Coated articles and coating formulations

Abstract

An article for use in food contact applications. The article comprises a substrate having at least one surface and a coating arranged on the at least one surface. The coating comprises a polymeric material (A) and at least one non-stick enhancing additive, wherein the polymeric material has: a repeat unit of formula: -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety. The coating provides a non-stick coating to the article. A coating formulation, a method of forming a non-stick coating on an article for use in food contact applications and an associated use are also disclosed.

Description

[0001] Coated Articles and Coating Formulations

[0002] Field

[0003] The present invention relates to an article intended for food contact which has a non-stick coating. The present invention also relates to a coating formulation for forming such a non-stick coating on an article, a coating composition, methods of forming such a non-stick coating and associated uses of a polymeric material to form such non-stick coatings. In particular, the present invention relates to non-stick coatings which are free of per / polyfluoroalkyl substances.

[0004] Background

[0005] Many articles intended for food contact, such as cookware (e.g. frying pans and rice cookers) and bakeware (e.g. baking trays and tins) which are currently manufactured, including consumer, professional and industrial items of cookware and bakeware, are provided with a non-stick coating. Articles with such non-stick coatings have a lower tendency to react with food and / or have an increased tendency to release food during and after cooking / baking said food compared to an uncoated article. This is advantageous for the use and particularly in the subsequent cleaning of cookware or bakeware.

[0006] The majority of such non-stick coatings for cookware and bakeware are currently formed using per- and polyfluoroalkyl substances (PFASs). The PFAS group of chemicals include the perfluorosulfonic acids, such as perfluorooctanesulfonic acid (PFOS), and the perfluorocarboxylic acids such as perfluorooctanoic acid (PFOA). PFASs have found wide utility in industry and have proven to have excellent properties for use in non-stick coatings. Polytetrafluoroethylene (PTFE) is a PFAS widely used in forming such non-stick coatings on cookware and bakeware.

[0007] However, concerns over the public health effects of PFASs have grown over time with the increasing use of these chemicals in industry. PFASs, especially PFOS and PFOA, have been termed “forever chemicals” due to their resistance to breakdown in the environment and theirtendency to accumulate in groundwater, in plants and in animals and humans. The exposure to and the build-up of high levels of PFASs in humans has been strongly linked to serious medical conditions such as dyslipidemia, reduced infant and foetal growth and kidney cancer.

[0008] Regulatory authorities have been seeking to limit the use of PFASs and reduce the accumulation of these chemicals in the environment. In particular, such authorities are considering a ban on the use of PFASs such as PTFE in non-stick coatings, in order to reduce PFAS pollution from the manufacture, use and disposal of non-stick articles and to reduce the exposure to PFASs of users of such articles. For these reasons, researchers have sought to develop alternative non-stick coatings which do not comprise PFASs and do not require such chemicals in the manufacture of non-stick coated articles. Advances towards this goal have been made using High Performance Polymer (HPP) based coatings. HPP coatings can be applied by similar techniques as PFAS based non-stick coatings, for example by coil coating, roller coating, curtain coating, flame spray coating, electrostatic powder coating or spray coating. All of these coating techniques require HPP particles to be heated above their melting or fusion point to form a continuous HPP film coating on a substrate.

[0009] HPP coatings do not necessarily provide inherent non-stick properties and therefore may require the use of non-stick enhancing additives to achieve non-stick properties comparable to those of PFAS based coatings or suitable for a particular use case.

[0010] Such non-stick enhancing additives include silica-based or alumina-based metal alkoxides, wax, oils, fats, talc, ceramics, boron nitride, graphite, carbon black, siloxanes I silicones, nano particles or glass-fibres. However, to date it has proved difficult to provide PFAS-free non-stick coatings with comparable properties to PFAS based non-stick coatings, which can be formed reliably and efficiently. Therefore, there remains a need for alternative, high-performance PFAS-free non-stick coatings.

[0011] Summary of the Invention

[0012] Polyaryletherketone (PAEK) polymers are a well-known group of high performance thermoplastic polymers, many of which have excellent chemical and mechanical properties, for example poly etheretherketone (PEEK) polymers. PEEK polymers can form coatings with long-term durability due to their wear, scratch, abrasion, chemical and thermal degradation resistance. However, PEEK polymer based non-stick coatings have often relied on PFAS non-stick enhancing additives to achieve the properties required of non-stick coatings for cookware and bakeware. Such coatings are therefore not free of the problematic PFASs.

[0013] It is one aim of the present invention, amongst others, to provide a non-stick coating composition, formulation and method that addresses at least one disadvantage of the prior art, whether identified here or elsewhere, or to provide an alternative to existing non-stick coating compositions, formulations and methods. For instance, it may be an aim of the present invention to provide a cookware or bakeware article which has a PAEK type polymer coating which is non-stick and which does not comprise PFASs.

[0014] According to aspects of the present invention, there is provided an article, coating formulation, coating, method and use as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and from the description which follows. According to the present invention, there is provided an article for use in food contact applications, the article comprising a substrate having at least one surface and a coating arranged on the at least one surface, wherein the coating comprises a polymeric material (A) having: a repeat unit of formula:

[0015] -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula

[0016] -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety.

[0017] According to a first aspect of the present invention, there is provided an article for use in food contact applications, the article comprising a substrate having at least one surface and a coating arranged 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: a repeat unit of formula:

[0018] -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula

[0019] -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety.

[0020] The article of this first aspect is for use in food contact applications. Suitably the article is for use in the preparation and / or serving of food. In particular, the article may be intended for use in the heating or cooking of food. For example, the article of this first aspect may be an article of cookware and / or bakeware. The at least one surface of the article on which the coating is arranged is a surface intended to contact food, in use. Therefore, the coating is intended to contact food, in use, through an outer surface of the coating. Suitably the coating is intended to contact food whilst the food is heated. Heat may be transferred from the article to the food, via said surface. The coating suitably has a “non-stick” outer surface and therefore provides a “non-stick” outer surface of the article. The non-stick surface is intended to contact food, in use, suitably to contact food whilst the food is heated. Such non-stick surfaces may be described as having an improved tendency to release food stuffs contacting said surfaces and a lower tendency to react with food during heating. A non-stick coating is a coating that seeks to reduce the adherence between the surface of a first material which it is coated onto and a second material or surface which the first material is intended to contact in use. In case of non-stick cookware or bakeware articles, a non-stick coating is applied to the cookware or bakeware article in order to reduce the adherence of food on the surface of the cookware or bakeware article.

[0021] 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), the repeat units of formula I (which may be referred to as EEK) providing the PEEK polymer component and the repeat units of formula II (which may be referred to as EDEK) providing the PEDEK. Therefore, the polymeric material (A) may be referred to as a PEEK / PEDEK copolymer.

[0022] The inventors have found that the use of PEEK polymer for producing non-stick coatings which are free of PFASs limits the possible non-stick enhancing additives which can be used to provide the required properties to the coated surface, due to the relatively high temperature processing window for these polymers. Such relatively high temperatures can degrade many of the suitable types of non-stick enhancing additives, reducing their usefulness in providing non-stick properties, or add complexity to the coating process. The typical processing temperature window for PEEK polymers is from 380 to 420°C. Processing a PEEK polymer and a non-stick enhancing additive such as a siloxane I silicone composition at this temperature has been found to partially degrade the siloxane I silicone composition, which severely reduces the non-stick enhancing effect of the additive and impairs the overall reliability of the coating process.

[0023] The inventors have surprisingly found that an effective non-stick coating can be produced on an article according to this first aspect using the polymeric material (A) as defined herein which is a PEEK / PEDEK copolymer. Such coatings can advantageously provide thermomechanical durability, hydrophobicity, wear resistance, chemical resistance and scratch resistance which is at least comparable to PFAS based non-stick coatings such PTFE, without the problematic PFASs being included in the coating or used in the manufacture of the coating.

[0024] In some embodiments, the coating of the article of this first aspect comprises a non-stick enhancing additive. The inventors have found that non-PFAS non-stick enhancing additives used in combination with the polymeric material (A) may provide a PFAS-free non-stick coating on an article with enhanced non-stick characteristics compared to a coating with the polymeric material (A) on an article in absence of any non-stick enhancing additives. Forming such a non-stick coating may advantageously avoid degradation of the non-stick enhancing additive, such as a siloxane or silicone, due to the processing temperature window of polymeric material (A) being lowerthan the temperature which induces substantial degradation of such suitable non-stick enhancing additives. For example, the polymeric material (A) may be processable into a coating at a temperature of less than 380°C. Suitably the polymeric material (A) may be processable into a coating at a temperature of less than 360°C, or less than 350°C or less than 340°C. The polymeric material (A) suitably has a processing temperature window of 200 to 600°C, a preferred processing temperature window of 300 to 550°C and a particularly preferred processing temperature window of 300 to 380°C or 340 to 380°C. At such temperatures, a coating comprising the polymeric material (A) and a non-stick enhancing additive can be formed on an article without degrading the non-stick enhancing additive, such as a siloxane / silicone, and therefore provide an effective non-stick coating wherein the additive retains its non-stick enhancing properties.

[0025] Furthermore, the use of polymeric material (A) as disclosed herein may allow the non-stick coating to be applied in one layer, the single layer of non-stick coating having sufficient durability and substrate adhesion due to the advantageous physical properties of the polymeric material (A). A single layer application may provide an efficient manufacturing process for the articles intended for food contact applications, such as cookware and bakeware. However, the non-stick coating may also be applied in more than one layer.

[0026] The polymeric material (A)

[0027] The coating on the article of this first aspect comprises polymeric material (A). Polymeric material (A) is suitably crystalline and generally has a crystalline melting point which is below that of the homopolymer of repeating unit I or the homopolymer of repeating unit II. However, the glass transition temperature of the polymeric material (A) is generally the same as, or slightly higher than, the glass transition temperature of the homopolymer of repeating unit I. More specifically, the polymeric material (A) suitably has a glass transition temperature of greater than 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 units I and II in the relative proportions of 80:20 has a glass transition temperature of about 149°C and a crystalline melting temperature of about 309°C.

[0028] Suitably the polymeric material (A) has a processing temperature in the range of 200 to 600 °C, a preferred processing temperature in the range of 250 to 550 °C and a particularly preferred processing temperature in the range of 300 to 380°C or 340 to 380°C. A processing temperature is understood to mean a temperature at which the polymeric material at least partially melts and / or is sufficiently fluid to be worked into a desired form, such as a substantially continuous coating on a surface of an article as described herein.

[0029] The phenylene moieties (Ph) in each repeat unit may independently have 1 ,4-para linkages to the atoms to which they are bonded or 1 ,3-meta linkages. Where a phenylene moiety includes 1 ,3- linkages, the moiety will be in the amorphous phase of the polymer. Crystalline phases will include phenylene moieties with 1 ,4- linkages. In many applications it is preferred for the polymeric material to be highly crystalline and, accordingly, the polymeric material preferably includes high levels of phenylene moieties with 1 ,4- linkages. Suitably at least 95% or at least 99%, of the number of phenylene moieties (Ph) in the repeat unit of formula I have 1 ,4-linkages to the moieties to which they are bonded. It is especially preferred that each phenylene moiety in the repeat unit of formula I has 1 ,4- linkages to the moieties to which it is bonded.

[0030] Suitably at least 95% or at least 99%, of the number of phenylene moieties (Ph) in the repeat unit of formula II have 1 ,4-linkages to the moieties to which they are bonded. It is especially preferred that each phenylene moiety in the repeat unit of formula II has 1 ,4- linkages to the moieties to which it is bonded.

[0031] Preferably, the phenylene moieties in the repeat units of formula I are unsubstituted. Preferably, the phenylene moieties in the repeat units of formula II are unsubstituted.

[0032] The repeat unit of formula I suitably has the structure la:

[0033] The repeat unit of formula II suitably has the structure Ila:

[0034] Preferably, in the polymeric material (A) of the coating: the repeat unit of formula I has the structure la: the repeat unit of formula II has the structure Ila:

[0035] 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 up to 95 mol%, up to 90 mol% or suitably up to 85 mol% of repeat units of formula I. The polymeric material (A) suitably comprises from 10 to 95 mol%, preferably from 20 to 90 mol% of units of formula I. 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 up to 95 mol%, up to 90 mol% or suitably up to 80 mol% of repeat units of formula II. The polymeric material (A) suitably comprises from 5 to 95 mol%, preferably from 10 to 80 mol% of units of formula II.

[0036] The sum of the mol% of units of formula I and II in the polymeric material (A) is suitably at least 95 mol%, is preferably at least 98 mol%, is more preferably at least 99 mol% and, especially, is about 100 mol%.

[0037] Suitably the polymeric material (A) of the coating comprises repeat units I and II in the relative molar proportions l:ll of from 10:90 to 95:5, suitably of from 40:60 to 90:10 or from 20:80 to 90:10..

[0038] In some embodiments, the polymeric material (A) of the coating comprises repeat units I and II in the relative molar proportions l:ll of from 65:35 to 95:5.

[0039] In some embodiments, the polymeric material (A) of the coating comprises repeat units I and II in the relative molar proportions l:ll of from 20:80 to 45:55.

[0040] In some embodiments, the polymeric material (A) may 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) may include up to 55 mol%, up to 45 mol% or suitably up to 40 mol% of repeat units of formula I. The polymeric material (A) may include 15 to 50 mol%, preferably 20 to 45 mol%, more preferably 25 to 40 mol% of units of formula I.

[0041] In such embodiments, the polymeric material (A) may include at least 40 mol%, preferably at least 50 mol% or at least 55 mol%, of repeat units of formula II. The polymeric material (A) may include less than 90 mol%, preferably less than 80 mol% of repeat units of formula II. The polymeric material (A) may include 40 to 90 mol%, preferably 50 to 85 mol%, more preferably 55 to 80 mol% of units of formula II.

[0042] In such embodiments, the sum of the mol% of units of formula I and II in the polymeric material (A) is suitably at least 95 mol%, is preferably at least 98 mol%, is more preferably at least 99 mol% and, especially, is about 100 mol%.

[0043] In such embodiments, the polymeric material (A) suitably contains repeat units I and II in the molar proportions l:ll of from 15:85 to 50:50 or of from 20:80 to 45:55.

[0044] Such polymeric materials (A) may be formed according to the methods described in WO 19215304 A1 , which is incorporated herein by reference. In some embodiments, the polymeric material (A) may include at least 68 mol%, preferably at least

[0045] 71 mol% of repeat units of formula I. Particular advantageous polymeric materials (A) may include at least 72 mol%, or, especially, at least 74 mol% of repeat units of formula I. The polymeric material (A) may include up to 95 mol%, up to 90 mol% or suitably up to 82 mol% of repeat units of formula I. The polymeric material (A) may include 68 to 82 mol%, preferably 70 to 80 mol%, more preferably

[0046] 72 to 77 mol% of units of formula I.

[0047] In such embodiments, the polymeric material (A) may include at least 10 mol%, preferably at least 18 mol%, of repeat units of formula II. The polymeric material (A) may include less than 32 mol%, preferably less than 29 mol% of repeat units of formula II. Particularly advantageous polymeric materials (A) may include 28 mol% or less; or 26 mol% or less of repeat units of formula II. The polymeric material (A) may include 18 to 32 mol%, preferably 20 to 30 mol%, more preferably 23 to 28 mol% of units of formula II.

[0048] In such embodiments, the sum of the mol% of units of formula I and II in the polymeric material (A) is suitably at least 95 mol%, is preferably at least 98 mol%, is more preferably at least 99 mol% and, especially, is about 100 mol%.

[0049] In such embodiments, the polymeric material (A) suitably contains repeat units I and II in the molar proportions l:ll of from 70:30 to 90:10 or of from 70:30 to 80:20.

[0050] Typically, the polymeric material (A) of this first aspect of the present invention will have end units of the polymer which may be the same as the repeat units, but with a terminal OH or F group. However, the process for forming the polymer may include a separate end-capping step at completion of polymerisation, in which case a separate monomer or reagent may be added as an end-capping agent so that the end units may differ from the repeat units of the polymer. Such end-capping is well known in the field of nucleophilic polycondensation reactions.

[0051] In some embodiments, the polymeric material of formula (A) may have a melt viscosity (MV) of at least 0.06 kN.s.nr2and more preferably of at least 0.10 kN.s.rrr2. Suitably the polymeric material (A) has an MV of at least 0.20 kN.s.rrr2.

[0052] Suitably, the polymeric material has an MV of up to 1.80 kN.s.nr2, up to 1.50 kN.s.rrr2or up to 1.00 kN.s.rrr2.

[0053] Suitably the polymeric material (A) has an MV of from 0.06 to 1 .80 kN.s.rrr2, from 0.10 to 1 .50 kN.s.rrr2or from 0.20 to 1 .00 kN.s.rrr2.

[0054] In some embodiments, the polymeric material (A) has an MV of from 0.20 to 0.50 kNsrrr2, or from 0.25 to 0.40 kNsrrr2. The melt viscosity (MV) may be measured, unless otherwise stated herein, using capillary rheometry at 400°C at a shear rate of 1000s-1by extrusion through a tungsten carbide capillary die of 0.5mm diameter and 8.0 mm length.

[0055] The melt viscosity of the polymeric material may be measured by capillary rheometry using an RH10 capillary rheometer (Malvern Instruments Rosand RH10 capillary rheometer), fitted 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 for 3 hours at 150°C. 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) placed on top of the polymer followed by the piston and the screw manually turned until the proof ring of the pressure gauge just engages the piston to help remove any trapped air. The column of polymeric material is allowed to heat and melt over a period of at least 5 minutes. After the preheat stage the screw was is in motion so that the melted polymeric material is extruded through the die to form a thin fibre at a shear rate of 1000s-1, while recording the pressure (P) required to extrude the polymeric material. The Melt Viscosity is given by the formula

[0056] Melt Viscosity = Pur4kNsm-28LSA where P = Pressure I kN m-2

[0057] L = Length of die I m S = ram speed I m s-1A = barrel cross-sectional area I m2r = Die radius I m

[0058] The relationship between shear rate and the other parameters is given by the equation:

[0059] Apparent wall shear rate = 4Q / irr3where Q = volumetric flow rate I m3s-1= SA.

[0060] Suitable polymeric materials (A) may be prepared by polycondensation of monomers containing carbonyl chloride groups in the presence of Friedel Crafts reagents or by polycondensation of phenolic compounds with halo-compounds in the presence of an alkaline reagent.

[0061] More specifically, a suitable polymeric material (A) may be obtained by the polycondensation of a mixture of at least one dihydroxybenzene compound and at least one dihydroxybiphenyl compound with at least one dihalobenzophenone. Preferably hydroquinone; 4,4'-dihydroxybiphenyl and 4,4'- difluorobenzophenone are used as the monomers. Polycondensation is preferably carried out in the presence of an alkali metal carbonate or bicarbonate, or a mixture thereof. The polymerisation is preferably carried out in the presence of a polymerisation solvent such as an aryl sulphone.

[0062] Further suitable polymeric materials (A) (PEEK / PEDEK copolymers) and methods of preparing them are as described in US 4717761 , WO 2014 / 207458 A1 and WO 2015 / 124903 A1 , the contents of which are incorporated herein by reference.

[0063] WO 2014 / 207458 A1 discloses PEEK / PEDEK copolymers, which have repeat units of formula I and II in a molar proportion from 55:45 to 95:5 and with an MV measured at 340°C and 1000s-1shear rate of at least 0.25 kNsm-2and less than 1 .2 kNsm-2.

[0064] WO 2015 / 124903 A1 discloses PEEK / PEDEK copolymers which have repeat units of formula I and II in a molar ratio from 55:45 to 95:5 and an MV of at least 0.25 and less than 1 .2 measured at 340°C and at 1000s-1shear rate.

[0065] In some embodiments, the polymeric material (A) may be as described in WO 2020 / 141329 A1 , the contents of which are incorporated herein by reference. In such embodiments, the polymeric material (A) may have a repeat unit of formula la: repeat units of formula Ila: Ila; wherein at least 95 mol% of the repeat units are repeat units of formula la and of formula Ila; wherein the repeat units la and Ila have a molar ratio la: Ila from 65:35 to 95:5 or from 55:45 to 80:20.

[0066] In other words, in the polymeric material (A), 95 mol% of all repeat units present are units of formula la and of formula Ila in the specified molar ratio la: I la from 55:45 to 80:20. This may be established by virtue of knowledge of the numbers of moles of monomers employed in in the preparation of the polymer.

[0067] The phenylene moieties in each repeat unit la and Ila have 1 ,4- para linkages to atoms to which they are bonded. This results in the polymeric material being crystalline in nature. Suitably in such embodiments the polymeric material (A) has an MV of from 0.35 to 0.55 kNsm-2as measured using capillary rheometry at 400°C at a shear rate of 1000s-1by extrusion through a tungsten carbide capillary die of 0.5mm diameter and 8.0 mm length.

[0068] Preferably, the MV of the polymeric material (A), measured at 1000s-1and at 400°C as described above is from 0.40 to 0.50 kNsm-2.

[0069] Preferably, the molar ratio la: Ila is from 60:40 to 75:25.

[0070] Preferably, at least 98 mol% of the repeat units are repeat units of formula la and of formula Ila, more preferably 99 mol %. Most preferably, the polymeric material consists essentially of repeat units of formula la and formula Ila.

[0071] In some embodiments, the polymeric material (A) may be as described in WO 2022013520 A1 , the contents of which are incorporated herein by reference. In such embodiments, the polymeric material (A) may consist essentially of repeat units of formula I:

[0072] -O-Ph-O-Ph-CO-Ph- I; repeat units of formula Ila: and end units; wherein the molar ratio of repeat units of formula I to repeat units of formula Ila is from 55:45 to 95:5; and wherein the repeat units of formula I consist essentially of 50 to 90 molar % of repeat units of formula la: la and 10 to 50% molar % of repeat units which are of formula lb, of formula Ic or of a mixture thereof; wherein the repeat unit of formula lb is: lb; and the repeat unit of formula Ic is:

[0073] Ic.

[0074] Preferably, the molar ratio of repeat units of formula I to repeat units of formula Ila is from 60:40 to 90:10, preferably from 70:30 to 90:10, more preferably from 80:20 to 90:10.

[0075] The repeat units of formula I consist essentially of, or preferably consist of, 50 to 90 molar% of repeat units of formula la in combination with 10 to 50 molar% 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% molar% of repeat units of formula la in combination with 10 to 35 molar% of repeat units which are of formula lb, of formula Ic, or of a mixture thereof. More preferably, the repeat units of formula I consist essentially of, or preferably consist of, 80 to 90% molar% of repeat units of formula la in combination with 10 to 20 molar% of repeat units which are of formula lb, of formula Ic, or of a mixture thereof.

[0076] The repeat units la are referred to as RPEEK, the repeat units lb are referred to as RmPEEK and the repeat units Ic are referred to as ROPEEK.

[0077] So, in other words, the repeat units of formula I have, expressed as molar proportions:

[0078] RPEEK: ( RmPEEK + ROPEEK) from 90:10 to 50:50, preferably from 90:10 to 65:35, more preferably from 90:10 to 80:20.

[0079] In a preferred embodiment, the polymeric material (A) is a copolymer as described above wherein the molar ratio of repeat units of formula I to repeat units of formula II is from 90:10 to 80:20 and wherein the repeat units of formula I consist essentially of, or preferably consist of, 80 to 90 molar% of repeat units of formula la in combination with 10 to 20 molar% of repeat units which are of formula lib, of formula Ic, or of a mixture thereof.

[0080] It will be understood that formula I: -O-Ph-O-Ph-CO-Ph- provides no information concerning whether the ether linkages on the -O-Ph-O- moiety are arranged in para-, meta- or ortho- configuration, whereas this is specified for formulae la, lb and Ic, as are all other configurations within the repeat units.

[0081] In one embodiment, the copolymer according to the first aspect of the invention may be a copolymer which does not include repeat units of formula lb.

[0082] In another embodiment, the copolymer according to the first aspect of the invention may be a copolymer which does not include repeat units of formula Ic.

[0083] The coating

[0084] The coating of the article of this first aspect suitably has a thickness of from 300 nm to 6,000 pm, suitably a thickness of from 3 to 600 pm.

[0085] The coating is suitably provided as at least one layer on the 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 the at least one surface of the substrate. Preferably, the coating is provided in one layer on the at least one surface of the substrate, suitably with a thickness as described above.

[0086] Preferably, the at least one layer has a thickness of from 3 to 200 pm, preferably a thickness of from 5 to 150 pm, more preferably 15 to 100pm, more preferably 25 to 75 pm.

[0087] Preferably, the overall combined thickness of the coating layers is preferably 3 to 200 pm, preferably a thickness of from 5 to 150 pm, for example 45 to 150 pm. Preferably, the combined thickness of the layers is 125 pm.

[0088] In a preferred arrangement, the coating comprises at least a first layer and a second layer. Preferably, the first layer is adjacent the substrate. Preferably, the second layer is adjacent the first layer and preferably remote from the substrate. Preferably, the first layer comprises the polymeric material (A) as hereinbefore described. The polymeric material (A) may have any of the preferred features described herein. Most preferably, the first layer consists of said polymeric material (A) and is preferably adjacent the substrate. Preferably, the first layer has a thickness of from 3 to 100 pm, preferably 25 to 75 pm, most preferably substantially 50 pm. Preferably, the second layer comprises polymeric material (A) and an at least one non-stick enhancing additive. Preferably, the second layer comprises at least 90 wt% polymeric material (A). Most preferably, the second layer comprises at least 95wt% polymeric material (A), for example, 97wt% polymeric material (A), and at least 2wt% of non-stick enhancing additive, preferably a silicon oil and / or fumed silica. In a most preferred arrangement, the second layer comprises substantially 97.6wt% polymeric material (A), substantially 2wt% silicon oil, 0.4wt% fumed silica. Preferably, the second layer has a thickness of from 3 to 100 pm, preferably 25 to 75 pm, most preferably substantially 75 pm, Preferably, the combined thickness of the first and the second layers is between 100 and 200 pm, preferably, between 75 pm and 150 pm, preferably 125pm,

[0089] 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).

[0090] Suitably the coating comprises up to 100 wt% of the polymeric material (A), suitably up to 95 wt% or up to 80 wt% of the polymeric material (A).

[0091] As discussed above, the article and coating is suitably free of PFASs. The coating suitably comprises less than 1 wt%, less than 0.1 wt% or less than 0.01 wt% of PFASs, based on the total weight of the coating. Preferably the coating does not comprise any per- or polyfluoroalkyl substances. Preferably, the coating does not comprise PTFE. Suitably the article does not comprise any per- or polyfluoroalkyl substances. Suitably the article does not comprise PTFE.

[0092] 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 material. Such non-stick properties may be measured by water contact angle or advancing and receding contact angles at different sliding angles.

[0093] The coating suitably has a hydrophobic outer surface. Hydrophobicity may be assessed by measuring the water contact of a 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 may 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 may be assessed as described in Example 3 of WO 2012175965 A1 , which is incorporated herein by reference.

[0094] Hydrophobicity may also be determined using contact angle measurements with ethylene glycol as testing fluid. The receding contact angle of a 30 pl droplet of ethylene glycol may be measured on a test surface. Satisfactory non-stick properties may be demonstrated by the test surface having a receding contact angle of greater than 60°. Suitably the coating of the article of this first aspect has such a receding contact angle of greater than 60°.

[0095] Satisfactory non-stick properties may be further demonstrated by the test surface having a roll-off angle (plane tilt angle sufficient to cause displacement of the droplet) of less than 20°. Suitably the coating of the article of this first aspect has such a roll off angle of less than 20°.

[0096] Furthermore, satisfactory non-stick properties may include sufficient cohesion, a lack of surface cracking, thermal inertia in the cooking temperature environment, and lack of reactivity with food. The latter may be demonstrated in burnt milk and fried egg tests, as described in WO 2022241019 A1 , which is incorporated herein by reference. Suitably the coating of the article of this first aspect provides satisfactory performance in such tests.

[0097] The desired non-stick properties of the coating comprising polymeric material (A) may be achieved in the present invention in several ways, as described further below.

[0098] In some embodiments, the coating comprises at least one non-stick enhancing additive. Such nonstick enhancing additives are substances which can improve the non-stick characteristics of a polymer coating, such as the coating comprising the polymeric material (A) of the present invention. The non-stick enhancing additives may improve the non-stick characteristics of the coating by increasing the hydrophobicity of the coating I the polymeric material (A) and / or reducing the tendency of the coating to react with food during heating and / or to increase the tendency of the coating to release food which contacts the coating, particularly during heating.

[0099] The at least one non-stick enhancing additive is preferably not a PFAS. Preferably the article and specifically the coating does not comprise any PFASs, as discussed above.

[0100] Suitably, the at least one non-stick enhancing additive is selected from silica-based or alumina-based metal alkoxides, wax, oils, fats, talc, ceramics, boron nitride, graphite, carbon black, siloxanes I silicones including silicon resin, silicon oil, fumed silica, nano particles or glass-fibres. In some preferred embodiments, the at least one non-stick enhancing additive is a polysiloxane. Suitable polysiloxanes (silicones) may be selected from the group of linear or branched polydimethylsiloxanes, linear or branched polydiphenylsiloxanes, linear or branched polymethylphenylsiloxanes their copolymers and mixtures. In some embodiments, such polysiloxanes may contain or be mixed with polysiloxanes that may contain reactive groups such as hydroxy-, alkoxy-, acetoxy-, vinyl-, silane-, amino- silazane- or others. Suitably the at least one nonstick enhancing additive is selected from polydimethylsiloxane (PDMS), polydiphenylsiloxane (PDPS) and polydimethyldiphenylsiloxane (PDMDPS, i.e. a PDMS / PDPS copolymer).

[0101] A suitable siloxane / silicone non-stick enhancing additive may be provided by polydimethylsiloxanes marketed under the trade names SILBIONE FLD 70047V350 by company ELKEM, WACKER AK200 by company WACKER as well as polysiloxanes with methyl- and phenyl-groups marketed under the trade names WACKER AP 150, WACKER AP200, WACKER AR200 by company WACKER and DOWSIL 550 Fluid by company DOW.

[0102] In such embodiments, the article has the advantage that the polymeric material (A) is provided with sufficient non-stick properties for the coating to function effectively in food contact applications without the use of a PFAS, such as PTFE. Furthermore, the polymeric material (A) allows the coating to be formed at a temperature which does not degrade the non-stick enhancing additive, in particular the siloxanes / silicones discussed above. The at least one non-stick enhancing additive may be present in the coating in an amount of from 0.1 wt% to 90 wt%, based on the total weight of the coating, in an amount of from 0.1 wt% to 50 wt%, based on the total weight of the coating, in a preferred embodiment and in an amount of from 1 .0 wt% to 30 wt% based on the total weight of the coating, in an especially preferred embodiment.

[0103] In a further preferred embodiment, the at least one non-stick enhancing additive may be present in the coating in an amount of from 0.001wt% - 50wt%, most preferably, in an amount of from 0.1 wt% to 40wt% based on the total weight of the coating.

[0104] Preferably, when more than one non-stick enhancing additive is present in the coating, the combined amount of said additive is from 0.1 to 50wt%, preferably, 0.5 to 40wt%, most preferably 0.6 to 36wt%. Preferably, the combination of additives comprises silicon resin, silicon oil, fumed silica, boron nitride. In a preferred arrangement, the coating comprises silicon resin preferably in an amount 0.1 to 30wt%, silicon oil preferably in an amount 0.1 to 30wt%, fumed silica 0.1 to 10wt%, boron nitride in an amount 0.5 to 20wt%.

[0105] In a most preferred combination, the coating comprises polymeric material (A), silicon oil, and fumed silica. Preferably, the silicon oil is present in an amount between 1 to 2.5wt%, preferably substantially 2wt%, and the fumed silica is present in an amount between 0.2 and 0.5wt%, preferably substantially 0.4wt% of the coating composition.

[0106] When more than one non-stick enhancing additive is present in the coating, the total amount of the non-stick enhancing additives present is suitably as defined above.

[0107] The coating is suitably a substantially uniform and continuous layer arranged on a surface of the substrate of the article. In some embodiments, the coating has a relatively smooth and continuous outer surface, i.e not comprising significant pores or topographical features at the outer surface of the coating. In such embodiments, the coating may be non-porous. Such a substantially uniform and non-porous coating may be formed by applying a suitable coating formulation in the form of a liquid dispersion and drying I curing the coating formulation. Alternatively, such a coating may be formed by dry powder coating, coil coating, roller coating, curtain coating, flame spray coating and electrostatic powder coating. Spray coating and electrostatic powder coating are preferred methods.

[0108] In such embodiments, the coating suitably comprises the at least one non-stick enhancing additive discussed above and the required non-stick properties of the coating are suitably achieved or improved by the use of non-stick enhancing additive. In such embodiments, the at least one nonstick enhancing additive is suitably dispersed, but not necessarily evenly dispersed, within and throughout the polymeric material (A) of the coating, therefore at least some of the non-stick enhancing additive is present at the outer surface of the coating, but not necessarily at all times. In some embodiments, the coating has a porous structure and / or comprises significant surface topographical features at the outer surface of the coating. In such embodiments, the polymeric material (A) forms the porous structure and / or the topographical features. In such embodiments, the required non-stick properties of the coating may be provided by the porous structure and / or the topographical features of the coating. The non-stick properties of the porous structure and / or the topographical features of the coating may be enhanced by the presence of the non-stick enhancing additives discussed above.

[0109] In embodiments wherein the coating has a porous structure, the coating suitably has a pore size of 300 nm to 6000 pm, preferred of 1 pm to 10 pm.

[0110] The porous structure of the coating suitably provides pores into which a non-stick enhancing additive can be impregnated into the coating. Therefore in such embodiments, the coating suitably comprises a non-stick enhancing additive, as defined above.

[0111] Alternatively, the at least one non-stick enhancing additive may be retained in pores of the porous structure. In such embodiments, the non-stick enhancing additive may be a liquid, for example an oil such as silicone oil. Therefore 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 retain and substantially immobilise the non-stick enhancing additive oil in the coating, including at the outer surface of the coating, to provide non-stick properties to the outer surface of the coating. In use, the non-stick enhancing additive oil may be removed from the outer surface of the coating over time, for example due to wear and leaching. Suitably the non-stick enhancing additive oil is replaced at the outer surface of the coating by the migration of the non-stick enhancing additive oil to the outer surface of the coating from pores within the bulk of the coating. Therefore the coating of such embodiments may provide long-lasting non-stick properties to the article which is maintained despite some expected loss of the non-stick enhancing additive oil from the outer surface of the coating.

[0112] Such porous coatings may be formed by any suitable method including additive manufacturing, filament fusion, laser sintering, porogen leaching, laser puncturing, film cavitation, fibre printing / weaving or amorphous particle sintering of polymeric material (A), or by using blowing agents in the polymeric material (A).

[0113] In embodiments wherein the coating comprises topographical features at the outer surface of the coating, the coating suitably has an outer surface having an array of topographical features formed by the polymeric material (A), wherein the array of topographical features comprises spaced apart projections and / or recesses, wherein said projections and / or recesses have a maximum dimension which is less than 3pm and said topographical features are separated by a distance which is less than 10pm. In such embodiments, the coating may be referred to as having a texturized outer surface, which suitably comprises said topographical features.

[0114] Advantageously, the provision of said topographical features is found to influence the hydrophobicity and / or hydrophilicity of the surface; and by selection of 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 polymeric material (A) compared to a substantially uniform and smooth coating of polymeric material (A).

[0115] The outer surface of the coating which comprises said 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 may be less than 120°, 110° or 100°. The water contact angle may be assessed as described in Example 3 of WO 2012175965 A1 , which is incorporated herein by reference.

[0116] Said array of topographical features may include at least 100, preferably at least 1 ,000, more preferably at least 10,000 of said topographical features. Said array suitably includes at least 100,000 of said topographical features per mm2, preferably at least 3,000,000 per mm2, more preferably at least 6,000,000 per mm2.

[0117] When said topographical features comprise projections, the maximum height of said projections is less than 3 pm, preferably less than 500 nm, more preferably less than 200 nm. The projections may have a height of at least 10 nm.

[0118] When said 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 may have a depth of at least 10 nm.

[0119] Said array of topographical features preferably comprise projections or recesses, but not both projections and recesses. Preferably, said topographical features comprise projections, preferably solely projections.

[0120] Said topographical features may be circular, triangular or square in plan view. Preferably, said topographical features are circular in plan view.

[0121] Suitably, at least 50%, preferably at least 90%, more preferably substantially all of the topographical features (e.g. projections) associated with said surface have maximum dimensions as specified herein. Said surface preferably includes less than 10% (preferably substantially 0%) of topographical features (e.g. projections) which have a maximum dimension greater than 3 pm. Said topographical features (e.g. projections) may have a maximum dimension (e.g. diameter in the case of a circular projections) of less than 0.5 pm, preferably less than 0.25 pm, more preferably less than 0.2 pm.

[0122] Said topographical features may be spaced apart (i.e. the shortest distance between 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.

[0123] Said topographical features may individually have a maximum area of less than 20 pm2, suitably less than 0.8 pm2, preferably less than 0.2 pm2, especially less than 0.14 pm2. Preferably, at least 50%, 80%, 90%, 95% or 99% of topographical features provided on said surface have the aforementioned maximum areas. The minimum area of said topographical features (preferably at least 50%, 80%, 90%, 95% or 99% of the topographical features provided on said surface) may be at least 200 nm2or at least 7,000 nm2.

[0124] Said array of topographical features preferably comprises at least 1 ,000, preferably at least 10,000, especially at least 106topographical features which have substantially the same maximum dimension (e.g. diameter). Said array may comprise at least 1 ,000, preferably at least 10,000, especially at least 106topographical features which have substantially the same height, or in the case of recesses, substantially the same depth. Said array of topographical features may comprise at least 1 ,000, preferably at least 10,000, especially at least 106topographical features of substantially the same surface area. Said array of topographical features preferably comprises at least 1 ,000, preferably at least 10,000, especially at least 106topographical features (preferably projections) of substantially the same size and substantially the same shape.

[0125] The outer surface of the coating suitably has an arrangement of topographical features arrayed in a pattern based on a notional symmetrical lattice in which the distance between nearest neighbour notional lattice points is C and is between 10 nm and 10 pm, and wherein the topographical features are locally mis-ordered such that the centre of each topographical feature is a distance of up to one half of C from its respective notional lattice point.

[0126] 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.

[0127] 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.

[0128] The most preferred range for C is between 30 nm and 3 pm. Preferably, the height or depth (e.g. the average height or depth) of the topographical features 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 may be at least 10 nm.

[0129] Preferably, each topographical feature has the same shape. The topographical features may be cylindrical pits or projections, cuboid pits or projections, hemi-spherical pits or projections, part- spherical pits or projections, or another regular shape.

[0130] 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 may be at least 20 nm.

[0131] 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 notional lattice point.

[0132] 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 notional lattice point. More preferably, at least 60%, at least 70%, at least 80% or at least 90% of the topographical features satisfy this criterion. The lower limit for the distance of the centre of each topographical feature from its respective notional lattice point is preferably at least 12% of C, at least 14% of C or at least 16% of C. The upper limit for the distance of the centre of each topographical feature from its respective notional lattice point is preferably at most 22% of C, at most 20% of C or at least 18% of C.

[0133] The nature of the symmetry on which the notional lattice is based may be selected from a parallelogram lattice, a rectangular lattice, a square lattice, a rhombic lattice, a trigonal lattice and a hexagonal lattice. Preferably, the notional lattice is either a rectangular lattice or a square lattice.

[0134] In one embodiment, topographical features may be defined to mimic the Lotus effect exhibited by the leaves of the lotus flower.

[0135] Such topographical features at the outer surface of the coating may be formed as described in WO 2012175965 A1 , which is incorporated herein by reference.

[0136] Such topographical features at the outer surface of the coating may be achieved by forming the coating by laser sintering, filament fusion, porogen leaching, laser puncturing and fibre weaving.

[0137] The coating may also comprise further additives such as pigments, stabilizers, lubricants and fillers. Suitably additives for these purposes are known in the art. The article

[0138] Suitably, the article of this first aspect is a bakeware or cookware article. Suitably the article is intended for contacting food whilst the article and / or said food is being heated. For example, the article may be a frying pan, a saucepan, a griddle, a skillet, a rice cooker, a baking tray or sheet or a baking tin.

[0139] The substrate of the article may be formed of metal, enamel or glass-fibre reinforced material.

[0140] The substrate of the article is suitably formed of metal. Such bakeware or cookware articles formed predominantly of metal tend to be the articles which require and benefit most from a non-stick coating.

[0141] The substrate of the article may be formed of stainless steel, aluminium, electrolytic chromium coated steel or carbon steel. Suitably the coating is provided on the substrate to coat a surface of the substrate which is intended to contacting food in use. In some embodiments, the coating is provided only on such a surface. In some embodiments, the coating is provided on substantially the entire outer surface of the substrate.

[0142] The coating suitably provides the article with a non-stick surface, as defined above. Therefore the article may be referred to as a non-stick article, suitably a non-stick cookware or bakeware article.

[0143] The coating may be applied directly onto the substrates or may be applied on top of a primer or previously applied coating layer on the substrate.

[0144] According to a second aspect of the present invention, there is provided a solid composition comprising a polymeric material (A) and at least one non-stick enhancing additive; wherein polymeric material (A) has: a repeat unit of formula:

[0145] -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula

[0146] -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety.

[0147] The polymeric material (A) and the at least one non-stick enhancing additive may have any of the suitable features and advantages described in relation to the first aspect. The solid composition of this second aspect may have any of the suitable features and advantages of the coating described in relation to the first aspect.

[0148] The solid composition of this second aspect suitably has a non-stick outer surface as described in relation to the first aspect.

[0149] The solid composition of this second aspect suitably arranged on an article as described in relation to the first aspect.

[0150] Coating formulation

[0151] According to a third aspect of the present invention, there is provided a coating formulation comprising a polymeric material (A) and at least one non-stick enhancing additive; wherein polymeric material (A) has: a repeat unit of formula:

[0152] -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula

[0153] -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety.

[0154] The polymeric material (A) and the at least one non-stick enhancing additive may have any of the suitable features and advantages described in relation to the first aspect. For example, the polymeric material (A) may be as described in WO 2020 / 141329 A1 , the contents of which are incorporated herein by reference. In such embodiments, the polymeric material (A) may have a repeat unit of formula la: wherein at least 95 mol% of the repeat units are repeat units of formula la and of formula Ila; wherein the repeat units la and Ila have a molar ratio la: Ila from 65:35 to 95:5 or from 55:45 to 80:20. the polymeric material (A) of the coating comprises repeat units I and II in the relative molar proportions l:ll of from 65:35 to 95:5.

[0155] Suitably the at least one non-stick enhancing additive is a siloxane / silicone. Suitable siloxanes / silicones are as described in relation to the first aspect.

[0156] The coating formulation suitably comprises from 10 to 99.9 wt% of the polymeric material (A) and from 0.001 to 90wt%, preferably 0.1 to 90 wt% of the at least one non-stick enhancing additive.

[0157] The coating formulation suitably comprises from 10 to 99.9 wt% of polymeric material (A), suitably from 50 to 99.9 wt% or from 70 to 99 wt%.

[0158] The coating formulation suitably comprises from 0.001wt% to 50wt%, preferably from 0.1 to 50 wt% of the at least one non-stick enhancing additive, suitably from 1 to 30 wt%, suitably wherein the at least one non-stick enhancing additive is a siloxane I silicone.

[0159] In some embodiments, the polymeric material (A) of the coating formulation is provided as dry powder. The polymeric material (A) may have a particle size d50 of from 100 nm to 2,000 pm, suitably a particle size d50 of froml pm to 200 pm or a particle size d50 of from 1 to 50 pm.

[0160] 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.

[0161] In such embodiments, the coating formulation may be applied to an article to form a coating on said article using any suitable method known in the art, for example using electrostatic powder coating.

[0162] The coating formulation in the form of a powder may be formed by milling the polymeric material (A) to the required particle size in the presence of the non-stick enhancing additive.

[0163] 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 therefore the coating formulation may 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. Dispersing agents may be present in such formulations to facilitate the formation and stabilisation of such dispersions.

[0164] In such embodiments, the coating formulation may be applied to an article to form a coating on said article using any suitable method known in the art for applying liquid coating formulations, for example spray coating. 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 per / polyfluoroalkyl substances.

[0165] Method of coating

[0166] According to a fourth aspect of the present invention, there is provided a method of forming a nonstick coating on an article for use in food contact applications, the method comprising the steps of: a) providing an article for use in food contact applications, the article comprising a substrate, the substrate having a surface; b) treating the surface of the substrate with a polymeric material (A) having: a repeat unit of formula:

[0167] -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula

[0168] -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety; c) treating the surface of the substrate with a non-stick enhancing additive.

[0169] The polymeric material (A), the at least one non-stick enhancing additive, the article, the substrate and the coating may have any of the suitable features and advantages described in relation to the first aspect.

[0170] Suitably the at least one non-stick enhancing additive is a siloxane / silicone. Suitable siloxanes / silicones are as described in relation to the first aspect.

[0171] 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.

[0172] In some embodiments, the steps of the method are carried out in the order step a) followed by step b) followed by step c).

[0173] In some embodiments, steps b) and c) are carried out simultaneously after step a).

[0174] In embodiments wherein steps b) and c) are carried out simultaneously after step a), steps b) and c) suitably involve treating the surface of the substrate with a coating formulation comprising the polymeric material (A) and the at least one non-stick enhancing additive. Suitably such a coating formulation is a coating formulation according to the third aspect. Therefore the coating formulation may have any of the suitable features and advantages described in relation to the coating formulation of the third aspect.

[0175] In such embodiments, the coating formulation comprising the polymeric material (A) and the at least one non-stick enhancing additive may be a powder, suitably as described in relation to the third aspect, and may 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 to form the coating upon cooling.

[0176] Alternatively, the coating formulation in the form of a powder may be applied by a thermal spraying technique. Such a coating technique may involve spraying the coating formulation powder onto the surface of the substrate through a flame which melts the polymeric material (A). The melted coating formulation then impacts and adheres to the surface of the substrate, which is suitably also heated, and solidifies on cooling to form the coating.

[0177] In some embodiments, a coating formulation comprising the polymeric material (A) and the at least one non-stick enhancing additive may be extruded onto the substrate.

[0178] In some embodiments, the coating formulation comprising the polymeric material (A) and the at least one non-stick enhancing additive may be a liquid, suitably as described in relation to the third aspect, which may be applied to the surface of the substrate using a liquid spray coating technique. Such a coating technique may involve spraying the coating formulation in the form of a liquid dispersion of polymeric material (A) and the at least one non-stick enhancing additive onto the surface of the substrate and then heating the substrate to form the coating on the substrate. Heating the substrate suitably evaporates a solvent from the coating formulation which causes the polymeric material (A) to solidify on the surface of the substrate to form the coating which contains the non-stick enhancing additive dispersed within the polymeric material (A).

[0179] In a further embodiment, the coating formulation comprising the polymeric material (A) and the at least one non-stick enhancing additive may be a liquid, suitably as described in relation to the third aspect, which may be applied to the surface of the substrate using a liquid spray coating technique. Such a coating technique may involve spraying the coating formulation in the form of a liquid dispersion of polymeric material (A) and the at least one non-stick enhancing additive onto the surface of the substrate and then heating the substrate to form the coating on the substrate. Heating the substrate evaporates solvent from the coating formulation pursuing heating the polymeric material (A) melts forming a homogeneous film on the surface of the substrate. By cooling down the polymeric material (A) solidifies on the surface of the substrate to form the coating which contains the non-stick enhancing additive dispersed within the polymeric material (A). In embodiments wherein the steps of the method are carried out in the order step a) followed by step b) followed by step c), step b) suitably involves forming a coating comprising polymeric material (A) on the surface of the substrate and step c) suitably involves treating the coating of polymeric material (A) with the non-stick enhancing additive.

[0180] In such embodiments, step b) suitably involves forming the coating comprising polymeric material (A) with a porous structure and / or comprising significant surface topographical features at the outer surface of the coating, as described in relation to the first aspect. Suitably step b) involves forming the coating comprising polymeric material (A) with a porous structure. Such a porous structure of the polymeric material (A) may be formed by one of the techniques described below.

[0181] The porous structure of polymeric material (A) may be formed by a porogen leaching technique in which a porogen (for example salt) is dispersed within the polymeric material (A) by a mixing process, like an extrusion process, and later processed to a coating. The coating may then be treated with a solvent to dissolve the porogen using a solvent which is removed from the coating to leave a porous structure of polymeric material (A).

[0182] The porous structure of polymeric material (A) may be formed by laser puncturing of a film of polymeric material (A) to create thin membranes supporting porous structures. The membranes can then be applied to the surface of the substrate to form the porous coating.

[0183] The porous structure of polymeric material (A) may be formed by film cavitating by mono- or biaxial orientation of mineral filled films of polymeric material (A). By adding a suitable additive, for example CaCOs and carrying out subsequent stretching I orienting of a semicrystalline film, a voided I cavitated I porous film can be obtained.

[0184] The porous structure of polymeric material (A) may be formed by printing / weaving of fibres of polymeric material (A) onto the surface of the substrate.

[0185] The porous structure of polymeric material (A) may be formed by using dedicated blowing (foaming) agents. For example, the polymeric material (A) may be loaded with pressurized CO2 and expanded by decreasing the pressure and rapidly evaporating the CO2. To create vacant pores in the polymeric material (A).

[0186] The porous structure of polymeric material (A) may be formed by amorphous particle sintering. In such a technique, powder of polymeric material (A) in an amorphous state can be induced to undergo controlled diffusion and re-crystallization to provide a porous sintered structure.

[0187] In such embodiments, the coating comprising polymeric material (A) having a porous structure formed in step b) is suitably then treated with the non-stick enhancing additive in step c). The nonstick enhancing additive is suitably a non-stick enhancing additive oil as described in relation to the first aspect, for example a silicon oil. 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 an outer surface of the coating to provide a non-stick outer surface of the coating, as described in relation to the first aspect.

[0188] The non-stick enhancing additive which is used to treat the surface of the substrate in step c) may be provided in a solution with a solvent. In such embodiments, the solvent is suitably removed subsequently. Alternatively, the non-stick enhancing additive may be added neat to coating comprising polymeric material (A) having a porous structure. For example, the non-stick enhancing additive used in step c) may be a neat non-stick enhancing additive oil, such as silicone oil.

[0189] The non-stick coating formed by the methods of this fourth aspect described above may have any of the suitable features and advantages described in relation to the first aspect, for example the nonstick properties described therein.

[0190] According to a further aspect of the present invention, there is provided a method of forming a nonstick coating on an article for use in food contact applications, the method comprising the steps of: a) providing an article for use in food contact applications, the article comprising a substrate, the substrate having a surface; b) treating the surface of the substrate with a polymeric material (A) to form the 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 projections and / or recesses, wherein said projections and / or recesses have a maximum dimension which is less than 3pm and said topographical features are separated by a distance which is less than 10pm; and wherein the polymeric material (A) has: a repeat unit of formula:

[0191] -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula

[0192] -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety;

[0193] In such embodiments, step b) may be carried out by injection moulding the polymeric material (A) in a mould configured to define said topographical features. In other embodiments, step b) may be carried out by technologies of additive manufacturing practice or technologies of reductive manufacturing practice. Such practices include methods like direct 3D laser texturing methods, esp. laser-induced periodic surface structures (LIPSS), direct laser interference patterning (DLIP) or direct laser writing (DLW).

[0194] In such embodiments, the non-stick coating comprising the topographical features may have any of the suitable features and advantages described in relation to the first aspect. Such topographical features at the outer surface of the coating may be formed as described in WO 2012175965 A1 , which is incorporated herein by reference.

[0195] According to a fifth aspect of the present invention, there is provided a use of a composition comprising a polymeric material (A) for providing a non-stick surface to an article for use in food contact applications, wherein polymeric material (A) has: a repeat unit of formula:

[0196] -O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula

[0197] -O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety.

[0198] Suitably in the use of this fifth aspect, the composition comprises at least one non-stick enhancing additive.

[0199] The polymeric material (A), article, non-stick surface and non-stick enhancing additive of the use of this fifth aspect may have any of the suitable features and advantages described in relation to the first aspect.

[0200] The use of this fifth aspect may involve the method steps described in relation to the fourth aspect.

[0201] Any feature of any aspect of any invention or embodiment described herein may be combined with any feature of any other invention described herein mutatis mutandis.

[0202] Specific embodiments of the invention will now be described, by way of example to the following assessments.

[0203] Example 1 : Assessment of coating non-stick behaviour

[0204] Polymeric material (A) as hereinbefore described, both with and without non-stick enhancing additive, was tested against PTFE and Sol-Gel (ceramic) as shown in Table 1 . Comparative Coating 1 : PTFE (PFAS): Pan used fortesting - KitchenCraft PFOA-free Eco Non-Stick Fry Pan 20 cm - Aluminium substrate

[0205] Comparative Coating 2: Sol-Gel (ceramic) : Pan used fortesting - Salter BW09277 Earth 24cm Frying Pan - Aluminium substrate

[0206] The polymeric material (A) (PEEK / PEDEK copolymer) and method of preparing are as described in US 4717761 , WO 2014 / 207458 A1 and WO 2015 / 124903 A1 , the contents of which are incorporated herein by reference. In the examples in the Tables below, the polymeric material (A) is that described in WO 2020 / 141329 A1 , the contents of which are incorporated herein by reference, having a repeat unit of formula la: la; and repeat units of formula Ila: wherein at least 95 mol% of the repeat units are repeat units of formula la and of formula Ila; wherein the repeat units la and Ila have a molar ratio la: I la 75:25.

[0207] The polymeric material (A) blends were prepared in powder form by adding first the dry material and subsequently any wet additive, for example silicon oil. This mixture was blended in a Henschel mixer for up to 2 minutes at approximately 38000 rpm to obtain a homogeneous composition.

[0208] The Coating 2 to 14 containing the polymeric material (A) were tested against incumbent cookware coating coatings, PTFE (Comparative Coating 1), and the current commercial PFAS free solution known as Sol-Gel (ceramic) (Comparative Coating 2). In addition, the Comparative Coatings 1 &2 were also tested against PEEK (Coating 1). The substrate in all cases was aluminium.

[0209] All Coatings in Table 1 were single layer coatings deposited on the aluminium substrate.

[0210] The water contact angle was measured in accordance with DIN EN 828 using a drop Shape Analyser DAS100S, by Kruss GmbH, to measure the dynamic contact angle of water. The droplet application set up was 0.2 pL / s for a total volume of 6.0 pL.

[0211] Table 1

[0212] Table 1 shows a substantial increase in contact angle for those coatings (3 to 14) comprising a blend of the polymeric material (A) having at least one non-stick enhancing additive. For example, the tests show low levels of silicon resin and boron nitride give a coating having superior qualities in contact angle compared to the incumbent PTFE cookware coating solution, or the currently available PFAS free Sol Gel ceramic solution.

[0213] Example 2: Assessment of polymeric material (A) non-stick coating versus comparative coatings

[0214] Polymeric material (A) as hereinbefore described, both with and without non-stick enhancing additive, was tested against PTFE and Sol-Gel (ceramic) against several standards associated with cookware use as shown in Table 2. The polymeric material (A) (PEEK / PEDEK copolymer 75:25) and method of preparing are as described above and in US 4717761 , WO 2014 / 207458 A1 and WO 2015 / 124903 A1 , the contents of which are incorporated herein by reference.

[0215] Comparative Coating 1 : PTFE (PFAS): Pan used fortesting - KitchenCraft PFOA-free Eco Non-Stick Fry Pan 20 cm - Aluminium substrate.

[0216] Comparative Coating 2: Sol-Gel (ceramic) : Pan used fortesting - Salter BW09277 Earth 24cm Frying Pan - Aluminium substrate

[0217] Coating 5 was prepared as a single layer coating in Table 1. However, in the example in Table 2 below, Coating 5 was prepared as a dual polymeric layer as follows. A first layer of the polymeric material (A) was deposited on the aluminium substrate. The first layer consisted of polymeric material (A) as hereinbefore described and being free from additives. A second layer comprising the polymeric material (A) Coating 5 was deposited on top of the first layer. The second layer comprised both the polymeric material (A) together with non-stick enhancing additives. The two-layer coating (Coating 5) was evaluated for performance in application regarding the non-stick and mechanical behaviour. Table 2 shows the findings in comparison to the incumbent cookware coating systems of Comparative Coatings 1 and 2 being PFAS (PTFE) and Sol-Gel ceramic respectively. The dry coating thickness was measured using an amplitude-sensitive eddy-current instrument by BYK Gardner, the byko-test 8500, following the standard ISO 2808 for the determination of a film coating thickness and particularly standard ISO 2360 for non-magnetic substrates.

[0218] Table 2 In both Tables 1 and 2, the substrate was first cleaned with IPA and grit blasted with a Corundum K 100 to 300 to achieve a roughness (Rz) between 13 and 20 pm. The Coating 5 was applied by spray application with an OptiFlex 2 GM03 manual gun combined to an OptiFlex 2 CG09 control unit from company GEMA. The d50 of the powder was approximately 25pm,

[0219] The Egg test was carried out 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 assesses the cleanability of a product by heating the cookware between approximately 150 and 180°C (160 °C in Table 2) and subsequently cooking an egg, without fat or lubricant, until firmly set. The ability to remove the egg using a plastic or nylon spatula is recorded. A “pass” denotes no solid material is recorded upon wiping the surface of the cookware. A “fail” indicates traces of solid material remains on the cookware.

[0220] As shown in Table 2, Coating 5 (97.6% polymeric material (A), 2% silicon oil, 0.4% fumed silica) displayed a performance similar to that of the PFAS (PTFE) coating. Advantageously, this formulation outperformed the Sol-Gel ceramic alternative. The test demonstrates that the blend of polymeric material (A) being PFAS free, is at least equivalent in tests to the PTFE (PFAS) solution.

[0221] The polymeric material (A) coating may be applied using electrostatic powder deposition and hot flocking in order to build up the desired thickness. For example, the polymeric material (A) powders are sprayed directly onto a substrate and then heated to a temperature ranging from 340°C to 360°C. As soon as the powder has melted the part is cooled or another coat of the same material or a blend is hot flocked on top of the first coating. Subsequent coats can be applied to build up the coating thickness by the hot flocking technique.

[0222] 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) may be sprayed onto a cleaned and grit blasted substrate which is subsequently heated to form a thin film on the substrate. In particular, the substrate is grit blasted to achieve a profile of 20-25% of the total coating DFT (Dry Film Thickness). A further solvent wash of the substrate is preferably performed, and the aqueous dispersion applied until an even wet surface is achieved (HVLP guns with tip sizes between 0.7mm and 1.8mm). The coated surface is maintained at an ambient air temperature for approximately 5 minutes, before heating in an oven at 120°C for approximately 5 minutes. The oven temperature is then ramped up to between 340°C to 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 flow. The part is then removed from the oven and cooled to ambient temperature. Further coatings can be applied to build thickness.

[0223] In some embodiments the polymeric material (A) coating comprises a porous structure providing pores into which a non-stick enhancing additive (such as silicon oil) can be impregnated into the coating. Such polymeric material (A) porous coatings can be fabricated through additive manufacturing (for example, selective laser sintering or filament fusion) processes.

[0224] One example of achieving a porous coating of polymeric material (A) and additive (e.g. silicon oil) is by 3D printing filament fusion process following the conditions described below in Table 3.

[0225] Table 3

[0226] Table 4

[0227] In a further embodiment, the polymeric material (A) coating comprises topographical features designed to influence the hydrophobicity and / or hydrophilicity of the surface (coating non-stick behaviour).

[0228] Such topographical features comprising projections or recesses are generated by exploiting the different melting temperatures of a polymeric material (A) and PEEK (or polyetherketone (PEK)) blend. An effect more or less pronounced of the topographical features can also be obtained by varying the gradient of the particle size, particularly defined by its d50, d90, d99, between polymeric material (A) and PEEK (or PEK) powders. The polymeric material (A) and the PEEK (or PEK) powders may be deposited onto the substrate in order to provide a coating. Such final dry film coating may comprise at least one layer of polymeric material (A) coating and PEEK (or PEK) blend; or at least two layers, an underlayer giving topographical features comprising polymeric material (A) and PEEK (or PEK) blend, followed by a top layer comprising polymeric material (A) coating. Heating the polymeric material (A) powder (for example in an oven) to temperatures ranging from 340-360°C, allows for the melting of the polymeric material (A) polymer leading to flow out and embedment of the partially melted and glassy PEEK (or PEK) particles, generating topographical features that coalesce on cooling (for example by removing from the oven).

[0229] On cooling to ambient temperature, the combined polymeric material (A) and PEEK (or PEK) coating provide a coated surface with topographical features, leading to improved non-stick properties as well as durability, abrasion and scratch resistance.

[0230] Alternatively, other heat generation manufacturing processes such as selective laser sintering (SLS) or laser-based directed energy deposition (DED) may be used to produce such polymeric material (A) coating with topographical features.

[0231] Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

[0232] Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of other components. The term “consisting essentially of’ or “consists essentially of’ means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effect of the invention. Typically, when referring to compositions, a composition consisting essentially of a set of components will comprise less than 5% by weight, typically less than 3% by weight, more typically less than 1 % by weight of non-specified components.

[0233] The term “consisting of’ or “consists of’ means including the components specified but excluding addition of other components.

[0234] Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to encompass or include the meaning “consists essentially of’ or “consisting essentially of’, and may also be taken to include the meaning “consists of’ or “consisting of’.

[0235] For the avoidance of doubt, wherein amounts of components in a composition are described in wt%, this means the weight percentage of the specified component in relation to the whole composition referred to.

[0236] The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention as set out herein are also to be read as applicable to any other aspect or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each exemplary embodiment of the invention as interchangeable and combinable between different exemplary embodiments. Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0237] All of the features disclosed in this specification (including any accompanying claims, and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0238] Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0239] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims1 . An article for use in food contact applications, the article comprising a substrate having at least one surface and a coating arranged 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: a repeat unit of formula:-O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula-O-Ph-Ph-O-Ph-CO-Ph-wherein Ph represents a phenylene moiety.

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 of metal, enamel or glass-fibre reinforced material.

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

6. The article according to any one of the preceding claims, wherein in the polymeric material (A) of the coating, repeat units I and II are in the relative molar proportions l:ll of 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 repeat unit of formula I has the structure la:la; and the repeat unit of formula II has the structure Ila:

8. The article according to any one of the preceding claims, wherein the at least one nonstick enhancing additive selected from silica-based or alumina-based metal alkoxides, wax, oils, fats, talc, ceramics, boron nitride, graphite, carbon black, siloxanes I silicones, nano particles or glass-fibres.

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

10. The article according to any one of the preceding claims, wherein the least one non-stick enhancing additive is a siloxane I silicone.11 . The article according to any one of the preceding claims, wherein the coating has a porous structure and / or comprises significant surface topographical features at the outer surface of the coating.

12. The article according to claim 11 , wherein the coating has a porous structure and the at least one non-stick enhancing additive is retained in pores of the porous structure.

13. An article for use in food contact applications, the article comprising a substrate having at least one surface and a coating arranged on the at least one surface, wherein the coating comprises a polymeric material (A) having: a repeat unit of formula:-O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula-O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety; wherein the coating has an outer surface having an array of topographical features formed by the polymeric material (A), wherein the array of topographical features comprises spaced apart projections and / or recesses, wherein said projections and / or recesses have a maximum dimension which is less than 3pm and said topographical features are separated by a distance which is less than 10pm.

14. A coating formulation comprising a polymeric material (A) and at least one non-stick enhancing additive; wherein polymeric material (A) has: a repeat unit of formula:-O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula-O-Ph-Ph-O-Ph-CO-Ph- II; 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 I silicone.

16. A method of forming a non-stick coating on an article for use in food contact applications, the method comprising the steps of: a) providing an article for use in food contact applications, the article comprising a substrate, the substrate having a surface; b) treating the surface of the substrate with a polymeric material (A) having: a repeat unit of formula:-O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula-O-Ph-Ph-O-Ph-CO-Ph- II; 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 use in food contact applications, wherein polymeric material (A) has: a repeat unit of formula:-O-Ph-O-Ph-CO-Ph- I; and a repeat unit of formula-O-Ph-Ph-O-Ph-CO-Ph- II; wherein Ph represents a phenylene moiety.

18. The use of claim 17, wherein the composition comprises at least one non-stick enhancing additive.

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