POST-CONSUMER RESIN CONTAINER

Abstract

The present invention relates to a sustainable packaging article that could be manufactured substantially free of natural petroleum-based compounds; in particular, it relates to novel packaging made from colored post-consumer recycled (PCR) resin that has high near-infrared (NIR) absorption. There remains a need to create a circular economy for colored and / or black plastic by converting colored and black plastic waste into new packaging while using near-infrared (NIR) detectable pigment in the coloring masterbatch. Therefore, it is an objective of the present invention to convert colored or black plastic waste into new packaging.It has been found that a consumer-acceptable sustainable black packaging using NIR detectable pigment can be obtained using a multi-layer post-consumer resin, comprising a thinner outer layer of post-consumer resin from natural plastic waste (N-PCR); and a thicker inner layer comprising at least 50% colored plastic waste (J-PCR).

Description

POST-CONSUMER RESIN CONTAINER FIELD OF INVENTION The present invention relates to a sustainable packaging article that could be manufactured substantially free of natural petroleum-based compounds; in particular, it relates to novel packaging made from colored post-consumer recycled (PCR) resin that has high NIR absorption. BACKGROUND OF THE INVENTION Around the world, plastic has become an integral part of people's lives, but with it has also come the growing problem of plastic waste. Plastics are useful, versatile, inexpensive, and convenient materials. The problem isn't the use of plastic itself, but its single use. With just one use, 95% of the value of plastic is lost. However, recent years have seen a substantial effort to recycle plastic. Plastic that has been collected through established consumer recycling streams, sorted, washed, and reprocessed into pellets is defined as post-consumer recycled (PCR) resin. This can be used in place of natural resin to create new plastic packaging for consumer goods. Plastic recycling efforts are becoming larger in scale, allowing for grading. Broadly defined, there are food-grade and non-food-grade PCR materials. Non-food grade PCR is generally classified into 4 types: recycled high-density polyethylene (HDPE), recycled polypropylene (PP), recycled low-density polyethylene (LDPE), and recycled polyethylene terephthalate (PET). Recycled HDPE comes in three grades: natural PCR (transparent) obtained from milk bottles or dairy waste, whitish PCR (opaque) obtained from white and / or colored bottles, and gray PCR (light or dark) obtained from mixed-colored bottles. While the natural, off-white grade can be readily used in the manufacture of new packaging, whether as white or colored bottles or containers, the same cannot be said for gray PCR due to its gray color. It was thought that the gray granules could be used to manufacture dark-colored packaging materials such as black or shades of black. However, when attempts were made to color the gray PCR with a black pigment detectable by near-infrared (NIR) spectroscopy, it was observed that the resulting color was not truly black and there was a substantial difference in color when compared to the black of natural plastic colored with the same detectable black pigment. This renders the recycled bottles unsuitable for sale, at least for the sale of premium products. One possible alternative is to use carbon black as a pigment. However, carbon black-colored plastic or PCR cannot be detected by the near-infrared (NIR) automated sorting systems predominantly used in material recovery facilities (MRFs), plastic recovery facilities (PRFs), and reprocessors to separate plastics into different polymer streams for PCR reprocessing. Therefore, carbon black-colored plastic generally ends up in the unsorted residue, which is less suitable for reprocessing, and is generally treated as waste. EP 0654496 A2 describes plastic containers made from post-consumer resin, in particular lightweight plastic containers having resistance to stress cracking and comprising at least one layer comprising post-consumer plastic film resin; a melt blend of post-consumer plastic film resin and post-consumer plastic milk resin; or a melt blend of post-consumer plastic film resin, post-consumer plastic milk resin and high-density ethylene copolymer natural plastic material. Therefore, there remains a need to create a circular economy for colored and / or black plastic by taking colored and black plastic waste to new packaging while using near-infrared (NIR) detectable pigment in the colorant master batch. Therefore, it is an objective of the present invention to transfer colored or black plastic waste into a new container. Another objective of the present invention is to provide a sustainable packaging article that can be manufactured substantially free of natural petroleum-based compounds. Yet another objective of the present invention is to provide a sustainable article made from colored or black plastic waste while using a near-infrared (NIR) detectable pigment as the master batch of the dye. Yet another objective of the present invention is to provide a black article with more than 95% POR. Yet another objective of the present invention is to provide a black article with more than 95% PCR and with a reduced odor. An additional objective of the invention is to provide such a sustainable container in a consumer-acceptable black color. Surprisingly, it has been found that a consumer-acceptable sustainable black packaging using NIR detectable pigment can be obtained using a multi-layer post-consumer resin, comprising a thinner outer layer of post-consumer resin from natural plastic waste (N-PCR); and a thicker inner layer comprising at least 50% colored plastic waste (J-PCR). BRIEF DESCRIPTION OF THE INVENTION Therefore, in a first aspect, the present invention provides a sustainable packaging article comprising a multilayer post-consumer resin (PCR) wherein the multilayer comprises: an outer layer comprising post-consumer resin from natural plastic waste (N-PCR); and an inner layer comprising post-consumer resin from natural plastic waste (N-PCR) or colored plastic waste (J-PCR) wherein at least 50% of the inner layer comprises post-consumer resin from colored plastic waste (J-PCR), wherein the outer and / or inner layer comprises a master batch of NIR-detectable colorant. In a second aspect, the present invention provides the use of the article in accordance with any invention for packaging fast-moving consumer goods (FMCG). In the context of the present invention, the reference to “post-consumer resin (PCR)” generally means plastic that has been collected through established consumer recycling streams, sorted, RQZRnn / zznz / E / YiAi washed and reprocessed into granules. In the context of the present invention, the term “sustainable” generally means a material that has an improvement of more than 10% in some aspect of its Life Cycle Assessment or Life Cycle Inventory, compared to the relevant natural petroleum-based plastic material that would otherwise have been used to manufacture the article. As used herein, “Life Cycle Assessment (LCA)” or “Life Cycle Inventory” (LCI) relates to the investigation and evaluation of the environmental impacts of a product or service provided, caused, or required by its existence. An LCA or LCI may involve an “origin-to-severe” analysis, which relates to the assessment of the entire life cycle or Life Cycle Inventory from manufacture (“origin”) through the use phase and the disposal phase (“severe”).For example, high-density polyethylene (HDPE) containers can be recycled into HDPE resin granules and then used to form containers, films, or injection-molded items, saving a significant amount of fossil fuel energy. At the end of its useful life, the polyethylene can be disposed of by incineration, for example. All inputs and outputs are considered for all phases of the life cycle. These and other aspects, features, and advantages will be evident to those of ordinary experience in the art from reading the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be used in any other aspect of the invention. The word “comprising” is intended to mean “including,” but not necessarily “consisting of” or “composed of.” In other words, the steps or options listed need not be exhaustive. Note that the examples provided in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise stated.Except in performance and comparative examples, or where explicitly stated otherwise, all numbers in this description indicating quantities of material or reaction conditions, physical properties of materials, and / or use shall be understood to be modified by the word “approximately.” Numerical variations expressed in the format “xay” shall be understood to include x and y. When multiple preferred variations are described for a specific characteristic in the format “xay,” it shall be understood that all variations combining different endpoints are also included. DETAILED DESCRIPTION OF THE INVENTION In one aspect, the present invention relates to a sustainable packaging article. The sustainable article of the present invention is made of post-consumer recycled (PCR) resin and is preferably substantially free of natural plastic. “Substantially free” means that the article comprises less than 5% by weight, preferably less than 3% by weight, more preferably less than 2% by weight, more preferably less than 1% by weight or even 0% by weight of natural plastic. The PCR used in the present invention is recycled polyethylene, preferably recycled high-density polyethylene (HDPE). Preferably, the article of the present invention comprises a post-consumer resin (PCR) Rdzpnn / zznz / E / YiAi multilayer. The multilayer comprises at least two layers: an outer layer and an inner layer. The outer layer is typically the layer that is on the outside of the item, usually directly visible to the consumer. The outer layer of the multilayer system comprises post-consumer natural plastic waste (NPCR) resin. The natural plastic waste generally comes from milk cartons, newspaper bottles, or similar materials. The inner layer of the multilayer comprises post-consumer resin from natural plastic waste (NPCR) or colored plastic waste (J-PCR). Preferably, at least 50% of the inner layer comprises post-consumer resin from colored plastic waste (J-PCR). Preferably, the inner layer comprises at least 60%, more preferably at least 70%, even more preferably at least 80%, still more preferably at least 90%, or even 100% colored plastic waste (J-PCR). Colored plastic waste typically comes from mixed colored waste bottles and / or consumer bottles. Post-consumer resin made from colored plastic waste is commonly known as Jazz PCR (J-PCR). Both N-PCR and J-PCR are available on the market from various suppliers such as Viridor, QCP and Biffa in Europe and KW Plastics in North America. When present as a bilayer, the weight ratio of the outer layer to the inner layer is normally 99:1 to 1:99, although preferably 1:1, more preferably 3:7 or even 1:3, while preferably 1:20, more preferably 1:10 or even 1:5. The multilayer of the present invention may further comprise a second inner layer, which when present will become the innermost layer that will normally be the layer in contact with the product. When present, the second inner layer comprises post-consumer natural plastic waste resin (N-PCR). While the use of the outer layer of N-PCR is primarily intended to provide a more intense color on the outside of the item, the arrangement of the second inner layer (or innermost layer) of N-PCR in multi-layered items reduces the unpleasant odor that often comes from J-PCR. When present as a three-layer, the weight ratio of the outer layer to the inner layer to the second inner layer is from 1:1.5:1 to 1:98:1, although preferably 1:2:1, more preferably 1:3:1, although more preferably 1:18:1, more preferably 1:10:1 or even 1:8:1 or even 1:5:1. Preferably, the outer and / or inner layer comprises a master batch of dye. More preferably, the outer layer comprises a master batch of dye. "Master batch of dye" means a mixture in which pigments are dispersed at high concentration in a carrier material. The master batch of dye is used to impart color to the article. The carrier can be a bio-based plastic or a petroleum-based plastic, or a bio-based oil or a petroleum-based oil, or made from post-consumer recycled (PCR) resin. Non-limiting examples of carrier materials include oil-derived or bio-derived polyethylene (e.g., LLDPE, LDPE, HDPE), bio-derived oil (e.g., olive oil, rapeseed oil, peanut oil), petroleum-derived oil, recycled oil, petroleum-derived or bio-derived polyethylene terephthalate, polypropylene, recycled high-density polyethylene (rHDPE), and recycled low-density polyethylene (rLDPE). Preferably, the carrier material is recycled high-density polyethylene (rHDPE) or recycled low-density polyethylene (rLDPE). When it is desired that all layers be composed of 100% PCR, the preferred carrier is also selected from PCR. Similarly, when it is desired that a layer be composed of 100% of a specific PCR, the preferred carrier is selected from that same PCR. The pigment, when present, in the master batch is an NIR-detectable pigment. Carbon black is not preferred within the scope of the present invention. The preferred NIR-detectable pigment is black. The pigment is typically made from a combination of known colors. Acceptable consumer black can be defined as the color measured using a reflectometer and expressed as the CIE L*a*b* value, where L values ​​are less than 25, preferably less than 23, more preferably less than 20, even more preferably less than 15, still more preferably less than 12 or even less than 10, a values ​​are in the range of -5 to 5, preferably -2 to 3, more preferably 0 to 2, and b values ​​are in the range of -10 to 10, preferably -8 to 5. NIR detectable pigment means detectable by near-infrared (NIR) spectroscopy. The carrier pigment may include, for example, an inorganic pigment, an organic pigment, a polymeric resin, or a mixture thereof. Optionally, the master batch of colorant may also include one or more additives. Non-limiting examples of additives include slip agents, UV absorbers, nucleating agents, UV stabilizers, heat stabilizers, clarifying agents, clays, brighteners, processing aids, perfumes, flavors, and mixtures thereof. These NIR-detectable pigments are known in the technique and are supplied by various providers such as Clariant globally and Colourtone Masterbatch Ltd. in Europe. The article according to the invention is preferably a container; in particular, the article according to the invention is a non-food grade container. Method The article of the invention can be produced using blow molding. Blow molding is a manufacturing process by which hollow plastic parts are formed from thermoplastic materials. The blow molding process begins with melting the thermoplastic and forming it into a parison or preform. The parison is a tube-shaped piece of plastic with an orifice at one end through which compressed air can pass. Pressurized gas, generally air, is used to expand the heated parison or preform and press it against the mold cavity. The pressure is maintained until the plastic cools. After the plastic has cooled and hardened, the mold opens and the part is ejected. There are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding. In extrusion blow molding, a molten plastic tube is extruded into a mold cavity and inflated with compressed air. The end of the cylinder is closed by compression. After the plastic part has cooled, it is removed from the mold. Extrusion blow molding can be used to produce the multilayer articles of the invention. Use In another aspect, the invention provides the use of the article according to the invention for packaging fast-moving consumer goods (FMCG), such as personal care products, beauty products, cosmetic products, household care products and / or food products. Examples Example 1 In this example, a bottle having both an inner and outer layer made of J-PCR (Comp. A) and colored with 1% of the layer at 80% with Colourtone F95884 and 4% of the outer layer with Colourtone F95884 is compared to a bottle having layers according to the invention and colored with 1% of the layer at 80% with Colourtone F95884 and 4% of the outer layer with Colourtone F95884 (Ex. 1). Weight ratio of outer and inner layer Outer layer material % by weight Inner layer material % by weight Comp. A 20:80 J-PCR 20 J-PCR 80 Ex.1 20:80 J-PCR 20 J-PCR + NJ-PCR 40+40 Control 20:80 Natural HDPE 20 Natural HDPE 80 Pantone Color Code L Value a Value b Value Comp. A Pantone 432c 25.68 -2.8 -7.33 Ex.1 Pantone 532c 11.95 1.26 -7.71 Control Pantone 2c 19.37 0.31 9.78 The resulting color of the bottle in Comp. A was gray, even though it was colored with a master batch of black (Colourtone F95884). The desired consumer-acceptable black is obtained in the control bottle, which uses natural HDPE for both layers. This color matches the color of the bottle that has layers according to the invention (Ex. 1), but not Comp. A. Example 2 In this example, three-layer bottles having all layers made of J-PCR (Comp. B) and colored with 3% of the middle layer at 60% (inner layer) with Clariant PE94000797 and 3% of the outer layer at 20% with Clariant PE94000804, are compared with bottles having layers according to the invention and colored with 3% of the middle layer at 60% (inner layer) with Clariant PE94000797 and 3% of the outer layer at 20% with Clariant PE94000804 (Ex. 2 and Ex. 3). Weight ratio of outer and inner layer Outer layer material % by weight Inner layer material % by weight Second inner layer % by weight Comp. B 20:60:20 J-PCR 20 J-PCR 60 J-PCR 20 Ex. 2 20:60:20 N-PCR 20 J-PCR 60 N-PCR 20 Ex. 3 20:60:20 N-PCR 20 J-PCR + N-PCR 30 + 30 N-PCR 20 RozAnn / zznz / E / YiAi The resulting color of the bottle in Comp. B was grayer, even though it was colored with a master batch of black color (inner layer Clariant PE94000797 and outer layer Clariant PE94000804). The desired consumer-acceptable black was obtained in the bottles of Ex. 2 and Ex. 3, which had layers according to the invention, but not in Comp. B.

Claims

1. A sustainable packaging article comprising a multilayer post-consumer (PCR) resin characterized in that the multilayer comprises: a) an outer layer comprising a post-consumer resin of natural plastic waste (N-PCR); and b) an inner layer comprising post-consumer resin of natural plastic waste (NPCR) or colored plastic waste (J-PCR) wherein at least 50% of the inner layer comprises post-consumer resin of the colored plastic waste (J-PCR), wherein the outer and / or inner layer comprises a master batch of NIR-detectable colorant and wherein the article is substantially free of natural plastic, meaning that the article comprises less than 5% by weight of natural plastic.

2. The article according to claim 1, further characterized in that the inner layer comprises 100% colored plastic waste (J-PCR).

3. The article in accordance with any of the preceding claims, further characterized in that the weight ratio of the outer layer to the inner layer is from 99:1 to 1:99, preferably from 1:3 to 1:5, most preferably from 1:

4.

4. The article according to claims 1 or 2, further characterized in that the multilayer comprises a second inner layer.

5. The article in accordance with any of the preceding claims, further characterized in that the master batch of NIR detectable dye is black.

6. The article in accordance with any of the preceding claims, further characterized in that the plastic residue is a high-density polyethylene (HDPE) residue.

7. The article in accordance with any of the preceding claims, further characterized in that the article comprises less than 3%, more preferably 0%, of natural plastic.

8. The article in accordance with any of the preceding claims, further characterized in that the article is a container.

9. The article in accordance with any of the claims, further characterized in that the article is a non-food grade article.

10. Use of the article according to any of claims 1 to 9, for packaging fast-moving consumer goods (FMCG).