strong film properties are needed. Also needed are methods of making barrier films having suitable barrier properties using lower amounts of HCR and a wider range of component polymers. Summary of the invention

[0016] The present invention generally relates to methods for preparing films having improved barrier properties.

[0017] Embodiments of the invention disclosed herein broadly relate to methods for preparing masterbatch compositions comprising a nucleating agent, a hydrocarbon resin, or both a nucleating agent and a hydrocarbon resin, and a polyolefin, preferably polyethylene, more preferably a high-density polyethylene (HDPE), and to the use of such masterbatch compositions for preparing a high-barrier polyolefin (HBP) layer in a film, such as a HBP barrier layer. Other embodiments disclosed herein relate to the use of masterbatch technology for preparing a high-barrier polyolefin (HBP) composition, and the use of an HBP composition for preparing a high-barrier polyolefin (HBP) layer in a high-density polyethylene film.

[0018] More specifically, the present invention relates to a process for preparing a mixture comprising a synergistic combination of a nucleating agent and a hydrocarbon resin in a polyolefin such as polyethylene, more preferably high density polyethylene (HDPE). Such synergistic mixtures allow the use of relatively low concentrations of hydrocarbon resin, preferably concentrations below the threshold concentrations considered necessary in the prior art, while still achieving acceptable (or in some cases improved) barrier properties. In preferred embodiments, the synergistic combination and processing of hydrocarbon resin and nucleating agent achieves suitable or improved barrier properties balanced with good mechanical properties and processability.

[0019] In a preferred embodiment, the polyolefin is selected from polyethylene, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene linear low density polyethylene (mLLDPE), ultra low density linear polyethylene (VLLDPE), ethylene vinyl acetate (EVA) and plastomers, more preferably high density polyethylene (HDPE).

[0020] In one aspect, the present invention provides a method for preparing a high barrier polyolefin masterbatch, comprising the following steps:

[0021] a) melt mixing a nucleating agent in polyethylene to form a nucleating agent masterbatch;

[0022] b) melt mixing a hydrocarbon resin in polyethylene to form a hydrocarbon resin masterbatch; and

[0023] c) melt-mixing the nucleating agent masterbatch of step a) with the hydrocarbon resin masterbatch of step b) to produce a uniform high barrier polyolefin masterbatch.

[0024] In one embodiment, the barrier properties of the high barrier film prepared from the high barrier polyolefin masterbatch are greater than the barrier properties based on the additive effect of the nucleating agent and the hydrocarbon resin, wherein the additive effect is preferably based on the effect of each additive when applied alone or used or processed independently of the other additives.

[0025] In another aspect, the present invention provides a method for preparing a nucleating agent masterbatch, comprising the steps of:

[0026] The nucleating agent is melt mixed in the polyethylene, wherein the melt mixing step is sufficient to produce a homogeneous nucleating agent masterbatch.

[0027] In another aspect, the present invention provides a method for preparing a hydrocarbon resin masterbatch, comprising the steps of:

[0028] The hydrocarbon resin is melt mixed in the polyethylene, wherein the melt mixing step is sufficient to produce a homogeneous hydrocarbon resin masterbatch.

[0029] In another aspect, the present invention provides a method for preparing a high barrier polyolefin masterbatch, comprising the following steps:

[0030] The nucleating agent masterbatch disclosed herein is melt mixed with the hydrocarbon resin masterbatch disclosed herein, wherein the melt mixing step is sufficient to produce a homogeneous high barrier polyolefin masterbatch.

[0031] In another aspect, the present invention provides a method for preparing a high barrier polyolefin masterbatch, comprising the following steps:

[0032] A nucleating agent mixture and a hydrocarbon resin are melt mixed with polyethylene, wherein the nucleating agent mixture comprises a nucleating agent and a polyolefin, and wherein the melt mixing step is sufficient to produce a homogeneous high barrier polyolefin masterbatch.

[0033] In preferred embodiments of the methods disclosed herein for preparing NA MB, HCR MB, HBP MB, HBP composition or barrier layer, any one or more of the melt mixing steps sufficient to produce homogeneity is performed using a twin screw compounder or a single screw compounder, preferably a twin screw compounder.

[0034] In preferred embodiments of the methods disclosed herein for making NA MB, HCR MB, HBP MB, HBP compositions or barrier layers, each melt mixing step is conducted with sufficient residence time to produce a substantially homogeneous blend.

[0035] In one or more preferred embodiments, the barrel zone temperature of the twin screw extruder is set to provide a constant melt temperature of about 150-220°C.

[0036] In one or more preferred embodiments, the inventive method disclosed herein for preparing NA MB, HCR MB, HBPMB, HBP composition or barrier layer further comprises the step of adding one or more optional additives. Representative optional additives include anti-acid metal salts and antioxidants (including primary antioxidants and secondary antioxidants), flame retardants, lubricants, UV stabilizers, antistatic agents, processing aids, etc. If desired, such additives can be added to the extruder and melt compounded into the relevant NA MB, HCR MB, HBP MB, HBP composition or barrier layer.

[0037] In various embodiments of the invention disclosed herein, the nucleating agent is present in the nucleating agent masterbatch or HBP masterbatch in an amount of about 0.1 wt % to about 30 wt %, or about 0.2 wt % to about 25 wt %, or about 0.3 wt % to about 25 wt %, or about 0.2 wt % to about 15 wt %, or about 0.3 wt % to about 20 wt %, or about 0.3 wt % to about 15 wt %, or about 0.5 wt % to about 20 wt %, or about 0.5 wt % to about 15 wt %, or about 0.5 wt % to about 10 wt %.

[0038] In various embodiments of the invention disclosed herein, the hydrocarbon resin is present in the hydrocarbon resin masterbatch or HBP masterbatch in an amount from about 5 wt % to about 80 wt %, or from about 2.5 wt % to about 80 wt %, or from about 2.5 wt % to about 70 wt %, or from about 2.5 wt % to about 60 wt %, or from about 10 wt % to about 70 wt %, or from about 15 wt % to about 65 wt %, or from about 20 wt % to about 60 wt %, or from about 5 wt % to about 50 wt %, or from about 7.5 wt % to about 45 wt %, or from about 10 wt % to about 40 wt %, or from about 30 wt % to about 50 wt %, or from about 25 wt % to about 55 wt %.

[0039] In another embodiment, the nucleating agent is present in the high barrier polyolefin masterbatch in an amount of about 0.2 wt % to about 25 wt % and the hydrocarbon resin is present in the high barrier polyolefin masterbatch in an amount of about 2.5 wt % to about 70 wt %.

[0040] In one or more embodiments of the methods described herein for preparing HCR MB, HBP MB, HBP composition or barrier layer, the hydrocarbon resin has a lower weight average molecular weight than polyethylene. Preferably, the hydrocarbon resin is derived from a crude olefin feed selected from the group consisting of a C5 olefin feed stream, a C9 olefin feed stream, a terpene olefin, a norbornene, pure monomers, and combinations thereof. Preferably, the hydrocarbon resin is a hydrogenated hydrocarbon resin or a cyclic olefin copolymer.

[0041] In one or more embodiments of the methods described herein for preparing NA MB, HBP MB, HBP composition or barrier layer, the nucleating agent is organic or inorganic. Preferably, the nucleating agent comprises a metal salt. Preferably, the nucleating agent comprises a metal salt of hydrogenated phthalate, a metal salt of dicycloheptane dicarboxylate, a branched alkyl phosphonic acid or a combination thereof. Preferably, the nucleating agent comprises a metal salt of hydrogenated phthalate. Preferably, the nucleating agent comprises a metal salt of hexahydrophthalate.

[0042] In another aspect, the present invention provides a kit comprising a nucleating agent masterbatch as described herein and a hydrocarbon resin or hydrocarbon resin masterbatch as described herein, wherein:

[0043] The nucleating agent is present in the nucleating agent masterbatch in an amount of about 0.1 wt % to about 30 wt %; and

[0044] The hydrocarbon resin is present in the hydrocarbon resin masterbatch in an amount of about 5 wt % to about 80 wt %.

[0045] In another aspect, the present invention provides a kit comprising a nucleating agent mixture as described herein and a hydrocarbon resin masterbatch as described herein, wherein:

[0046] The hydrocarbon resin is present in the hydrocarbon resin masterbatch in an amount of about 5 wt % to about 80 wt %.

[0047] In another aspect, the present invention provides a high barrier polyolefin masterbatch produced by the method described herein.

[0048] Other embodiments of the invention disclosed herein relate to a kit as described herein, or use of a high barrier polyolefin masterbatch as described herein to form a high barrier polyolefin composition, comprising the following steps:

[0049] blending a nucleating agent masterbatch and a hydrocarbon resin or a hydrocarbon resin masterbatch as described herein with a bulk polyolefin; or

[0050] blending a nucleating agent mixture as described herein and a hydrocarbon resin masterbatch with a bulk polyolefin; or

[0051] The high barrier polyolefin masterbatch described herein is blended with a bulk polyolefin.

[0052] Preferably, the bulk polyolefin is bulk polyethylene, such as bulk HDPE.

[0053] In another aspect, the present invention provides a high barrier polyolefin composition produced according to the invention disclosed herein, wherein the high barrier polyolefin composition comprises:

[0054] From about 0.01 wt % to about 1 wt % of a nucleating agent; and

[0055] From about 0.1 wt. % to about 10 wt. % hydrocarbon resin.

[0056] In various embodiments of the invention disclosed herein, the nucleating agent and the hydrocarbon resin are present in the HBP masterbatch, or the kit, or the HBP composition, or the barrier layer in a ratio of about 1:4 to about 1:200, preferably about 1:7 to about 1:150, more preferably about 1:10 to about 1:100, and even more preferably about 1:15 to about 1:50. In a preferred embodiment, the nucleating agent and the hydrocarbon resin are present in a ratio of about 1:4 to about 1:200. Preferably, the nucleating agent and the hydrocarbon resin are present in a ratio of about 1:10 to about 1:100.

[0057] In some embodiments, the density of one or both of the HDPE and bulk HDPE is from about 0.94 to about 0.97 g / cm 3 .

[0058] In a preferred embodiment, the HDPE has a melt flow index of about 0.08 to 40.0 g / 10 min, preferably about 0.08 to 10.0 g / 10 min.

[0059] In another aspect, the present invention provides a barrier layer formed from the high barrier polyolefin composition as described herein.

[0060] In preferred embodiments, the nucleating agent is present in the barrier layer in an amount of about 0.01 wt % to about 1 wt %, preferably about 0.02 wt % to about 0.7 wt %, preferably about 0.03 wt % to about 0.5 wt %, preferably about 0.03 wt % to about 0.2 wt %, or preferably about 0.05 wt % to about 0.2 wt %.

[0061] In preferred embodiments, the hydrocarbon resin is present in the barrier layer in an amount from about 0.1 wt % to about 10 wt %, preferably from about 0.2 wt % to about 9 wt %, preferably from about 0.3 wt % to about 8 wt %, preferably from about 0.5 wt % to about 7 wt %, preferably from about 0.5 wt % to about 6 wt %, preferably from about 0.5 wt % to about 5 wt %, preferably from about 0.5 wt % to about 4 wt %, preferably from about 0.7 wt % to about 3 wt %, or preferably from about 1 wt % to about 2 wt %.

[0062] In another aspect, the present invention provides a film comprising a barrier layer as described herein, wherein the film has a water vapor transmission rate measured by ASTM F1249-20 relative to a film of equivalent thickness not comprising a barrier layer as described herein that is reduced by at least about 10%. In a preferred embodiment, the film has a water vapor transmission rate measured by ASTM F 1249-20 relative to a film of equivalent thickness not having a barrier layer of the present invention that is reduced by at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80%. In some embodiments, the film is a multilayer film or a monolayer film.

[0063] In another aspect, the present invention provides a method of reducing the water vapor transmission rate of a film, the method comprising incorporating a barrier layer as described herein into the film, wherein the film has a water vapor transmission rate measured by ASTM F 1249-20 that is reduced by at least about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80% relative to a film of equivalent thickness without the barrier layer as described herein.

[0064] In another aspect, the present invention provides a method for reducing the water vapor transmission rate and oxygen transmission rate of a polyethylene film, the method comprising the steps of:

[0065] A blend comprising polyethylene and no greater than 10 weight percent of a composition is melt mixed, wherein the composition is formed by mixing:

[0066] a nucleating agent masterbatch comprising a nucleating agent uniformly dispersed in a polyolefin; and

[0067] A hydrocarbon resin masterbatch comprising a hydrocarbon resin uniformly dispersed in a polyolefin,

[0068] The hydrocarbon resin masterbatch and the nucleating agent masterbatch are combined in a ratio of about 1:5 to about 60:1.

[0069] In another aspect, the present invention provides a method for reducing the water vapor transmission rate and oxygen transmission rate of a polyethylene film, the method comprising the steps of:

[0070] A blend comprising not less than 90 weight percent polyethylene and not more than 10 weight percent of a composition is melt mixed, wherein the composition is formed by mixing:

[0071] a nucleating agent masterbatch comprising a nucleating agent uniformly dispersed in a polyolefin; and

[0072] A hydrocarbon resin having a lower molecular weight than polyethylene,

[0073] The hydrocarbon resin and the nucleating agent masterbatch are combined in a ratio of about 1:5 to about 60:1.

[0074] In another aspect, the present invention provides a method for reducing the water vapor transmission rate and oxygen transmission rate of a polyethylene film, the method comprising the steps of:

[0075] A blend comprising not less than 90 weight percent polyethylene and not more than 10 weight percent of a composition comprising:

[0076] a nucleating agent uniformly dispersed in the polyolefin; and

[0077] A hydrocarbon resin masterbatch comprising a hydrocarbon resin uniformly dispersed in a polyolefin,

[0078] The hydrocarbon resin masterbatch and the nucleating agent are combined in a ratio of about 5:1 to about 150:1.

[0079] In another aspect, the present invention provides a composition prepared by melt mixing a nucleating agent masterbatch and a hydrocarbon resin, the nucleating agent masterbatch comprising a nucleating agent uniformly dispersed in a polyolefin, wherein the hydrocarbon resin and the nucleating agent masterbatch are combined in a ratio of about 1:5 to about 60:1.

[0080] In a preferred embodiment, the synergistic effect provided by the present invention between the nucleating agent and the hydrocarbon resin is at least 5% greater than the additive effect of the nucleating agent and the hydrocarbon resin, preferably at least 10% greater, 15% greater, 20% greater, 25% greater, 30% greater, 35% greater, 40% greater, 45% greater or 50% greater. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 is a graph showing thickness normalized water vapor transmission rate (WVTR) for films according to embodiments of the present invention as described in Table 1 and comparative films produced using alternative processes.

[0082] Figure 2 A schematic diagram illustrating a non-limiting embodiment of the present invention is shown:

[0083] (a) blending a polyolefin and a nucleating agent (NA) mixture using a melt mixer to produce a nucleating agent masterbatch (NAMB);

[0084] (b) blending a polyolefin and a hydrocarbon resin (HCR) using a melt mixer to produce a hydrocarbon resin masterbatch (HCR MB);

[0085] (c) using a melt mixer Figure 2 (a)NAMB and Figure 2 (b) and HCR MB were blended to produce a high barrier polyolefin masterbatch (HBP MB).

[0086] (d) The NA mixture, HCR and polyolefin are blended using a melt mixer to produce a high barrier polyolefin masterbatch (HBPMB).

[0087] Figure 3 is a schematic diagram of one embodiment of the present invention, wherein HBP MB and bulk HDPE are blended using a melt mixer to produce a high barrier polyolefin (HBP) composition.

[0088] Figure 4is a schematic diagram of one embodiment of the present invention wherein NAMB, HCR or HCRMB and bulk HDPE are blended using a melt mixer to produce a HBP composition suitable for forming a barrier layer.

[0089] Figure 5 A representative melt mixer in the form of a twin screw extruder is shown, which can be used to prepare any one or more of the masterbatch compositions and HBP compositions as described herein. As shown, the components to be melt mixed can be fed through port 1. The HCR components can be added through ports 2 and 3 by side arm feeders. The emission of volatiles or gaseous materials can be optionally directed through ports 4 and 5.

[0090] Figure 6 is a graph showing the effect of different mixing methods on water vapor transmission rate when using the same amount of nucleating agent and hydrocarbon resin. DETAILED DESCRIPTION

[0091] definition

[0092] As used herein, the singular forms "a", "an", and "the" refer to both the singular and the plural, unless explicitly stated to refer to the singular only.

[0093] As used herein, the term "about" and the use of general ranges, whether or not qualified by the term "about", mean that the numbers understood are not limited to the exact numbers recited herein, and are intended to refer to values ​​substantially within the cited ranges while not departing from the scope of the invention. As used herein, one of ordinary skill in the art will understand that "about" allows for small or insubstantial changes that reflect an appropriate level of precision depending on the context in which it is used. If the use of the term is not clear to one of ordinary skill in the art given the context in which the term is used, "about" will mean no more than plus or minus 10% of the particular term.

[0094] As used herein with respect to a material such as a layer, the term "barrier" means that the material controls the permeation of one or more molecules or compounds, which may be gases, vapors or liquids, including but not limited to oxygen and water vapor.

[0095] As used herein, the term "includes" or similar terms are intended to mean a non-exclusive inclusion / comprising, such that a method, process, system, product, composition, or apparatus that includes a list of integers includes not only these integers but may also include other integers that are not listed.

[0096] As used herein, the term "consisting of is an exclusive term and means consisting of only.

[0097] As used herein, the term "consisting essentially of" means that integers other than the recited integers may be included and these integers do not substantially change or affect the characteristics or functions of the method, process, system, product, composition, or apparatus.

[0098] Unless otherwise stated, all percentages (%) described herein are percentages by weight (w / w).

[0099] Unless otherwise indicated, polymer molecular weights referred to herein are weight average molecular weight (MW).

[0100] As used herein, the term "masterbatch" refers to a concentrated or premixed composition of a particular additive or mixture of additives, wherein the components are dispersed (preferably to achieve a substantially uniform dispersion) in a carrier material. In the context of this specification, the carrier material is a polyolefin.

[0101] As used herein, term " polyolefin " refers to the polymer of olefin monomer.Polyolefin can be homopolymer or copolymer." homopolymer " polyolefin refers to the polymer that is basically (that is, at least 90 weight %, preferably at least 95 weight %, more preferably at least 97 weight %) composed of olefin, and therefore homopolymer preferably mainly comprises described olefin." copolymer " polyolefin refers to the polymer formed by a kind of olefin and at least one other olefin copolymerization.The limiting examples of polyolefin include polyethylene, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene linear low density polyethylene (mLLDPE), ultra low density linear polyethylene (VLLDPE), ethylene vinyl acetate (EVA) and plastomer.

[0102] As used herein, the term "bulk high density polyethylene" ("bulk HDPE") refers to a masterbatch composition compounded into HDPE to form a HBP composition.

[0103] The term "HBP composition" as used herein comprises a nucleating agent and a hydrocarbon resin, and refers to the mixture produced when bulk HDPE is blended or mixed with a HBP masterbatch or a nucleating masterbatch and a hydrocarbon resin masterbatch composition.

[0104] As used herein, the term "film" can refer to a substantially planar material of any thickness. In some embodiments, the film described herein can be a substantially planar material having an average thickness of no more than about 500 μm, such as about 10 μm to about 500 μm, preferably about 20 μm to about 200 μm, or about 25 μm to about 100 μm, or about 30 μm to about 80 μm, or about 35 μm to about 70 μm, or about 40 μm to about 60 μm. The film of the present invention can be a monolayer or multilayer film, for example, in the form of a substantially planar sheet or net. It can also be considered that the film of the present invention is in the form of a non-planar arrangement or shape, for example, the film can include one or more layers in the article formed by a molding process such as blow molding or injection molding. Injection molding can be used to prepare parts and shells, such as caulking guns and sealant boxes, and blow molding containers, such as bottles.

[0105] As used herein, the term "layer" refers to a discrete film component having a substantially uniform composition. For a monolayer film, the terms "film" and "layer" will be synonymous. A "layer" or "barrier layer" may also be in a non-planar arrangement or shape.

[0106] As used herein, the term "multilayer" refers to multiple layers in a single-layer film structure. These layers can be bonded together by any conventional means known in the art, such as coextrusion, lamination, coating, or a combination of the like.

[0107] As used herein, the term "substantially" means mainly or mostly to a great or significant extent. That is, the term "substantially" is used to define that there may be slight variations, so that a parameter, measurement, condition or feature is not absolutely 100% or slightly less than 100% (e.g., 90%, 95%, 98%, 99%), or there may be slight insubstantial variations.

[0108] As used herein, the term "synergistic effect" refers to an effect or result, when produced by two or more components, that is greater than the sum of the effects of each component when used alone. For example, when used to prepare a barrier layer according to the invention disclosed herein, the synergistic combination of a hydrocarbon resin and a nucleating agent improves the barrier properties of the barrier layer to a greater extent than the additive or cumulative effect of the improvements resulting from the use of the hydrocarbon resin and the nucleating agent.

[0109] As used herein, the term "melt compounding" or "melt mixing" refers to the process of blending two or more components to form a compound or composition, typically wherein one or more properties, such as stiffness, puncture resistance or tear resistance, rheological properties such as melt flow index, melt flow ratio, complex viscosity, processability, fluidity, crystallinity, permeability, porosity, etc., are changed in the resulting compound or composition. Those skilled in the art will appreciate that these properties can be measured or analyzed directly or indirectly during melt compounding or melt mixing, which enables the blending parameters (such as residence time, temperature, mixing energy intensity, specific energy input, production rate, etc.) to be adjusted during blending to obtain the desired properties, or blending to be stopped once the desired properties are obtained.

[0110] As used herein, when referring to a composition, the term "homogeneous" means that the components within the composition are substantially uniformly distributed throughout the composition. Homogeneity can also refer to the dispersion or distribution of components within different phases, such as crystalline and amorphous phases, as well as the interfaces and interactions between different phases. Preferably, homogeneity is achieved by dynamic melt mixing, shear and extensional mixing, which are achieved by techniques such as twin-screw compounding, single-screw compounding, twin-roll milling, etc.

[0111] abbreviation

[0112] The following abbreviations used throughout this specification have the following meanings:

[0113] "NA" means "nucleating agent".

[0114] "MB" means "masterbatch".

[0115] "HCR" means "hydrocarbon resin".

[0116] "HHCR" means "hydrogenated hydrocarbon resin".

[0117] "HBP" means "High Barrier Polyolefin".

[0118] "HDPE" means "high-density polyethylene."

[0119] "MFI" means "Melt Flow Index".

[0120] "MFR" means "melt flow ratio".

[0121] "OTR" means "oxygen transmission rate".

[0122] "WVTR" means "water vapor transmission rate".

[0123] Description of the implementation plan

[0124] The present invention generally relates to methods of making films having barrier properties. The premise of the present invention is the surprising discovery that polyolefins, such as polyethylene, containing a mixture of a nucleating agent and a relatively low concentration of a hydrocarbon resin (particularly, a concentration below the threshold concentration considered essential in the prior art) can achieve suitable or improved barrier properties balanced with good mechanical properties and processability.

[0125] In particular, it has been discovered that hydrocarbon resins and nucleating agents can act synergistically to improve the barrier properties of barrier layers containing these components, including any one or more of the properties described herein, such as water vapor transmission rate, oxygen transmission rate, rheological properties, processability, etc. That is, the combination of hydrocarbon resins and nucleating agents according to the present invention can improve the barrier properties of the barrier layer better than the additive or cumulative effects of the hydrocarbon resin and the nucleating agent.

[0126] When hydrocarbon resin is blended with polyolefin, nucleator is blended with polyolefin, hydrocarbon resin and nucleator are blended with polyolefin together, or masterbatch comprising hydrocarbon resin and nucleator is blended with bulk resin, or two independent masterbatches, i.e., nucleator masterbatch and hydrocarbon resin masterbatch are blended, by modifying the blending parameters of melt compounding or melt mixing process, surprisingly found synergy. In a preferred embodiment, by blending the masterbatch comprising nucleator and hydrocarbon resin or two independent masterbatches comprising hydrocarbon resin and nucleator respectively with bulk resin, realize synergy. In a preferred embodiment, one or more blending parameters can be modified, such as residence time, temperature, mixing energy intensity, specific energy input and productivity, to realize sufficiently uniform dispersion, thereby produce synergy between hydrocarbon resin and nucleator. Preferably, the residence time of melt compounding or melt mixing process is changed so that sufficiently uniform dispersion can be formed to produce synergy.

[0127] Without wishing to be bound by any theory, it is believed that a hydrocarbon resin, preferably a hydrogenated hydrocarbon resin, dispersed in a polyolefin, such as polyethylene, preferably HDPE, can help render the amorphous phase of the polyolefin less permeable to elements such as oxygen and water vapor, while at the same time enhancing the dispersion of the crystalline phase within the polymer by altering the rheology of the polymer, thereby making it more amenable to melt relaxation during extrusion and molding processes, which can help enhance barrier properties if the resin has been effectively nucleated. In this manner, the hydrocarbon resin can thus enhance the effect of the nucleating agent in the polyolefin, and thus help further reduce oxygen and / or water vapor permeation and go beyond an additive or cumulative effect, i.e., produce a synergistic effect. Based on the conventional understanding that hydrocarbon resins are limited to being dispersed in and affecting the amorphous phase, thereby limiting any effect on the crystalline phase and the nucleating agent dispersed therein, the present invention provides an unexpected result demonstrating a synergistic effect not taught or suggested in the prior art.

[0128] Those skilled in the art will be able to recognize when an appropriate degree of uniformity has been achieved using conventional techniques, for example, by measuring one or more physical properties of the composition during or after the melt compounding or melt mixing process. In addition, those skilled in the art will be able to modify one or more blending parameters to achieve uniformity in the composition sufficient to produce the synergistic effects of the present invention. Exemplary parameters include, for example, residence time, mixing energy input, melt temperature, and mixing time, etc. Those skilled in the art will understand how parameters such as mixing energy input, melt temperature, and mixing time relate to achieving uniformity in a melt mixer.

[0129] In practicing the present invention, one skilled in the art may sample at appropriate time intervals during the course of the blending / mixing step to determine whether the blending / mixing parameters (e.g., residence time) are sufficient to produce the desired synergistic effect. For example, one skilled in the art may compare the WVTR of films prepared from samples extracted during blending to determine whether the desired characteristic threshold has been reached. If not, the blending process may be continued until subsequent samples confirm that the desired characteristics (e.g., WVTR, OTR, rheology, etc.) have been achieved. Preferably, the mixing / blending process will continue until the sample shows that the WVTR and / or OTR reflect a synergistic effect caused by NA and HCR, rather than an additive effect.

[0130] Preferred embodiments disclosed herein relate to the use of nucleating agents and hydrocarbon resins in defined ratios and / or amounts. In some embodiments, the synergistic effect is at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% greater than the cumulative effect of the hydrocarbon resin and the nucleating agent when used alone.

[0131] Advantageously, the method of preparing the masterbatch composition can promote substantially uniform dispersion of the nucleating agent while using a reduced amount or concentration of hydrocarbon resin (e.g., less than 10% w / w HCR concentration) to achieve improved barrier film properties such as lower WVTR balanced with good mechanical properties such as puncture resistance and tear resistance when the masterbatch composition is used. This is in contrast to the conventional understanding in the art that a relatively high concentration of HCR of at least about 10%-20% w / w is required to achieve suitable WVTR performance, such as about 30% reduction in WVTR in a typical film.

[0132] In a preferred embodiment, the present invention relates to a method for preparing a masterbatch composition comprising a substantially uniform blend of the constituent components. In other embodiments, the present invention relates to the use of such a masterbatch composition for forming a high barrier polyolefin (HBP) composition, and the use of the HBP composition for forming a HBP layer in a polyolefin film.

[0133] Masterbatch technology is a particularly effective technology for preparing the high barrier polyolefin (HBP) layer according to the present invention. Advantageously, using masterbatch technology to prepare the barrier layer in the film can provide one or more benefits, such as improving the dispersion of the nucleating agent and / or hydrocarbon resin in the polyolefin such as HDPE, improving the crystallization characteristics of the resulting barrier layer, and promoting the effectiveness of the compounding, melt mixing and / or extrusion process.

[0134] In preferred embodiments, methods of preparing masterbatch compositions as described herein can provide efficient and substantially uniform nucleation of polyolefins such as HDPE, even when hydrocarbon resins are simultaneously introduced. In other embodiments, a method of preparing a masterbatch composition comprising both a nucleating agent and a hydrocarbon resin, or a separate nucleating agent masterbatch and a hydrocarbon masterbatch to be used simultaneously or sequentially, is provided. Such methods can balance the necessary amounts of each component while maintaining suitable processability requirements in such masterbatches. When such masterbatches are used to form a barrier layer, films comprising the barrier layer can achieve significantly improved barrier properties while maintaining good mechanical properties.

[0135] Thus, in preferred embodiments, such methods of preparing masterbatches and the use of masterbatches in methods of preparing barrier layers and barrier films can provide overall cost feasibility in production. Advantageously, embodiments of the present invention provide blending components in selected amounts or proportions, which can achieve a substantially uniform or consistent dispersion of the hydrocarbon resin and the nucleating agent in a polyolefin such as HDPE. In other embodiments, such methods of preparing masterbatches and methods of using masterbatches in preparing barrier layers can advantageously reduce the amount of hydrocarbon resin required to provide the desired barrier layer resistance, particularly in terms of WVTR, while still maintaining good mechanical properties, such as puncture resistance and tear resistance. A reduction in the amount or concentration of hydrocarbon resin can reduce overall manufacturing costs, which provides a significant commercial advantage.

[0136] Tear strength (in both the longitudinal and transverse directions) is the ability of a film to withstand the propagation of a defect or crack in the film. It is an important property in many film applications. Poorly made films may have an undesirable tendency to break easily due to orientation effects once a defect or crack appears in the film. Tear strength, or more specifically, tear propagation resistance, is usually measured in two directions, the longitudinal and transverse directions, by a pendulum in the Elmendorf test. This test measures the energy required for a tear to propagate into a small crack in a film sample.

[0137] Puncture resistance refers to the ability of a film to resist damage and puncture by protrusions and pointed structures that tend to induce high stress areas in the material. This property is typically measured by puncture energy, which is a measure of the maximum force or energy required to penetrate a material. This type of biaxial stress is seen in packaging films when packaging hard protrusions such as granular dry foods like cereals and pet food, as well as frozen vegetables.

[0138] Other embodiments disclosed herein advantageously allow for the use of hydrocarbon resins in smaller amounts (eg, less than 10% w / w) than previously believed necessary in the prior art, while still maintaining or improving the resulting barrier layer properties.

[0139] In a preferred embodiment, the process according to the present invention improves the dispersion of the nucleating agent and / or hydrocarbon resin within the masterbatch composition and / or with the bulk HDPE in the resulting high barrier polyolefin composition, thereby improving the crystallization characteristics of the resulting barrier layer.

[0140] In a preferred embodiment, the process of the present invention may include an extended residence time in a melt mixer, including a twin screw extruder or a single screw extruder.

[0141] In one or more embodiments, the present invention utilizes an efficient method of melt mixing or melt compounding one or more of a hydrocarbon resin, a nucleating agent, a HCR MB, a NA MB, or a HBP MB with a bulk HDPE. In a preferred embodiment, masterbatch technology can be used to produce a substantially uniform or consistent dispersion of a hydrocarbon resin and / or a nucleating agent in a polyolefin such as HDPE. In a preferred embodiment, masterbatch technology can be used to produce a substantially uniform or consistent dispersion of a hydrocarbon resin and / or a nucleating agent in a bulk HDPE in a resulting high barrier polyolefin composition to produce a barrier layer. The use of masterbatch technology in accordance with the present invention unexpectedly enables the production of a barrier film having a reduced WVTR that contains a relatively low concentration of hydrocarbon resin.

[0142] Advantageously, when the masterbatch composition is used to prepare a barrier layer for a film, the method of preparing the masterbatch composition as described herein can impart to the film a water vapor transmission rate of no more than about 4 g / m2 measured at about 38° C. and 90% external relative humidity. 2 / sky.

[0143] In one or more embodiments, a HBP composition suitable for forming a barrier layer can be prepared by melt compounding HCR MB and NA MB into bulk HDPE in an appropriate extrusion device to form the HBP composition. The amounts of HCRMB and NA MB can be selected to achieve the desired ratio of HCR and NA in the barrier layer. The extrusion device can include a single-pass extruder or a multi-pass extruder, preferably a single-pass extruder. In a preferred embodiment, the extrusion device is a twin-screw extruder.

[0144] By mixing a nucleating agent and / or a hydrocarbon resin with a polyolefin such as HDPE to form a masterbatch, the nucleating agent or hydrocarbon resin, respectively, can be incorporated directly during processing. Thus, the use of a masterbatch eliminates the need for a separate compounding step to incorporate the nucleating agent or hydrocarbon resin into the bulk HDPE. For economic reasons, it is preferred to achieve the desired HCR and / or NA concentration in the masterbatch without compromising the ability of the masterbatch to be uniformly blended into the bulk HDPE during the melt mixing and / or extrusion process. In a preferred embodiment, it is desirable to achieve as high an HCR content as possible in the masterbatch while still balancing the desired properties and cost of the resulting HBP composition.

[0145] As is well known, nucleating agents are generally difficult to disperse directly into HDPE due to relatively poor miscibility. The use of masterbatch technology to pre-disperse the nucleating agent in a carrier resin, such as a polyolefin such as HDPE as a concentrate to produce a substantially uniform dispersion of the nucleating agent in the masterbatch is another advantage of the present invention, particularly when the nucleating agent masterbatch is blended with a hydrocarbon resin masterbatch to form an HBP masterbatch, which can then be blended with bulk HDPE to form an HBP composition that can be used to form a barrier layer or a film containing a barrier layer. Advantageously, the use of a masterbatch enables small amounts of NA to be dispersed in a carrier resin in a convenient and controllable manner.

[0146] Masterbatch Technology

[0147] The term "masterbatch" as used herein with respect to nucleating agent (NA) or hydrocarbon resin (HCR) or a combination of NA and HCR refers to a composition containing a relatively high concentration of NA, HCR or a combination of NA and HCR in a polyolefin resin, preferably a polyethylene resin, more preferably HDPE.

[0148] Typically, a hydrocarbon resin masterbatch (HCR MB) may contain from about 5% to about 80% w / w, or from about 2.5% to about 80% w / w, or from about 2.5% to about 70% w / w, or from about 2.5% to about 60% w / w, or from about 10% to about 70% w / w, or from about 15% to about 65% w / w, or from about 20% to about 60% w / w, or from about 5% to about 50% w / w, or from about 7.5% to about 45% w / w, or from about 10% to about 40% w / w, or from about 30% to about 50% w / w, or from about 25% to about 55% w / w of HCR, with the remainder being a polyolefin resin as described herein and optionally one or more conventional additives.

[0149] Typically, the nucleating agent masterbatch (NA MB) may contain from about 0.1% to about 30% w / w, or from about 0.2% to about 25% w / w, or from about 0.3% to about 25% w / w, or from about 0.2% to about 15% w / w, or from about 0.3% to about 20% w / w, or from about 0.3% to about 15% w / w, or from about 0.5% to about 20% w / w, or from about 0.5% to about 10%, or from about 0.3% to about 10% w / w of nucleating agent, the remainder being a polyolefin resin as described herein and optionally one or more conventional additives.

[0150] Depending on the scale, an appropriate amount (eg, part or all) of NA MB and / or HCR MB may be blended with bulk HDPE to obtain a desired amount or concentration of nucleating agent and / or hydrocarbon resin in the resulting HBP masterbatch or HBP composition.

[0151] One advantage of the present invention is that it can enable the addition of small amounts of nucleating agents and / or hydrocarbon resins to bulk HDPE during the extrusion process in such a way as to achieve homogeneous mixing, preferably resulting in improved barrier properties. Accordingly, embodiments of the present invention relate to:

[0152] A process for preparing a high barrier polyolefin masterbatch (HBP MB) composition comprising a nucleating agent and a hydrocarbon resin in a polyolefin carrier, preferably a HDPE resin;

[0153] A process for preparing a nucleating agent masterbatch (NA MB) comprising a nucleating agent in a polyolefin carrier, preferably a HDPE resin, and a hydrocarbon resin masterbatch (HCR MB) comprising a hydrocarbon resin in a polyolefin carrier, preferably a HDPE resin;

[0154] A process for preparing a HBP MB composition formed by melt mixing NAMB and HCR MB as described herein, or by melt mixing NA and HCR with a polyolefin carrier, preferably a HDPE resin,

[0155] Among other things, the process provides for a substantially uniform dispersion of the components in the resulting masterbatch.

[0156] The masterbatch composition prepared according to these methods can be blended with the bulk HDPE resin used to form the barrier layer. Therefore, the polyolefin carrier in the masterbatch composition is also blended with the bulk HDPE resin.

[0157] In a preferred embodiment, the polyolefin carrier is selected to provide a resulting viscosity in the masterbatch composition that is lower than or close to the viscosity of bulk HDPE, preferably to facilitate blending between the masterbatch composition and bulk HDPE.

[0158] In another embodiment, the polyolefin carrier in the nucleating agent masterbatch has a lower viscosity than the bulk HDPE. In another embodiment, the polyolefin carrier in the nucleating agent masterbatch is a HDPE having a higher MFI than the bulk HDPE.

[0159] In other embodiments, the polyolefin carrier in the hydrocarbon resin masterbatch has a higher or similar viscosity than the bulk HDPE. In other embodiments, the polyolefin carrier in the hydrocarbon resin masterbatch is a HDPE having a lower or similar MFI than the bulk HDPE.

[0160] Delivery of nucleating agents and hydrocarbon resins via a masterbatch can be particularly advantageous because it can promote a more uniform dispersion of the desired amount of nucleating agent and / or hydrocarbon resin in the final HBP composition. In addition, delivery of nucleating agents and / or hydrocarbon resins via a masterbatch can also advantageously improve the crystallization characteristics of the resulting barrier layer. Delivery of nucleating agents and / or hydrocarbon resins via a masterbatch can also advantageously promote the effectiveness of compounding, melt mixing and / or extrusion processes for forming a barrier layer while maintaining good mechanical properties. In a preferred embodiment, the inventors have developed a method for preparing a masterbatch composition, and a method for using the masterbatch composition so prepared to form a barrier layer having one or more advantageous properties. For example, due to the use of relatively low levels of HCR, processability, mechanical properties such as stiffness are improved, and production costs are reduced.

[0161] NA Masterbatch

[0162] Another embodiment of the present invention is directed to a process for preparing a nucleating agent masterbatch (NAMB), and the resulting NAMB.

[0163] Preferably, the process provides a substantially uniform dispersion of the components in the resulting masterbatch.

[0164] In one or more preferred embodiments, the nucleating agent masterbatch comprises from about 0.1% to about 30% w / w, or from about 0.2% to about 25% w / w, or from about 0.2% to about 15% w / w, or from about 0.3% to about 25% w / w, or from about 0.3% to about 20% w / w, for example, from about 5% to about 15% nucleating agent.

[0165] In one or more embodiments, the nucleating agent masterbatch can include from about 0.1% w / w to about 1% w / w, or from about 1% w / w to about 3% w / w, or from about 3% w / w to about 5% w / w, or from about 5% w / w to about 7% w / w, or from about 7% w / w to about 8% w / w, or from about 8% w / w to about 10% w / w, or from about 10% w / w to about 12% w / w, or from about 12% w / w to about 14% w / w, or from about 14% w / w to about 16% w / w, or from about 16% w / w to about 18% w / w, or from about 18% w / w to about 20% w / w, or from about 20% w / w to about 22% w / w, or from about 22% w / w to about 25% w / w, or from about 25% w / w to about 30% w / w of nucleating agent.

[0166] In another embodiment, the present invention relates to a method comprising blending a nucleating agent mixture comprising a nucleating agent with a polyolefin carrier, preferably polyethylene, to form a nucleating agent masterbatch. More preferably, the polyethylene is a high density polyethylene (HDPE).

[0167] Preferably, the nucleating agent mixture comprises a nucleating agent and a polyolefin, preferably polyethylene. The polyethylene may be a polyethylene powder. In a preferred embodiment, the nucleating agent may be dry mixed with the polyethylene powder to form a nucleating agent mixture.

[0168] Preferably, the nucleating agent mixture comprises one or more additive components as described herein.

[0169] Another embodiment of the present invention is directed to a nucleating agent masterbatch produced by the method described herein.

[0170] Preferably, the nucleating agent masterbatch comprises one or more additive components as described herein.

[0171] Representative embodiments are shown in Figure 2 (a) In.

[0172] HCR Masterbatch

[0173] In another embodiment, the present invention is directed to a process for preparing a hydrocarbon resin masterbatch (HCR MB), and the resulting HCR MB.

[0174] In one or more preferred embodiments, the present invention is directed to a process comprising blending a hydrocarbon resin with a polyolefin carrier, preferably high density polyethylene (HDPE), to form a hydrocarbon resin masterbatch.

[0175] Preferably, the process provides a substantially uniform dispersion of the components in the resulting masterbatch.

[0176] In one or more preferred embodiments, the hydrocarbon resin masterbatch comprises from about 5% to about 80% w / w, preferably from about 10% to about 70% w / w, more preferably from about 20% to about 60% w / w, even more preferably from about 30% to about 50% w / w hydrocarbon resin.

[0177] In one or more embodiments, the hydrocarbon resin masterbatch can include from about 5% w / w to about 10% w / w, or from about 10% w / w to about 15% w / w, or from about 15% w / w to about 20% w / w, or from about 20% w / w to about 25% w / w, or from about 25% w / w to about 30% w / w, or from about 30% w / w to about 35% w / w, or from about 35% w / w to about 40% w / w, or from about 40% w / w to about 45% w / w, or from about 45% w / w to about 50% w / w, or from about 50% w / w to about 55% w / w, or from about 55% w / w to about 60% w / w, or from about 60% w / w to about 65% w / w, or from about 65% w / w to about 70% w / w, or from about 70% w / w to about 80% w / w of hydrocarbon resin.

[0178] Preferably, the hydrocarbon resin masterbatch comprises one or more additive components as described herein.

[0179] Another embodiment of the present invention is directed to a hydrocarbon resin masterbatch produced by the process described herein.

[0180] Representative embodiments of this aspect are shown in Figure 2 (b) in.

[0181] HBP Masterbatch

[0182] In a further embodiment, the present invention is directed to a method for preparing a high barrier polyolefin (HBP) masterbatch composition, which can be used to form a barrier layer in a film.

[0183] HBP masterbatch (HBP MB) refers to a concentrated composition comprising a nucleating agent and a hydrocarbon resin dispersed in a polyolefin carrier, preferably polyethylene. More preferably, the polyethylene is a high density polyethylene (HDPE). In one embodiment, HBP MB can be produced by blending NA MB or a mixture of NA with HCR MB or HCR. In another embodiment, HBP MB can be produced by blending NA and HCR with HDPE.

[0184] In various embodiments, the HBP masterbatch comprises one or more nucleating agents, preferably one nucleating agent; one or more hydrocarbon resins, preferably one hydrocarbon resin, and the remainder of the HBP masterbatch composition comprises a polyolefin carrier, preferably polyethylene, more preferably HDPE, and optionally one or more conventional additives described herein.

[0185] Preferably, the nucleating agent is present in the HBP masterbatch in an amount of about 0.1% to about 30% w / w, or about 0.2% to about 25% w / w, or about 0.3% to about 25% w / w, or about 0.2% to about 15% w / w, or about 0.3% to about 20% w / w, or about 0.3% to about 15% w / w, or about 0.5% to about 20% w / w, or about 0.5% to about 10%, or about 0.3% to about 10% w / w.

[0186] Preferably, the HCR is present in the HBP masterbatch in an amount of about 5% to about 80% w / w, or about 2.5% to about 80% w / w, or about 2.5% to about 70% w / w, or about 2.5% to about 60% w / w, or about 10% to about 70% w / w, or about 15% to about 65% w / w, or about 20% to about 60% w / w, or about 5% to about 50% w / w, or about 7.5% to about 45% w / w, or about 10% to about 40% w / w, or about 30% to about 50% w / w, or about 25% to about 55% w / w.

[0187] In one or more embodiments, the HBP masterbatch may include from about 0.2% w / w to about 2% w / w, or from about 2% w / w to about 4% w / w, or from about 4% w / w to about 6% w / w, or from about 6% w / w to about 8% w / w, or from about 8% w / w to about 10% w / w, or from about 10% w / w to about 12% w / w, or from about 12% w / w to about 14% w / w, or from about 14% w / w to about 16% w / w, or from about 16% w / w to about 18% w / w, or from about 18% w / w to about 20% w / w, or from about 20% w / w to about 22% w / w, or from about 22% w / w to about 25% w / w of a nucleating agent.

[0188] In one or more embodiments, the HBP masterbatch can include from about 2.5% w / w to about 5% w / w, or from about 5% w / w to about 10% w / w, or from about 10% w / w to about 15% w / w, or from about 15% w / w to about 20% w / w, or from about 20% w / w to about 25% w / w, or from about 25% w / w to about 30% w / w, or from about 30% w / w to about 35% w / w, or from about 35% w / w to about 40% w / w, or from about 40% w / w to about 45% w / w, or from about 45% w / w to about 50% w / w, or from about 50% w / w to about 60% w / w, or from about 60% w / w to about 70% w / w of hydrocarbon resin.

[0189] In one aspect, the present invention relates to a method for producing a high barrier polyolefin masterbatch (HBP MB) comprising a nucleating agent (NA) and a hydrocarbon resin (HCR), the method comprising the steps of:

[0190] (a) blending a nucleating agent mixture comprising a nucleating agent with a first polyolefin to form a nucleating agent masterbatch (NA MB);

[0191] (b) blending a hydrocarbon resin into a second polyolefin to form a hydrocarbon resin masterbatch (HCR MB); and

[0192] (c) blending the nucleating agent masterbatch and the hydrocarbon resin masterbatch to form a HBP MB.

[0193] In another aspect, the present invention relates to a method for producing a high barrier polyolefin masterbatch (HBP MB) comprising a nucleating agent (NA) and a hydrocarbon resin (HCR), the method comprising the steps of:

[0194] A nucleating agent masterbatch or a mixture of nucleating agents is mixed with a hydrocarbon resin or a hydrocarbon resin masterbatch and optionally a polyolefin, such as polyethylene, such as HDPE, to form a high barrier polyolefin masterbatch (HBP MB)

[0195] Preferably, the first polyolefin is polyethylene, more preferably HDPE.

[0196] Preferably, the second polyolefin is polyethylene, more preferably HDPE.

[0197] Step (a) and step (b) may be performed in any order.

[0198] Representative embodiments of this aspect of the invention are shown in Figure 2 (a)-2(c).

[0199] In one or more embodiments, the ratio of nucleating agent masterbatch to hydrocarbon resin masterbatch is from about 10: 1 to about 1: 100, or from about 25: 4 to about 1: 80, or from about 50: 9 to about 1: 70, or from about 5: 1 to about 1: 60, or from about 5: 1 to about 1: 50. Preferably, the ratio of nucleating agent masterbatch to hydrocarbon resin masterbatch is from about 5: 1 to about 1: 60, or from about 5: 1 to about 1: 50.

[0200] In another aspect, the present invention relates to a method for producing a high barrier polyolefin masterbatch (HBP MB) comprising a nucleating agent (NA) and a hydrocarbon resin (HCR), the method comprising the steps of:

[0201] (i) a nucleating agent mixture comprising a nucleating agent, (ii) a hydrocarbon resin, and (iii) a polyolefin are blended to form an HBPMB.

[0202] Preferably, the polyolefin is polyethylene, more preferably HDPE.

[0203] Representative embodiments of this aspect of the invention are shown in Figure 2 (d) in.

[0204] In some embodiments of the above aspects, the nucleating agent and the hydrocarbon resin are present in the masterbatch in a ratio of about 1:4 to about 1:200, preferably about 1:7 to about 1:150, more preferably about 1:10 to about 1:100 or about 1:15 to about 1:50.

[0205] In a preferred embodiment, the nucleating agent mixture comprises a nucleating agent and a polyolefin carrier, preferably polyethylene. The polyethylene can be a polyethylene powder. In a preferred embodiment, the nucleating agent is dry mixed with the polyethylene powder to form a nucleating agent mixture.

[0206] The first and second polyolefins can be the same or different. In some embodiments, the first and second polyolefins can have the same or different MFI. In some embodiments, the first and second polyolefins can have the same or different density. In some embodiments, the first and / or second polyolefins are polyethylene, preferably HDPE, wherein the HDPE is the same or different. In some embodiments, the first and second polyolefins are polyethylene, preferably HDPE, and each HDPE has the same or different MFI. In some embodiments, the first and second polyolefins are polyethylene, preferably HDPE, and each HDPE has the same or different density. In a preferred embodiment, the first polyolefin, preferably polyethylene, more preferably HDPE, has a higher melt index than the second polyolefin, preferably polyethylene, more preferably HDPE.

[0207] In other embodiments, the HBP masterbatch may be produced by blending a nucleating agent masterbatch (NA MB) and a hydrocarbon resin or hydrocarbon resin masterbatch (HCR MB) as described herein.

[0208] Aspects of the present invention also relate to a high barrier polyolefin masterbatch (HBP MB) produced by the process described herein.

[0209] Preferably, the method as described herein provides a substantially uniform dispersion of the nucleating agent and the hydrocarbon resin in the resulting masterbatch. Preferably, wherein the uniformity is sufficient to provide a synergistic effect between the nucleating agent and the hydrocarbon resin. Preferably, the HBP masterbatch comprises a synergistic combination of the nucleating agent and the hydrocarbon resin.

[0210] In a preferred embodiment, blending comprises melt mixing. Preferably, melt mixing is performed for a sufficient time, such as a residence time, to produce a substantially uniform dispersion.

[0211] In a preferred embodiment, the blending is performed using an extruder, such as a twin-screw extruder.

[0212] Masterbatch preparation

[0213] Masterbatches according to the present invention, including NAMB, HCR MB and HBP MB, can be prepared using the methods disclosed herein. General techniques and equipment for preparing masterbatches are also known to those skilled in the art, for example, and are also described in WO 00 / 56806 (Eastman), the entire contents of which are incorporated herein by cross-reference.

[0214] In a preferred embodiment, the masterbatch is formed by melt compounding. In one embodiment, the nucleating agent and hydrocarbon resin can be melt compounded in a polyolefin carrier such as polyethylene, preferably HDPE, to prepare a HBP masterbatch. Melt compounding techniques can also be used to prepare the barrier layer, for example by melt compounding the HBP masterbatch with bulk HDPE.

[0215] In preferred embodiments, melt blending is the technique used for masterbatch preparation because it advantageously enhances the effective dispersion of the nucleating agent and hydrocarbon resin in a polyolefin carrier such as polyethylene, preferably HDPE. Substantially uniform dispersion of the nucleating agent and hydrocarbon resin in the polyolefin carrier is preferred because the inventors surprisingly discovered that adequate dispersion, preferably uniform or uniform dispersion, of the nucleating agent and hydrocarbon resin within the polyolefin contributes to the desired barrier properties. Also surprisingly, the inventors discovered that improved desired barrier properties can be achieved with low ratios of hydrocarbon resin. In other embodiments, dry blending can be used for masterbatch preparation.

[0216] Preferably, the process as described herein provides a substantially uniform dispersion of the nucleating agent and the hydrocarbon resin in the resulting masterbatch. Preferably, wherein the uniformity is sufficient to provide a synergistic effect between the nucleating agent and the hydrocarbon resin.

[0217] In one or more embodiments, the masterbatch can be formed by melt compounding a selected amount of a nucleating agent and / or a hydrocarbon resin in a polyolefin carrier such as polyethylene, preferably HDPE, in a single-pass extruder or a multi-pass extruder, preferably a twin-screw extruder. In an exemplary embodiment, the barrel zone temperature of the twin-screw extruder is set to provide a constant melt temperature of about 150-220°C.

[0218] HBP Composition

[0219] In another aspect, the present invention relates to a method for producing a high barrier polyolefin (HBP) composition comprising a combination of a nucleating agent and a hydrocarbon resin, the method comprising: blending a nucleating agent (NA), a hydrocarbon resin (HCR) and a polyolefin carrier such as polyethylene, preferably HDPE to form a substantially uniform dispersion using a masterbatch composition as described herein. Preferably, wherein the uniformity is sufficient to provide a synergistic effect between the nucleating agent and the hydrocarbon resin. Preferably, the HBP composition comprises a synergistic combination of a nucleating agent and a hydrocarbon resin.

[0220] Preferably, the HBP composition comprises one or more additive components as described herein.

[0221] Figure 2-5 Various embodiments of this aspect are shown in .

[0222] The resulting HBP composition produced according to the embodiments disclosed herein can then be processed to form a barrier layer. Techniques for forming a barrier layer are described herein. In one embodiment, the barrier layer is formed by extrusion. Suitable extrusion techniques are known in the art, and representative techniques are described herein.

[0223] In one or more embodiments, blending can be achieved by melt compounding (e.g., melt mixing) the individual components to blend the components together. Melt compounding can be achieved using techniques and equipment known to those skilled in the art, such as, an extruder or other suitable blending equipment. The extruder can be a twin-screw extruder or a single-screw extruder. Preferably, the extruder is a twin-screw extruder.

[0224] In one or more embodiments, a suitable amount or ratio of nucleating agent masterbatch and hydrocarbon resin masterbatch can be blended with the bulk HDPE by melt compounding. The desired amount of nucleating agent and hydrocarbon resin can be introduced into the HBP composition for melt blending with the bulk HDPE by blending the NA masterbatch and the HCR masterbatch with the bulk HDPE. The NA masterbatch can be introduced into the bulk HDPE before or after the HCR masterbatch. Alternatively, the NA masterbatch and the HCR masterbatch can be introduced into the bulk HDPE at the same or different rates.

[0225] According to embodiments described herein, desired amounts or ratios of nucleating agent and hydrocarbon resin may be introduced into a HBP composition for melt compounding with bulk HDPE by adding (eg, blending) a HBP masterbatch containing the nucleating agent and hydrocarbon resin with bulk HDPE.

[0226] In one or more embodiments, the present invention relates to a method for producing a high barrier polyolefin (HBP) composition comprising the steps of:

[0227] (a) blending a mixture comprising a nucleating agent into a first polyolefin to form a nucleating agent masterbatch (NA MB);

[0228] (b) blending a hydrocarbon resin into a second polyolefin to form a hydrocarbon resin masterbatch (HCR MB);

[0229] (c) blending a nucleating agent masterbatch and a hydrocarbon resin masterbatch to form a high barrier polyolefin masterbatch (HBP MB);

[0230] (d) blending a high barrier polyolefin masterbatch (HBP MB) and bulk HDPE to form a high barrier polyolefin (HBP) composition.

[0231] In one or more embodiments, the present invention relates to a method for producing a high barrier polyolefin (HBP) composition comprising the steps of:

[0232] (a) blending a nucleating agent masterbatch or a nucleating agent mixture with a hydrocarbon resin or a hydrocarbon resin masterbatch and optionally a polyolefin, such as polyethylene, such as HDPE, to form a high barrier polyolefin masterbatch (HBP MB),

[0233] (b) blending a high barrier polyolefin masterbatch (HBP MB) and bulk HDPE to form a high barrier polyolefin (HBP) composition.

[0234] Preferably, the method as described herein provides a substantially uniform dispersion of the nucleating agent and the hydrocarbon resin in the HBP MB. Preferably, wherein the uniformity is sufficient to provide a synergistic effect between the nucleating agent and the hydrocarbon resin.

[0235] Representative implementations are Figure 2and 3 Shown in.

[0236] In one or more embodiments, the present invention relates to a method for producing a high barrier polyolefin (HBP) composition comprising the steps of:

[0237] (a) blending a mixture comprising a nucleating agent into a first polyolefin to form a nucleating agent masterbatch (NA MB);

[0238] (b) blending a hydrocarbon resin into a second polyolefin to form a hydrocarbon resin masterbatch (HCR MB);

[0239] (c) blending the nucleating agent masterbatch, the hydrocarbon resin masterbatch and the bulk HDPE to form a high barrier polyolefin (HBP) composition.

[0240] Preferably, the first polyolefin is polyethylene, more preferably HDPE.

[0241] Preferably, the second polyolefin is polyethylene, more preferably HDPE.

[0242] Preferably, the methods as described herein provide a substantially uniform dispersion of the nucleating agent and the hydrocarbon resin in the HBP composition. Preferably, wherein the uniformity is sufficient to provide a synergistic effect between the nucleating agent and the hydrocarbon resin.

[0243] Representative implementations are Figure 2 (a), 2(b) and 4.

[0244] With respect to the concentrations of these components in the respective masterbatch compositions, one skilled in the art can readily determine the appropriate amounts of the respective masterbatches and bulk HDPE to be blended together to produce a HBP composition having the desired amounts or concentrations of nucleating agent and hydrocarbon resin. In one or more embodiments, the amount of the nucleating agent masterbatch may be from about 0.04% to about 30% w / w of the HBP composition, and the amount of the hydrocarbon resin masterbatch may be from about 0.14% to about 70% w / w of the HBP composition.

[0245] In one or more embodiments, the HBP composition may comprise from about 0.04% w / w to about 0.1% w / w, or from about 0.1% w / w to about 0.5% w / w, or from about 0.5% w / w to about 1% w / w, or from about 1% w / w to about 3% w / w, or from about 3% w / w to about 5% w / w, or from about 5% w / w to about 7% w / w, or from about 7% w / w to about 8% w / w, or from about 8% w / w to about 10% w / w. 0% w / w, or about 10% w / w to about 12% w / w, or about 12% w / w to about 14% w / w, or about 14% w / w to about 16% w / w, or about 16% w / w to about 18% w / w, or about 18% w / w to about 20% w / w, or about 20% w / w to about 22% w / w, or about 22% w / w to about 25% w / w, or about 25% w / w to about 30% w / w of a nucleating agent masterbatch.

[0246] In one or more embodiments, the HBP composition may comprise from about 0.14% w / w to about 1% w / w, or from about 1% w / w to about 5% w / w, or from about 5% w / w to about 10% w / w, or from about 1% w / w to about 10% w / w, or from about 10% w / w to about 20% w / w, from about 20% w / w to about 25% w / w, or from about 25% w / w to about 30% w / w, or from about 3 0% w / w to about 35% w / w, or about 35% w / w to about 40% w / w, or about 40% w / w to about 45% w / w, or about 45% w / w to about 50% w / w, or about 50% w / w to about 55% w / w, or about 55% w / w to about 60% w / w, or about 60% w / w to about 65% w / w, or about 65% w / w to about 70% w / w of a hydrocarbon resin masterbatch.

[0247] In one or more embodiments, a nucleating agent masterbatch or nucleating agent mixture and a hydrocarbon resin or hydrocarbon resin masterbatch are blended with bulk HDPE to produce a HBP composition having a desired or suitable amount and distribution of nucleating agent and hydrocarbon resin dispersed in the HBP composition, particularly to achieve a synergistic effect.

[0248] In one or more embodiments, a suitable amount of HBP masterbatch can be blended with bulk HDPE by melt compounding. In one or more embodiments, an amount of HBP masterbatch from about 0.2% to about 75% w / w can be mixed with a desired amount of bulk HDPE resin to produce a HBP composition having a desired amount or ratio of nucleating agent and hydrocarbon resin dispersion.

[0249] In one or more embodiments, the HBP composition may comprise from about 0.2% w / w to about 2% w / w, or from about 2% w / w to about 4% w / w, or from about 4% w / w to about 6% w / w, or from about 6% w / w to about 8% w / w, or from about 8% w / w to about 10% w / w, or from about 10% w / w to about 12% w / w, or from about 12% w / w to about 14% w / w, or from about 14% w / w to about 16% w / w, or from about 16% w / w to about 18% w / w, or from about 18% w / w to about 20% w / w, or from about 20% w / w to about 22% w / w. w / w, or about 22% w / w to about 25% w / w, or about 25% w / w to about 30% w / w, or about 30% w / w to about 35% w / w, or about 35% w / w to about 40% w / w, or about 40% w / w to about 45% w / w, or about 45% w / w to about 50% w / w, or about 50% w / w to about 55% w / w, or about 55% w / w to about 60% w / w, or about 60% w / w to about 65% w / w, or about 65% w / w to about 70% w / w, or about 70% w / w to about 75% w / w of HBP masterbatch.

[0250] In one embodiment, the amount of HBP masterbatch blended with the bulk HDPE resin is about 7 wt %, based on the total weight of the masterbatch composition and HDPE.

[0251] In one or more preferred embodiments, the nucleating agent masterbatch comprises from about 0.1% to about 30% w / w nucleating agent.

[0252] In one or more embodiments, the nucleating agent masterbatch can include from about 0.1% w / w to about 1% w / w, or from about 1% w / w to about 3% w / w, or from about 3% w / w to about 5% w / w, or from about 5% w / w to about 7% w / w, or from about 7% w / w to about 8% w / w, or from about 8% w / w to about 10% w / w, or from about 10% w / w to about 12% w / w, or from about 12% w / w to about 14% w / w, or from about 14% w / w to about 16% w / w, or from about 16% w / w to about 18% w / w, or from about 18% w / w to about 20% w / w, or from about 20% w / w to about 22% w / w, or from about 22% w / w to about 25% w / w, or from about 25% w / w to about 30% w / w of nucleating agent.

[0253] In one or more preferred embodiments, the hydrocarbon resin masterbatch comprises from about 5% to about 80% w / w hydrocarbon resin.

[0254] In one or more embodiments, the hydrocarbon resin masterbatch can include from about 5% w / w to about 10% w / w, or from about 10% w / w to about 15% w / w, or from about 15% w / w to about 20% w / w, or from about 20% w / w to about 25% w / w, or from about 25% w / w to about 30% w / w, or from about 30% w / w to about 35% w / w, or from about 35% w / w to about 40% w / w, or from about 40% w / w to about 45% w / w, or from about 45% w / w to about 50% w / w, or from about 50% w / w to about 55% w / w, or from about 55% w / w to about 60% w / w, or from about 60% w / w to about 65% w / w, or from about 65% w / w to about 70% w / w, or from about 70% w / w to about 80% w / w of hydrocarbon resin.

[0255] In one or more embodiments, the ratio of nucleating agent masterbatch to hydrocarbon resin masterbatch is from about 10:1 to about 1:100, or from about 25:4 to about 1:80, or from about 50:9 to about 1:70, or from about 5:1 to about 1:60, or from about 5:1 to about 1:50.

[0256] Preferably, the nucleating agent mixture comprises a nucleating agent and polyethylene. The polyethylene can be a polyethylene powder. In a preferred embodiment, the nucleating agent is dry-mixed with the polyethylene powder to form a nucleating agent mixture.

[0257] In a preferred embodiment, the polyolefin is a polyethylene, preferably a high density polyethylene (HDPE). Therefore, in one or more embodiments, the bulk HDPE melt compounded with the nucleator masterbatch and the hydrocarbon resin masterbatch, with the hydrocarbon resin and the nucleator mixture, or with the nucleator masterbatch and the hydrocarbon resin to form the HBP composition may be the same or different from the HDPE contained in the respective masterbatch compositions. It is generally preferred that the polyolefin, preferably the HDPE, in the masterbatch composition is substantially linear without long chain branching. In a preferred embodiment, the polyolefin, preferably the HDPE in the masterbatch composition and the bulk HDPE blended with the masterbatch composition to form the HBP composition are of the same type or grade, as this can avoid or minimize incompatibility issues or the risk of dilution or degradation of the properties of the barrier layer that may result from the use of different types or grades of HDPE resins. Preferably, the polyolefin, preferably the HDPE, in the masterbatch composition, and the bulk HDPE are substantially linear without long chain branching.

[0258] Hydrocarbon resin

[0259] Hydrocarbon resin (HCR) that can be used for the present invention includes cycloolefin copolymer or the low molecular weight material of the crude olefin feed produced in the oil cracking process.The example of these crude olefin feeds includes that the average carbon number is 5 carbon atoms (C5 feed) of each olefin molecule, or each olefin molecule has the light olefin fraction of average 6-9 carbon atoms.It is also possible to use the hydrocarbon resin produced by the olefin stream rich in dicyclopentadiene (DCPD), the hydrocarbon resin produced by the limonene of citrus products for example derived from terpene olefins or the hydrocarbon resin derived from the polymerization of one or more pure monomer feeds selected from styrene, alpha-methyl styrene, 4-methyl styrene, norbornene and vinyl toluene.

[0260] In one or more embodiments, the weight average molecular weight (MW) of the hydrocarbon resin is lower than that of polyethylene. In some embodiments, the weight average molecular weight (MW) of the hydrocarbon resin is no more than about 5,000 Daltons, preferably no more than about 2,000 Daltons, more preferably no more than about 1,000 Daltons, and most preferably the weight average molecular weight of the hydrocarbon resin is from about 400 to about 800 Daltons.

[0261] The MW of a resin can be determined using techniques known to those skilled in the art including, for example, size exclusion chromatography (SEC) using polystyrene as a standard.

[0262] In some embodiments, it is preferred that the hydrocarbon resin is aliphatic in nature to aid its compatibility with the polyolefin carrier, preferably wherein the polyolefin is HDPE. Hydrocarbon resins of aliphatic type resins can be prepared by copolymerization with other unsaturated monomers such as ethylene or by catalytic hydrogenation to convert hydrocarbon resins having unsaturated characteristics. By hydrogenation, the unsaturated olefins and / or aromatic groups remaining in the hydrocarbon resin are converted into saturated species by reduction with hydrogen. The hydrogenation reaction can be carried out under various conditions, an example being at a temperature of about 150° C. to about 320° C., using a hydrogen pressure of about 50 to about 2,000 psi, in the presence of a catalyst such as Ni metal supported on carbon black.

[0263] In a preferred embodiment, the hydrocarbon resin described herein can be a hydrogenated hydrocarbon resin (HHCR) or a cyclic olefin copolymer. Such hydrogenated hydrocarbon resins can be partially or completely hydrogenated. In one embodiment, it may be desirable to have a hydrogenated resin with a small amount of residual unsaturated groups. For example, more than about 80%, preferably more than about 90%, and even more preferably more than about 95% of the residual olefins and / or aromatic groups in a preferred type of hydrogenated hydrocarbon resin are hydrogenated.

[0264] In one or more embodiments, the hydrocarbon resin comprises a hydrogenated hydrocarbon resin selected from the group consisting of a hydrogenated C5 resin, a C9 resin, a norbornene ethylene copolymer resin, a hydrogenated aromatic resin, and a hydrogenated dicyclopentadiene resin, or any combination thereof.

[0265] Representative examples of hydrocarbon resins are resins derived from the polymerization of crude C5 and / or C9 feedstocks that are hydrogenated. The C5 feedstock is an olefin stream produced during petroleum cracking, which includes hydrocarbon olefin components with about 5 carbon atoms per molecule. Examples of olefins found in the C5 feed include, but are not limited to: trans-1,3-pentadiene, cis-1,3-hexadiene, 2-methyl-2-butene, cyclopentadiene, cyclopentene, and dicyclopentadiene. The C9 feedstock is an olefin stream produced during petroleum cracking, which includes hydrocarbon olefin components with about 9 carbon atoms per molecule. Examples of olefins found in the C9 feed include, but are not limited to: styrene, α-methylstyrene, indene, various methyl-substituted indenes, 4-methylstyrene, β-methylstyrene, and ethylstyrene.

[0266] In one embodiment, the hydrocarbon resin comprises a hydrogenated C5 hydrocarbon resin, a hydrogenated C9 hydrocarbon resin, or a norbornene ethylene copolymer resin.

[0267] In another embodiment, the hydrocarbon resin comprises a hydrogenated C5 / C9 hydrocarbon resin.Such resins can be produced using techniques known in the art, such as by copolymerizing C5 and C9 feedstocks and hydrogenating the resulting resins, or by blending hydrogenated resins derived from such feedstocks.

[0268] Another example of a hydrocarbon resin suitable for use according to the present invention is a resin derived from an olefin feed polymerization rich in dicyclopentadiene (DCPD). A hydrocarbon resin rich in DCPD can be produced by thermally polymerizing an olefin stream containing about 50% to about 100% DCPD at a temperature of about 200° C. to about 325° C. to produce a resin product that can be hydrogenated to form a fully saturated material. In another embodiment, the hydrocarbon resin can include a hydrogenated dicyclopentadiene resin.

[0269] Another example of a hydrocarbon resin that can be used in accordance with the present invention is a resin derived from the polymerization of pure monomers such as styrene, alpha-methylstyrene, 4-methylstyrene, vinyltoluene, or any combination of these or similar pure monomer feedstocks. The product produced by such polymerization is aromatic in nature, but can be converted to an aliphatic type resin by catalytic hydrogenation in a manner similar to that described above. In another embodiment, the hydrocarbon resin may include a hydrogenated aromatic resin or a cycloolefin copolymer.

[0270] In another example, hydrocarbon resins suitable for use in accordance with the present invention may be derived from the polymerization of terpene olefins such as α-pinene, β-pinene or d-limonene. These resins are aliphatic type materials and generally do not require hydrogenation to achieve aliphatic properties.

[0271] Thus, in one or more embodiments, the hydrocarbon resin is selected from the group consisting of hydrogenated C5 resins, hydrogenated C9 resins, norbornene ethylene copolymer resins, hydrogenated aromatic resins, hydrogenated dicyclopentadiene resins, and combinations thereof.

[0272] Preferably, hydrogenated hydrocarbon resins suitable for use in the present invention have a low softening point, which is preferably below 180° C. The low softening point can help promote compatibility and interaction of the resin with the polyolefin in which the resin is dispersed, wherein the polyolefin is preferably HDPE.

[0273] The softening point of a hydrogenated hydrocarbon resin can be determined using methods and techniques known to those skilled in the art. An exemplary method for measuring the softening point of a resin is the ring and ball method described in ASTM E28.

[0274] In one or more embodiments, the softening point of the hydrogenated hydrocarbon resin measured according to ASTM E28 is less than about 160°C, preferably less than about 150°C, more preferably less than about 140°C, preferably about 124°C.

[0275] In a preferred embodiment, the hydrocarbon resin is a hydrogenated hydrocarbon resin, preferably the hydrogenated hydrocarbon resin has a softening point of less than about 140°C as measured according to ASTM E28.

[0276] A range of commercially available hydrogenated hydrocarbon resins may be suitable for use in the present invention. Representative, non-limiting examples of commercially available hydrogenated hydrocarbon resins include: Piccotac 1115, Eastotac TM H-100W, H-115W, H-130W and H-142W; Regalite TM R1090 and R1125 (available from Eastman Chemical Company); Arkon P100, Arkon P125, Arkon P140 (available from Arakawa Chemical Company, Japan); Bitoner LH 3115, LH3100, DH 1100, DH1120, LH3100W and LH2100W (available from Qingdao Bater Chemical Co., Ltd); Fuclear FD-100, Fuclear FD-120 (available from UPM Sun-Tack); Oppera TM and Escorez TM Resin (commercially available from ExxonMobil Chemical Company); HCR-D100 series hydrogenated DCPD resin (commercially available from PuyangTiancheng Chemical Company); Regalrez TMhydrocarbon resins (commercially available from Eastman Chemical Company); and Clearon P series resins (commercially available from Yasuhara Chemicals Japan).

[0277] Examples of commercially available hydrogenated hydrocarbon resins that may be particularly useful according to embodiments of the present invention include Escorez TM 5320、Escorez TM 5340, 8007F-04, Oppera TM PR100N and Oppera TM PR120.

[0278] An advantage of one or more embodiments of the present invention is that relatively small amounts of hydrocarbon resins can be incorporated into the barrier layer of the film of the present invention. Advantageously, it has been found that small amounts of hydrocarbon resins, particularly hydrogenated hydrocarbon resins, can be blended with nucleating agents and bulk HDPE to achieve significant improvements in barrier properties, particularly WVTR.

[0279] In one or more embodiments, the hydrocarbon resin may be included in the barrier layer in an amount of about 0.1 wt % to about 10 wt %, based on the total weight of the components in the barrier layer. In a specific embodiment, the barrier layer comprises 0.5 wt % to about 7 wt %, preferably 1 wt % to about 4 wt % hydrocarbon resin. Preferably, the hydrocarbon resin is a hydrogenated hydrocarbon resin.

[0280] Nucleating Agent

[0281] Nucleating agents are additives that form nuclei in a polymer melt, which promote crystal growth and the formation of small and numerous crystalline regions in the polymer as the polymer solidifies from the molten state.

[0282] According to the present invention, any suitable and effective nucleating agent can be used. Preferred nucleating agents are compatible with the polyolefin carrier and can be dispersed in the polyolefin, preferably wherein the polyolefin is polyethylene, preferably HDPE. Polyolefin-compatible nucleating agents, preferably HDPE-compatible nucleating agents, can be inorganic or organic. Combinations of two or more nucleating agents can be used. In a preferred embodiment, a single nucleating agent is used.

[0283] The inorganic nucleating agent can be a nano-sized particle inorganic material. Examples of inorganic nucleating agents include, but are not limited to, calcium carbonate; talc; barium sulfate; silicon dioxide; carbon particles, such as expanded graphite or carbon nanotubes; polyhedral oligomeric silsesquioxane (POSS); nanoclays, such as halloysite and montmorillonite; silicate minerals, such as vermiculite; and combinations thereof.

[0284] The organic nucleating agent can be a suitable organic material. Examples of organic nucleating agents include, but are not limited to, carboxylic acid metal salts, such as benzoic acid metal salts, phthalic acid metal salts, hydrogenated phthalic acid metal salts, and dicycloheptane dicarboxylic acid metal salts; phosphates; anthracene; zinc monoglyceride; benzoates; organic derivatives of dibenzylidene sorbitol; sorbitol acetals; metal salts of branched alkylphosphonic acids; cyclic organic phosphoric acid metal salts; and combinations thereof.

[0285] Further examples of nucleating agents are known to those skilled in the art and are described, for example, in WO 2022 / 226247, WO 2022 / 226249 and WO 2022 / 226250 (Milliken), the entire contents of which are incorporated herein by cross-reference.

[0286] In one or more embodiments, the nucleating agent is selected from a hydrogenated metal phthalate, a metal dicycloheptane dicarboxylate, or a combination thereof. In one embodiment, the hydrogenated metal phthalate is a metal hexahydrophthalate or a metal heptahydrophthalate. In one embodiment, the nucleating agent is preferably a metal hexahydrophthalate.

[0287] Metal salts of nucleating agents include, but are not limited to, zinc, magnesium, sodium, and calcium salts and mixtures of such metal salts.

[0288] In one embodiment, the nucleating agent is bicyclo[2,2,1]heptane-2,3-dicarboxylic acid disodium salt, which is HPN-68L is commercially available from Milliken. In another preferred embodiment, the nucleating agent is hexahydrophthalic acid calcium salt, which is HPN-20E is commercially available from Milliken. Combinations of these nucleating agents may also be used.

[0289] The nucleating agent may be present in the barrier layer in an effective amount, and may generally be present in an amount of about 0.01 wt % to about 1 wt % based on the total weight of the components in the barrier layer. In one embodiment, the nucleating agent is present in the barrier layer in an amount of about 0.03 wt % to about 0.5 wt %. In specific embodiments, the nucleating agent may be present in the barrier layer in an amount of about 0.05 wt % to about 0.2 wt %, or about 0.075 wt % to about 0.125 wt %.

[0290] High-density polyethylene (HDPE)

[0291] High density polyethylene (HDPE) is a preferred embodiment of polyethylene, which is a preferred embodiment of the polyolefin carrier used in the masterbatch compositions as disclosed herein.

[0292] HDPE is also the resin into which the masterbatch composition is mixed to form the HBP composition. In this case, the HDPE is referred to as bulk HDPE.

[0293] HDPE is a type of polyethylene in which the generally linear polymer has a low level of branching in the polymer chain. Due to its regular structure, HDPE is a highly crystalline material. Preferably, HDPE is selected from those suitable for forming layers and films.

[0294] In some preferred embodiments, the HDPE is "substantially linear". This means that the HDPE has substantially no long chain branching and has a relatively narrow molecular weight distribution. Long chain branching can be measured by NMR, 3D-GPC, and rheology.

[0295] In one or more embodiments, the HDPE useful according to the present invention can be a homopolymer or a copolymer of ethylene.Thus, the terms "high density polyethylene" and "HDPE" are used herein to refer to homopolymers of ethylene as well as copolymers of ethylene.

[0296] The term "ethylene homopolymer" refers to an ethylene polymer consisting essentially (ie at least 90 wt%, preferably at least 95 wt%, more preferably at least 97 wt%) of ethylene, thus a polyethylene homopolymer preferably comprises mainly ethylene monomers.

[0297] The term "ethylene copolymer" refers to a polymer formed by copolymerization of ethylene and at least one comonomer. Preferably, the comonomer is at least one alpha-olefin. The alpha-olefin comonomer may contain 3 to 20 carbon atoms, preferably 4 to 8 carbon atoms. In some embodiments, the alpha-olefin comonomer is selected from 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene and mixtures thereof. In one preferred embodiment, the alpha-olefin comonomer is selected from C4, C5 and C6 olefins and mixtures thereof, and preferably, may be selected from 1-butene, 1-pentene, 1-hexene and mixtures thereof.

[0298] In one or more embodiments, HDPE suitable for use in accordance with the present invention may have a density of about 0.94 to about 0.97 g / cm at 23°C. 3 The density of HDPE can be determined by one skilled in the art using known techniques. An exemplary technique is described in ASTM D792. Density is a measure of the crystallinity of HDPE, where higher density is associated with a higher degree of crystallinity formed by the polymer.

[0299] In a preferred embodiment, the density of HDPE (including, for example, bulk HDPE) at 23°C measured according to ASTM D792 is at least about 0.940 g / cm 3In one embodiment, the density of HDPE at 23°C measured according to ASTM D792 may be from about 0.95 to about 0.965 g / cm 3 .

[0300] The melt flow index (MFI) of bulk HDPE measured at 190°C and 2.16 kg according to ISO 1133 can be about 0.08 to 40.0 g / 10 min. The melt flow index (MFI) provides an indication of the fluidity and processability of the HDPE resin and is related to the viscosity of the HDPE in its molten state. The MFI may also be related to the average molecular weight of the polymer chains in the HDPE resin. A lower melt index at a specified load and temperature indicates that the HDPE has a higher viscosity and a higher average molecular weight. In one or more preferred embodiments, the MFI of the HDPE is about 0.08 to 20.0 g / 10 min, or about 0.10 to 10 g / 10 min, or about 0.10 to 4 g / 10 min, or about 0.5 to 3 g / 10 min, or about 0.8 to 2.0 g / 10 min, as measured at 190°C and 2.16 kg according to ISO 1133.

[0301] In one or more embodiments, the MFI of the HDPE is the same or different than the MFI of the bulk HDPE when used as a polyolefin carrier in one or more of the related masterbatches. In a preferred embodiment, the HDPE in the nucleating agent masterbatch has a higher MFI than the bulk HDPE. In a preferred embodiment, the HDPE in the hydrocarbon resin masterbatch has a lower or similar MFI than the bulk HDPE.

[0302] Polyethylene is typically composed of a mixture of polymer molecules having different molecular weight distributions, which can be represented graphically as a molecular weight distribution curve. In one or more embodiments, the weight average molecular weight of HDPE can be from about 5,000 to 5,000,000 g / mol.

[0303] In some embodiments, the ratio of the viscosity of the HDPE measured at two different shear rates can be used to provide an indication of the breadth of the HDPE molecular weight distribution. In some cases, the melt flow index ratio (MFR) can provide an indication of the breadth of the molecular weight distribution. The melt flow index ratio is the ratio of the MFI measured at standard conditions at 190°C with a load of 21.6 kg to the MFI measured at the same conditions with a load of 2.16 kg (e.g., MFR = 1.16 kg). 21 / MI2). In some embodiments of the present invention, the MI of the bulk HDPE 21 The melt flow index ratio (MFR) of the resin is less than 100, preferably less than 70, more preferably less than 60. In some embodiments, the MFR of the resin is less than 50, more preferably less than 45.

[0304] In one or more embodiments, the HDPE comprises at least one polyethylene polymer and may comprise a blend of two or more polyethylene polymers, such as a blend of a polyethylene copolymer and a polyethylene homopolymer or a blend of two or more polyethylene homopolymers or copolymers of different molecular weights and / or compositions.

[0305] According to an embodiment of the present invention, the HDPE described herein may optionally contain one or more other additives. Representative examples of additives include antioxidants (including primary antioxidants and secondary antioxidants), anti-acid metal salts, flame retardants, lubricants, UV stabilizers, antistatic agents, processing aids, etc. If desired, such additives can be added to the extruder and melt-compounded into the relevant masterbatch or HBP composition.

[0306] For the avoidance of doubt, for each respective embodiment described herein, the nucleating agent, hydrocarbon resin and polyolefin, preferably polyethylene, more preferably HDPE may be selected from any of those described herein.

[0307] Barrier layer

[0308] In another aspect, the present invention is directed to a method for producing a barrier layer, the method comprising forming the barrier layer from the HBP composition described herein. Other embodiments of the present invention are also directed to barrier layers produced by such methods.

[0309] In a preferred embodiment, the HBP composition is extruded to form the barrier layer.

[0310] In another embodiment, the present invention provides a barrier layer produced by the method described herein.

[0311] In another aspect, the present invention relates to a method for preparing a barrier layer for a film, the method comprising blending a HBP masterbatch comprising a synergistic combination of a nucleating agent, a hydrocarbon resin and a polyolefin with bulk HDPE to form a HBP composition; and forming a barrier layer from the resulting blended HBP composition, wherein the polyolefin is preferably polyethylene, more preferably HDPE.

[0312] In another embodiment, the HBP composition may be formed by blending a nucleating agent masterbatch, a polyolefin, preferably polyethylene, more preferably HDPE, and a hydrocarbon resin without using a hydrocarbon resin masterbatch.

[0313] Another embodiment of the present invention is directed to a method of producing a barrier layer for a film, the method comprising: (a) melt mixing a nucleating agent masterbatch into a bulk HDPE, (b) simultaneously or sequentially melt mixing a hydrocarbon resin masterbatch into the bulk HDPE of step (a) to form a HBP composition, and (c) forming a barrier layer from the HBP composition. In one embodiment, the nucleating agent masterbatch can be blended into the bulk HDPE in an amount of about 0.04% w / w to about 30% w / w, preferably about 0.1% w / w to about 10% w / w of the barrier layer. In one embodiment, the hydrocarbon resin masterbatch can be blended into the bulk HDPE in an amount of about 0.14% w / w to about 70% w / w, preferably about 0.5% w / w to about 25% w / w of the barrier layer.

[0314] Barrier Film

[0315] The barrier layers described herein may be incorporated within the film to form part of the film.The film according to the present invention incorporates a barrier layer as described herein.

[0316] Thus, in another aspect, the present invention relates to a method for reducing the water vapor transmission rate of a film, the method comprising incorporating into the film a barrier layer as described herein. Preferably, the water vapor transmission rate of the film measured at about 38°C and 90% external relative humidity is no more than about 4 g / m 2 / sky.

[0317] As used herein, the term "film" can refer to a substantially planar material of any thickness. In some embodiments, film described herein can be an average thickness no more than about 500 μm, for example, a substantially planar material of about 10 μm to about 500 μm, preferably about 20 μm to about 200 μm, or about 25 μm to about 100 μm, or about 30 μm to about 80 μm, or about 35 μm to about 70 μm, or about 40 μm to about 60 μm. It can also be considered that the film in the form of non-planar arrangement or shape, for example, the film can include one or more layers in the article formed by blow molding or injection molding.

[0318] The film comprising the barrier layer may be a monolayer film consisting of the barrier layer alone, typically in the form of a substantially planar sheet.

[0319] Alternatively, the film can be a multilayer film in which the barrier layer is a component of the film together with other layers. Thus, the term "multilayer" refers to multiple layers in a single film structure. These layers can be combined together by any conventional means known in the art, such as by coextrusion, lamination, or a combination thereof. The multilayer films described in the present application may include as many layers as desired, such as at least three, four, five or more film layers. At least one layer in the multilayer film is a barrier layer as described herein. The barrier layer can be sandwiched between the other layers of the multilayer film. For example, the multilayer film may include three layers, and the barrier layer can be the central core layer of the multilayer film.

[0320] Other layers in the multilayer film may comprise or consist of conventional materials suitable for films for packaging applications, including other oxygen barrier materials and / or water vapor barrier materials.

[0321] The film of the present invention may be an oriented film or a non-oriented film.

[0322] Oriented films may be molecularly oriented in the machine direction (LD) and / or the transverse (ie lateral) direction (TD). Orientation of the film in either or both directions may be achieved by any suitable technique, for example by the well-known bubble process and / or tenter frame process.

[0323] The films of the present invention advantageously exhibit one or more advantageous barrier properties, including low water vapor transmission rate and / or oxygen transmission rate. For a particular film, the trends of water vapor and oxygen transmission rates can be correlated. Thus, a film exhibiting a low water vapor transmission rate would be expected to exhibit a corresponding low oxygen transmission rate.

[0324] In one or more embodiments, the water vapor transmission rate (WVTR) of the film according to the present invention measured at about 38°C and 90% external relative humidity is no more than about 4 g / m 2 / day. The test temperature can be within ±10% of 38°C (100°F).

[0325] Water vapor transmission rate (WVTR) is the steady-state rate at which water vapor permeates through a membrane under specific conditions. WVTR is usually expressed in g / m 2 / day (i.e., 24 hours) and conditions of about 38°C and 90% relative humidity. WVTR can increase with increasing humidity and temperature or pressure. A suitable method for determining WVTR is described in ASTM E3. In one embodiment, WVTR is measured using a film having a thickness of not less than about 40 μm.

[0326] In one or more embodiments, the barrier layer may be primarily responsible for imparting the desired WVTR properties to the film.

[0327] In some embodiments, the barrier layer itself may have a relative humidity of no more than about 4 g / m 2 measured at about 38° C. and 90% external relative humidity. 2 For example, in embodiments where the film is a monolayer film, preferably when the film has a thickness of about 40 μm to about 60 μm, the barrier layer itself may have a water vapor transmission rate of no more than about 4 g / m2 measured at about 38°C and 90% external relative humidity. 2 / day water vapor transmission rate.

[0328] In embodiments where the film is a multilayer film, preferably when the film has a thickness of about 40 μm to about 60 μm, the water vapor transmission rate of the film measured at about 38° C. and 90% external relative humidity may be no more than about 4 g / m 2 / day, not exceeding about 3.5g / m 2 / day, preferably not more than about 3g / m 2 / day, preferably not more than about 2.5g / m 2 / day, preferably not more than about 2.0 g / m 2 / day, preferably not more than about 1.5 g / m 2 / day, preferably not more than about 1.0 g / m 2 / day, preferably not more than about 0.5g / m 2 / sky.

[0329] According to the present invention, the barrier film may have a low oxygen transmission rate (OTR). OTR is the steady-state rate at which oxygen permeates through a film under specific conditions. OTR is usually measured in cc / m 2 / day (i.e., 24 hours) and 23°C and 0% relative humidity. Higher OTR values ​​may be observed in humid environments and may increase with increasing temperature or pressure. In one embodiment, the film of the present invention may have an OTR of no more than 1,000 cc / cm as measured with a film thickness of not less than about 40 μm. 2 / day OTR. OTR can be determined using methods known to those skilled in the art. A suitable method for determining OTR is described in ASTM D3985.

[0330] Advantageously, the barrier layers described herein can control the permeation of oxygen and / or water vapor. In one embodiment, the barrier layer can inhibit or reduce the permeation of oxygen and / or water vapor. Therefore, films comprising the barrier layer can exhibit WVTR and / or OTR values ​​that are lower than conventional films.

[0331] According to embodiments of the present invention, the barrier layer may be formed from a HBP composition as defined herein. In one or more embodiments, the HBP composition and the resulting barrier layer comprise one or more polyolefins, preferably HDPE; one or more nucleating agents and one or more hydrocarbon resins. Preferably, the HBP composition and the barrier layer comprise one nucleating agent and one hydrocarbon resin. Conventional techniques for forming polymer layers and films may be used to prepare the barrier layer from the HBP composition.

[0332] Techniques for preparing barrier layers are known to those skilled in the art. According to one embodiment, the barrier layer may be formed by extruding a melt-compounded HBP composition comprising a synergistic blend of a nucleating agent and a hydrocarbon resin dispersed in a polyolefin, preferably HDPE, into a substantially planar sheet or web. This may involve, for example, extruding the molten HBP composition through a slot die onto a casting roll and then drawing the extruded blend in the molten state to a desired sheet thickness.

[0333] In alternative embodiments, the barrier layer may be prepared using a cast film process or a blown film process.Other film making techniques suitable for making polymeric films or layers (eg, tenter frame) may also be used.

[0334] In a blown film process, a HBP composition comprising a synergistic blend of a nucleating agent and a hydrocarbon resin dispersed in HDPE can be extruded through an annular die to form a cylindrical tube which is then expanded using internal gas pressure within the tube of molten polymer material to form a layer of desired thickness.

[0335] Some suitable film extrusion techniques are also described in a technical guide entitled "Film Extrusion and Converting" published by Qenos Pty Ltd (published July 2015), the contents of which are incorporated herein by reference.

[0336] In some embodiments, the method of preparing the thermoplastic composition of the present invention comprises the following steps:

[0337] (a) adding a high barrier polyolefin composition as described herein to an apparatus comprising a die and a mold having an inner surface defining the shape of a molded article;

[0338] (b) melting the composition by heating, wherein the heating is sufficient to melt the composition and extrude it through a die;

[0339] (c) forming a melt (also called a parison) from the extruded composition;

[0340] (d) capturing the melt in a mold;

[0341] (e) inflating the extruded melt with a pressurized fluid to produce a molded article by causing the melt to conform to the inner surface of a mold;

[0342] (f) cooling the molded article to at least partially solidify the composition; and

[0343] (g) Obtaining a molded product from the mold.

[0344] The above composition can be any embodiment of the composition of the present invention. Preferably, the equipment is any suitable extrusion blow molding equipment, such as continuous extrusion blow molding equipment such as rotary extrusion blow molding equipment and shuttle extrusion blow molding equipment, and intermittent extrusion blow molding equipment such as reciprocating screw extrusion blow molding equipment and storage type extrusion blow molding equipment. Preferably, the equipment includes a die head, and the plasticized (melting) composition is extruded through the die head to form a parison. Preferably, the equipment also includes a mold with a mold cavity. Preferably, the shape of the molded product is limited by the inner surface of the mold cavity or the mold cavity. Preferably, the outer surface of the molded product is limited by the inner surface of the mold cavity.

[0345] In some embodiments, a method of producing a film from the thermoplastic composition of the present invention comprises the following steps:

[0346] (a) adding a high barrier polyolefin composition as described herein to an apparatus comprising:

[0347] a die head having an annular die opening suitable for extruding the tube;

[0348] means for blowing a pressurized fluid into the tube exiting the annular die; and

[0349] means for withdrawing and collecting the tube;

[0350] (b) melting the composition by heating, wherein the heating is sufficient to melt the composition and extrude it through a die;

[0351] (c) forming a tube by extruding the molten composition through an annular die, exiting the annular die in a first direction, the tube having a diameter and a length;

[0352] (d) expanding the tube by blowing a pressurized fluid into the tube to increase its diameter while pulling the tube in a first direction to increase its length, thereby producing a membrane;

[0353] (e) cooling the film to solidify the composition; and

[0354] (f) Obtaining a membrane.

[0355] In one or more embodiments, incorporation of the barrier layer in a film can reduce the water vapor transmission rate (WVTR) of the film by at least 10%, at least 20%, at least 40%, or at least 60% compared to a comparable film of equivalent thickness having no barrier layer or having a barrier layer that is not prepared with a HBP composition as described herein (e.g., a barrier layer that does not include a synergistic combination of a nucleating agent and a hydrocarbon resin substantially uniformly dispersed within the barrier composition). Thus, the barrier layer according to the present invention enables a film to be obtained that exhibits a greater reduction in WVTR when compared to the WVTR of a comparative film.

[0356] The comparative film as described herein may be a film including or consisting of a barrier layer formed only of a bulk HDPE resin without a nucleating agent or a hydrocarbon resin contained or dispersed therein.

[0357] In one or more embodiments, incorporation of the barrier layer in a film can reduce the oxygen transmission rate (OTR) of the film by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, or at least 60% compared to a comparable film of equivalent thickness having no barrier layer or having a barrier layer that is not prepared using the HBP composition as described herein (e.g., a barrier layer that does not include a nucleating agent and a hydrocarbon resin substantially uniformly dispersed within the barrier composition). Thus, the barrier layer according to the present invention enables a film to be obtained that exhibits a greater reduction in OTR when compared to the OTR of the comparative film.

[0358] Thus, the inventors have surprisingly discovered that a reduction in WVTR can be achieved by blending bulk HDPE with a nucleating agent and a hydrocarbon resin via a polyolefin carrier to form a HBP composition, and forming a barrier layer from the HBP composition using a masterbatch composition according to embodiments as disclosed herein.

[0359] The observed effect is unexpected due to the relatively small amounts of hydrocarbon resin and nucleating agent used.

[0360] Another advantage of the present invention is that the nucleating agent and hydrocarbon resin (preferably hydrogenated hydrocarbon resin) can be used with many different types of polyolefins, such as polyethylene, preferably HDPE, including those that are generally considered to be less responsive to nucleation. Thus, improved barrier properties can be advantageously imparted to a wider range of polyolefins, including but not limited to polyethylene and HDPE.

[0361] The improved films described herein have value in packaging applications where low water vapor transmission rate and / or oxygen transmission rate and maintenance of good mechanical properties such as puncture resistance and tear resistance are desirable to help extend the shelf life of the packaging material. In turn, in addition to environmental advantages, the improved barrier properties can also allow the thickness of the barrier layer and the film containing the barrier layer to be reduced, thereby saving costs.

[0362] The present invention will now be described with reference to the following examples. However, it should be understood that these examples are provided by way of illustration of the present invention and they in no way limit the scope of the present invention.

[0363] Example 1: Effect of Method on Synergy

[0364] Material:

[0365] The following materials were used in the examples described below:

[0366] HDPE(b) – Qenos Alkatane HDF895 – High-density polyethylene homopolymer: 0.8MI2, 58MFR, 0.962g / cm 3 Density

[0367] NA – Milliken Hyperform 20E – 66.6% cyclohexanedicarboxylic acid calcium salt (1:1) and 33.3% zinc stearate [ALLENS note: please confirm]

[0368] HCR – Hydrogenated alicyclic hydrocarbon resin: softening point 124°C, Mn 400, Mw 700 [ALLENS note: please confirm]

[0369] Experiments using industry standard operating procedures

[0370] Table 1 shows the inventors' early experiments, all conducted using a twin screw extruder. These experiments did not use the method of the present invention, but rather used industry standard operating procedures.

[0371] Compound 1: When the effects (in terms of increased WVTR) of a membrane containing (a) 2% HCR and a membrane containing (b) 0.1% NA are added together, the expected added WVTR is (c) 39%. The WVTR of a membrane containing both 2% HCR and 0.1% NA gives a 36% increase in WVTR.

[0372] Compound 2: When the effects (in terms of increased WVTR) of a membrane containing (a) 2% HCR and a membrane containing (b) 0.1% NA are added together, the expected added WVTR is (c) 34%. The WVTR of a membrane containing both 2% HCR and 0.1% NA gives a 38% increase in WVTR.

[0373] These results indicate that when industry standard operating procedures are used, improvements in WVTR are additive at best, suggesting that no synergistic effects are observed.

[0374] Table 1: WVTR results using industry standard operating procedures

[0375]

[0376] Effects of using different methods on WVTR

[0377] Figure 6 It is shown that using different methods to prepare the masterbatch produces different results even when the same type of extruder is used.

[0378] Compare films:

[0379] (a) No HCR or NA is used in the membrane

[0380] (b) Only 2% HCR

[0381] (c) Only 0.1% NA

[0382] Membranes with the same NA and HCR amounts prepared according to different methods:

[0383] (d) 0.1% NA + 2% HCR (SSC) - single screw extruder compound; single pass

[0384] (e) 0.1% NA + 2% HCR (TSC) 1 pass - twin screw extruder compound; single pass

[0385] (f) 0.1% NA + 2% HCR (TSC) 2-pass - twin screw extruder compound; two-pass

[0386] (g) 0.1% NA + 2% HCR (TSC) 3-pass - twin screw extruder compound; three-pass

[0387] (h) 0.1% NA + 2% HCR (TSC) - twin screw extruder compound; single pass, using the process of the present invention

[0388] The results show that the worst results were obtained in the single screw extruder (d). A single pass in a twin screw extruder (e) produced films comparable to additive effects, and the addition of passes (f) and (g) gave higher WVTR performance in the resulting films.

[0389] However, by using the method of the present invention, while maintaining the same amount of NA and HCR(h), significantly higher WVTR was obtained, much higher than the expected additive effect, indicating that a synergistic effect can be obtained.

[0390] Example 2: Comparative membrane and membrane of the present invention

[0391] Material:

[0392] The following materials were used in the examples described below:

[0393] HDPE(a)–Qenos Alkatane HD0195FX–High-density polyethylene homopolymer: 1.4MI2, 45MFR, 0.955g / cm 3 Density

[0394] HDPE(b)–Qenos Alkatane HDF895–high-density polyethylene homopolymer: 0.8MI2, 58MFR, 0.962g / cm 3 Density

[0395] HDPE (c) – Qenos Alkatane HDF995X – High-density polyethylene homopolymer: 0.9MI2, 70MFR, 0.965g / cm 3 Density

[0396] HDPE(d)–Qenos Alkatane GF7660–High-density polyethylene copolymer: 0.3MI2, 120MFR, 0.959g / cm 3 Density

[0397] HDPE(e)–Qenos Alkatane HD1090–High-density polyethylene copolymer: 10MI2, 0.956g / cm 3 Density

[0398] NA – Milliken Hyperform 20E – 66.6% cyclohexanedicarboxylic acid calcium salt (1:1) and 33.3% zinc stearate

[0399] HCR – Hydrogenated alicyclic hydrocarbon resin: softening point 124°C, Mn 400, Mw 700

[0400] Table 2: Barrier layer composition and film properties

[0401]

[0402]

[0403]

[0404] Process for producing HDPE compositions for barrier film formation

[0405] Method 1: C1 to C15

[0406] To the selected HDPE resin, the specified amounts of nucleating agent (NA) and hydrocarbon resin (HCR) additives were added as follows:

[0407] C1: None

[0408] C2: 1% HCR (using 33% HCR MB)

[0409] C3: 3% HCR (using 33% HCR MB)

[0410] C4: 0.1% NA (using 20% ​​NA MB)

[0411] C5: None

[0412] C6: 0.1% NA (using 20% ​​NAMB)

[0413] C7: None

[0414] C8: 1% HCR (using 50% HCR MB)

[0415] C9: 2% HCR (using 50% HCR MB)

[0416] C10: 0.1% NA (using 20% ​​NAMB)

[0417] C11: None

[0418] C12: 0.1% NA (using 20% ​​NAMB)

[0419] C13: 4% HCR (using 60% HCR MB)

[0420] C14: None

[0421] C15: 0.1% NA (use 20% NA MB)

[0422] The resulting composition was melt blended in a twin-screw extruder and then blown into a film.

[0423] Method 2: S1, S2, S5, S6, S7, and S8

[0424] To the selected HDPE resin, the specified amounts of nucleating agent (NA) and hydrocarbon resin (HCR) additives were added as follows:

[0425] S1: 0.1% NA (using 20% ​​NA MB) + 1% HCR (using 33% HCR MB); NA MB and HCR MB are used at a ratio of 1:7

[0426] S2: 0.1% NA (using 20% ​​NAMB) + 3% HCR (using 33% HCR MB); NAMB and HCR MB are used at a ratio of 1:18

[0427] S5: 0.1% NA (using 20% ​​NA MB) + 1% HCR (using 33% HCR MB)

[0428] S6: 0.1% NA (using 20% ​​NAMB) + 2% HCR (using 33% HCR MB); NAMB and HCR MB are used at a ratio of 2:25

[0429] S7: 0.1% NA (using 20% ​​NAMB) + 4% HCR (using 60% HCR MB); NAMB and HCR MB are used at a ratio of 2:27

[0430] S8: 0.1% NA (using 20% ​​NA MB) + 4% HCR (using 60% HCR MB)

[0431] The resulting composition was melt blended in a twin-screw extruder and then blown into a film.

[0432] Method 3: S3 and S4

[0433] The specified amounts of NA, HCR and HDPE were melt mixed on a twin screw extruder to produce HBP MB [2.5% NA + 50% HCR + 47.5% HDPE w / w of HBP MB]. HBP MB was mixed with bulk HDPE on a twin screw extruder to produce the HBP composition.

[0434] S3: 0.05% NA + 1% HCR (using 2% HBP MB)

[0435] S4: 0.1% NA + 2% HCR (using 4% HBP MB)

[0436] The resulting composition is then blown into a film.

[0437] The barrier layer compositions are summarized in Table 2.

[0438] Synergy

[0439] The following table shows synergy based on a comparison of: (a) the actual WVTR observed from the combination of hydrocarbon resin and nucleating agent in the inventive samples, and (b) the expected additive WVTR calculated from the addition of the WVTR of the hydrocarbon resin and nucleating agent when used alone in the comparative film. Column (c) shows the difference between (a) and (b), indicating the value of synergy.

[0440] Table 3: Synergistic effects

[0441]

[0442] The above examples demonstrate that in all of the examples of the invention, the observed synergy provided an increase of more than 5% over the expected additive WVTR.

[0443] General method for forming films :

[0444] Films were produced from the HDPE blends and comparative HDPE blends using a blown film extrusion process on a blown film line. Films containing only bulk HDPE resin (ie, without nucleating agent or hydrocarbon resin) were also prepared for comparison.

[0445] Using the blown film process, HDPE is melted and then extruded vertically upward through an annular die to obtain a tube with controllable diameter and thickness. The extruded melt is air cooled by a cooling ring near the die, and the film tube is expanded to a bubble of the desired diameter by air introduced through the center of the die mandrel. The film is pulled through a pair of pressure rollers to contain a constant volume of expanded air within the bubble formed between the pressure roller and the die. The bubble is then collapsed in a collapse frame and flattened by a pressure roller to form a flat folded film, which can be wound into a tubular film or cut into a sheet film.

[0446] The films were formed by blown film extrusion using the following process parameters:

[0447] Membrane specification: 40-50μm

[0448] Blowing ratio (BUR): 2.5

[0449] Frost line height: 300mm (low) or 800mm (high)

[0450] Flat fold width: 40-45cm

[0451] Zone temperature: 190°C max 20

[0452] Screw speed: 300rpm

[0453] WVTR test:

[0454] The formed films were evaluated for WVTR according to test method ASTM E398-20 using a Permatran-W Model 1 / 50G from Mocon at a temperature of about 38°C and an external relative humidity of about 90%.

[0455] The improvement in WVTR (i.e., the reduction in water vapor transmission rate) is determined by evaluating the difference in WVTR of films made with bulk HDPE resin alone and films formed with HDPE blends. The improvement can be expressed as a change in WVTR (ΔWVTR) using the following equation:

[0456]

[0457] From the above results, it can be seen that compared to the comparative films, the films formed from HBP compositions containing (i) 0.1% NA + 1-3% HCR (using Method 2 (i.e., Samples S1 and S2)); and (ii) 0.05-0.1% NA + 1-2% HCR (using Method 3 (i.e., S3 and S4)) provide significantly improved barrier results balanced with good film mechanical properties.

[0458] OTR test:

[0459] The formed films were evaluated for OTR using Mocon's Ox-Tran 2 / 22 according to test method ASTM D3985-05 at a temperature of about 23°C and an external relative humidity of about 0%.

[0460] The improvement in OTR (i.e., the reduction in oxygen transmission rate) was determined by evaluating the difference in OTR of films made with bulk HDPE resin alone and films formed with HDPE blends. The improvement can be expressed as a change in OTR (ΔOTR) using the following equation:

[0461]

[0462] The examples provided herein demonstrate that one or more embodiments of barrier layers and barrier films prepared by the methods of the present invention can provide useful alternatives to barrier layers and barrier films known in the art, or, particularly in preferred embodiments, provide one or more advantages, such as one or more of the following:

[0463] Improve the balance of mechanical properties, such as stiffness or puncture and tear resistance;

[0464] For example, lower production costs due to the use of relatively low levels of hydrocarbon resins;

[0465] Improved processability;

[0466] Improve the uniform dispersion of nucleating agents or hydrocarbon resins;

[0467] Providing a synergistic combination of a nucleating agent and a hydrocarbon resin;

[0468] improving the crystallization characteristics of the resulting barrier layer;

[0469] Facilitates the effectiveness of compounding, melt mixing and / or extrusion processes;

[0470] Enables the addition of small or precise amounts of nucleating agents and / or hydrocarbon resins to bulk HDPE;

[0471] Improved barrier film properties, such as lower WVTR or OTR; and

[0472] This enables the thickness of the barrier layer or film to be reduced while maintaining one or more of the above properties.

[0473] For the avoidance of doubt, any reference or discussion in this specification to any document, act or item of knowledge is included solely for the purpose of providing a background to the present invention. It is not intended or represented that any one of these matters, or any combination thereof, formed part of the common general knowledge at the priority date, or was considered relevant to the solution of any problem addressed by this specification.

[0474] It is to be understood that various other modifications and / or variations may be made without departing from the spirit of the invention as outlined herein.

Claims

1. A method for preparing a high barrier polyolefin masterbatch, comprising the following steps: a) melt mixing a nucleating agent in polyethylene to form a nucleating agent masterbatch; b) melt mixing a hydrocarbon resin in polyethylene to form a hydrocarbon resin masterbatch; as well as c) melt-mixing the nucleating agent masterbatch of step a) with the hydrocarbon resin masterbatch of step b), To produce a uniform high barrier polyolefin masterbatch.

2. A method for preparing a nucleating agent masterbatch, comprising the following steps: The nucleating agent is melt mixed in the polyethylene, wherein the melt mixing step is sufficient to produce a homogeneous nucleating agent masterbatch.

3. A method for preparing a hydrocarbon resin masterbatch, comprising the steps of: The hydrocarbon resin is melt mixed in the polyethylene, wherein the melt mixing step is sufficient to produce a homogeneous hydrocarbon resin masterbatch.

4. A method for preparing a high barrier polyolefin masterbatch, comprising the following steps: Melting and mixing the nucleating agent masterbatch according to claim 2 and the hydrocarbon resin masterbatch according to claim 3, The melt mixing step is sufficient to produce a uniform high barrier polyolefin masterbatch.

5. A method for preparing a high barrier polyolefin masterbatch, comprising the following steps: The nucleating agent mixture and hydrocarbon resin are melt mixed with polyethylene, wherein the nucleating agent mixture comprises a nucleating agent and a polyolefin, and The melt mixing step is sufficient to produce a uniform high barrier polyolefin masterbatch.

6. The process of any one of claims 1 to 5, wherein any one or more of the melt mixing steps are performed with a twin screw mixer.

7. The method of any one of claims 1 to 6, wherein any one or more of the melt mixing steps are melt mixed with sufficient residence time to produce sufficient homogeneity.

8. The method of any one of claims 1 to 7, wherein any one or more of the melt mixing step of forming the nucleating agent masterbatch, the melt mixing step of forming the hydrocarbon resin masterbatch, or the melt mixing step of forming the high barrier polyolefin masterbatch further comprises the step of adding one or more additives.

9. The method of any one of claims 1 or 4 to 8, wherein: The nucleating agent is present in the high barrier polyolefin masterbatch in an amount of about 0.2 wt % to about 15 wt %; and The hydrocarbon resin is present in the high barrier polyolefin masterbatch in an amount of about 2.5 wt % to about 80 wt %.

10. The method of any one of claims 1 to 9, wherein the polyethylene is HDPE.

11. The method of any one of claims 1 or 3 to 10, wherein the hydrocarbon resin has a lower weight average molecular weight than the polyethylene.

12. The process of any one of claims 1 or 3 to 11, wherein the hydrocarbon resin is a cyclic olefin copolymer or a hydrocarbon resin derived from a crude olefin feed selected from the group consisting of a C5 olefin feed stream, a C9 olefin feed stream, a terpene olefin, a norbornene, pure monomers, and combinations thereof.

13. The method of any one of claims 1, 2, or 4 to 12, wherein the nucleating agent comprises a metal salt.

14. The method of any one of claims 1, 2, or 4 to 13, wherein the nucleating agent comprises a branched alkylphosphonic acid, a metal hydrogenated phthalate, a metal bicycloheptane dicarboxylate, or a combination thereof.

15. A kit comprising the nucleating agent masterbatch of claim 2 and the hydrocarbon resin or hydrocarbon resin masterbatch of claim 3, wherein: The nucleating agent is present in the nucleating agent masterbatch in an amount of about 0.1 wt % to about 30 wt %; and The hydrocarbon resin is present in the hydrocarbon resin masterbatch in an amount of about 5 wt % to about 80 wt %.

16. A kit comprising a nucleating agent mixture as defined in claim 5 and a hydrocarbon resin masterbatch as claimed in claim 3, wherein: The hydrocarbon resin is present in the hydrocarbon resin masterbatch in an amount of about 5 wt % to about 80 wt %.

17. A high barrier polyolefin masterbatch produced by the method of any one of claims 1 or 4 to 13.

18. Use of the kit according to claim 15 or 16 or the high barrier polyolefin masterbatch according to claim 17 for forming a high barrier polyolefin composition, comprising the following steps: blending a nucleating agent masterbatch and a hydrocarbon resin masterbatch as defined in claim 15 with a bulk polyolefin; blending a nucleating agent mixture as defined in claim 16 and a hydrocarbon resin masterbatch with a bulk polyolefin; or A high barrier polyolefin masterbatch as defined in claim 16 is blended with a bulk polyolefin.

19. A high barrier polyolefin composition prepared by the use according to claim 17 or 18, comprising: From about 0.01 wt % to about 1 wt % of a nucleating agent; and From about 0.1 wt. % to about 10 wt. % hydrocarbon resin.

20. The high barrier polyolefin composition of claim 19, wherein the nucleating agent and the hydrocarbon resin are present in a ratio of about 1:4 to about 1:

200.

21. A barrier layer formed from the high barrier polyolefin composition according to claim 19 or 20.

22. A film comprising the barrier layer of claim 21, wherein the film has a vapor transmission rate as measured by ASTM F 1249-20 that is reduced by at least about 10% relative to a film of equivalent thickness that does not comprise the barrier layer of claim 21.

23. A method of reducing the water vapor transmission rate of a film, the method comprising incorporating the barrier layer of claim 21 into the film, whereby the film has a water vapor transmission rate as measured by ASTM F 1249-20 that is reduced by at least about 10% relative to a film of equivalent thickness not having the barrier layer of claim 21.

24. A method for reducing the water vapor transmission rate and oxygen transmission rate of a polyethylene film, the method comprising: A blend comprising polyethylene and no greater than 10 weight percent of a composition is melt mixed, wherein the composition is formed by melt mixing: a nucleating agent masterbatch comprising a nucleating agent uniformly dispersed in a polyolefin; and A hydrocarbon resin masterbatch comprising a hydrocarbon resin uniformly dispersed in a polyolefin, wherein the hydrocarbon resin masterbatch and the nucleating agent masterbatch are combined in a ratio of about 1:5 to about 50:

1.

25. A method for reducing the water vapor transmission rate and oxygen transmission rate of a polyethylene film, the method comprising the following steps: A blend comprising not less than 90 weight percent polyethylene and not more than 10 weight percent of a composition is melt mixed, wherein the composition is formed by mixing: a nucleating agent masterbatch comprising a nucleating agent uniformly dispersed in a polyolefin; and A hydrocarbon resin having a lower molecular weight than polyethylene, wherein the hydrocarbon resin and the nucleating agent masterbatch are combined in a ratio of about 1:5 to about 60:

1.

26. A method for reducing the water vapor transmission rate and oxygen transmission rate of a polyethylene film, the method comprising the steps of: A blend comprising not less than 90 weight percent polyethylene and not more than 10 weight percent of a composition comprising: a nucleating agent uniformly dispersed in the polyolefin; and A hydrocarbon resin masterbatch comprising a hydrocarbon resin uniformly dispersed in a polyolefin, wherein the hydrocarbon resin masterbatch and the nucleating agent are combined in a ratio of about 5:1 to about 150:

1.

27. The method of any one of claims 1 or 4 to 14, the kit of claims 15 or 16, the high barrier polyolefin masterbatch of claim 17, the use of claim 18, the high barrier polyolefin composition of claims 19 or 20, the barrier layer of claim 21, the film of claim 22, or the method of any one of claims 23 to 26, wherein the synergistic effect between the nucleating agent and the hydrocarbon resin is at least 5% greater than the additive effect of the nucleating agent and the hydrocarbon resin.

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