Coated articles and coating formulations

Abstract

An article for food contact applications is provided. The article includes a substrate having at least one surface and a coating disposed on the at least one surface. The coating comprises a polymeric material (A) and at least one non-stick reinforcing additive, wherein the polymeric material has: repeating units of the formula:; and a repeating unit of the following formula; wherein Ph represents a phenylene moiety. The coating provides a non-stick coating for the article. A coating formulation, a method of forming a non-stick coating on an article for food contact applications, and related uses are also disclosed.

Description

TECHNICAL FIELD

[0001] The present invention relates to an article for food contact having a non-stick coating. The present invention also relates to a coating formulation, coating composition, method of forming such a non-stick coating on an article, and related uses of a polymeric material to form such a non-stick coating for use on an article. In particular, the present invention relates to a non-stick coating that is free of perfluoroalkyl substances / polyfluoroalkyl substances. BACKGROUND

[0002] Many articles for food contact, such as cookware (such as frying pans and electric rice cookers) and bakeware (such as baking trays and baking pots) currently manufactured, including consumer, professional and industrial cookware and bakeware articles, have a non-stick coating. Articles having such a non-stick coating have a lower tendency to react with food, and / or an increased tendency to release food during and after cooking / baking the food, compared to uncoated articles. This facilitates use, and in particular cleaning of the cookware or bakeware afterwards.

[0003] Currently, most such non-stick coatings for cookware and bakeware are formed using perfluoroalkyl substances and polyfluoroalkyl substances (PFAS). The PFAS chemical group includes perfluorosulfonic acids (such as perfluorooctane sulfonic acid (PFOS)) and perfluorocarboxylic acids (such as perfluorooctanoic acid (PFOA)). PFAS have a wide range of uses in industry, and have proven to have excellent properties for use in non-stick coatings. Polytetrafluoroethylene (PTFE) is a PFAS that is widely used to form such non-stick coatings on cookware and bakeware.

[0004] However, as these chemicals have been used more and more in industry, concerns about the public health effects of PFAS have grown over time. PFAS, and in particular PFOS and PFOA, are known as “forever chemicals” due to their resistance to breakdown in the environment and their tendency to accumulate in groundwater, in plants, and in animals and humans. High level exposure and accumulation of PFAS in humans has been linked to serious medical conditions, such as dyslipidemia, reduced growth in infants and fetuses, and kidney cancer.

[0005] Regulatory bodies have been seeking to limit the use of PFAS, and to reduce the accumulation of these chemicals in the environment. In particular, such bodies are considering banning the use of PFAS, such as PTFE, in non-stick coatings to reduce PFAS contamination in the manufacture, use and disposal of non-stick articles, and to reduce the exposure of users of such articles to PFAS.

[0006] For these reasons, researchers have sought to develop alternative non-stick coatings that do not contain PFAS and do not require such chemicals in the manufacture of non-stick coated articles. The use of high performance polymer (HPP)-based coatings has made progress in achieving this goal. HPP coatings can be applied by similar techniques to PFAS-based non-stick coatings, for example by web coating, roll coating, curtain coating, flame spraying, electrostatic powder coating or spraying. All of these coating techniques require heating of the HPP particles above their melting or fusion point to form a continuous HPP film coating on the substrate.

[0007] HPP coatings do not necessarily provide inherent non-stick properties and so can require the use of non-stick enhancing additives to achieve non-stick properties comparable to PFAS-based coatings or suitable for particular use cases.

[0008] Such non-stick enhancing additives include silica-based or alumina-based metal alkoxides, waxes, oils, fats, talc, ceramics, boron nitride, graphite, carbon black, siloxane / silicone, nanoparticles or glass fibres. However, it has proved difficult to date to provide PFAS-free non-stick coatings with comparable properties to PFAS-based non-stick coatings that can be reliably and efficiently formed. There is therefore still a need for alternative high performance PFAS-free non-stick coatings. SUMMARY

[0009] Polyaryletherketone (PAEK) polymers are a well-known group of high performance thermoplastic polymers and many of them have excellent chemical and mechanical properties, for example polyether ether ketone (PEEK) polymers. PEEK polymers can form coatings with long-term durability due to their abrasion resistance, scratch resistance, wear resistance, chemical resistance and heat degradation resistance. However, PEEK polymer-based non-stick coatings typically rely on PFAS non-stick enhancing additives to achieve the properties required for non-stick coatings of cookware and bakeware. Such coatings are therefore not PFAS-free.

[0010] It is an object of the present invention, among others, to provide a non-stick coating composition, formulation and method that addresses at least one of the shortcomings of the prior art, whether discovered here or elsewhere, or to provide an alternative to prior non-stick coating compositions, formulations and methods. For example, it can be an object of the present invention to provide a cookware or bakeware article having a PAEK-type polymer coating that is non-stick and does not contain PFAS.

[0011] According to an aspect of the present invention, there is provided an article, coating formulation, coating, method and use as shown in the appended claims. Other features of the present invention will be apparent from the dependent claims and the following description.

[0012] According to the present application, there is provided an article for food contact applications, the article comprising a substrate having at least one surface and a coating disposed on the at least one surface, wherein the coating comprises a polymeric material (A) having:

[0013] repeating units of the formula

[0014] ;

[0015] and repeating units of the formula

[0016] ;

[0017] wherein Ph represents a phenylene moiety.

[0018] According to a first aspect of the present application, there is provided an article for food contact applications, the article comprising a substrate having at least one surface and a coating disposed on the at least one surface, wherein the coating comprises a polymeric material (A) and at least one non-stick enhancing additive, wherein the polymeric material has:

[0019] repeating units of the formula

[0020] ;

[0021] and repeating units of the formula

[0022] ;

[0023] wherein Ph represents a phenylene moiety.

[0024] The article of this first aspect is for food contact applications. Suitably, the article is for the preparation and / or serving of food. In particular, the article can be intended for the heating or cooking of food. For example, the article of this first aspect can be an article of cookware and / or bakeware. The at least one surface of the article on which the coating is disposed is a surface for contact with food in use. Thus, the coating is for contact with food in use by the outer surface of the coating. Suitably, the coating is for contact with food as the food is heated. Heat can be transferred from the article to the food through the surface. The coating suitably has a "non-stick" outer surface and thus provides a "non-stick" outer surface of the article. The non-stick surface is for contact with food in use, suitably for contact with food as the food is heated. Such a non-stick surface can be described as having an improved propensity to release food material in contact with the surface and a lower propensity to react with the food during heating.

[0025] A non-stick coating is a coating which is intended to reduce adhesion between the surface of a first material on which the coating is applied and a second material or surface with which the first material is intended to come into contact in use. In the case of a non-stick cookware or bakeware article, a non-stick coating is applied to the cookware or bakeware article to reduce the adhesion of food to the surface of the cookware or bakeware article.

[0026] The polymeric material (A) is a polyaryletherketone (PAEK) polymer. More specifically, the polymeric material (A) is a copolymer of poly(ether ether ketone) (PEEK) and poly(ether diphenyl ether ketone) (PEDEK), i.e. repeating units of formula I which can be referred to as EEK providing a PEEK polymer component and repeating units of formula II which can be referred to as EDEK providing a PEDEK. Thus, the polymeric material (A) can be referred to as a PEEK / PEDEK copolymer.

[0027] The inventors have found that, due to the relatively high temperature processing window of these polymers, the use of PEEK polymers to produce non-PFAS containing non-stick coatings limits the possible non-stick enhancing additives which can be used to provide the required properties to the coated surface. Such relatively high temperatures can degrade many suitable types of non-stick enhancing additives, reduce their usefulness in providing non-stick properties, or increase the complexity of the coating process. The typical processing temperature window for PEEK polymers is 380°C to 420°C. It has been found that processing PEEK polymers and non-stick enhancing additives such as siloxane / silicone compositions at this temperature partially degrades the siloxane / silicone composition, which severely reduces the non-stick enhancing effect of the additive and compromises the overall reliability of the coating process.

[0028] The inventors have surprisingly found that the use of a polymeric material (A) as defined herein, i.e. a PEEK / PEDEK copolymer, can produce an effective non-stick coating on an article according to this first aspect. Such a coating can advantageously provide thermal mechanical durability, hydrophobicity, abrasion resistance, chemical resistance and scratch resistance at least comparable to PFAS based non-stick coatings such as PTFE, without including problematic PFAS in the coating or for the manufacture of the coating.

[0029] In some embodiments, the coating of the article of this first aspect comprises a nonstick enhancing additive. The inventors have found that the use of a non-PFAS nonstick enhancing additive in combination with the polymeric material (A) can provide a non-PFAS nonstick coating on the article with enhanced nonstick properties compared to a coating with the polymeric material (A) on an article in the absence of any nonstick enhancing additive. The formation of such a nonstick coating can advantageously avoid degradation of the nonstick enhancing additive (such as a siloxane or silicone) as the processing temperature window of the polymeric material (A) is below the temperature at which substantial degradation of such suitable nonstick enhancing additives is induced. For example, the polymeric material (A) can be processable into a coating at a temperature below 380 °C. Suitably, the polymeric material (A) can be processable into a coating at a temperature below 360 °C, or below 350 °C, or below 340 °C. The polymeric material (A) suitably has a processing temperature window of 200 °C to 600 °C, a preferred processing temperature window of 300 °C to 550 °C and a particularly preferred processing temperature window of 300 °C to 380 °C or 340 °C to 380 °C. At such temperatures, a coating comprising the polymeric material (A) and the nonstick enhancing additive can be formed on the article without degrading the nonstick enhancing additive (such as a siloxane / silicone) and thus provides an effective nonstick coating in which the additive retains its nonstick enhancing properties.

[0030] Furthermore, the use of the polymeric material (A) as disclosed herein can allow the nonstick coating to be applied in the form of a single layer, which is sufficiently durable and substrate adherent due to the advantageous physical properties of the polymeric material (A). Single layer application can provide an efficient manufacturing process for articles for food contact applications (such as cookware and bakeware). However, the nonstick coating can also be applied in the form of more than one layer.

[0031] Polymeric material (A)

[0032] The coating on the article of this first aspect comprises a polymeric material (A). The polymeric material (A) is suitably crystalline and typically has a crystalline melting point which is lower than the crystalline melting point of a homopolymer of repeating unit I or a homopolymer of repeating unit II. However, the glass transition temperature of the polymeric material (A) is typically the same as or slightly higher than the glass transition temperature of a homopolymer of repeating unit I. More specifically, the polymeric material (A) suitably has a glass transition temperature of above 143 °C and up to 160 °C and a crystalline melting temperature of 300 °C and up to 330 °C. For example, a polymer containing repeating unit I and repeating unit II in a relative ratio of 80:20 has a glass transition temperature of about 149 °C and a crystalline melting temperature of about 309 °C.

[0033] Suitably, the polymeric material (A) has a processing temperature in the range of 200°C to 600°C, a preferred processing temperature in the range of 250°C to 550°C, and a particularly preferred processing temperature in the range of 300°C to 380°C or 340°C to 380°C. Processing temperature is understood to mean the temperature at which the polymeric material at least partially melts and / or sufficiently flows to be processed into a desired form, such as a substantially continuous coating on a surface of an article as described herein.

[0034] The phenylene moieties (Ph) in each repeat unit can independently have a 1,4-para bond or a 1,3-meta bond to the atom to which it is bonded. In the case that the phenylene moieties include 1,3-bonds, the moieties will be in the amorphous phase of the polymer. The crystalline phase will include phenylene moieties having 1,4-bonds. In many applications, the polymeric material is preferably highly crystalline, and thus the polymeric material preferably includes a high level of phenylene moieties having 1,4-bonds.

[0035] Suitably, at least 95% or at least 99% of the number of phenylene moieties (Ph) in the repeat unit of Formula I have a 1,4-bond to the moiety to which it is bonded. It is especially preferred that each phenylene moiety in the repeat unit of Formula I have a 1,4-bond to the moiety to which it is bonded.

[0036] Suitably, at least 95% or at least 99% of the number of phenylene moieties (Ph) in the repeat unit of Formula II have a 1,4-bond to the moiety to which it is bonded. It is especially preferred that each phenylene moiety in the repeat unit of Formula II have a 1,4-bond to the moiety to which it is bonded.

[0037] Preferably, the phenylene moieties in the repeat unit of Formula I are unsubstituted. Preferably, the phenylene moieties in the repeat unit of Formula II are unsubstituted.

[0038] The repeat unit of Formula I suitably has the structure la:

[0039] .

[0040] The repeat unit of Formula II suitably has the structure Ila:

[0041] .

[0042] Preferably, in the polymeric material (A) of the coating:

[0043] the repeat unit of Formula I has the structure la:

[0044] ; and

[0045] the repeat unit of Formula II has the structure Ila:

[0046] .

[0047] The polymeric material (A) suitably comprises at least 10 mol%, at least 20 mol% or preferably at least 30 mol% of repeat units of Formula I. The polymeric material (A) suitably comprises at most 95 mol%, at most 90 mol% or suitably at most 85 mol% of repeat units of Formula I. The polymeric material (A) suitably comprises 10 mol% to 95 mol%, preferably 20 mol% to 90 mol% of units of Formula I.

[0048] The polymeric material (A) suitably comprises at least 10 mol%, at least 20 mol% or preferably at least 30 mol% of repeat units of Formula II. The polymeric material (A) suitably comprises at most 95 mol%, at most 90 mol% or suitably at most 80 mol% of repeat units of Formula II. The polymeric material (A) suitably comprises 5 mol% to 95 mol%, preferably 10 mol% to 80 mol% of units of Formula II.

[0049] The sum of the mol% of units of Formula I and units of Formula II in the polymeric material (A) is suitably at least 95 mol%, preferably at least 98 mol%, more preferably at least 99 mol% and especially about 100 mol%.

[0050] Suitably, the polymeric material (A) of the coating comprises repeat units I and repeat units II in a relative molar ratio I:II of 10:90 to 95:5, suitably 40:60 to 90:10 or 20:80 to 90:10.

[0051] In some embodiments, the polymeric material (A) of the coating comprises repeat units I and repeat units II in a relative molar ratio I:II of 65:35 to 95:5.

[0052] In some embodiments, the polymeric material (A) of the coating comprises repeat units I and repeat units II in a relative molar ratio I:II of 20:80 to 45:55.

[0053] In some embodiments, the polymeric material (A) can include at least 10 mol%, at least 20 mol% or preferably at least 30 mol% of repeat units of Formula I. The polymeric material (A) can include at most 55 mol%, at most 45 mol% or suitably at most 40 mol% of repeat units of Formula I. The polymeric material (A) can include 15 mol% to 50 mol%, preferably 20 mol% to 45 mol%, more preferably 25 mol% to 40 mol% of units of Formula I.

[0054] In such embodiments, the polymeric material (A) can comprise at least 40 mol%, preferably at least 50 mol% or at least 55 mol% of repeat units of formula II. The polymeric material (A) can comprise less than 90 mol%, preferably less than 80 mol% of repeat units of formula II. The polymeric material (A) can comprise 40 mol% to 90 mol%, preferably 50 mol% to 85 mol%, more preferably 55 mol% to 80 mol% of units of formula II.

[0055] In such embodiments, the sum of the mol% of units of formula I and units of formula II in the polymeric material (A) is suitably at least 95 mol%, preferably at least 98 mol%, more preferably at least 99 mol%, and especially about 100 mol%.

[0056] In such embodiments, the polymeric material (A) suitably contains repeat units I and repeat units II in a molar ratio I:II of 15:85 to 50:50 or 20:80 to 45:55.

[0057] Such polymeric material (A) can be formed according to the method described in WO 19215304 Al, which is incorporated herein by reference.

[0058] In some embodiments, the polymeric material (A) can comprise at least 68 mol%, preferably at least 71 mol% of repeat units of formula I. Particularly advantageous polymeric material (A) can comprise at least 72 mol% or especially at least 74 mol% of repeat units of formula I. The polymeric material (A) can comprise at most 95 mol%, at most 90 mol% or suitably at most 82 mol% of repeat units of formula I. The polymeric material (A) can comprise 68 mol% to 82 mol%, preferably 70 mol% to 80 mol%, more preferably 72 mol% to 77 mol% of units of formula I.

[0059] In such embodiments, the polymeric material (A) can comprise at least 10 mol%, preferably at least 18 mol% of repeat units of formula II. The polymeric material (A) can comprise less than 32 mol%, preferably less than 29 mol% of repeat units of formula II. Particularly advantageous polymeric material (A) can comprise 28 mol% or less; or 26 mol% or less of repeat units of formula II. The polymeric material (A) can comprise 18 mol% to 32 mol%, preferably 20 mol% to 30 mol%, more preferably 23 mol% to 28 mol% of units of formula II.

[0060] In such embodiments, the sum of the mol% of units of Formula I and units of Formula II in the polymeric material (A) is suitably at least 95 mol%, preferably at least 98 mol%, more preferably at least 99 mol%, and especially about 100 mol%.

[0061] In such embodiments, the polymeric material (A) suitably contains repeating units I and repeating units II in a molar ratio I:II of 70:30 to 90:10 or 70:30 to 80:20.

[0062] Typically, the polymeric material (A) of the first aspect of the application will have terminal units of the polymer which can be the same as the repeating units but with terminal OH or F groups. However, the process for forming the polymer can include a separate end-capping step at the completion of the polymerisation, in which case a separate monomer or reagent can be added as an end-capping agent, such that the terminal units can be different from the repeating units of the polymer. Such end-capping is well known in the art of nucleophilic polycondensation reactions.

[0063] In some embodiments, the polymeric material of Formula (A) can have a melt viscosity (MV) of at least 0.06 kN.s.m -2 and more preferably at least 0.10 kN.s.m -2 . Suitably, the polymeric material (A) has a MV of at least 0.20 kN.s.m -2 .

[0064] Suitably, the polymeric material has a MV of at most 1.80 kN.s.m -2 , at most 1.50 kN.s.m -2 or at most 1.00 kN.s.m -2 .

[0065] Suitably, the polymeric material (A) has a MV of 0.06 kN.s.m -2 to 1.80 kN.s.m -2 , 0.10 kN.s.m -2 to 1.50 kN.s.m -2 or 0.20 kN.s.m -2 to 1.00 kN.s.m -2 .

[0066] In some embodiments, the polymeric material (A) has a MV of 0.20 kNsm -2 to 0.50 kNsm -2 or 0.25 kNsm -2 to 0.40 kNsm -2 .

[0067] The melt viscosity (MV) can be measured by capillary rheometry at 400 °C with a shear rate of 1000 s -1 The melt viscosity (MV) can be measured by capillary rheometry at 400 °C with a shear rate of 1000 s

[0068] The melt viscosity of the polymeric material can be measured by capillary rheometry using a RH10 capillary rheometer (Malvern Instruments Rosand RH10 Capillary Rheometer) equipped with a tungsten carbide die, 0.5 mm (capillary diameter) x 8.0 mm (capillary length). Approximately 5 grams of the polymeric material is dried in an air circulating oven at 150 °C for 3 hours. The extruder is allowed to equilibrate to 400 °C. The dried polymeric material is loaded into the heated barrel of the extruder, a brass tip (12 mm long x 9.92 + 0.01 mm diameter) is placed on top of the polymer and then the piston and screw are turned by hand until the pressure gauge relief ring just engages the piston to help remove any trapped air. The column of polymeric material is allowed to heat and melt for a period of at least 5 minutes. After the pre-heat stage, the screw is put into motion so that the molten polymeric material is extruded through the die, forming a thin fibre at a shear rate of 1000 s -1 The melt viscosity is given by the following equation

[0069]

[0070] The relationship between the shear rate and other parameters is given by the following equation:

[0071] Apparent wall shear rate = 4Q / πr 3

[0072] where Q = volumetric flow rate / m 3 s -1 = SA.

[0073] Suitable polymeric materials (A) can be prepared by the polycondensation of a monomer containing a carbonyl chloride group in the presence of a Friedel Crafts reagent or by the polycondensation of a phenolic compound with a halogen compound in the presence of a basic reagent.

[0074] More specifically, suitable polymeric materials (A) can be obtained by polycondensation of a mixture of at least one dihydroxybenzene compound and at least one dihydroxydiphenyl compound with at least one dihalogenated benzophenone. Preferably hydroquinone; 4,4'-dihydroxydiphenyl and 4,4'-difluorobenzophenone are used as monomers. The polycondensation is preferably carried out in the presence of an alkali metal carbonate or bicarbonate or a mixture thereof. The polymerization is preferably carried out in the presence of a polymerization solvent such as an aryl sulfone.

[0075] Further suitable polymeric materials (A) (PEEK / PEDEK copolymers) as well as processes for their preparation are described in US 4717761, WO 2014 / 207458 Al and WO 2015 / 124903 Al, the contents of which are incorporated herein by reference.

[0076] WO 2014 / 207458 Al discloses PEEK / PEDEK copolymers having a molar ratio of repeat units of formula I and formula II of 55:45 to 95:5 and having a MV measured at 340°C and 1000 s -1 of at least 0.25 kNsm -2 and less than 1.2 kNsm -2 at a shear rate.

[0077] WO 2015 / 124903 Al discloses PEEK / PEDEK copolymers having a molar ratio of repeat units of formula I and formula II of 55:45 to 95:5 and having a MV measured at 340°C and 1000 s -1 of at least 0.25 and less than 1.2 at a shear rate.

[0078] In some embodiments, the polymeric material (A) can be as described in WO 2020 / 141329 Al, the contents of which are incorporated herein by reference. In such embodiments, the polymeric material (A) can have repeat units of formula la:

[0079] ; and

[0080] repeat units of formula Ila:

[0081] ;

[0082] wherein at least 95 mol% of the repeat units are repeat units of formula la and repeat units of formula Ila;

[0083] wherein the repeat units la and Ila have a molar ratio la:lla of 65:35 to 95:5 or 55:45 to 80:20.

[0084] In other words, in the polymeric material (A), 95 mol% of all repeating units present are units of formula Ia and units of formula IIa in a molar ratio Ia:IIa of 55:45 to 80:20. This can be determined by knowing the number of moles of monomers employed in the preparation of the polymer.

[0085] The phenylene moieties in each repeating unit Ia and IIa have a 1,4-para linkage with the atoms to which they are bonded. This makes the polymeric material intrinsically crystalline.

[0086] Suitably, in such embodiments, the polymeric material (A) has a MV of 0.35 kNsm -2 to 0.55 kNsm -2 as measured using capillary rheometry at 400 °C at a shear rate of 1000 s -1 with a tungsten carbide capillary die of 0.5 mm diameter and 8.0 mm length.

[0087] Preferably, the MV of the polymeric material (A) as described above at 1000 s -1 and at 400 °C is 0.40 kNsm -2 to 0.50 kNsm -2 .

[0088] Preferably, the molar ratio Ia:IIa is 60:40 to 75:25.

[0089] Preferably, at least 98 mol%, more preferably 99 mol% of the repeating units are repeating units of formula Ia and repeating units of formula IIa. Most preferably, the polymeric material consists essentially of repeating units of formula Ia and formula IIa.

[0090] In some embodiments, the polymeric material (A) can be as described in WO 2022013520 Al, the contents of which are incorporated herein by reference. In such embodiments, the polymeric material (A) can consist essentially of:

[0091] ;

[0092] repeating units of formula IIa:

[0093] ;

[0094] and terminal units;

[0095] wherein the molar ratio of the repeating units of formula I to the repeating units of formula IIa is 55:45 to 95:5; and

[0096] wherein the repeat units of formula I consist essentially of 50 to 90 mole % of repeat units of formula la:

[0097]

[0098] and 10 to 50 mole % of repeat units of formula lb, repeat units of formula Ic, or mixtures thereof;

[0099] wherein the repeat units of formula lb are:

[0100] ; and

[0101] the repeat units of formula Ic are:

[0102] .

[0103] Preferably, the mole ratio of repeat units of formula I to repeat units of formula Ila is 60:40 to 90:10, preferably 70:30 to 90:10, more preferably 80:20 to 90:10.

[0104] The repeat units of formula I consist essentially of, or preferably consist of, 50 to 90 mole % of repeat units of formula la in combination with 10 to 50 mole % of repeat units of formula lb and / or formula Ic. Preferably, the repeat units of formula I consist essentially of, or preferably consist of, 65 to 90 mole % of repeat units of formula la in combination with 10 to 35 mole % of repeat units of formula lb, repeat units of formula Ic, or mixtures thereof. More preferably, the repeat units of formula I consist essentially of, or preferably consist of, 80 to 90 mole % of repeat units of formula la in combination with 10 to 20 mole % of repeat units of formula lb, repeat units of formula Ic, or mixtures thereof.

[0105] Repeat unit la is referred to as R PEEK , repeat unit lb is referred to as R mPEEK , and repeat unit Ic is referred to as R oPEEK .

[0106] Thus, in other words, the repeat units of formula I have a mole ratio expressed as:

[0107] 90:10 to 50:50, preferably 90:10 to 65:35, more preferably 90:10 to 80:20 of R PEEK : (R mPEEK + R oPEEK ).

[0108] In a preferred embodiment, the polymeric material (A) is a copolymer as described above, wherein the molar ratio of the repeating units of formula I to the repeating units of formula II is from 90:10 to 80:20, and wherein the repeating units of formula I consist essentially of a combination of from 80 mole % to 90 mole % of repeating units of formula la and from 10 mole % to 20 mole % of repeating units of formula lib, of repeating units of formula Ic, or mixtures thereof, or preferably consist thereof.

[0109] It is to be understood that formula I: -0-Ph-0-Ph-CO-Ph- does not provide information on whether the ether bond in the -0-Ph-0- moiety is arranged in para, meta or ortho configuration, which is specified for formula la, lb and Ic, as is for all other configurations within the repeating units.

[0110] In one embodiment, the copolymer according to the first aspect of the application can be a copolymer which does not comprise repeating units of formula lb.

[0111] In another embodiment, the copolymer according to the first aspect of the application can be a copolymer which does not comprise repeating units of formula Ic.

[0112] Coating

[0113] The coating of the article of this first aspect suitably has a thickness of from 300 nm to 6,000 pm, suitably from 3 pm to 600 pm.

[0114] The coating is suitably provided as at least one layer on at least one surface of the substrate. In some embodiments, the coating is provided in more than one layer, for example in two layers, on at least one surface of the substrate. Preferably, the coating is provided in one layer on at least one surface of the substrate, suitably having a thickness as described above.

[0115] Preferably, the at least one layer has a thickness of from 3 pm to 200 pm, preferably from 5 pm to 150 pm, more preferably from 15 pm to 100 pm, more preferably from 25 pm to 75 pm.

[0116] Preferably, the total combined thickness of the coating is preferably from 3 pm to 200 pm, preferably from 5 pm to 150 pm, for example from 45 pm to 150 pm. Preferably, the combined thickness of the layers is 125 pm.

[0117] In a preferred arrangement, the coating comprises at least a first layer and a second layer. Preferably, the first layer is adjacent to the substrate. Preferably, the second layer is adjacent to the first layer and preferably remote from the substrate. Preferably, the first layer comprises the polymeric material (A) as described above. The polymeric material (A) can have any of the preferred features described herein. Most preferably, the first layer consists of the polymeric material (A) and is preferably adjacent to the substrate. Preferably, the first layer has a thickness of 3 pm to 100 pm, preferably 25 pm to 75 pm, most preferably substantially 50 pm. Preferably, the second layer comprises the polymeric material (A) and at least one non-stick enhancing additive. Preferably, the second layer comprises at least 90 wt% of the polymeric material (A). Most preferably, the second layer comprises at least 95 wt% of the polymeric material (A) (e.g. 97 wt% of the polymeric material (A)) and at least 2 wt% of a non-stick enhancing additive, preferably a silicone oil and / or fumed silica. In the most preferred arrangement, the second layer comprises substantially 97.6 wt% of the polymeric material (A), substantially 2 wt% of a silicone oil, 0.4 wt% of fumed silica. Preferably, the second layer has a thickness of 3 pm to 100 pm, preferably 25 pm to 75 pm, most preferably substantially 75 pm. Preferably, the combined thickness of the first layer and the second layer is between 100 pm and 200 pm, preferably between 75 pm and 150 pm, preferably 125 pm.

[0118] The coating suitably comprises at least 1.0 wt%, at least 50 wt% or at least 80 wt%, most preferably at least 90 wt% of the polymeric material (A).

[0119] Suitably, the coating comprises at most 100 wt% of the polymeric material (A), suitably at most 95 wt% or at most 80 wt% of the polymeric material (A).

[0120] As discussed above, the article and the coating are suitably free of PFAS. The coating suitably comprises less than 1 wt%, less than 0.1 wt% or less than 0.01 wt% of PFAS, based on the total weight of the coating. Preferably, the coating does not comprise any perfluoroalkyl or polyfluoroalkyl substances. Preferably, the coating does not comprise PTFE. Suitably, the article does not comprise any perfluoroalkyl or polyfluoroalkyl substances. Suitably, the article does not comprise PTFE.

[0121] The coating is suitably a non-stick coating. The coating suitably has equal or better non-stick properties compared to similar coatings formed from PEEK polymeric materials. Such non-stick properties can be measured by water contact angle or advancing and receding contact angles at different sliding angles.

[0122] The coating suitably has a hydrophobic outer surface. Hydrophobicity can be assessed by measuring the water contact of the surface. The outer surface of the coating suitably has a water contact angle of at least 80°, preferably at least 90°, more preferably at least 92°, especially at least 94°. The water contact angle can be less than 120°, 110° or 100°. The water contact angle is preferably between 80° and 160°, for example between 80° and 120°. The water contact angle can be assessed as described in Example 3 of WO 2012175965 Al, which is incorporated herein by reference.

[0123] Hydrophobicity can also be determined using contact angle measurements with ethylene glycol as the test fluid. The receding contact angle of a 30 pl droplet of ethylene glycol can be measured on the test surface. A satisfactory non-stick property can be demonstrated by the test surface having a receding contact angle of greater than 60°. Suitably, the coating of the article of the first aspect has such a receding contact angle of greater than 60°.

[0124] A satisfactory non-stick property can be further demonstrated by the test surface having a roll-off angle (the angle of inclination of a plane sufficient to cause displacement of a droplet) of less than 20°. Suitably, the coating of the article of the first aspect has such a roll-off angle of less than 20°.

[0125] Furthermore, a satisfactory non-stick property can include sufficient cohesion, lack of surface cracking, thermal inertia in a cooking temperature environment, and lack of reactivity with foodstuffs. The latter can be demonstrated in the burnt milk and fried egg tests as described in WO 2022241019 Al, which is incorporated herein by reference. Suitably, the coating of the article of the first aspect provides satisfactory performance in such tests.

[0126] In the present application, the required non-stick properties of the coating comprising the polymeric material (A) can be achieved in several ways, as further described below.

[0127] In some embodiments, the coating comprises at least one non-stick enhancing additive. Such non-stick enhancing additives are substances which can improve the non-stick properties of a polymeric coating, such as a coating comprising the polymeric material (A) of the present application. The non-stick enhancing additive can improve the non-stick properties of the coating by increasing the hydrophobicity of the coating / polymeric material (A) and / or reducing the tendency of the coating to react with foodstuffs during heating and / or increasing the tendency of the coating to release foodstuffs in contact with the coating, particularly during heating.

[0128] The at least one non-stick enhancing additive is preferably not a PFAS. Preferably, as discussed above, the article (and in particular the coating) does not comprise any PFAS.

[0129] Suitably, the at least one non-stick reinforcing additive is selected from the group consisting of silica-based or alumina-based metal alkoxides, waxes, oils, fats, talc, ceramics, boron nitride, graphite, carbon black, siloxanes / silicones (including silicone resins, silicone oils, fumed silica), nanoparticles or glass fibers. In some preferred embodiments, the at least one non-stick reinforcing additive is a polysiloxane. Suitable polysiloxanes (silicones) can be selected from the group consisting of linear or branched polydimethylsiloxanes, linear or branched polydiphenylsiloxanes, linear or branched polymethylphenylsiloxanes, copolymers and mixtures thereof. In some embodiments, such polysiloxanes can contain or be mixed with polysiloxanes that can contain reactive groups such as hydroxyl-, alkoxy-, acetoxy-, vinyl-, silane-, amino-, silazane- or others. Suitably, the at least one non-stick reinforcing additive is selected from the group consisting of polydimethylsiloxane (PDMS), polydiphenylsiloxane (PDPS) and polydimethyldiphenylsiloxane (PDMDPS, i.e. PDMS / PDPS copolymer).

[0130] Suitable siloxane / silicone non-stick reinforcing additives can be provided by ELKEM under the trade name SILBIONE FLD70047V350, by WACKER under the trade name WACKER AK200, a polymethylsiloxane, and by WACKER under the trade names WACKER AP 150, WACKER AP 200, WACKER AR 200 and by DOW under the trade name DOWSIL 550 Fluid, a polysiloxane with methyl and phenyl groups.

[0131] In such embodiments, the article has the advantage that the polymeric material (A) has sufficient non-stick properties so that the coating effectively functions in food contact applications without the use of PFAS such as PTFE. Furthermore, the polymeric material (A) allows the formation of the coating at temperatures that do not degrade the non-stick reinforcing additive, in particular the siloxane / silicone discussed above.

[0132] In a preferred embodiment, the at least one non-stick reinforcing additive can be present in the coating in an amount of 0.1 wt% to 90 wt%, based on the total weight of the coating, in a preferred embodiment in an amount of 0.1 wt% to 50 wt%, based on the total weight of the coating, and in a particularly preferred embodiment in an amount of 1.0 wt% to 30 wt%, based on the total weight of the coating.

[0133] In further preferred embodiments, the at least one non-stick reinforcing additive can be present in the coating in an amount of 0.001 wt% - 50 wt%, most preferably in an amount of 0.1 wt% to 40 wt%, based on the total weight of the coating.

[0134] Preferably, when more than one non-stick enhancing additive is present in the coating, the combined amount of the additives is 0.1 wt% to 50 wt%, preferably 0.5 wt% to 40 wt%, most preferably 0.6 wt% to 36 wt%. Preferably, the combination of additives comprises silicone resin, silicone oil, fumed silica, boron nitride. In a preferred arrangement, the coating comprises silicone resin in a preferred amount of 0.1 wt% to 30 wt%, silicone oil in a preferred amount of 0.1 wt% to 30 wt%, fumed silica in an amount of 0.1 wt% to 10 wt%, boron nitride in an amount of 0.5 wt% to 20 wt%.

[0135] In the most preferred combination, the coating comprises polymeric material (A), silicone oil and fumed silica. Preferably, the silicone oil is present in an amount of between 1 wt% and 2.5 wt%, preferably substantially 2 wt% of the coating composition, and the fumed silica is present in an amount of between 0.2 wt% and 0.5 wt%, preferably substantially 0.4 wt%.

[0136] When more than one non-stick enhancing additive is present in the coating, the total amount of non-stick enhancing additives present is suitably as defined above.

[0137] The coating is suitably a substantially uniform and continuous layer disposed on the surface of the substrate of the article. In some embodiments, the coating has a relatively smooth and continuous outer surface, i.e. does not include significant pores or topographical features at the outer surface of the coating. In such embodiments, the coating can be non-porous. Such substantially uniform and non-porous coatings can be formed by applying a suitable coating formulation in the form of a liquid dispersion and drying the coating formulation / solidifying the coating formulation. Alternatively, such coatings can be formed by dry powder coating, web coating, roll coating, curtain coating, flame spraying and electrostatic powder coating. Spray coating and electrostatic powder coating are preferred methods.

[0138] In such embodiments, the coating suitably comprises at least one non-stick enhancing additive discussed above, and the non-stick properties required of the coating are suitably achieved or improved by the use of the non-stick enhancing additive. In such embodiments, the at least one non-stick enhancing additive is suitably dispersed within and throughout the polymeric material (A) of the coating, but is not necessarily uniformly dispersed, so that at least some of the non-stick enhancing additive is present at the outer surface of the coating, but is not necessarily present at all times.

[0139] In some embodiments, the coating has a porous structure and / or comprises significant surface topography features at the outer surface of the coating. In such embodiments, the polymeric material (A) forms the porous structure and / or the topography features. In such embodiments, the non-stick properties required of the coating can be provided by the porous structure and / or the topography features of the coating. The non-stick properties of the porous structure and / or the topography features of the coating can be enhanced by the presence of the non-stick enhancing additive discussed above.

[0140] In embodiments where the coating has a porous structure, the coating suitably has a pore size of 300 nm to 6000 pm, preferably 1 pm to 10 pm.

[0141] The porous structure of the coating suitably provides pores into which the non-stick enhancing additive can penetrate to impregnate into the coating. Thus, in such embodiments, the coating suitably comprises a non-stick enhancing additive as defined above.

[0142] Alternatively, the at least one non-stick enhancing additive can be retained in the pores of the porous structure. In such embodiments, the non-stick enhancing additive can be a liquid, such as an oil (e.g. a silicone oil). Thus, in such embodiments, the non-stick enhancing additive is suitably a non-stick enhancing additive oil. In such embodiments, the non-stick enhancing additive oil is suitably impregnated into the pores of the coating. The pores of the coating suitably hold and substantially fix the non-stick enhancing additive oil in the coating (including at the outer surface of the coating) to provide the non-stick properties to the outer surface of the coating. In use, the non-stick enhancing additive oil can be removed from the outer surface of the coating over time, for example due to abrasion and leaching. Suitably, the non-stick enhancing additive oil is replaced at the outer surface of the coating by migration of the non-stick enhancing additive oil from the pores within the bulk of the coating to the outer surface of the coating. Thus, the coating of such embodiments can provide a durable non-stick property to the article, despite some expected loss of the non-stick enhancing additive oil from the outer surface of the coating, which is maintained.

[0143] Such porous coatings can be formed by any suitable method including additive manufacturing of the polymeric material (A), filament fusion, laser sintering, pore former leaching, laser piercing, membrane cavitation, fibre printing / weaving or amorphous particle sintering or by using a blowing agent in the polymeric material (A).

[0144] In embodiments where the coating comprises topography features at the outer surface of the coating, the coating suitably has an outer surface having an array of topography features formed from the polymeric material (A), wherein the array of topography features comprises spaced apart protrusions and / or depressions, wherein the protrusions and / or depressions have a maximum dimension of less than 3 pm and the topography features are spaced apart by a distance of less than 10 pm.

[0145] In such embodiments, the coating can be referred to as having a textured outer surface, suitably comprising the topographical features.

[0146] Advantageously, it is found that the provision of the topographical features influences the hydrophobicity and / or hydrophilicity of the surface; and by selecting appropriate topographical features the hydrophobicity and / or hydrophilicity can be controlled in a reproducible and predictable manner. The topographical features are suitably arranged and configured to increase the hydrophobicity of the polymeric material (A) and to increase the non-stick properties of the outer surface of the coating of the polymeric material (A) compared to a substantially uniform and smooth coating of the polymeric material (A).

[0147] The outer surface of the coating comprising the array of topographical features suitably has a water contact angle of at least 80°, preferably at least 90°, more preferably at least 92°, especially at least 94°. The water contact angle can be less than 120°, 110° or 100°. The water contact angle can be assessed as described in Example 3 of WO 2012175965 Al, which is incorporated herein by reference.

[0148] The array of topographical features can comprise at least 100, preferably at least 1,000, more preferably at least 10,000 topographical features. The array suitably comprises at least 100,000 topographical features / mm 2 , preferably at least 3,000,000 / mm 2 , more preferably at least 6,000,000 / mm 2 .

[0149] When the topographical features comprise protrusions, the maximum height of the protrusions is less than 3 pm, preferably less than 500 nm, more preferably less than 200 nm. The protrusions can have a height of at least 10 nm.

[0150] When the topographical features comprise recesses, the maximum depth of the recesses is less than 3 pm, preferably less than 500 nm, more preferably less than 200 nm. The recesses can have a depth of at least 10 nm.

[0151] The array of topographical features preferably comprises either protrusions or recesses, but not both. Preferably, the topographical features comprise protrusions, preferably only protrusions.

[0152] The topographical features can be circular, triangular or square in plan view. Preferably, the topographical features are circular in plan view.

[0153] Suitably, at least 50%, preferably at least 90%, more preferably substantially all of the topographical features (e.g. protrusions) associated with the surface have a maximum dimension as specified herein. The surface preferably comprises less than 10% (preferably substantially 0%) of topographical features (e.g. protrusions) having a maximum dimension greater than 3 pm.

[0154] The topographical features (e.g. protrusions) can have a maximum dimension (e.g. diameter in the case of circular protrusions) of less than 0.5 pm, preferably less than 0.25 pm, more preferably less than 0.2 pm.

[0155] The topographical features can be spaced apart (i.e. the shortest distance between the edges of adjacent features) by a distance of less than 5 pm, preferably less than 1 pm, more preferably less than 750 nm, especially less than 500 nm.

[0156] The topographical features can individually have a maximum area of less than 20 pm 2 , suitably less than 0.8 pm 2 , preferably less than 0.2 pm 2 , especially less than 0.14 pm 2 . Preferably, at least 50%, 80%, 90%, 95% or 99% of the topographical features provided on the surface have the foregoing maximum area. The minimum area of the topographical features (preferably at least 50%, 80%, 90%, 95% or 99% of the topographical features provided on the surface) can be at least 200 nm 2 or at least 7,000 nm 2 .

[0157] The array of topographical features preferably comprises at least 1,000, preferably at least 10,000, especially at least 10 6 topographical features having substantially the same maximum dimension (e.g. diameter). The array can comprise at least 1,000, preferably at least 10,000, especially at least 10 6 topographical features having substantially the same height (or substantially the same depth in the case of recesses). The array of topographical features can comprise at least 1,000, preferably at least 10,000, especially at least 10 6 topographical features having substantially the same surface area. The array of topographical features preferably comprises at least 1,000, preferably at least 10,000, especially at least 10 6 topographical features (preferably protrusions) which are substantially the same size and substantially the same shape.

[0158] The outer surface of the coating suitably has an arrangement of topographical features arranged in a pattern based on a conceptual lattice, wherein the distance between nearest neighbouring conceptual lattice points is C, and is between 10 nm and 10 pm, and wherein the topographical features are locally disordered such that the centre of each topographical feature is at most half of C from its respective conceptual lattice point.

[0159] Preferably, C is at least 20 nm, at least 30 nm, at least 40 nm, at least 50 nm, at least 60 nm, at least 70 nm, at least 80 nm, at least 90 nm, at least 100 nm, at least 110 nm, at least 120 nm, at least 130 nm, at least 140 nm, at least 150 nm, at least 160 nm, at least 170 nm, at least 180 nm, at least 190 nm, at least 200 nm, at least 210 nm, at least 220 nm, at least 230 nm, at least 240 nm, at least 250 nm, at least 260 nm, at least 270 nm, at least 280 nm, at least 290 nm, or about 300 nm.

[0160] Preferably, C is at most 9 pm, at most 8 pm, at most 7 pm, at most 6 pm, at most 5 pm, at most 4 pm, at most 3 pm, at most 2 pm, at most 1 pm, at most 900 nm, at most 800 nm, at most 700 nm, at most 600 nm, at most 500 nm, at most 400 nm.

[0161] The most preferred range of C is between 30 nm and 3 pm.

[0162] Preferably, the height or depth of the topographical features (e.g. the average height or depth) is at least 5%, more preferably at least 10%, of C from the remainder of the surface of the device. For example, the height or depth of the topographical features can be at least 10 nm.

[0163] Preferably, each topographical feature has the same shape. The topographical features can be cylindrical pits or protrusions, cubic pits or protrusions, hemispherical pits or protrusions, partially spherical pits or protrusions, or another regular shape.

[0164] Preferably, the diameter of the topographical features is at least 10%, more preferably at least 20%, at least 30%, at least 40%, or at least 50% of C. For example, the diameter of the topographical features can be at least 20 nm.

[0165] Preferably, the centre of each topographical feature is at most 45%, more preferably at most 40%, at most 35%, at most one third, at most 30%, at most 25%, at most 20%, at most 15%, at most 10%, or at most 5% of C from its respective conceptual lattice point.

[0166] Preferably, for at least 50% of the topographical features, the centre of each topographical feature is between one tenth and one quarter of C from its respective conceptual lattice point. More preferably, at least 60%, at least 70%, at least 80% or at least 90% of the topographical features meet this criterion. The lower limit of the distance of the centre of each topographical feature from its respective conceptual lattice point is preferably at least 12% of C, at least 14% of C or at least 16% of C. The upper limit of the distance of the centre of each topographical feature from its respective conceptual lattice point is preferably at most 22% of C, at most 20% of C or at least 18% of C.

[0167] The nature of the symmetry on which the conceptual lattice is based can be selected from the following: parallelogram lattice, rectangular lattice, square lattice, rhombic lattice, triangular lattice and hexagonal lattice. Preferably, the conceptual lattice is a rectangular lattice or a square lattice.

[0168] In one embodiment, the topographical features can be defined to mimic the Lotus effect exhibited by the leaves of a Lotus flower.

[0169] Such topographical features at the outer surface of the coating can be formed as described in WO 2012175965 Al, which is incorporated herein by reference.

[0170] Such topographical features at the outer surface of the coating can be achieved by forming the coating by laser sintering, filament fusion, leaching of a pore former, laser piercing and weaving of fibres.

[0171] The coating can also comprise further additives such as pigments, stabilisers, lubricants and fillers. Suitable additives for these purposes are known in the art.

[0172] Article

[0173] Suitably, the article of the first aspect is a bakeware or cookware article. Suitably, the article is for contact with food when the article and / or the food is heated. For example, the article can be a frying pan, a saucepan, a sauté pan, a stockpot, a rice cooker, a baking tray or plate or a baking tin.

[0174] The substrate of the article can be formed from metal, enamel or glass fibre reinforced material.

[0175] The substrate of the article is suitably formed from metal. Such bakeware or cookware articles formed predominantly from metal tend to be the articles that require and benefit most from a non-stick coating.

[0176] The substrate of the article can be formed from stainless steel, aluminium, electrogalvanised steel or carbon steel. Suitably, a coating is provided on the substrate to coat the surface of the substrate which is used in use to contact food. In some embodiments, the coating is provided only on such surfaces. In some embodiments, the coating is provided substantially over the entire outer surface of the substrate.

[0177] The coating suitably provides a non-stick surface to the article as defined above. Thus, the article can be referred to as a non-stick article, suitably a non-stick cookware or bakeware article.

[0178] The coating can be applied directly to the substrate, or can be applied on top of a primer or coating previously applied to the substrate.

[0179] According to a second aspect of the application, there is provided a solid composition comprising a polymeric material (A) and at least one non-stick enhancing additive; wherein the polymeric material (A) has:

[0180] a repeat unit of the formula:

[0181] ;

[0182] and a repeat unit of the formula

[0183] ;

[0184] wherein Ph represents a phenylene moiety.

[0185] The polymeric material (A) and at least one non-stick enhancing additive can have any suitable features and advantages described in relation to the first aspect.

[0186] The solid composition of this second aspect can have any suitable features and advantages of the coating described in relation to the first aspect.

[0187] The solid composition of this second aspect suitably has a non-stick outer surface as described in relation to the first aspect.

[0188] The solid composition of this second aspect is suitably arranged on an article as described in relation to the first aspect.

[0189] Coating formulation

[0190] According to a third aspect of the application, there is provided a coating formulation comprising a polymeric material (A) and at least one non-stick enhancing additive; wherein the polymeric material (A) has:

[0191] a repeat unit of the formula:

[0192] ;

[0193] and repeat units of the formula

[0194] ;

[0195] wherein Ph represents a phenylene moiety.

[0196] The polymeric material (A) and the at least one non-stick reinforcing additive can have any suitable features and advantages described in relation to the first aspect. For example, the polymeric material (A) can be as described in WO 2020 / 141329 Al, the contents of which are incorporated herein by reference. In such embodiments, the polymeric material (A) can have repeat units of formula la:

[0197] ; and

[0198] repeat units of formula la:

[0199] ;

[0200] wherein at least 95 mol% of the repeat units are repeat units of formula la and repeat units of formula lla;

[0201] wherein the repeat units la and lla have a molar ratio la:lla of 65:35 to 95:5 or 55:45 to 80:20.

[0202] The polymeric material (A) of the coating comprises repeat units I and repeat units II in a relative molar ratio I:II of 65:35 to 95:5.

[0203] Suitably, the at least one non-stick reinforcing additive is a polysiloxane / silicone. Suitable siloxanes / silicones are as described in relation to the first aspect.

[0204] The coating formulation suitably comprises 10wt% to 99.9wt% of the polymeric material (A) and 0.001wt% to 90wt%, preferably 0.1wt% to 90wt% of the at least one non-stick reinforcing additive.

[0205] The coating formulation suitably comprises 10wt% to 99.9wt% of the polymeric material (A), suitably 50wt% to 99.9wt% or 70wt% to 99wt%.

[0206] The coating formulation suitably comprises 0.001wt% to 50wt%, preferably 0.1wt% to 50wt% of the at least one non-stick reinforcing additive, suitably 1wt% to 30wt%, suitably wherein the at least one non-stick reinforcing additive is a siloxane / silicone.

[0207] In some embodiments, the polymeric material (A) of the coating formulation is provided as a dry powder. The polymeric material (A) can have a particle size d50 of 100 nm to 2,000 pm, suitably 1 pm to 200 pm or 1 pm to 50 pm.

[0208] In some embodiments, the coating formulation is provided in the form of a powder. Suitably, the powder comprises the polymeric material (A) and the non-stick enhancing additive in the amounts and forms discussed above.

[0209] In such embodiments, the coating formulation can be applied to an article to form a coating on the article using any suitable method known in the art, for example using electrostatic powder coating.

[0210] The coating formulation in the form of a powder can be formed by milling the polymeric material (A) to the desired particle size in the presence of the non-stick enhancing additive.

[0211] In some embodiments, the coating formulation is provided in the form of a liquid. In such embodiments, the coating formulation suitably comprises a solvent. Suitably, the solvent is water and thus the coating formulation can be a water-based coating formulation. In such water-based coating formulations, the polymeric material (A) and the non-stick enhancing additive are suitably dispersed in the water. A dispersant can be present in such formulations to facilitate the formation and stability of such dispersions.

[0212] In such embodiments, the coating formulation can be applied to an article to form a coating on the article using any suitable method known in the art for applying a liquid coating formulation, for example spraying.

[0213] In the coating formulation of this third aspect, the at least one non-stick enhancing additive is suitably a siloxane and the coating formulation does not comprise any perfluoroalkyl substances / polyfluoroalkyl substances.

[0214] Coating method

[0215] According to a fourth aspect of the present application, there is provided a method of forming a non-stick coating on an article for food contact applications, the method comprising the steps of:

[0216] a) providing an article for food contact applications, the article comprising a substrate, the substrate having a surface;

[0217] b) treating the surface of the substrate with a polymeric material (A), the polymeric material (A) having:

[0218] repeating units of the formula:

[0219] ;

[0220] and a repeat unit of the formula

[0221] ;

[0222] wherein Ph represents a phenylene moiety;

[0223] c) treating the surface of the substrate with a non-stick reinforcing additive.

[0224] The polymeric material (A), the at least one non-stick reinforcing additive, the article, the substrate and the coating can have any suitable features and advantages described in relation to the first aspect.

[0225] Suitably, the at least one non-stick reinforcing additive is a polysiloxane / silicone. Suitable siloxanes / silicones are as described in relation to the first aspect.

[0226] Suitably, the method of this fourth aspect provides an article according to the first aspect and / or a solid composition according to the second aspect.

[0227] In some embodiments, the steps of the method are carried out in the order of step a), followed by step b), followed by step c).

[0228] In some embodiments, step b) and step c) are carried out simultaneously after step a).

[0229] In embodiments in which step b) and c) are carried out simultaneously after step a), step b) and step c) suitably involve treating the surface of the substrate with a coating formulation comprising a polymeric material (A) and at least one non-stick reinforcing additive. Suitably, such a coating formulation is a coating formulation according to the third aspect. Thus, the coating formulation can have any suitable features and advantages described in relation to the coating formulation of the third aspect.

[0230] In such embodiments, the coating formulation comprising a polymeric material (A) and at least one non-stick reinforcing additive can be a powder, suitably as described in relation to the third aspect, and can be applied by an electrostatic powder coating technique. Such a coating technique suitably involves spraying the coating formulation powder onto the substrate, and then heating the substrate after cooling to form the coating.

[0231] Alternatively, the coating formulation in the form of a powder can be applied by a thermal spraying technique. Such a coating technique can involve spraying the coating formulation powder onto the surface of the substrate by a flame which melts the polymeric material (A). The molten coating formulation then impacts and adheres to the surface of the substrate, which is also suitably heated, and solidifies after cooling to form the coating.

[0232] In some embodiments, the coating formulation comprising the polymeric material (A) and the at least one non-stick reinforcing additive can be a liquid, which can be applied to the surface of the substrate using a liquid spray technique, suitably as described in relation to the third aspect. Such coating techniques can involve spraying the coating formulation in the form of a liquid dispersion of the polymeric material (A) and the at least one non-stick reinforcing additive onto the surface of the substrate, and then heating the substrate to form a coating on the substrate. Heating the substrate suitably evaporates the solvent from the coating formulation, which causes the polymeric material (A) to solidify on the surface of the substrate to form a coating containing the non-stick reinforcing additive dispersed within the polymeric material (A).

[0233] In some embodiments, the coating formulation comprising the polymeric material (A) and the at least one non-stick reinforcing additive can be a liquid, which can be applied to the surface of the substrate using a liquid spray technique, suitably as described in relation to the third aspect. Such coating techniques can involve spraying the coating formulation in the form of a liquid dispersion of the polymeric material (A) and the at least one non-stick reinforcing additive onto the surface of the substrate, and then heating the substrate to form a coating on the substrate. Heating the substrate suitably evaporates the solvent from the coating formulation, which causes the polymeric material (A) to solidify on the surface of the substrate to form a coating containing the non-stick reinforcing additive dispersed within the polymeric material (A).

[0234] In a further embodiment, the coating formulation comprising the polymeric material (A) and the at least one non-stick reinforcing additive can be a liquid, which can be applied to the surface of the substrate using a liquid spray technique, suitably as described in relation to the third aspect. Such coating techniques can involve spraying the coating formulation in the form of a liquid dispersion of the polymeric material (A) and the at least one non-stick reinforcing additive onto the surface of the substrate, and then heating the substrate to form a coating on the substrate. Heating the substrate causes the solvent to evaporate from the coating formulation, which in turn heats the polymeric material (A) melt, thereby forming a uniform film on the surface of the substrate. Upon cooling, the polymeric material (A) solidifies on the surface of the substrate to form a coating containing the non-stick reinforcing additive dispersed within the polymeric material (A).

[0235] In embodiments in which the steps of the method are performed in the order of step a), followed by step b), followed by step c), step b) suitably involves forming a coating comprising the polymeric material (A) on the surface of the substrate, and step c) suitably involves treating the coating of the polymeric material (A) with the non-stick reinforcing additive.

[0236] In such embodiments, step b) suitably involves forming a coating comprising the polymeric material (A) having a porous structure and / or comprising a significant surface topography feature at an outer surface of the coating, as described in relation to the first aspect. Suitably, step b) involves forming a coating comprising the polymeric material (A) having a porous structure. Such a porous structure of the polymeric material (A) can be formed by one of the techniques described below.

[0237] The porous structure of the polymeric material (A) can be formed by a pore former leaching technique, in which a pore former (e.g. a salt) is dispersed within the polymeric material (A) by a mixing process (such as an extrusion process) and then processed into a coating. The coating can then be treated with a solvent to dissolve the pore former using the solvent removed from the coating, leaving a porous structure of the polymeric material (A).

[0238] The porous structure of the polymeric material (A) can be formed by laser piercing a film of the polymeric material (A) to create a thin film supporting the porous structure. The film can then be applied to the surface of the substrate to form a porous coating.

[0239] The porous structure of the polymeric material (A) can be formed by film cavitation of a uniaxial or biaxial oriented film of the polymeric material (A) mineral filled film. By adding suitable additives (e.g. CaCCb) and subsequently stretching / orienting the semi-crystalline film, void / cavitated / porous films can be obtained.

[0240] The porous structure of the polymeric material (A) can be formed by printing / weaving fibres of the polymeric material (A) on the surface of the substrate.

[0241] The porous structure of the polymeric material (A) can be formed by using a dedicated blowing agent. For example, the polymeric material (A) can be loaded with pressurized CO2 and expanded by reducing the pressure and allowing the CO2 to rapidly evaporate. Pores are created in the polymeric material (A).

[0242] The porous structure of the polymeric material (A) can be formed by amorphous particle sintering. In such a technique, a powder of the polymeric material (A) in an amorphous state can be induced to undergo controlled diffusion and recrystallization to provide a porous sintered structure.

[0243] In such embodiments, the coating comprising the polymeric material (A) having a porous structure formed in step b) is then suitably treated with a non-stick enhancing additive in step c). The non-stick enhancing additive is suitably a non-stick enhancing additive oil, such as a silicone oil, as described in relation to the first aspect. Suitably, step c) impregnates the non-stick enhancing additive oil into the pores of the porous coating, such that the non-stick enhancing additive oil is present at the outer surface of the coating to provide a non-stick outer surface of the coating, as described in relation to the first aspect.

[0244] The non-stick enhancing additive used in step c) for treating the surface of the substrate can be provided in a solution with a solvent. In such embodiments, the solvent is subsequently suitably removed. Alternatively, the non-stick enhancing additive can be added in pure form to the coating comprising the polymeric material (A) having a porous structure. For example, the non-stick enhancing additive used in step c) can be a pure non-stick enhancing additive oil, such as a silicone oil.

[0245] The non-stick coating formed by the method of the fourth aspect described above can have any suitable features and advantages described in relation to the first aspect, such as the non-stick properties described herein.

[0246] According to a further aspect of the application, there is provided a method of forming a non-stick coating on an article for food contact applications, the method comprising the steps of:

[0247] a) providing an article for food contact applications, the article comprising a substrate, the substrate having a surface;

[0248] b) treating the surface of the substrate with a polymeric material (A) to form a coating having an outer surface comprising an array of topographical features of the polymeric material (A), wherein the array of topographical features comprises spaced apart protrusions and / or depressions, wherein the protrusions and / or depressions have a maximum dimension of less than 3 pm, and the topographical features are spaced apart by a distance of less than 10 pm; and wherein the polymeric material (A) has:

[0249] repeating units of the formula:

[0250] ;

[0251] and repeating units of the formula

[0252] ;

[0253] wherein Ph represents a phenylene moiety;

[0254] In such embodiments, step b) can be carried out by injection moulding the polymeric material (A) in a mould configured to define the topographical features. In other embodiments, step b) can be carried out by additive manufacturing practice techniques or subtractive manufacturing practice techniques. Such practices include methods such as direct 3D laser texturing methods, in particular laser induced periodic surface structures (LIPSS), direct laser interference patterning (DLIP) or direct laser writing (DLW).

[0255] In such embodiments, the non-stick coating comprising topographical features can have any suitable features and advantages described in relation to the first aspect. Such topographical features at the outer surface of the coating can be formed as described in WO 2012175965 Al, which is incorporated herein by reference.

[0256] According to a fifth aspect of the application, there is provided use of a composition comprising a polymeric material (A) for providing a non-stick surface for an article for food contact applications, wherein the polymeric material (A) has:

[0257] repeating units of the formula:

[0258] ;

[0259] and repeating units of the formula

[0260] ;

[0261] wherein Ph represents a phenylene moiety.

[0262] Suitably in the use of the fifth aspect, the composition comprises at least one non-stick enhancing additive.

[0263] The polymeric material (A), the article, the non-stick surface and the non-stick enhancing additive of the use of this fifth aspect can have any suitable features and advantages described in relation to the first aspect.

[0264] The use of this fifth aspect can involve the method steps described in relation to the fourth aspect.

[0265] Any feature of any aspect of any application or embodiment described herein can be combined with any feature of any other application described herein (with necessary modifications).

[0266] Particular embodiments of the application will now be described by way of the following evaluated examples.

[0267] Example 1 : Evaluation of the non-stick behavior of the coating

[0268] As shown in Table 1, comparative tests were performed on polymeric materials (A) as described above (both with and without non-stick enhancing additives) against PTFE and sol-gel (ceramic).

[0269] Comparative coating 1 : PTFE (PFAS): KitchenCraft PFOA Free Eco Non-Stick Frying Pan 20cm - aluminium substrate used for testing.

[0270] Comparative coating 2: Sol-gel (ceramic): Cooks pot used for testing - Salter BW09277 Earth 24 cm frying pan - aluminium substrate.

[0271] Polymeric material (A) (PEEK / PEDEK copolymer) and method of preparation as described in US 4717761, WO 2014 / 207458 Al and WO 2015 / 124903 Al, the contents of which are incorporated herein by reference. In the examples in the table below, the polymeric material (A) is a polymeric material described in WO 2020 / 141329 Al, the contents of which are incorporated herein by reference, having repeat units of formula la:

[0272] ; and

[0273] repeat units of formula IIa:

[0274] ;

[0275] wherein at least 95 mol% of the repeat units are repeat units of formula la and repeat units of formula IIa;

[0276] wherein repeat units la and IIa have a molar ratio la:IIa of 75:25.

[0277] The polymeric material (A) blends were prepared in powder form by first adding the dry materials and subsequently adding any wet additives (e.g. silicone oil). This mixture was blended in a Henschel mixer at approximately 38000 rpm for up to 2 minutes to obtain a homogeneous composition.

[0278] Coatings 2 to 14 containing polymeric material (A) were tested in comparison to a market share holding cookware coating coating PTFE (comparative coating 1) and a currently commercially available PFAS-free solution (name: Sol-gel (ceramic)) (comparative coating 2). In addition, comparative coatings 1 and 2 were also tested in comparison to PEEK (coating 1). In all cases, the substrate was aluminium.

[0279] All coatings in table 1 are single layer coatings deposited on an aluminium substrate.

[0280] The water contact angle was measured using a drop shape analyser DAS100S by Kruess GmbH according to DIN EN 828 to measure the dynamic contact angle of water. The drop application setting was 0.2 pL / s with a total volume of 6.0 pL.

[0281]

[0282]

[0283] Table 1

[0284] Table 1 shows the significant increase in contact angle for those coatings (3 to 14) comprising a blend of polymeric material (A) with at least one non-stick reinforcing additive. For example, the tests show that low levels of silicone and boron nitride can provide a coating of superior contact angle quality compared to market share dominant PTFE cookware coating solutions or currently available PFAS-free sol-gel ceramic solutions.

[0285] Example 2: Evaluation of the non-stick coating of polymeric material (A) in comparison to comparative coatings

[0286] As shown in Table 2, comparative tests were performed on polymeric material (A) as described above (both with and without non-stick reinforcing additives) versus PTFE and sol-gel (ceramic) against several standards relevant to cookware use. The polymeric material (A) (PEEK / PEDEK copolymer 75:25) and method of preparation are as described above and in US 4717761, WO 2014 / 207458 Al and WO 2015 / 124903 Al, the contents of which are incorporated herein by reference.

[0287] Comparative coating 1 : PTFE (PFAS): Pan used for testing - KitchenCraft PFOA Free Eco Non-Stick Frying Pan 20cm - Aluminium base material.

[0288] Comparative coating 2: Sol-gel (ceramic): Pan used for testing - Salter BW09277 Earth 24cm Frying Pan - Aluminium base material.

[0289] Coating 5 was prepared as a single layer coating in Table 1. However, in the examples below in Table 2, coating 5 was prepared as a dual polymer layer as follows. A first layer of polymeric material (A) was deposited on an aluminium base material. The first layer consisted of polymeric material (A) as described above and was free of additives. A second layer of coating 5 comprising polymeric material (A) was deposited on top of the first layer. The second layer comprised both polymeric material (A) and non-stick reinforcing additives. The performance of the two layer coating (coating 5) was evaluated for application performance in terms of non-stick and mechanical behaviour. Table 2 shows the findings compared to market share dominant cookware coating systems of comparative coatings 1 and 2 which were PFAS (PTFE) and sol-gel ceramic respectively.

[0290] Dry coating thicknesses were measured using the amplitude sensitive eddy current instrument byko-test 8500 from BYK Gardner, following the standard ISO 2808 for the determination of film coating thicknesses and in particular the standard ISO 2360 for non-magnetic substrates.

[0291]

[0292] Table 2

[0293] In both Tables 1 and 2, the substrates were first cleaned with IPA and blasted with corundum K 100 to 300 to achieve a roughness (Rz) of between 13 pm and 20 pm. Coating 5 was applied by spray application with a GEMA OptiFlex 2 GM03 manual spray gun combined with an OptiFlex 2 CG09 control unit. The d50 of the powder was approximately 25 pm.

[0294] The egg test was performed according to The Cookware and Bakeware Alliance (CBA) Engineering Standards for Cookware and Bakeware (CBA 21.3.1 Egg Test (Adapted from British Standard 7069:1988) Revision October 2022). The test evaluates the cleanability of a product by heating the cookware between approximately 150°C and 180°C (160°C in Table 2) and then cooking an egg without fat or lubricant until it is firmly set. The ability to remove the egg with a plastic or nylon spatula is recorded. “Pass” indicates no solid material was recorded when wiping the surface of the cookware. “Fail” indicates traces of solid material remained on the cookware.

[0295] As shown in Table 2, coating 5 (97.6% polymer material (A), 2% silicone oil, 0.4% fumed silica) showed similar performance to the PFAS (PTFE) coating. Advantageously, this formulation is superior to the sol-gel ceramic alternatives. The tests show that the blend of polymer material (A) without PFAS is at least comparable to the PTFE (PFAS) solution in the test.

[0296] Polymer material (A) coatings can be applied using electrostatic powder deposition and hot flocking to form the desired thickness. For example, polymer material (A) powder is sprayed directly onto the substrate and then heated to a temperature of 340°C to 360°C. Once the powder is melted, the part is cooled or another coating of the same material or a blend is hot-flocked on top of the first coating. Subsequent coatings can be applied by hot-flocking techniques to form the coating thickness.

[0297] An alternative method of applying the coating is by liquid dispersion coating with an aqueous polymeric material (A) dispersion. For example, the polymeric material (A) can be sprayed onto a cleaned and blasted substrate, whereupon the polymeric material is heated to form a thin film on the substrate. Specifically, the substrate is blasted to achieve a profile of 20-25% of the total coating DFT (dry film thickness). The substrate is preferably further solvent washed and the aqueous dispersion applied until a uniform wet surface is achieved (HVLP gun with tip size between 0.7 mm and 1.8 mm). The coated surface is maintained at ambient air temperature for approximately 5 minutes, after which it is heated in an oven at 120 °C for approximately 5 minutes. The oven temperature is then ramped to between 340 °C and 360 °C. Once the polymer melt temperature is reached, the part is left for a further 5 to 10 minutes to allow the coating to melt. The part is then removed from the oven and allowed to cool to ambient temperature. Further coatings can be applied to build up the thickness.

[0298] In some embodiments, the polymeric material (A) coating comprises a porous structure that provides pores into which a non-stick enhancing additive, such as silicone oil, can be impregnated into the coating. Such polymeric material (A) porous coatings can be manufactured by an additive manufacturing (e.g., selective laser sintering or filament fusion) process.

[0299] One example of achieving a porous coating of polymeric material (A) and additive (e.g., silicone oil) is by a 3D printing filament fusion process following the conditions described in Table 3 below.

[0300]

[0301] Table 3

[0302]

[0303] Table 4

[0304] In a further embodiment, the polymeric material (A) coating comprises topographical features designed to affect the hydrophobicity and / or hydrophilicity of the surface (coating non-stick behavior).

[0305] Such topographical features comprising protrusions or recesses are created by taking advantage of the different melting temperatures of the polymer material (A) and PEEK (or polyether ketone (PEK)) blend. By varying the gradient of particle size (defined in particular by its d50, d90, d99) between the polymer material (A) and the PEEK (or PEK) powder, more or less pronounced topographical feature effects can also be obtained. The polymer material (A) and PEEK (or PEK) powder can be deposited onto a substrate to provide a coating. Such final dry film coating can comprise at least one polymer material (A) coating and PEEK (or PEK) blend; or at least two layers, the bottom layer having topographical features comprising polymer material (A) and PEEK (or PEK) blend, followed by a top layer comprising a polymer material (A) coating.

[0306] Heating the polymer material (A) powder (for example in an oven) to a temperature in the range 340-360°C allows the polymer material (A) polymer to melt, causing the partially molten and glassy PEEK (or PEK) particles to flow and embed, creating upon cooling (for example removal from the oven) coalesced topographical features.

[0307] Upon cooling to ambient temperature, the combination of the polymer material (A) and PEEK (or PEK) coating provides a coated surface having topographical features, resulting in non-stick properties as well as improvements in durability, wear resistance and scratch resistance.

[0308] Alternatively, other heat-generating manufacturing processes such as selective laser sintering (SLS) or laser-based directed energy deposition (DED) can be used to create such polymer material (A) coatings having topographical features.

[0309] While the written preferred embodiments have been shown and described, it is to be understood that various changes and modifications can be made without departing from the scope of the present application as defined in the appended claims.

[0310] Throughout this specification, the term "comprising," or "comprises," means including the components identified, but not to the exclusion of other components. The term "consisting essentially of," or "consists essentially of," means including the components identified, but not to the exclusion of other components except that other components present are not essential to the technical effect of the invention. Generally, when referring to a composition, a composition consisting essentially of a group of components will include less than 5% by weight, typically less than 3% by weight, more typically less than 1% by weight of non-specified components.

[0311] The term "consisting of," or "consists of," means including the components identified, but not including other components.

[0312] The use of the term "comprises" or "comprising" also can be used, according to context, to include or encompass the meaning of "consists essentially of" or "consisting essentially of," and can be used to include or encompass the meaning of "consists of" or "consisting of," as appropriate.

[0313] For the avoidance of doubt, where the amount of a component in a composition is described in wt%, this means the weight percent of the particular component relative to the entire composition referred to.

[0314] Optional features of the aspects and exemplary embodiments of the application described herein can be used individually or in any appropriate combination, and particularly in the combinations described in the appended claims. Optional features of each aspect or exemplary embodiment of the application shown herein are also to be understood as applicable to any other aspect or exemplary embodiment of the application, where appropriate. In other words, the skilled person reading the specification will understand that optional features of each exemplary embodiment of the application are interchangeable and combinable between different exemplary embodiments.

[0315] Attention is directed to all papers and documents which can be cited in the above specification and to the publications cited in the Background Art section, which are hereby incorporated by reference into the present application in their entirety. Papers and documents cited in the Background Art section are hereby incorporated by reference into the present application in their entirety.

[0316] All of the features disclosed in this specification (including any accompanying claims and drawings) and / or all of the steps of any methods or processes described herein can be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0317] Every feature disclosed in this specification (including any accompanying claims and drawings) can be replaced by an alternative feature serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, every feature disclosed in this specification is one example only of a generic series of equivalent or similar features.

[0318] The application is not restricted to the details of the foregoing embodiments. The application encompasses any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or any novel one, or any novel combination, of the steps of any of the methods or processes disclosed.

Claims

1. An article for food contact applications, the article comprising a substrate having at least one surface and a coating disposed on the at least one surface, wherein the coating comprises a polymeric material (A) and at least one non-stick reinforcing additive, wherein the polymeric material has: recurring units of the formula: recurring units of the formula 2. The article according to claim 1, wherein the coating is a non-stick coating. ； 3. The article according to claim 1 or claim 2, wherein the article is a bakeware or cookware article. ； 4. The article according to any one of the preceding claims, wherein the substrate of the article is formed from a metal, an enamel or a glass fibre reinforced material.

5. The article according to any one of the preceding claims, wherein the coating does not comprise any perfluoroalkyl substances / multifluoroalkyl substances.

6. The article according to any one of the preceding claims, wherein the relative molar ratio I:II of recurring unit I and recurring unit II in the polymeric material (A) of the coating is from 65:35 to 95:

5.

7. The article according to any one of the preceding claims, wherein in the polymeric material (A) of the coating: the recurring units of the formula I have the structure la: the recurring units of the formula II have the structure Ila:

8. The article according to any one of the preceding claims, wherein the at least one non-stick reinforcing additive is selected from a metal alkoxide based on silica or based on alumina, a wax, an oil, a fat, talc, a ceramic, boron nitride, graphite, carbon black, a siloxane / silicone, a nanoparticle or a glass fibre.

9. The article according to any one of the preceding claims, wherein the at least one non-stick additive is present in an amount from 0.001 wt% to 40 wt%.

10. The article according to any one of the preceding claims, wherein the at least one non-stick reinforcing additive is a siloxane / silicone.

11. The article according to any one of the preceding claims, wherein the coating has a porous structure and / or comprises a significant surface topography feature at an outer surface of the coating. ; and 12. The article according to claim 11, wherein the coating has a porous structure and the at least one non-stick reinforcing additive is retained in the pores of the porous structure. 。 13. An article for food contact applications, the article comprising a substrate having at least one surface and a coating disposed on the at least one surface, wherein the coating comprises a polymeric material (A) having: recurring units of the formula: recurring units of the formula wherein Ph represents a phenylene moiety; wherein the coating has an outer surface having an array of topographical features formed from the polymeric material (A), wherein the array of topographical features comprises spaced apart protrusions and / or depressions, wherein the protrusions and / or depressions have a maximum dimension of less than 3 pm and the topographical features are spaced apart by a distance of less than 10 pm. ​ ​ ​ ​ ​ ； ​ ； ​ ​ 14. A coating formulation comprising a polymeric material (A) and at least one non-stick enhancing additive; wherein polymeric material (A) has: recurring units of the formula: ###0002### and recurring units of the formula ###0003### wherein Ph represents a phenylene moiety. ； 15. The coating formulation according to claim 14, wherein the at least one non-stick enhancing additive is a siloxane / silicone. ； 16. A method of forming a non-stick coating on an article for food contact applications, the method comprising the steps of: a) providing an article for food contact applications, the article comprising a substrate having a surface; b) treating the surface of the substrate with a polymeric material (A), the polymeric material (A) having: recurring units of the formula: ###0004### and recurring units of the formula ###0005### wherein Ph represents a phenylene moiety; c) treating the surface of the substrate with a non-stick enhancing additive.

17. Use of a composition comprising a polymeric material (A) for providing a non-stick surface to an article for food contact applications, wherein polymeric material (A) has: recurring units of the formula: ###0006### and recurring units of the formula ###0007### wherein Ph represents a phenylene moiety.

18. The use according to claim 17, wherein the composition comprises at least one non-stick enhancing additive. ​ ； ​ ； ​ ​ ​ ​ ； ​ ； ​ ​

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