Polyethylene Terephthalate (PET) / Polyethylene Terephthalate Glycol (PETG) Material, Substrate with such Material, and Forming Method

Abstract

A modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material is disclosed as including polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt% (preferably 85-99 wt%); a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt% (preferably 0.5-4 wt%); a cross-linker in an amount of 0.1-5 wt% (preferably 0.5-2 wt %); and optionally, a color masterbatch in an amount of not more than 18 wt%.

Description

Polyethylene Terephthalate (PET) / Polyethylene Terephthalate Glycol (PETG) Material,Substrate with such Material, and Forming Method 

[0001] FIELD OF THE INVENTION

[0002] The present invention relates to a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PET-G or PETG) material with accelerated anaerobic biodegradability, card substrate with such a material, card with such a card substrate, methods of forming such a PET / PETG material, such a card substrate, and such a card.  

[0003] BACKGROUND OF THE INVENTION

[0004] Integrated circuit (IC) cards (also referred to as “smart cards”) are very common in the modern society, as they are widely used, for example, for such purposes as personal identification, non-cash payments, membership subscriptions, access restrictions for security reasons, and the like. Smart cards are typically made of a plastics substrate with circuitry (including at least one integrated circuit (IC) module) fixedly engaged therewith, e.g., by being embedded therein. Many smart cards are not reusable and will be destroyed at the end of their life. Discarded smart cards (because of the plastics material with which the card substrate is made) are difficult to degrade naturally and are considered a major environmental pollutant. Increasing consumer awareness of sustainability has prompted the industry to develop smart cards with eco-friendly materials to reduce environmental pollution. 

[0005] The methods commonly used in the industry to improve the degradation performance of plastic is by adding a small amount of additives to the plastic. “Oxo-degradable” additives with oxidant components which are available in the market have been developed and adopted in the plastic industry for years. However, the oxo-degradation mechanism may cause oxo-fragmentation and microplastic issue. Thus, such “oxo-degradable” additives may be banned by many regions in the world. Unlike oxo-additives, additives of anaerobic biodegradation do not contain oxidant components, and thus oxo-fragmentation can be avoided. Under the landfill condition, additives of anaerobic biodegradation attract microbes onto the plastic surface to initiate anaerobic biodegradation to generate biomass and enzymes, which facilitate biofilm formation and accelerate biodegradation, which may be referred to as “biodigestion.” 

[0006] US Patent Application Publication Number US2023 / 0151194 A1 discloses an additive for accelerated biodegradation of common plastic, including polyethylene (PE), polypropylene (PP), poly(ethylene-vinyl acetate)(EVA), polystyrene (PS), polyoxymethylene (POM), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polyamides (PA), polycarbonate (PC), polyurethanes (PU), thermoplastic elastomer (TPE), cellulose acetate (CA), polyvinyl chloride (PVC), polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polybutylene succinate (PBS), polycaprolactone (PCL), polybutylene adipate terephthalate (PBAT), polyglycolic acid (PGA), and poly(lactic-co-glycolic acid) (PLGA) for the application in plastic bags and food contact safe products. However, the effect of the additive on the degradation performance of specific polymer (like polyethylene terephthalate glycol (PETG)) and the practical application of PETG incorporated with additives in substrates for cards (in particular smart cards) have not thus far been fully considered. 

[0007] It is thus an objective of the present invention to provide a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, a substrate made at least partly of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, a card including a substrate made at least partly of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, a radio frequency identification (RFID) tag including a substrate made at least partly of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, a method of forming a masterbatch of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, a method of forming a substrate with a modified PET / PETG material, a method of forming a card, and a method of forming a radio frequency identification (RFID) tag, in which the aforesaid shortcomings are mitigated, or at least to provide useful alternatives to the trade and public. 

[0008] SUMMARY OF THE INVENTION

[0009] According to a first embodiment of the present invention, there is provided a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, including polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt% (preferably 85-99 wt%); a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt% (preferably 0.5-4 wt%); a cross-linker in an amount of 0.1-5 wt% (preferably 0.5-2 wt%); and optionally, a color masterbatch in an amount of not more than 18 wt%. 

[0010] Advantageously, the ADG masterbatch may include polyethylene terephthalate glycol (PETG) as a masterbatch carrier in an amount of 40-70 wt% (preferably 45-55 wt%); a component with biodegradability in an amount of 20-50 wt% (preferably 40-50 wt%); a bioactive component in an amount of 5-25 wt% (preferably 5-10 wt%); and a cross-linker in an amount of 0.1-5 wt% (preferably 3-4 wt%). 

[0011] Suitably, the ADG masterbatch may further include a wetting agent in an amount of up to 5 wt% (preferably 2-3 wt%). 

[0012] Preferably, the crystallinity of said component with biodegradability may be similar to that of polyethylene terephthalate glycol (PETG). 

[0013] The component with biodegradability may advantageously be of an amorphous model of the component with biodegradability for PETG and of a polyester structure. 

[0014] The component with biodegradability may suitably include amorphous oligomer or polymer of polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHAs), polycaprolactone (PCL), polybutylene adipate terephthalate (PBAT), or a combination thereof. 

[0015] The component with biodegradability may preferably be adapted to initiate and facilitate biodegradation in anaerobic conditions. 

[0016] Advantageously, the bioactive component may include bioactive polymers. 

[0017] Suitably, the bioactive component may include polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), gelatin, chitosan, starch, cellulose, or a combination thereof. 

[0018] Preferably, the cross-linker may chemically cross-link said polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG), said component with biodegradability and said bioactive component. 

[0019] The cross-linker may advantageously include diepoxides, epoxidized soybean oil, bis-oxazolidine, glycidyl methacrylate-styrene copolymer, modified styrene acrylic polymers, maleic anhydride, Tung oil anhydride, or a combination thereof. 

[0020] The wetting agent may suitably be adapted to facilitate water-uptake by the modified PET / PETG material during biodegradation. 

[0021] The wetting agent may preferably include polysorbates, sorbitan esters, alkylphenol ethoxylates, gum arabic, oxgall, fatty acids, or a combination thereof. 

[0022] According to a second aspect of the present invention, there is provided a substrate made at least partly of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, said material including polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; a cross-linker in an amount of 0.1-5 wt%; and optionally, a color masterbatch in an amount of not more than 18 wt%. 

[0023] According to a third aspect of the present invention, there is provided a card including a substrate made at least partly of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, said material including polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; a cross-linker in an amount of 0.1-5 wt%; and optionally, a color masterbatch in an amount of not more than 18 wt%. 

[0024] Advantageously, the card may be a smart card with an integrated circuit (IC) module. 

[0025] According to a fourth aspect of the present invention, there is provided a radio frequency identification (RFID) tag including a substrate made at least partly of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, said material including polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; a cross-linker in an amount of 0.1-5 wt%; and optionally, a color masterbatch in an amount of not more than 18 wt%. 

[0026] According to a fifth aspect of the present invention, there is provided a method of forming a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, including (i) homogenizing and mixing (a) polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; (b) a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; (c) a cross-linker in an amount of 0.1-5 wt%; and (d) optionally, a color masterbatch in an amount of not more than 18 wt%; at room temperature to form a mixture, and (ii) extruding said mixture at 200-290 °C to obtain said polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material in molten form. 

[0027] According to a sixth aspect of the present invention, there is provided a method of forming a substrate with a modified PET / PETG material, said modified PET / PETG material including (a) polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; (b) a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; (c) a cross-linker in an amount of 0.1-5 wt%; and (d) optionally, a color masterbatch in an amount of not more than 18 wt%; wherein said method includes (i) homogenizing said ingredients (a), (b), (c) and, optionally, (d) at room temperature to form a mixture; and (ii) extruding said mixture at 200-290 °C to obtain said modified PET / PETG in a film / sheet form. 

[0028] Advantageously, the method may include homogenizing and extruding said ingredients (a), (b), (c) and, optionally, (d) in an extrusion-sheet production system with multiple feeders at 200-290 °C to obtain the modified PET / PETG in a film / sheet form. 

[0029] According to a seventh aspect of the present invention, there is provided a method of forming a card, including (i) forming a substrate; and (ii) fixedly engaging an integrated circuit (IC) module with said substrate; wherein the substrate is formed by a method of forming a substrate with a modified PET / PETG material, said modified PET / PETG material including (a) polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; (b) a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; (c) a cross-linker in an amount of 0.1-5 wt%; and (d) optionally, a color masterbatch in an amount of not more than 18 wt%; wherein said method includes (1) homogenizing said ingredients (a), (b), (c) and, optionally, (d) at room temperature to form a mixture; and (2) extruding said mixture at 200-290 °C to obtain said modified PET / PETG in a film / sheet form. 

[0030] Advantageously, the card may be an integrated circuit (IC) card. 

[0031] According to an eighth aspect of the present invention, there is provided a method of forming a radio frequency identification (RFID) tag including (i) forming a substrate; and (ii) fixedly engaging an RFID module with said substrate; wherein the substrate is formed by a method of forming a substrate with a modified PET / PETG material, said modified PET / PETG material including (a) polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; (b) a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; (c) a cross-linker in an amount of 0.1-5 wt%; and (d) optionally, a color masterbatch in an amount of not more than 18 wt%; wherein said method includes (1) homogenizing said ingredients (a), (b), (c) and, optionally, (d) at room temperature to form a mixture; and (2) extruding said mixture at 200-290 °C to obtain said modified PET / PETG in a film / sheet form. 

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the present invention will now be described, as examples only, with reference to the accompanying drawings, in which:

[0034] Figure 1A shows schematically the formation of a masterbatch for accelerating anaerobic digestion (ADG) according to an embodiment of the present invention;

[0035] Figure 1B shows masterbatch for ADG according to an embodiment of the present invention, and the oval portion is an enlarged part of the main part of Figure 1B;

[0036] Figure 2 shows schematically the formation of a substrate made of a modified PET / PETG material according to an embodiment of the present invention;

[0037] Figure 3 shows biodegradability of a modified PET / PETG material according to an embodiment of the present invention compared with a PETG control under ASTM D5511 biodegradation test;

[0038] Figure 4 shows a flowchart of production of a substrate of a modified PET / PETG material according to an embodiment of the present invention;

[0039] Figure 5 shows a card with substrates of a modified PET / PETG material according to an embodiment of the present invention;

[0040] Figure 6A shows a radio frequency identification (RFID) tag with a substrate of a modified PET / PETG material according to an embodiment of the present invention; and

[0041] Figure 6B shows a number of the RFID tags of Figure 6A formed on a length of base material. 

[0042] DESCRIPTION OF THE EMBODIMENTS

[0043] PETG is an amorphous thermoplastic of the very commonly known polyethylene terephthalate (PET) family, normally by adding a certain amount of cyclohexanedimethanol (CHDM) to the PET polymer in place of ethylene glycol, making it an amorphous polymer with low crystallinity. PETG can be easily vacuumed and pressure-formed, and can be heat-bended thanks to its low forming temperature level(s). Therefore, PETG has recently attracted the interest as a quite novel and promising material in the field of processing and manufacturing. However, like other plastics, PETG also has the problem of being difficult to degrade, which can cause pollution in daily life. 

[0044] This invention provides a modified PET / PETG material, which has been developed by introducing a masterbatch based on PETG for accelerating anaerobic biodegradation / digestion (hereinafter referred to as “PETG masterbatch for anaerobic digestion” or “ADG”). The modified PET material (hereinafter referred to as “PETa”) or modified PETG material (hereinafter referred to as “PETGa”) includes PET or PETG, ADG masterbatch, cross-linker and, optionally, color masterbatch. The ADG masterbatch includes PETG as masterbatch carrier, component(s) with biodegradability, bioactive component(s), cross-linker(s) and, optionally, wetting agent. 

[0045] The modified PET material or PETG material may be made of recycled PET (hereinafter referred to as “rPET”) or recycled PET material (hereinafter referred to as “rPETG”). Similarly, the modified recycled PET material (hereinafter referred to as “rPETa”) and modified recycled PETG material (hereinafter referred to as “rPETGa”) include, respectively, rPET and rPETG, and ADG masterbatch, cross-linker and, optionally, color masterbatch. 

[0046] In addition, in order to meet the high requirements for uniformity in the manufacturing process and product of the card substrate and, thus the cards, on the one hand, PETG is used as the carrier of ADG masterbatch. Components with biodegradability with crystallization properties similar to those of PETG are selected to improve the uniformity of the prepared ADG masterbatch. On the other hand, PETG carrier and PET / PETG host polymeric material have good compatibility. Finally, in the preparation process of the ADG masterbatch and the mixing process of the ADG masterbatch and host polymeric material PET / PETG, cross-linker is introduced, which can realize the chemical cross-linking between polymers (inside masterbatch and between additives and host polymeric material PET / PETG) to improve the uniformity of products. 

[0047] Compared with substrates made with common PET / PETG, substrates made with the modified PET / PETG material have comparable properties (including whiteness, tensile strength, elongation at break, shelf life, roughness, surface tension, and vicat temperature), negligible cost increment, and accelerated anaerobic biodegradability, offering an economical solution for sustainability development of the smart card industry. 

[0048] According to the present invention, the ADG masterbatch may be prepared in a masterbatch form by a method shown schematically in Figure 1A. As shown in Figure 1A, virgin or recycled PETG pellets are combined with other components (including a component with biodegradability, a bioactive component, and a cross-linker) and homogenized in a mixer, and the resultant mixed material is subsequently extruded. After cooling and palletization, ADG masterbatch is formed, which could enhance anaerobic biodegradation when added to such other plastic material as PETG and PET. As shown schematically in Figure 1B, the ADG masterbatch includes PETG 10, component(s) with biodegradability and / or bioactive component(s) 12, cross-linker(s) 14 and other functional component(s) 16, such as a wetting agent. 

[0049] Figure 2 shows the illustration of a process for forming sheets of the modified PET material (PETa) / PETG material (PETGa). In particular, virgin or recycled PETG pellets are combined, mixed and homogenized with an ADG masterbatch according to the present invention, one or more cross-linkers and a color masterbatch (if necessary) in an extrusion-sheet production system. Substrate of a modified PET / PETG material according to the present invention is then extruded as shown in Figure 2. 

[0050] Figure 3 shows the masterbatch for accelerating anaerobic digestion (ADG) of the modified PETG material, with 11.50% biodegradation at Day 90 and 23.77% biodegradation at Day 180, while PETG control sample showed only 0.49% biodegradation at Day 90, under ASTM D5511 tests. It can thus be seen that, according to ASTM D5511 biodegradation test method, a card substrate produced by a sheet of the modified PETG material sheet has a more than 20 times accelerated biodegradability compared to common PETG card substrate. 

[0051] The component with biodegradability is to initiate and accelerate the biodegradation in anaerobic conditions, and its crystallinity is similar to PETG, preferably an amorphous model of the component and a polyester structure to improve the compatibility of PETG carrier with the component with biodegradability. The component with biodegradability includes amorphous oligomer or polymer of polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHAs), polycaprolactone (PCL), polybutylene adipate terephthalate (PBAT), or a combination thereof. 

[0052] The bioactive component is to initiate and facilitate biodegradation in anaerobic conditions, and includes bioactive polymers, such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), gelatin, chitosan, starch, cellulose, or a combination thereof. 

[0053] The cross-linker is to chemically cross-link the PET / PETG, the component with biodegradability and the bioactive component, so as to chemically introduce the structure with biodegradability in PETG, and to improve the compatibility of the bioactive component and the component with biodegradability with PETG. The cross-linker may include diepoxides, epoxidized soybean oil, bis-oxazolidine, glycidyl methacrylate-styrene copolymer, modified styrene acrylic polymers, maleic anhydride, Tung oil anhydride, or a combination thereof. 

[0054] The wetting agent is to facilitate water-uptake by the modified PET / PETG material during biodegradation in the soil to accelerate biodegradation, and includes polysorbates, sorbitan esters, alkylphenol ethoxylates, gum arabic, oxgall, fatty acids, or a combination thereof. 

[0055] Figure 4 shows a flowchart of the steps of producing a substrate of a modified PET / PETG material according to an embodiment of the present invention. 

[0056] Broadly speaking, the steps include:Pre-fabrication of functional masterbatch: PET / PETG resin, one or more component with biodegradability, one or more bioactive components, one or more cross-linker, and one or more wetting agent are proportionally weighed and mixed by high-speed mixer for 3-5 minutes, then fed into a twin-screw extruder with temperature set at 175-220 oC and extruded into strips through the holes of the molds, and then water-cooled and dried and cut into granules to produce the functional masterbatch (i.e., the ADG masterbatch). Mixing and drying: All the materials of the component formula (including PET / PETG material, the above functional masterbatch (i.e., ADG masterbatch), and (optionally) color masterbatch and online recycled crushed scrap of rPET / rPETG are put into a dryer for mixing and drying. The materials are continuously dried by hot air of 60-120 oC for not less than 4 hours to ensure that the water in the raw materials is fully discharged. The rPET / rPETG is scrap material formed of the same composition, and is crushed to fragments of a size of less than 10 mm, and constitute 0-40% wt% of the final material.Extrusion: The mixed ingredients after the above treatment are fed into an extruder through the screw, and the temperature of the extruder is 200-290 oC. The mixed ingredients are melted to reach the molten state.Mold head molding: The molten plastic is then extruded into film / sheet through the adjusted gap between the mold lips. The temperature of the mold head is set at 200-290 oC.Calendering and shaping: The film obtained after the above is calendered by a calendering machine with customized pattern and roughness to obtain the required thickness of the film, the thickness range is 40 μm-350 μm.Cooling and thickness measurement: The film obtained after the previous step is cooled and shaped, cooled to room temperature. Thickness distribution detection of the film thus obtained is monitored by infrared radiation thickness measurement, to monitor the uniformity of the thickness of the film.Trimming, traction, sheet / film roll collection and cutting into sheets: Trim both sides of the film from the above step to remove the uneven thickness of both sides. The film is then sent to the back by the traction machine or cut into finished products. 

[0057] Figure 5 shows an exploded view of a card with substrates of a modified PET / PETG material according to an embodiment of the present invention. 

[0058] As shown in Figure 5, a card 20, such as an integrated circuit (IC) card (also called a smart card) is shown includes an inner substrate 22 sandwiched between two outer substrates 24. The inner substrate 22 is made of common virgin / recycled PETG, and the outer substrates 24 are made of a modified PET / PETG material according to an embodiment of the present invention.  

[0059] An antenna coil 26 is formed on a major surface of the inner substrate 22 and electrically connected with an integrated circuit (IC) module 28 fixedly engaged with the inner substrate 22, to enable contactless or dual-interface (both contact and contactless) data communication between the card 20 and the outside environment (such as a card reader).  

[0060] Similarly, a radio frequency identification (RFID) module may be fixedly engaged with a substrate made of a modified PET / PETG material according to an embodiment of the present invention to form an RFID tag. 

[0061] A top view of an RFID tag 30 is shown in Figure 6A, which is formed of a substrate 32 made of a modified PET / PETG material according to the present invention, on a major surface 34 of which are fixedly engaged an RFID die / chip 36 and an aluminum antenna 38. The RFID die / chip 36 and aluminum antenna 38 are electrically connected with each other to enable data communication between the RFID die / chip 36 and the outside environment (such as an RFID reader). Figure 6B shows a number of RFID tags 30 of Figure 6A formed on a length of base material 40, from which each individual RFID tag 30 may be detached separately. 

[0062] Example 1

[0063] PET resin (80-98.8 wt%), color masterbatch (0-18 wt%), ADG masterbatch (0.2-5 wt%), cross-linker (1-5 wt%) and on-line crushed material (0-40 wt%) are provided according to the mass ratio. Put the resin and online crushed material, color masterbatch and functional masterbatch in the component formula into the dryer for mixing, and stir them through 120±2 oC, 60±2 oC, 60±2 oC continuous hot air, for a duration of not less than 4 hours, to ensure that the water in the raw materials can be fully discharged. The processed ingredients are transported into the extruder through the screw according to the mass ratio. The temperature of the extruder is 250-290 oC, which melts and plasticizes the mixed ingredients to reach a molten state. The molten material is extruded into the film / sheet through the adjusted gap of the die lip, and the temperature of the die head is set at 250-290 °C. The film / sheet obtained after treatment is calendered and shaped by a calenderer with customized patterns and roughness to obtain a film / sheet of the required thickness, with a thickness range of 40 μm-350 μm. The film / sheet is cooled and shaped, cooled to room temperature, and then subjected to infrared thickness measurement to check the thickness distribution and to monitor the thickness uniformity of the process. The resulting film / sheet is trimmed on both sides to remove the uneven thickness on both sides, and then sent to the rear by a tractor to be rolled or cut into finished products.  

[0064] Example 2

[0065] rPET resin (20-98.8 wt%), PET resin (0-80 wt%), color masterbatch (0-18 wt%), ADG masterbatch (0.2-5 wt%), cross-linker (1-5 wt%) and on-line crushed material (0-40 wt%) are provided according to the mass ratio. Put the resin and online crushed material, color masterbatch and ADG masterbatch in the component formula into the dryer for mixing, and stir them through 120±2 oC, 60±2 oC, 60±2 oC continuous hot air, for a duration of not less than 4 hours, to ensure that the water in the raw materials can be fully discharged. The processed ingredients are transported into the extruder through the screw according to the mass ratio. The temperature of the extruder is 250-290 oC, which melts and plasticizes the mixed ingredients to reach a molten state. The molten material is extruded into the film through the adjusted gap of the die lip, and the temperature of the die head is set at 250-290 °C. The film / sheet obtained after treatment is calendered and shaped by a calenderer with customized patterns and roughness to obtain a film / sheet of the required thickness, with a thickness range of 40 μm-350 μm. The film / sheet is cooled and shaped, cooled to room temperature, and then subjected to infrared thickness measurement to check the thickness distribution and to monitor the thickness uniformity of the process. The resulting film / sheet is trimmed on both sides to remove the uneven thickness on both sides, and then sent to the rear by a tractor to be rolled or cut into finished products. 

[0066] Example 3

[0067] PETG resin (80-99.7 wt%), color masterbatch (0-18 wt%), ADG masterbatch (0.2-5 wt%), cross-linker (0.1-2 wt%) and on-line crushed material (0-40 wt%) are provided according to the mass ratio. Put the resin and online crushed material, color masterbatch and ADG masterbatch in the component formula into the dryer for mixing, and stir them through 60±2 oC, 60±2 oC, 60±2 oC continuous hot air, for a duration of not less than 4 hours, to ensure that the water in the raw materials can be fully discharged. The processed ingredients are transported into the extruder through the screw according to the mass ratio. The temperature of the extruder is 200-250 oC, which melts and plasticizes the mixed ingredients to reach a molten state. The molten material is extruded into the film through the adjusted gap of the die lip, and the temperature of the die head is set at 200-250 °C. The film / sheet obtained after treatment is calendered and shaped by a calenderer with customized patterns and roughness to obtain a film / sheet of the required thickness, with a thickness range of 40 μm-350 μm. The film / sheet is cooled and shaped, cooled to room temperature, and then subjected to infrared thickness measurement to check the thickness distribution and to monitor the thickness uniformity of the process. The resulting film / sheet is trimmed on both sides to remove the uneven thickness on both sides, and then sent to the rear by a tractor to be rolled or cut into finished products. 

[0068] Example 4

[0069] rPETG resin (20-99.7 wt%), PETG resin (0-80 wt%), color masterbatch (0-18 wt%), ADG masterbatch (0.1-5 wt%), cross-linker (0.1-2 wt%) and on-line crushed material (0-40 wt%) are provided according to the mass ratio. Put the resin and online crushed material, color masterbatch and functional masterbatch in the component formula into the dryer for mixing, and stir them through 60±2 oC, 60±2 oC, 60±2 oC continuous hot air, for a duration of not less than 4 hours, to ensure that the water in the raw materials can be fully discharged. The processed ingredients are transported into the extruder through the screw according to the mass ratio. The temperature of the extruder is 200-250 oC, which melts and plasticizes the mixed ingredients to reach a molten state. The molten material is extruded into the film through the adjusted gap of the die lip, and the temperature of the die head is set at 200-250 °C. The film / sheet obtained after treatment is calendered and shaped by a calenderer with customized patterns and roughness to obtain a film / sheet of the required thickness, with a thickness range of 40 μm-350 μm. The film / sheet is cooled and shaped, cooled to room temperature, and then subjected to infrared thickness measurement to check the thickness distribution and to monitor the thickness uniformity of the process. The resulting film / sheet is trimmed on both sides to remove the uneven thickness on both sides, and then sent to the rear by a tractor to be rolled or cut into finished products. 

[0070] It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and / or alterations may be made thereto without departing from the spirit of the invention. It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.

Claims

1. A modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, including:polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%;a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%;a cross-linker in an amount of 0.1-5 wt%; andoptionally, a color masterbatch in an amount of not more than 18 wt%.

2. The material according to Claim 1, wherein said ADG masterbatch includes:polyethylene terephthalate glycol (PETG) as a masterbatch carrier in an amount of 40-70 wt%; a component with biodegradability in an amount of 20-50 wt%; a bioactive component in an amount of 5-25 wt%; and a cross-linker in an amount of 0.1-5 wt%.

3. The material according to Claim 2, wherein said ADG masterbatch further includes a wetting agent in an amount of up to 5 wt%.

4. The material according to Claim 2, wherein the crystallinity of said component with biodegradability is similar to that of polyethylene terephthalate glycol (PETG).

5. The material according to Claim 2, wherein said component with biodegradability is of an amorphous model of the component with biodegradability for PETG and of a polyester structure.

6. The material according to Claim 2, wherein said component with biodegradability includes amorphous oligomer or polymer of polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHAs), polycaprolactone (PCL), polybutylene adipate terephthalate (PBAT), or a combination thereof.

7. The material according to Claim 2, wherein said component with biodegradability is adapted to initiate and facilitate biodegradation in anaerobic conditions.

8. The material according to Claim 2, wherein said bioactive component includes bioactive polymers.

9. The material according to Claim 2, wherein said bioactive component includes polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), gelatin, chitosan, starch, cellulose, or a combination thereof.

10. The material according to Claim 2, wherein said cross-linker chemically cross-links said polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG), said component with biodegradability and said bioactive component.

11. The material according to Claim 2, wherein said cross-linker includes diepoxides, epoxidized soybean oil, bis-oxazolidine, glycidyl methacrylate-styrene copolymer, modified styrene acrylic polymers, maleic anhydride, Tung oil anhydride, or a combination thereof.

12. The material according to Claim 3, wherein said wetting agent is adapted to facilitate water-uptake by the modified PET / PETG material during biodegradation.

13. The material according to Claim 3, wherein said wetting agent includes polysorbates, sorbitan esters, alkylphenol ethoxylates, gum arabic, oxgall, fatty acids, or a combination thereof.

14. A substrate made at least partly of a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material according to Claim 1.

15. A card including a substrate according to Claim 14.

16. The card according to Claim 15, wherein said card is a smart card with an integrated circuit (IC) module.

17. A radio frequency identification (RFID) tag including a substrate according to Claim 14.

18. A method of forming a modified polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material, including:(i) homogenizing and mixing:(a) polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; (b) a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; (c) a cross-linker in an amount of 0.1-5 wt%; and(d) optionally, a color masterbatch in an amount of not more than 18 wt%;at room temperature to form a mixture, and(ii) extruding said mixture at 200-290 °C to obtain said polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) material in molten form.

19. A method of forming a substrate with a modified PET / PETG material, said modified PET / PETG material including:(a) polyethylene terephthalate (PET) / polyethylene terephthalate glycol (PETG) in an amount of 80-99.7 wt%; (b) a masterbatch for accelerating anaerobic digestion (ADG) in an amount of 0.2-10 wt%; (c) a cross-linker in an amount of 0.1-5 wt%; and(d) optionally, a color masterbatch in an amount of not more than 18 wt%; wherein said method includes:(i) homogenizing said ingredients (a), (b), (c) and, optionally, (d) at room temperature to form a mixture; and (ii) extruding said mixture at 200-290 °C to obtain said modified PET / PETG in a film / sheet form.

20. The method of Claim 19, including homogenizing and extruding said ingredients (a), (b), (c) and, optionally, (d) in an extrusion-sheet production system with multiple feeders at 200-290 °C to obtain the modified PET / PETG in a film / sheet form.

21. A method of forming a card, including:(i) forming a substrate according to Claim 19; and(ii) fixedly engaging an integrated circuit (IC) module with said substrate.

22. The method of Claim 21, wherein said card is an integrated circuit (IC) card.

23. A method of forming a radio frequency identification (RFID) tag including:(i) forming a substrate according to Claim 19; and(ii) fixedly engaging an RFID module with said substrate. 

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