A polyester substrate for an antistatic release film and a method for preparing the same

Abstract

The present application relates to the technical field of thin film materials, and particularly relates to a polyester substrate for antistatic release film and a preparation method thereof. The polyester substrate for antistatic release film comprises a polyester matrix layer and a coating layer coated on the upper surface and / or lower surface of the polyester matrix layer. The polyester matrix layer is made of polyester and an antistatic agent. The antistatic agent is dispersed in the polyester to form a three-dimensional conductive network. The coating layer and the polyester matrix layer are co-crystallized or chain segment entangled to form an integrated anchor. The polyester substrate for antistatic release film and the preparation method thereof aim to solve the problem that the antistatic performance of the release film substrate and the firm adhesion of the downstream offline coating release agent are difficult to achieve simultaneously.

Description

Technical Field

[0001] This invention relates to the field of thin film materials technology, specifically to a polyester substrate for antistatic release film and its preparation method. Background Technology

[0002] In the application of TPU (Polyether Thermoplastic Polyurethane) protective film for paint protection films, the release film, also known as the backing film or construction film, serves to protect the adhesive layer and aid in shaping. It is typically adhered to the adhesive side of the TPU film, protecting the adhesive layer from contamination and preventing the roll material from sticking together. During application, the release film needs to be peeled off from the TPU adhesive surface; this process is called "release."

[0003] Release films are typically made of BOPET (biaxially oriented polyethylene terephthalate) film as the substrate, coated with a release agent, primarily silicone. BOPET is the mainstream choice for release film substrates due to its excellent mechanical strength, dimensional stability, and temperature resistance (long-term temperature resistance up to 180℃, short-term resistance up to 200℃).

[0004] However, both BOPET and silicone are highly insulating materials, with surface resistivity typically as high as 10⁻⁶. 12 Ω / sq. or higher. During the winding, unwinding, and rapid peeling processes of release film, friction between films and rapid separation of the film from the adhesive layer easily generate and accumulate static charge. The presence of static charge can lead to a series of problems: 1. Charged release film can attract tiny particles such as dust and hair from the air. When these impurities fall onto the TPU adhesive layer and adhere to the paint surface, they can cause bubbles, bumps, or even delamination, seriously affecting the construction quality.

[0005] 2. Electrostatic adsorption makes it difficult to separate the release film from the TPU film, or the film may float or stick together after separation, affecting construction efficiency.

[0006] 3. In extreme cases, electrostatic discharge may damage the vehicle's sensitive electronic equipment.

[0007] Existing technologies typically address static electricity problems in two ways: Surface coating with antistatic agents: Antistatic agents such as quaternary ammonium salts or polythiophene are coated onto the release film surface. This method first coats an antistatic coating onto the BOPET substrate surface, and then coats an organosilicon release layer on top of the antistatic coating, forming a three-layer structure of BOPET substrate-antistatic coating-release layer. However, the antistatic coating applied to the release film surface is prone to friction and peeling off, has poor water resistance, and its antistatic effect deteriorates significantly over time. Poor compatibility between the antistatic coating and the release layer can easily lead to uneven application of the release agent or decreased adhesion. Two coats of antistatic coating + release coating are required, increasing production steps and equipment investment. Small molecule antistatic agents may migrate to the release layer surface, thereby contaminating the TPU adhesive layer and affecting the adhesion performance of the car cover.

[0008] Adding antistatic agents to the release agent: Antistatic components are added to the silicone oil release agent. The structure is an antistatic release coating + PET substrate, that is, the antistatic agent is directly mixed into the release agent to achieve integrated "antistatic + release" coating. However, directly adding antistatic agents, especially particulate conductive fillers, to the release agent can affect the curing reaction of the release agent, and the addition of antistatic agents can change the surface properties of the release layer, resulting in unstable or fluctuating release force.

[0009] Therefore, the inventors provide a polyester substrate for antistatic release film and a method for preparing the same. Summary of the Invention

[0010] (1) Technical problems to be solved This invention provides a polyester substrate for antistatic release film and its preparation method, solving the technical problem that it is difficult to simultaneously achieve the antistatic properties of the release film substrate and ensure the firm adhesion of the release agent applied offline downstream.

[0011] (2) Technical solution The present invention provides a polyester substrate for antistatic release film, comprising a polyester matrix layer and a coating applied to the upper and / or lower surfaces of the polyester matrix layer, wherein the polyester matrix layer is made of polyester and an antistatic agent, the antistatic agent is dispersed within the polyester to form a three-dimensional conductive network, and the coating and the polyester matrix layer undergo co-crystallization or segment entanglement to form an integral anchor.

[0012] Furthermore, the antistatic agent is a polyether ester amide block copolymer or a polyether ester elastomer.

[0013] Furthermore, the polyester matrix layer includes an upper surface layer, a lower surface layer, and a core layer located between the upper surface layer and the lower surface layer. The upper surface layer and the lower surface layer each include 5-25 wt.% antistatic masterbatch, 15-30 wt.% slip agent masterbatch, and 45-80 wt.% PET chips. The core layer includes 0-5 wt.% antistatic masterbatch and 95-100 wt.% PET chips.

[0014] Furthermore, the thickness of the coating is 10–100 nm.

[0015] Furthermore, the dry weight of the coating is 0.01–0.1 g / m³. 2 .

[0016] Furthermore, the surface resistivity of the polyester substrate is 1×10⁻⁶. 7 ~1×10 10 Ω / sq.

[0017] Furthermore, the surface wetting tension of the coating is ≥52mN / m.

[0018] Furthermore, the coating is a compound of waterborne copolyester and crosslinking agent.

[0019] This invention also provides a method for preparing a polyester substrate for an antistatic release film, comprising the following steps: The main extrusion raw material and the auxiliary extrusion raw material are melt-extruded separately and then co-extruded through a die to form a polyester matrix casting sheet; The polyester matrix casting is longitudinally stretched, and a coating is applied to the upper and / or lower surfaces of the stretched polyester matrix casting. The coated polyester substrate casting is subjected to transverse stretching, heat setting and cooling in sequence to obtain polyester substrate for antistatic release film.

[0020] Furthermore, the step of separately melting and extruding the main extrusion raw material and the auxiliary extrusion raw material, and then co-extruding them through a die to form a polyester matrix casting, specifically includes the following steps: The main extrusion material and the auxiliary extrusion material are melt-extruded separately and filtered to obtain the main extrusion melt as the core layer and the auxiliary extrusion melt as the surface layer. The main extrusion melt and the auxiliary extrusion melt are co-extruded through a die to form the polyester matrix casting; The main extrusion raw material consists of 0-5 wt.% antistatic masterbatch and 95-100 wt.% PET chips, while the auxiliary extrusion raw material consists of 5-25 wt.% antistatic masterbatch, 15-30 wt.% slip agent masterbatch, and 45-80 wt.% PET chips.

[0021] (3) Beneficial effects In summary, this invention achieves volumetric conductivity rather than surface coating by adding an antistatic agent within the substrate, thereby forming fine layered or mesh-like conductive channels. Utilizing the microscopic phase separation structure between the antistatic agent and PET, a three-dimensional conductive network is constructed within the film. The antistatic agent does not rely on migration to the surface to function; therefore, the antistatic properties are permanent, abrasion-resistant, and washable, and it does not contaminate the TPU adhesive layer. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a polyester substrate for antistatic release film provided in an embodiment of the present invention; Figure 2 This is a schematic flowchart of a method for preparing a polyester substrate for an antistatic release film provided in an embodiment of the present invention.

[0024] In the picture: 1-Polyester matrix layer; 101-Upper surface layer; 102-Lower surface layer; 103-Core layer; 2-Coating. Detailed Implementation

[0025] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] A first aspect of the present invention provides a polyester substrate for an antistatic release film, see [link to previous document]. Figure 1 It may include a polyester matrix layer 1 and a coating 2 applied to the upper and / or lower surfaces of the polyester matrix layer 1, wherein the polyester matrix layer 1 is made of polyester and an antistatic agent, the antistatic agent is dispersed in the polyester to form a three-dimensional conductive network, and the coating 2 co-crystallizes or segments entangle with the polyester matrix layer 1 to form an integral anchor.

[0028] In the above embodiments, a dual-layer synergistic structure is adopted: polyether ester amide is added to the substrate to form a permanent conductive network, solving the problems of antistatic durability, abrasion resistance, and no exudation. An online-coated polyester undercoat restores high surface energy and provides chemical anchoring sites, solving the release agent adhesion problem. These two measures are not simply superimposed, but rather complementary and synergistic. The antistatic agent is uniformly dispersed within the substrate, forming a three-dimensional conductive network (volume conductivity), independent of surface migration. Therefore, the antistatic performance is unaffected by friction, washing, or time, and is synchronized with the film's lifespan. Surface-coated antistatic coatings are easily worn, and their antistatic effect decreases sharply with repeated use. Antistatic agents added to the release layer may be encapsulated or migrated by the release agent, resulting in unstable performance. This invention meets the stability requirements of car cover release films under long-term storage, repeated handling, and high-temperature and high-humidity environments. The surface polarity of antistatic modified PET is reduced, resulting in poor adhesion of directly coated silicone oil (a problem not solved by existing technologies). This invention introduces a polyester undercoat with a chemical structure similar to PET. During high-temperature stretching, it undergoes co-crystallization or chain entanglement with the substrate, forming an "integrated" anchor. The surface of the undercoat is rich in polar groups such as hydroxyl and carboxyl groups, providing ample chemical bonding sites for the silicone oil. Therefore, the silicone oil coating does not peel off or migrate, the release force can be precisely controlled within the range of 5–30 g / inch, and batch stability is high.

[0029] Furthermore, compared to existing patents that incorporate release agents into the substrate, these lack a coating, resulting in poor release agent adhesion, large fluctuations in release force, and even silicone oil transfer contamination of the TPU adhesive layer. This invention overcomes the technical obstacle of "antistatic modification → difficulty in anchoring the release agent," achieving compatibility between antistatic and release properties. Simultaneously, polyether ester amide is a high molecular weight polymer with good compatibility with PET and will not migrate to the surface under normal operating temperatures. The coating undergoes cross-linking and curing, forming a three-dimensional network structure, and does not precipitate small molecules. Therefore, when the release film comes into contact with the TPU adhesive layer, no low-molecular-weight substances transfer to the adhesive surface. In contrast, surfactant-based antistatic agents: small molecules gradually migrate, contaminating the adhesive surface, leading to bubbling and delamination after TPU application, while uncross-linked coatings may precipitate oligomers due to thermal aging. This invention ensures that the release film does not contaminate the TPU adhesive layer even after long-term storage and high-temperature transportation, guaranteeing the final bonding quality of the car wrap.

[0030] The coating is applied online (after longitudinal stretching and before transverse stretching), utilizing the high temperature of transverse stretching to simultaneously complete drying, curing, and heat setting. No offline coating equipment is needed, no additional processes are added, and production is fast. The antistatic agent is added via masterbatch and co-extruded with PET, without altering the layout of mainstream BOPET production lines. In contrast, offline coating methods require secondary unwinding, coating, and curing, resulting in high equipment investment, high energy consumption, and low yield. This invention offers lower costs and is suitable for large-scale production. This invention also boasts high process compatibility and economy, facilitating rapid conversion of existing BOPET production lines.

[0031] The refractive index of polyether ester amide is similar to that of PET, and the addition amount is moderate (5-25%), having little impact on transparency. The particle size of the slip agent (silica) is controlled at 2-4 μm, and the increase in haze is controllable. The coating thickness is only 10-100 nm, and the refractive index is matched, so it has almost no impact on light transmittance. Therefore, the overall haze can be controlled at ≤2.5%, and the light transmittance is ≥90%, meeting the optical clarity requirements of car wrap films (no orange peel, no white haze). In contrast, antistatic solutions that add inorganic fillers (such as AZO, carbon nanotubes) will significantly increase haze or produce color, and are not suitable for transparent release films. This invention imparts antistatic properties while maintaining high film transparency, making it suitable for the car wrap field, which has strict requirements for optical appearance. The dosage of antistatic agent is small, and the total amount of antistatic agent can be reduced by more than 80%. The cost of the base coating liquid is about 1400 yuan / ton of film, and the cost of the slip agent is about 50 yuan / ton of film, with limited increase. The processing fee is similar to that of ordinary BOPET (approximately 3,000 RMB / ton). The total cost is approximately 12,000 to 16,000 RMB / ton, which is significantly cheaper than imported high-end release films (30,000 to 50,000 RMB / ton). In contrast, solutions using full-layer addition or the use of nano-conductive fillers may cost 2 to 3 times more. Therefore, this invention achieves a balance between high performance and low cost, making it economically feasible for industrial-scale promotion.

[0032] As an optional implementation, see [link to implementation details]. Figure 1 The polyester matrix layer 1 may include an upper surface layer 101, a lower surface layer 102, and a core layer 103 located between the upper surface layer 101 and the lower surface layer 102. The upper surface layer 101 and the lower surface layer 102 each include 5-25 wt.% antistatic masterbatch, 15-30 wt.% slip agent masterbatch, and 45-80 wt.% PET chips. The core layer 103 includes 0-5 wt.% antistatic masterbatch and 95-100 wt.% PET chips.

[0033] In the above embodiments, the thickness of coating 2 is 10–100 nm, and the dry weight of coating 2 is 0.01–0.1 g / m³. 2 The surface wetting tension of coating 2 is ≥52mN / m. Coating 2 is a compound of water-based copolyester and crosslinking agent. The surface resistivity of the polyester substrate is 1×10⁻⁶. 7 ~1×10 10 Ω / sq.

[0034] A second aspect of this invention provides a method for preparing a polyester substrate for an antistatic release film, see below. Figure 2 The method may include the following steps: S100: The main extrusion raw material and the auxiliary extrusion raw material are melt-extruded separately and then co-extruded through a die to form a polyester matrix casting.

[0035] Specifically, step S100 includes the following steps: S101. The main extrusion raw material and the auxiliary extrusion raw material are melt-extruded separately and filtered to obtain the main extrusion melt as the core layer and the auxiliary extrusion melt as the surface layer; wherein, the main extrusion raw material consists of 0-5 wt.% antistatic masterbatch and 95-100 wt.% PET chips, and the auxiliary extrusion raw material consists of 5-25 wt.% antistatic masterbatch, 15-30 wt.% slip agent masterbatch and 45-80 wt.% PET chips.

[0036] S102. The main extrusion melt and the auxiliary extrusion melt are co-extruded through a die to form a polyester matrix casting.

[0037] The primary and secondary extrusion raw materials are melted and vacuum-sealed to remove excess moisture and oligomers. After passing through a filter to remove impurities via a melt pipeline, the melt flows through a melt pump, adapter, and die to form an ABA-structured melt. This melt is then extruded onto a cooling drum using an electrostatic adsorption device to form a polyester matrix casting. The extrusion temperature of the ABA-structured melt in the die is 275–285℃, and the voltage and current of the electrostatic adsorption device are 7.1–8.5kV and 3.3–4.6mA.

[0038] S200, The polyester matrix casting is longitudinally stretched, and a coating is applied to the upper and / or lower surfaces of the stretched polyester matrix casting.

[0039] Specifically, the polyester substrate casting undergoes longitudinal stretching (MDO), followed by preheating rollers at 70–85°C, then heating with an infrared heater, and finally single-point stretching with stretching rollers at a stretch ratio of 3.2–3.6. After longitudinal stretching, it enters a pre-corona coating unit for surface pre-corona treatment, aiming to enhance the adhesion of the coating to the polyester substrate casting. Depending on the requirements, one side can be coated individually or both surfaces of the polyester substrate casting can be coated simultaneously. Furthermore, the base coating is formed by drying and curing an aqueous polyester resin composition in a transverse stretching machine to create a coated composite base film, with a dry weight of 0.01–0.1 g / m³. 2 (Thickness approximately 10–100 nm). The coating liquid formulation of this invention uses components that are all known chemical raw materials in the art. However, through specific combinations and proportions, particularly by selecting a water-based copolyester with a glass transition temperature of 50–70°C and an acid value of 5–15 mg KOH / g, combined with an oxazoline crosslinking agent and a polyether-modified siloxane wetting agent, and by strictly controlling the coating dry weight to 0.01–0.1 g / m³, the coating process is optimized. 2 A specialized anchoring layer formulation for polyether ester amide antistatic modified polyester substrates was developed. This formulation not only utilizes the availability of common raw materials but also solves the technical challenge of poor release agent adhesion on modified substrates through parameter optimization.

[0040] S300. The coated polyester substrate casting is subjected to transverse stretching, heat setting and cooling in sequence to obtain polyester substrate for antistatic release film.

[0041] Specifically, after coating, the sheet enters a transverse stretching machine, where it undergoes preheating, stretching, heat setting, and cooling in sequence. The preheating temperature for transverse stretching is 105–115℃, the stretching temperature is 115–120℃, the heat setting temperature is 170–245℃, the cooling zone temperature is 155–20℃, and the transverse stretch ratio is 3.8–4.2. The coated composite base film is then drawn, wound, slit, and packaged to produce the finished film.

[0042] Example 1 The purpose of this invention is to prepare a BOPET release film substrate with permanent antistatic properties without the need for surface coating with an antistatic agent on a polyester film production line with a width of 8700 mm, for use in the automotive protective film field. This release film substrate adopts an ABA-type composite structure, and the core of this invention lies in the synergistic design of "substrate body modification + online primer coating". Layer A is the surface layer, and layer B is the core layer, as shown in the schematic diagram below. Figure 1 As shown. The formulation system is as follows: The surface layer (upper and lower layers) of the polyester matrix layer contains 10% antistatic masterbatch, model PEBAX® MH1657 / PEBAX® MH2030 from Arkema, France, blended with PET chips. Simultaneously, the surface layer contains 3300ppm SiO2 slip agent masterbatch with a particle size of 3.5μm, brand FG610, added at 25% of the total surface layer feed, supplied by Yizheng, as an auxiliary extrusion raw material. The core layer contains 2% of the same antistatic masterbatch, blended with PET chips, as the primary extrusion raw material.

[0043] The preparation process of this polyester substrate includes the following steps: The primary and secondary extrusion raw materials are melted and vacuum-sealed to remove excess moisture and oligomers. After passing through a filter to remove impurities via a melt pipeline, the melt flows through a melt pump, adapter, and die to form an ABA-structured melt. This melt is then extruded onto a cooling drum using an electrostatic adsorption device to form a polyester matrix casting. The extrusion temperature of the melt in the die is 280℃, and the electrostatic adsorption device uses a voltage of 8.2kV and a current of 4.2mA. The polyester matrix casting undergoes longitudinal stretching, passes through an 81℃ preheating roller, is heated by an infrared heater, and then undergoes single-point stretching with a stretching roller at a stretch ratio of 3.3. After longitudinal stretching, it enters the coating pre-corona unit to pre-corona treat the surface layer, aiming to enhance the adhesion of the coating to the substrate. Depending on the requirements, one side can be coated individually or both surfaces of the substrate can be coated simultaneously.

[0044] The coating is formed by drying and curing an aqueous polyester resin composition in a transverse stretching machine to create a coated composite base film. The dry weight of the coating is 0.01–0.1 g / m³. 2 The thickness is approximately 10–100 nanometers. All components of the coating solution formulation are known chemical raw materials in the art, but through specific combinations and proportions, particularly the selection of a water-based copolyester with a glass transition temperature of 50–70°C and an acid value of 5–15 mg KOH / g, combined with oxazoline crosslinking agents and polyether-modified siloxane wetting agents, and strict control of the coating dry weight at 0.01–0.1 g / m², the coating thickness is significantly improved. 2 A specialized anchoring layer formulation for polyether ester amide antistatic modified polyester substrates has been developed. This formulation not only utilizes the availability of common raw materials but also solves the technical problem of poor release agent adhesion on modified substrates through parameter optimization, demonstrating the inventiveness and practicality of this invention.

[0045] After coating, the sheet enters a transverse stretching machine, where it undergoes preheating, stretching, heat setting, and cooling. The transverse stretching preheating temperature is 105–115℃ (different temperatures in different areas of the oven), the stretching temperature is 115–120℃ (different temperatures in different areas of the oven), the heat setting temperature is 170–245℃ (different temperatures in different areas of the oven), and the cooling zone temperature is 155–20℃ (different temperatures in different areas of the oven). The transverse stretching ratio is 3.9. The coated composite base film is then drawn, wound, slit, and packaged to produce the finished film.

[0046] Table 1. Multi-dimensional comparison between the present invention and existing technical solutions. It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0047] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A polyester substrate for antistatic release film, characterized in that, It includes a polyester matrix layer (1) and a coating (2) applied to the upper and / or lower surfaces of the polyester matrix layer (1), wherein the polyester matrix layer (1) is made of polyester and an antistatic agent, the antistatic agent being dispersed within the polyester to form a three-dimensional conductive network, and the coating (2) co-crystallizing or entangled with the polyester matrix layer (1) to form an integral anchor.

2. The polyester substrate for antistatic release film according to claim 1, characterized in that, The antistatic agent is a polyether ester amide block copolymer or a polyether ester elastomer.

3. The polyester substrate for antistatic release film according to claim 2, characterized in that, The polyester matrix layer (1) includes an upper surface layer (101), a lower surface layer (102), and a core layer (103) located between the upper surface layer (101) and the lower surface layer (102). The upper surface layer (101) and the lower surface layer (102) each include 5-25 wt.% antistatic masterbatch, 15-30 wt.% slip agent masterbatch, and 45-80 wt.% PET chips. The core layer (103) includes 0-5 wt.% antistatic masterbatch and 95-100 wt.% PET chips.

4. The polyester substrate for antistatic release film according to claim 1, characterized in that, The thickness of the coating (2) is 10-100 nm.

5. The polyester substrate for antistatic release film according to claim 1 or 4, characterized in that, The dry weight of the coating (2) is 0.01–0.1 g / m³. 2 .

6. The polyester substrate for antistatic release film according to claim 1, characterized in that, The surface resistivity of the polyester substrate is 1×10⁻⁶. 7 ~1×10 10 Ω / sq.

7. The polyester substrate for antistatic release film according to claim 1, characterized in that, The surface wetting tension of the coating (2) is ≥52mN / m.

8. The polyester substrate for antistatic release film according to claim 1, characterized in that, The coating (2) is a compound of waterborne copolyester and crosslinking agent.

9. A method for preparing a polyester substrate for an antistatic release film as described in any one of claims 1-8, characterized in that, The method includes the following steps: The main extrusion raw material and the auxiliary extrusion raw material are melt-extruded separately and then co-extruded through a die to form a polyester matrix casting sheet; The polyester matrix casting is longitudinally stretched, and a coating is applied to the upper and / or lower surfaces of the stretched polyester matrix casting. The coated polyester substrate casting is subjected to transverse stretching, heat setting and cooling in sequence to obtain polyester substrate for antistatic release film.

10. The preparation method according to claim 9, characterized in that, The process of separately melting and extruding the main extrusion raw material and the auxiliary extrusion raw material, and then co-extruding them through a die to form a polyester matrix casting, specifically includes the following steps: The main extrusion material and the auxiliary extrusion material are melt-extruded separately and filtered to obtain the main extrusion melt as the core layer and the auxiliary extrusion melt as the surface layer. The main extrusion melt and the auxiliary extrusion melt are co-extruded through a die to form the polyester matrix casting; The main extrusion raw material consists of 0-5 wt.% antistatic masterbatch and 95-100 wt.% PET chips, while the auxiliary extrusion raw material consists of 5-25 wt.% antistatic masterbatch, 15-30 wt.% slip agent masterbatch, and 45-80 wt.% PET chips.

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