Aqueous dispersions based on thermoplastic polymers

Abstract

An aqueous composition comprising a thermoplastic polymer, an inorganic thickener and / or stabilizer derived from a silicate, and a mineral dispersant, a method for making the composition, a method for applying the composition to a substrate, and a substrate coated with the composition.

Description

[Technical Field]

[0001] The present invention relates to aqueous formulations (compositions) based on thermoplastic polymers, such as polyaryletherketones, such as polyetherketones (PEK), polyetheretherketones (PEEK) or polyetherketoneketones (PEKK), stabilized with inorganic thickeners and / or stabilizers derived from silicates and mineral dispersants having a layered structure. [Background technology]

[0002] The polyaryletherketone family is well known and offers interesting properties such as temperature resistance, chemical resistance, and thermal conductivity.

[0003] Among these, polyetheretherketone (PEEK) is known for its good performance at high temperatures, very good mechanical strength, and very good chemical resistance. However, the high melting point of such molecules increases the cost and complexity of the application process. Furthermore, the need to work at high temperatures carries the risk of affecting other components of the formulation.

[0004] Therefore, various basic polyaryletherketone molecules have been developed that are substituted or have variations in the aryl ether repeats, such as other less crystalline molecules, that allow for either easier application or modification of properties.

[0005] Various attempts have been made to formulate these molecules.

[0006] Patent document 1 describes a mixture of particulate materials, such as kaolinite, and a deformable polymer, which can be placed in an alkaline solution. It also describes a filler.

[0007] Patent Document 2 describes a polymer containing polyetheretherketone in which the aryl groups are methylated. Fillers or reinforcing agents may be present. This polymer can be applied by molding onto metal.

[0008] Patent Document 3 describes the use of sulfonated aryl ketones as dispersants for aqueous solutions containing polyaryl ether ketones.

[0009] US Pat. No. 5,629,999 describes an aqueous dispersion comprising a polymeric material conforming to a particular chemical structure and an organic surfactant.

[0010] Therefore, to a certain extent, aqueous polyaryletherketone compositions have been produced.

[0011] However, the inventors have determined that these compositions are not stable over time or during heat treatment, or are difficult to apply uniformly to surfaces such as vertical surfaces. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] International Publication No. 2015 / 065710 [Patent Document 2] European Patent Application Publication No. 3728401 [Patent Document 3] European Patent Application Publication No. 3710517 [Patent Document 4] International Publication No. 2005 / 23893 Summary of the Invention

[0013] The object of the present invention is to - a water-insoluble thermoplastic polymer or polyaryletherketone, inorganic thickeners and / or stabilizers derived from silicates, and mineral dispersants with a layered structure or graphene oxide or boron nitride, optionally functionalized; The present invention addresses the above shortcomings by providing an aqueous composition comprising:

[0014] The present invention therefore provides for dissolving a water-insoluble thermoplastic polymer, such as a PAEK, in the presence of an inorganic thickener and / or stabilizer derived from silicate and a mineral dispersant with a layered structure.

[0015] The compositions according to the present invention can easily coat metal surfaces either directly or through an internal ceramic layer (e.g., boron nitride and aluminum oxide) to impart, for example, resistance to chemical agents, mechanical strength, and / or impact resistance.

[0016] In particular, this approach makes it possible to at least limit or eliminate the presence of toxic compounds, such as chromium (VI) or additives used in the formulation of Teflon, if desired.

[0017] Likewise, advantageously, the water-based formulations developed do not utilize toxic, corrosive, or hazardous products.

[0018] The dependent claims refer to further advantageous embodiments.

[0019] Preferably, the inorganic thickener and / or stabilizer derived from silicates is a talc or a clay or an aluminosilicate, preferably a phyllosilicate, more preferably a smectite.

[0020] Advantageously, the thermoplastic polymer is selected from the group comprising polyaryletherketones, such as polyetherketone (PEK), polyetheretherketone (PEEK) or polyetherketoneketone (PEKK), polysulfone, polyethersulfone, polyetherimide, polyamide, polyimide, aramid, polyphenylene oxide (PPO), compounds containing phenoxy groups, modified polyphenylene oxide (modified PPO), polyvinylpyrrolidone (PVP), poly(aryl)sulfide, polystyrene (PS), polycarbonate, polyarylether, polyaryletherketone, polyarylsulfide, polybenzimidazole, polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy, fluorinated ethylene-propylene (FEP), polychlorotrifluoroethylene (E-CTFE), ethylene vinyl alcohol (EVOH) and mixtures thereof.

[0021] More preferably, the silicate-derived inorganic thickener and / or stabilizer is potassium silicate and / or sodium silicate.

[0022] In the context of the present invention, thickeners can also function as stabilizers.

[0023] The ratio between the maximum surface area of ​​the thickener and the thickness of the inorganic thickener derived from silicates is advantageously greater than 100.

[0024] The aqueous composition according to the invention is preferably a dispersion.

[0025] According to a particularly preferred embodiment, the composition comprises at least 30% by weight of water relative to the total weight of the composition.

[0026] Advantageously, the composition further comprises at least 10% by weight, preferably at least 30% by weight, of a second polymer, preferably chosen from fluoropolymers, nylons and natural polymers.

[0027] Preferably, the composition has a coefficient of friction of less than 0.3, preferably less than 0.2, more preferably less than 0.1, and preferably comprises at least 5% by weight of an additive selected from tungsten sulfide, molybdenum sulfide, boron nitride, tungsten carbide, silicon carbide, inorganic oxides (titanium oxide, silicon oxide, zirconium oxide) and mixtures thereof.

[0028] Other embodiments of the composition are within the scope of the claims.

[0029] The present invention also provides the following elements: - inorganic thickeners and / or stabilizers which are silicates or silicate derivatives, then - mineral dispersants or graphene oxide and / or boron nitride, - Particles of water-insoluble thermoplastic polymers or polyaryletherketones to an aqueous solution with mechanical stirring, said mechanical stirring preferably being carried out at at least 2000 rpm and / or for at least 1 hour.

[0030] The thickener acts as a stabilizer, a feature already present in the thickeners described within the scope of the present invention.

[0031] The present invention preferably relates to a method of applying the composition according to the invention, which comprises spraying the composition onto a substrate, optionally at room temperature, and then curing the coated substrate, preferably for at least 5 minutes and / or at a temperature above the melting point of the thermoplastic polymer, preferably between 170 and 450°C, preferably between 400 and 430°C, for example around 420°C, to fix the coating on the substrate.

[0032] More preferably, the substrate is metal or ceramic.

[0033] According to an advantageous embodiment, the substrate is chosen from metals and ceramics and is coated with a coating comprising a polyaryletherketone.

[0034] Other embodiments of the method are set forth in the claims.

[0035] The invention also relates to a substrate selected from metals and ceramics, coated with a coating comprising a water-insoluble thermoplastic polymer or a polyaryletherketone, and obtainable by the process according to the invention.

[0036] Even more preferably, the present invention targets substrates coated as described above, wherein the coating comprises at least 30% by weight of a water-insoluble thermoplastic polymer or polyaryletherketone, and / or at least 0.01%, preferably at least 1%, of a silicate derivative, and / or at least 0.01%, preferably at least 0.1%, of a mineral dispersant or graphene oxide and / or boron nitride.

[0037] Preferably, the substrate comprises either at least 60% by weight of a water-insoluble thermoplastic polymer or polyaryletherketone, or at least 30% by weight of a water-insoluble thermoplastic polymer or polyaryletherketone and at least 30% by weight of another polymer, preferably selected from fluoropolymers, natural fibers and nylon.

[0038] The present invention also encompasses products comprising compositions according to the present invention.

[0039] Other embodiments of the product are set forth in the claims.

[0040] The present invention may also relate to a kitchenware comprising a coating comprising a water-insoluble thermoplastic polymer or polyaryletherketone, a silicate derivative (preferably an aluminosilicate and / or sodium or potassium silicate) and a mineral dispersant or graphene oxide and / or boron nitride, wherein said water-insoluble thermoplastic polymer or said polyaryletherketone is present in the coating in an amount of at least 30% by weight.

[0041] Advantageously, the coating further comprises a fluoropolymer, preferably in an amount of at least 30% by weight, or an inorganic material with a low coefficient of friction selected from the group comprising boron nitride, tungsten sulfide, molybdenum sulfide, silicon carbide, and tungsten carbide, preferably in an amount of at least 30% by weight.

[0042] More advantageously, the kitchenware according to the invention is free of perfluorooctanoic acid (PFOA) and / or per- and polyfluoroalkyl substances (PFAS).

[0043] Other embodiments of the article are set forth in the claims. [Brief explanation of the drawings]

[0044] [Figure 1] FIG. 1 illustrates the application of various aqueous compositions containing PEEK to a surface. DETAILED DESCRIPTION OF THE INVENTION

[0045] The composition according to the present invention uses a water-insoluble thermoplastic polymer.

[0046] Those skilled in the art recognize that the polyaryletherketone family of polymers are water-insoluble thermoplastic polymers.

[0047] In the context of the present invention, the water-insoluble thermoplastic polymer is advantageously selected from the group comprising polyaryletherketones, such as polyetherketone (PEK), polyetheretherketone (PEEK) or polyetherketoneketone (PEKK), polysulfones, polyethersulfones, polyetherimides, polyamides, polyimides, aramids, polyphenylene oxides (PPOs), compounds containing phenoxy groups, modified polyphenylene oxides (modified PPOs), polyvinylpyrrolidone (PVP), poly(aryl)sulfides, polystyrene (PS), polycarbonates, polyarylethers, polyaryletherketones, polyarylsulfides, polybenzimidazoles, polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy, fluorinated ethylene-propylene (FEP), polychlorotrifluoroethylene (E-CTFE), ethylene vinyl alcohol (EVOH) and mixtures thereof.

[0048] Advantageously, the thermoplastic polymer is PEEK or polyamide or polyimide.

[0049] Even more advantageously, the thermoplastic polymer can be combined with EVOH, the preferred combination being polyamide (or polyimide) and EVOH.

[0050] Thus, the inventors have discovered that these thermoplastic polymers can be stably formulated in the presence of mineral dispersants with layered structures, such as graphene oxide or boron nitride, which are optionally functionalized.

[0051] Thus, a first aspect of the present invention provides: - a water-insoluble thermoplastic polymer or polyaryletherketone, inorganic thickeners and / or stabilizers derived from silicates, and mineral dispersants with a layered structure or graphene oxide or boron nitride, optionally functionalized; The present invention relates to an aqueous composition comprising:

[0052] The inventors have surprisingly determined that mineral dispersants (e.g., graphene oxide or boron nitride) can stabilize aqueous compositions containing water-insoluble thermoplastic polymers or polyaryletherketones, such as PAEKs, polyamides, or polyimides. The inventors believe that graphene oxide (or boron nitride) functions advantageously as a dispersant in the formulations they have developed.

[0053] According to a preferred embodiment, the inorganic thickeners and / or stabilizers derived from silicates may have a layered structure and may be selected for a particular application.

[0054] Additionally, the mineral dispersant having a layered structure may be, for example, graphene oxide, boron nitride, or other functional equivalents known to those skilled in the art.

[0055] Furthermore, advantageously, the graphene oxide or boron nitride may be provided in multilayers, whereby a plurality of layers are parallel to one another, preferably at least 2 layers, more preferably at least 5 layers, and even more preferably at least 10 layers, and this also extends to other mineral dispersants with layered structures.

[0056] Advantageously, the mineral dispersant with a layered structure is graphene oxide (single layer or multilayer) or boron nitride (single layer or multilayer).

[0057] Advantageously, a combination of graphene oxide and boron nitride is also possible.

[0058] According to a particularly preferred embodiment of the present invention, the mineral dispersant may be functionalized by adding a functional group.

[0059] If the dispersing agent (e.g., boron nitride) is functionalized, it may or may not be in the form of a layer. Preferably, the functionalized boron nitride is in the form of a layer.

[0060] The silicate-derived inorganic thickeners and / or stabilizers, when present without graphene oxide (or boron nitride), provide a minor stabilizing effect to the PAEK composition.

[0061] However, surprisingly, the formulation of a thermoplastic polymer (PAEK, polyamide, or polyimide) in the presence of both a mineral dispersant (preferably graphene oxide or boron nitride) and an inorganic thickener and / or stabilizer derived from silicates results in very good stability, facilitating the application of the composition even on vertical surfaces.

[0062] This is also applicable to other mineral thickeners and / or stabilizers (other than phyllosilicates) in layered form.

[0063] Preferably, the inorganic thickener and / or stabilizer derived from silicates is talc or an aluminosilicate, preferably a phyllosilicate, preferably selected from the smectite group (e.g. hectorite or laponite). In the context of the present invention, bentonite is advantageously considered a smectite.

[0064] Alternatively or additionally, the inorganic thickener and / or stabilizer (e.g., aluminosilicate, phyllosilicate, smectite) is potassium silicate and / or sodium silicate, i.e., at least 10%, preferably at least 20%, or even at least 40% (by mole) of the alkali or alkaline earth cations in the molecules of the inorganic thickener and / or stabilizer that is a silicate are potassium or sodium.

[0065] The inventors have determined that these cations improve the stabilization of the composition.

[0066] Advantageously, the inorganic thickener and / or stabilizer has a lamellar structure, for example in the form of a rectangular or flat disk (for example Laponite).

[0067] Preferably, the inorganic thickener and / or stabilizer is a mineral with a layer thickness of less than 10 nm, preferably less than 5 nm, or approximately 0.2 nm to 1 nm.

[0068] The inventors have determined that this type of structure exhibits a synergistic effect with mineral dispersants, preferably graphene oxide or boron nitride.

[0069] In the layered structure of the organic thickener and / or stabilizer, the maximum surface area preferably varies between 25 and 300 nm. The layer preferably has a rectangular (maximum) surface area, e.g., a length of 200 to 400 (or 300) nm, e.g., approximately 250 nm, and a width of 30 to 75 nm, preferably approximately 50 nm. For example, the layer has a (maximum) substantially square surface, e.g., a side dimension of 200 to 400 nm, e.g., approximately 300 nm. Alternatively, the layer has a disk-shaped surface, the diameter of which is advantageously 10 to 50 nm, e.g., approximately 25 nm.

[0070] In the context of the present invention, thickeners and / or stabilizers may also refer to the same compound having both a thickening effect and a stabilizing effect.

[0071] In other words, the ratio of the maximum surface area to the thickness of the thickener and / or stabilizer is preferably greater than 100, preferably greater than 1000.

[0072] The inventors have found that thickeners and / or stabilizers (silicates, aluminosilicates) work well when incorporated at a content of 0.1 to 5% (by weight), preferably 0.5 to 2% by weight, for example approximately 0.8% by weight or approximately 1% by weight (weight of silicate:total weight of aqueous composition).

[0073] In other words, an advantageous weight ratio of water-insoluble thermoplastic polymer, for example PAEK (PEK, PEEK, PEKK) or polyamide or polyimide to thickener and / or stabilizer (silicate, aluminosilicate) is 10 to 100, preferably 20 to 75, for example 40 to 50 (weight of PAEK:weight of thickener and / or stabilizer).

[0074] In the context of the present invention, graphene oxide (CAS 1034343-98-0) refers to a two-dimensional layered structure (i.e., monolayer or multilayer) composed of carbon atoms, preferably hexagonally arranged and substituted with -OH, carbonyl, epoxy, and carboxyl residues. Advantageously, the graphene oxide of the present invention consists of fewer than 20, preferably fewer than 15, more preferably fewer than 10, layers stacked, preferably parallel to one another. Graphene oxide can contain 1, 2, 3, 4, 5, 6, or 7 layers (sheets), as well as mixtures of these structures. This also advantageously applies to boron nitride or other mineral dispersants with a layered structure.

[0075] Graphene oxide may be obtained by treating graphite with a strong oxidizing agent followed by separation into layers in an alkaline solution.

[0076] Those skilled in the art are familiar with methods for producing layered boron nitride. In the context of the present invention, the boron nitride is preferably always in layered form (single or multilayer).

[0077] The inventors have confirmed that graphene oxide works well when added at a weight content of 0.1% to 2% by weight, preferably 0.2% to 1%, for example about 0.4% (weight of graphene oxide:weight of aqueous composition), which applies to the mineral dispersant defined in the present invention.

[0078] In other words, an advantageous weight ratio of the water-insoluble thermoplastic polymer, such as PAEK (PEK, PEEK, PEKK) to the mineral dispersant (preferably graphene oxide or boron nitride) is 20 to 500, preferably 50 to 200, for example 100 to 150 (weight of PAEK:weight of graphene oxide).

[0079] Alternatively, boron nitride is added as a mineral dispersant in an amount of up to 5% by weight.

[0080] When boron nitride is used as an additive, it may be present in an amount of at least 5% by weight.

[0081] In other words, an advantageous weight ratio of the water-insoluble thermoplastic polymer, such as PAEK (PEK, PEEK, PEKK) to graphene oxide is 2 to 500, preferably 5 to 200, for example 10 to 150 (weight of PAEK:weight of graphene oxide).

[0082] Advantageously, the aqueous composition is a dispersion stabilized by a mineral dispersant (graphene oxide or boron nitride) and a silicate.

[0083] In the context of the present invention, a PAEK is preferably a polymer consisting (substantially) of units of formula (-Ar-X-) and units of formula (-Ar'-Y-), Ar and Ar' each represent a divalent aromatic radical; Ar and Ar' are preferably selected from optionally substituted 1,3-phenylene, 1,4-phenylene, 4,4'-biphenylene, 1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene, X represents an electron-withdrawing group which may preferably be chosen from a carbonyl group (more preferred) and a sulfonyl group, Y represents an oxygen atom (more preferred), a sulfur atom, an alkylene group, such as a group selected in particular from -CH2- and isopropylidene.

[0084] Of the X units, at least 50 mol %, preferably at least 70 mol %, more particularly at least 80 mol % of the X units represent a carbonyl group. Advantageously, all X units represent a carbonyl group.

[0085] Of the Y units, preferably at least 50 mol %, preferably at least 70 mol %, more particularly at least 80 mol % of the Y units represent oxygen atoms. Advantageously, all Y units represent oxygen atoms.

[0086] Preferably, the PAEK is a polyetheretherketone (PEEK) comprising a sequence of repeating units of the type -(Ar-O-Ar2-O-Ar3-CO)n-, where each Ar, Ar2, and Ar3 independently represents a divalent aromatic radical, preferably phenylene.

[0087] The bonds on both sides of each Ar, Ar2, and Ar3 unit (eg, groups forming an -O- or -CO- chain) may be para, meta, or ortho (preferably para).

[0088] Alternatively, the PAEK is a polyetherketoneketone (PEKK) which comprises a sequence of repeating units of the type -(Ar-O-Ar2-CO-Ar3-CO)n-, where each Ar, Ar2, and Ar3 independently represents a divalent aromatic radical, preferably phenylene.

[0089] Preferably, the PAEK consists essentially of monomers according to the following formulae (i), (ii), (iii), (iii) and (v):

[0090] [ka]

[0091] Advantageously, the PAEK of the aqueous composition consists essentially of monomers of formula (I), of formula (ii), of formula (iii), of formula (iiii) or of formula (v), the PAEK of the aqueous composition preferably consisting essentially of monomers of formula (ii), polyetheretherketone (PEEK). According to a preferred alternative, the PAEK of the aqueous composition consists essentially of monomers of formula (iii), polyetherketoneketone (PEKK), PEEK (CAS number 29658-26-2) being preferred to PEKK.

[0092] Preferably, in the context of the present invention, in addition to PAEK, the water-insoluble thermoplastic polymer is selected from the group comprising polyaryletherketones, such as polyetherketone (PEK), polyetheretherketone (PEEK) or polyetherketoneketone (PEKK), polysulfone, polyethersulfone, polyetherimide, polyamide, polyimide, aramid, polyphenylene oxide (PPO), compounds containing phenoxy groups, modified polyphenylene oxide (modified PPO), polyvinylpyrrolidone (PVP), poly(aryl)sulfide, polystyrene (PS), polycarbonate, polyarylether, polyaryletherketone, polyarylsulfide, polybenzimidazole, polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy, fluorinated ethylene-propylene (FEP), polychlorotrifluoroethylene (E-CTFE), ethylene vinyl alcohol (EVOH) and mixtures thereof.

[0093] Preferably, the water-insoluble thermoplastic polymer, such as a PAEK (eg, PEK, PEEK, or PEKK), is inserted in the form of particles, preferably substantially spherical particles.

[0094] Advantageously, these particles have a known size that is not excessively large.

[0095] In the context of the present invention, d50 preferably means that 50% of the particles have a size smaller than the value indicated below.

[0096] In the context of the present invention, d90 preferably means that 90% of the particles have a size smaller than the value indicated below.

[0097] In the context of the present invention, d99 means that 99% of the particles have a size smaller than the value indicated below.

[0098] Preferred d50 values ​​for the water insoluble thermoplastic polymers of the present invention, such as PAEK (PEEK), are 50 μm, preferably 40 μm, preferably 30 μm, preferably 20 μm, or alternatively 10 μm or 5 μm.

[0099] Alternatively or additionally, preferred d90 values ​​are 60 μm, preferably 50 μm, preferably 40 μm, preferably 25 μm, alternatively 15 μm or 10 μm.

[0100] Alternatively or additionally, preferred d99 values ​​are 80 μm, preferably 70 μm, preferably 60 μm, preferably 50 μm, alternatively 20 μm.

[0101] In the context of the present invention, if the water-insoluble thermoplastic polymer particles, such as PAEK, are not spherical, the diameter is preferably the equivalent volume diameter dv (V=π / 6.dv 3 ) is the equivalent diameter.

[0102] Preferably, the aqueous composition (dispersion) comprises at least 30% by weight of water.

[0103] Preferably, the aqueous composition (dispersion) comprises at least 30% by weight, such as 40-50% by weight, for example approximately 45% by weight, of a water-insoluble thermoplastic polymer such as PAEK (PEK, PEEK, PEKK).

[0104] Alternatively, the aqueous composition further comprises fluoropolymer or nylon fibers at the (partial) detriment of the PAEK (PEK, PEEK, PEKK). Such a composition comprises 10-30 wt. % of the PAEK (e.g., PEEK) and 10-30 wt. % of the fluoropolymer or nylon microbeads.

[0105] According to another preferred alternative, the aqueous composition further comprises an additive selected from the group comprising tungsten sulfide (WS2), molybdenum sulfide (MoS2), boron nitride, tungsten carbide, silicon carbide, inorganic oxides (titanium oxide, silicon oxide, zirconium oxide) and mixtures thereof.

[0106] The addition of fluoropolymer, boron nitride (also listed as a dispersant), tungsten sulfide, or molybdenum sulfide imparts good anti-stick properties to coatings made from this aqueous composition, for example, coatings for kitchenware such as cookware. The incorporation of PAEK (PEEK) imparts chemical, thermal, and mechanical resistance, and the fluoropolymer or the additives listed above impart anti-stick properties.

[0107] Additionally, metal carbides or oxides are advantageously included to improve mechanical strength, eg, wear or scratch resistance, for example when the thermoplastic polymer is not a PAEK.

[0108] The additives are advantageously incorporated in a weight content of at least 5%, preferably between 5 and 20%, more preferably between 10 and 15%.

[0109] Preferably, the fluoropolymer or additive is incorporated in powder or emulsion form in the process described below.

[0110] In the context of the present invention, the fluoropolymers referred to in this application may, if desired, be replaced by an inorganic material with a low coefficient of friction selected from the group comprising boron nitride, tungsten sulfide, molybdenum sulfide, silicon carbide, and tungsten carbide, preferably in an amount of at least 30% by weight. This applies to each paragraph specifying the addition of fluoropolymers.

[0111] Preferably, the fluoropolymer (or a composition comprising the fluoropolymer) does not contain toxic or potentially toxic compounds such as perfluorooctanoic acid (PFOA) and / or perfluoroalkyl and polyfluoroalkyl substances (PFAS). Advantageously, the fluoropolymer is compatible with culinary (food) applications. A preferred fluoropolymer is polytetrafluoroethylene (PTFE), which is preferably free of PFOA and / or perfluoroalkyl and polyfluoroalkyl substances (PFAS).

[0112] Therefore, the above additives (which are not fluoropolymers) are advantageous because they allow the fluoropolymer to be eliminated entirely if desired.

[0113] The incorporation of nylon microbeads reduces cost, but this comes at the expense of some reduction in mechanical strength and thermal stability.

[0114] A related aspect of the invention relates to a method of formulating this composition, comprising the steps of: 1 - The process of subjecting demineralized water to mechanical agitation 2 - Adding silicate or silicate derivative (clay) in small portions under vigorous mechanical stirring (2000-5000 rpm), advantageously obtaining layered clay (if the incorporated silicate is clay). 3 - Adding a mineral dispersant (e.g., graphene oxide and / or boron nitride) 4 - Adding water-insoluble thermoplastic polymer powder, e.g. PAEK (PEEK) 5 - Optionally, adding a second polymer or additive (selected from tungsten sulfide, molybdenum sulfide, tungsten carbide, silicon carbide, inorganic oxides, and mixtures thereof). 6 - Stirring is continued for 1-2 hours to completely disperse the water-insoluble thermoplastic polymer powder, for example PAEK (PEK, PEEK, PEKK), advantageously until a flowable liquid is obtained. Preferably, the viscosity decrease of the composition is monitored over time.

[0115] A related aspect of the invention relates to a method of applying the composition described above, which comprises spraying the composition onto a substrate and then curing the coated substrate.

[0116] The preferred substrates for this method are metals or ceramics, advantageously the metals being nickel, iron, aluminum, cobalt and their alloys.

[0117] Preferably, therefore, the substrate is metal and the method advantageously comprises a preliminary step of applying a primer layer consisting essentially of (i) aluminum oxide (hereinafter sometimes referred to as "first particles"), (ii) boron nitride (or beryllium oxide or aluminum nitride; hereinafter sometimes referred to as "second particles") and (iii) aluminum (tri)phosphate (and then spraying the composition onto this primer layer), which primer layer is advantageously cured on the substrate, for example, followed by applying a composition comprising PAEK (PEEK).

[0118] The preferred temperature for curing the primer layer is approximately 370°C.

[0119] A preferred temperature for curing a composition comprising PAEK (preferably PEEK) is approximately 420° C. (eg, 350° C. to 450° C.) A preferred duration is 5 to 30 minutes, for example, approximately 10 minutes.

[0120] In particular, Al2O3 particles (e.g., 1-10 μm in diameter, preferably 3-5 μm), BN particles (e.g., 1-20 μm in diameter), and aluminum phosphate Al(H2PO4)3 are suspended in water with stirring, then sprayed onto the metal layer and subsequently cured (e.g., including steps at 95°C and / or 370°C). The inventors have achieved good results when the Al2O3:BN mass ratio is 1:20 to 1:5, preferably 1:10 to 1:6.

[0121] The preferred BN has a hexagonal structure.

[0122] Another related aspect of the invention relates to a substrate selected from metals and ceramics coated with a coating comprising this water-insoluble thermoplastic polymer, such as a PAEK (e.g., PEEK), which further comprises graphene oxide (or boron nitride) and a silicate, and, if present, may further comprise one of the additives listed above.

[0123] Preferably, the coating on the substrate has a thickness of 5 to 200 μm, advantageously 20 to 150 μm, for example 50 to 120 μm, or 70 to 100 μm.

[0124] Advantageously, the coating comprises at least 30% by weight of a water-insoluble thermoplastic polymer, such as a PAEK (e.g., PEEK), and / or at least 0.5% of a silicate derivative (typically around 1%), and / or at least 0.3% of graphene oxide or boron nitride.

[0125] Alternatively, and preferably, the substrate coating comprises at least 10% by weight of PAEK (eg, PEEK) and at least 10% by weight of nylon microbeads.

[0126] Preferably, the coating of the substrate is free of chromium (VI) and / or fluoropolymers, such as perfluorooctanoic acid (PFOA) and / or per- and polyfluoroalkyl substances (PFAS).

[0127] Another related aspect of the present invention relates to a kitchen utensil comprising a coating comprising PAEK (e.g. PEEK), a silicate derivative, and graphene oxide, and preferably an anti-stick fluoropolymer, advantageously polytetrafluoroethylene (PTFE), or at least 5% by weight of an additive having a coefficient of friction of less than 0.3, preferably less than 0.2, more preferably less than 0.1, preferably selected from the group comprising tungsten sulfide, molybdenum sulfide, boron nitride, tungsten carbide, silicon carbide, inorganic oxides (titanium oxide, silicon oxide, zirconium oxide), and mixtures thereof.

[0128] Preferably, the additive is not a fluoropolymer. The kitchenware coating is preferably free of perfluorooctanoic acid (PFOA) and / or per- and polyfluoroalkyl substances (PFAS).

[0129] Another related aspect of the present invention is - aluminum oxide particles, - second particles selected from boron nitride, beryllium oxide, or aluminum nitride, and - Binder (preferably aluminum phosphate) and a surface layer comprising polyaryletherketone, a silicate derivative (preferably an aluminosilicate and / or a sodium or potassium silicate), and graphene oxide, wherein the polyaryletherketone is present in the surface layer in an amount of at least 30% by weight.

[0130] Preferably, in this primer layer, the mass ratio of aluminum oxide to second particles selected from boron nitride, beryllium oxide, or aluminum nitride (Al2O3:BN or Al2O3:BeO or Al2O3:AlN) is 1:20 to 1:5, preferably 1:10 to 1:6.

[0131] This allows for good thermal conductivity while maintaining sufficient mechanical strength.

[0132] The preferred second particles are boron nitride, preferably hexagonal boron nitride.

[0133] This provides maximum thermal conductivity.

[0134] A preferred binder for this primer layer is aluminum triphosphate. Preferably, the primer layer contains 20 to 50% by weight of the binder (aluminum triphosphate), more preferably 30 to 40% by weight of the binder.

[0135] This ensures good particle cohesion and good mechanical strength, as well as good thermal conductivity.

[0136] In the context of the present invention, the polyaryletherketone of the surface layer is preferably as described above for the aqueous composition. Preferred polyaryletherketones are polyetheretherketone (PEEK) or polyetherketoneketone (PEKK).

[0137] In the context of the present invention, the expression "water-insoluble" means that the thermoplastic polymer has a water solubility of less than 100 mg / L of water at room temperature (20°C).

[0138] Preferably, the thermoplastic polymers of the present invention are semi-crystalline, having a crystallinity level of 10 to 90%, preferably 20 to 80%, as measured by DSC.

[0139] The coefficient of friction used in the context of the present invention is measured using the horizontal plane method with equipment conforming to ISO 8295 (Plastics, Sheets and Films). Overall, the measurement device (Thwing-Albert FP-2260 Friction / Peel Tester) essentially comprises a horizontal test stand, a sled, and a traction mechanism capable of producing relative motion between the sled and the test stand (regardless of which of the two constitutes the moving part).

[0140] The coating to be tested is placed under uniform contact pressure in planar contact. The contact pressure must be exerted by a sled with a square contact base having an area of ​​40 cm* (edge ​​length: 63 mm). The total mass of the sled should be 200 g (exerting a pressure equal to 1.96 N). The force required to move the surfaces relative to each other is recorded. This force, recorded during sliding, allows the coefficient of friction to be calculated.

[0141] Other characteristics and advantages of the invention can be derived from the following non-limiting description, with reference to the drawings and examples. [Example]

[0142] It will be understood that the present invention is in no way limited to the above-described embodiments, and that many modifications may be made without departing from the scope of the appended claims.

[0143] [Example 1] Composition of PEEK dispersion: - PEEK powder: 45% - Smectite clay: 1% - Graphene oxide 1.5% (as a 25wt% paste in water) - Demineralized water: 52.5 Preparation of dispersion: 1 - Demineralized water is subjected to mechanical agitation 2 - Add clay in small amounts during vigorous mechanical stirring (2000-5000 rpm) 3 - Add graphene oxide (as a 25 wt% paste in water) 4 - Add PEEK powder 5 - Leave stirring for 1-2 hours to completely disperse the PEEK powder (to obtain a flowable liquid).

[0144] [Example 2] Composition of PEEK dispersion: - PEEK powder: 45% - Graphene oxide 1.5% (as a 25wt% paste in water) - Demineralized water: 53.5 Preparation of dispersion: 1 - Demineralized water is subjected to mechanical agitation 2 - Add graphene oxide under vigorous mechanical stirring (2000-5000 rpm) 3 - Add PEEK powder 4 - Leave stirring for 1-2 hours to completely disperse the PEEK powder (to obtain a flowable liquid).

[0145] [Example 3] Composition of PEEK dispersion: - PEEK powder: 45% - Smectite clay: 1% - Demineralized water: 54% Preparation of dispersion: 1 - Demineralized water is subjected to mechanical agitation 2 - Add clay in small amounts during vigorous mechanical stirring (2000-5000 rpm) 3 - Add PEEK powder 4 - Leave stirring for 1-2 hours to completely disperse the PEEK powder (to obtain a flowable liquid).

[0146] Dispersion Stability Test: The three dispersions (Examples 1, 2 and 3) were stored in test tubes and left for one month. Dispersion Example 1 is very stable and the PEEK powder remains uniformly dispersed. Dispersion Example 2: PEEK powder begins to settle. Dispersion Example 3: PEEK powder sediments strongly.

[0147] How to apply PEEK in dispersion: The three different PEEK dispersions are applied by spraying using a pneumatic gun (nozzle: 1-1.5 mm).

[0148] Substrate preparation: The surface of the metal substrate is prepared by sandblasting (to obtain a surface roughness Ra of 2 to 4 microns).

[0149] Conditions apply: Gun: 1mm nozzle Air pressure: 2-4 bar The metal substrate is positioned vertically to measure the effect of dispersion flow during application. Wet application thickness: 100-200 microns Dry application thickness: 50-100 microns.

[0150] Curing conditions: Cure at 420°C for 10 minutes.

[0151] Figure 1 shows that the composition of Example 1 is by far the best. The composition of Example 2 looked very good after the settling test, but did not allow for uniform application.

[0152] [Example 4] PEEK + Fluoropolymer Composition of PEEK dispersion: - PEEK powder: 22.5% - Fluoropolymer powder (PFA): 22.5% - Smectite clay: 1% - Graphene oxide 1.5% (as a 25wt% paste in water) - Demineralized water: 52.5 Preparation of dispersion: 1 - Demineralized water is subjected to mechanical agitation 2 - Add clay in small amounts during vigorous mechanical stirring (2000-5000 rpm) 3 - Adding graphene oxide 4 - Add PEEK powder 5 - Add fluoropolymer powder 6 - Leave stirring for 1-2 hours to completely disperse the PEEK powder (to obtain a flowable liquid). Application and curing are similar to the PEEK-based dispersion (Example 1).

[0153] Contact angle measurement Example 1 (PEEK only): Contact angle 30 to 40° (hydrophilic surface, low anti-sticking properties) Example 4 (PEEK + PFA): Contact angle 90 to 100° (hydrophobic surface, good anti-sticking properties)

[0154] [Example 5] PEEK + inorganic anti-stick additive Composition of PEEK dispersion: - PEEK powder: 25~35% - Additive powder 1 (WS2 particles with D50 of 0.5 to 8 microns): 1 to 5% - Additive powder 2 (BN particles with D50 of 0.5 to 8 microns): 1 to 5% - Additive powder 3 (SiC particles with D50 of 0.5 to 8 microns): 1 to 5% - Smectite clay: 0.5~1% - Graphene oxide 0.1-1% (as a 25wt% paste in water) - Demineralized water: 60-70% Preparation of dispersion: 1 - Demineralized water is subjected to mechanical agitation 2 - Add clay in small amounts during vigorous mechanical stirring (2000-5000 rpm) 3 - Adding graphene oxide 4 - Add PEEK powder 5 - Add additives 1, 2 and 3 powders 6 - Leave stirring for 1-2 hours to completely disperse the PEEK powder and additives (to obtain a flowable liquid). Application and curing are similar to the PEEK-based dispersion (Example 1).

[0155] Contact angle and anti-stick measurements Example 5 (PEEK + additives 1, 2 and 3): Contact angle 90 to 100° (hydrophobic surface, good anti-sticking properties).

[0156] [Example 6] Polyamide 11 (powder with D50 of 10 to 50 microns) Composition of polyamide 11 dispersion: - Polyamide 11 powder: 35~45% - Smectite clay: 0.5~1% - Graphene oxide 0.1-1% (as a 25wt% paste in water) - Demineralized water: 55-67% Preparation of dispersion: 1 - Demineralized water is subjected to mechanical agitation 2 - Add clay in small amounts during vigorous mechanical stirring (2000-5000 rpm) 3 - Adding graphene oxide 4 - Add polyamide 11 powder 5 - Keep stirring for 1-2 hours to completely disperse the polyamide 11 powder (to obtain a flowable liquid). The same application as for the PEEK-based dispersion (Example 1) is carried out.

[0157] Curing conditions: Cure at 250°C for 10 minutes.

[0158] [Example 7] Polyimide (powder with D50 of 10 to 50 microns, Tg=245°C, Tm=388°C) Polyimide dispersion composition: - Polyimide 11 powder: 35~45% - Smectite clay: 0.5~1% - Graphene oxide 0.1-1% (as a 25wt% paste in water) - Demineralized water: 55-67% Preparation of dispersion: 1 - Demineralized water is subjected to mechanical agitation 2 - Add clay in small amounts during vigorous mechanical stirring (2000-5000 rpm) 3 - Adding graphene oxide 4 - Add polyimide powder 5 - Keep stirring for 1-2 hours to completely disperse the polyimide powder (to obtain a flowable liquid). The same application as for the PEEK-based dispersion (Example 1) is carried out.

[0159] Curing conditions: Cure at 440°C for 10 minutes.

Claims

1. - a water-insoluble thermoplastic polymer or polyaryletherketone, inorganic thickeners and / or stabilizers derived from silicates, and mineral dispersants with a layered structure, or graphene oxide or boron nitride, optionally functionalized; 1. An aqueous composition comprising:

2. 2. Aqueous composition according to claim 1, wherein the inorganic thickener and / or stabilizer derived from silicates is talc or clay or an aluminosilicate, preferably a phyllosilicate, more preferably a smectite.

3. 3. The composition of claim 1 or 2, wherein the thermoplastic polymer is selected from the group comprising polyaryletherketones such as polyetherketone (PEK), polyetheretherketone (PEEK) or polyetherketoneketone (PEKK), polysulfone, polyethersulfone, polyetherimide, polyamide, polyimide, aramid, polyphenylene oxide (PPO), compounds containing phenoxy groups, modified polyphenylene oxide (modified PPO), polyvinylpyrrolidone (PVP), poly(aryl)sulfide, polystyrene (PS), polycarbonate, polyarylether, polyaryletherketone, polyarylsulfide, polybenzimidazole, polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy, fluorinated ethylene-propylene (FEP), polychlorotrifluoroethylene (E-CTFE), ethylene vinyl alcohol (EVOH), and mixtures thereof.

4. 4. A composition according to claim 1, wherein the inorganic thickener and / or stabilizer derived from silicates is potassium silicate and / or sodium silicate.

5. 5. The aqueous composition of claim 1, wherein the silicate-derived inorganic thickener and / or stabilizer has a maximum surface area to thickness ratio of greater than 100.

6. 6. The aqueous composition of claim 1, which is a dispersion.

7. At least 10% by weight, preferably at least 30% by weight, relative to the total weight of the composition, of a water-insoluble thermoplastic polymer, preferably a polyaryletherketone, preferably a polymer having the following formulae (i), (ii), (iii), (iii) and (v): 【Chemistry 1】 7. The aqueous composition of claim 1, comprising a polyaryletherketone consisting essentially of monomers according to formula (ii) and / or wherein the polyaryletherketone consists essentially of monomers of formula (ii).

8. 8. The aqueous composition of claim 1, comprising at least 30% by weight of water relative to the total weight of the composition.

9. 9. The aqueous composition according to any one of claims 1 to 8, further comprising at least 10% by weight, preferably at least 30% by weight, of a second polymer, preferably selected from fluoropolymers, nylons and natural polymers, or at least 5% by weight of an additive having a coefficient of friction of less than 0.3, preferably less than 0.2, more preferably less than 0.1, preferably selected from the group comprising tungsten sulfide, molybdenum sulfide, boron nitride, tungsten carbide, silicon carbide, inorganic oxides (titanium oxide, silicon oxide, zirconium oxide) and mixtures thereof.

10. The following elements: an inorganic thickener and / or stabilizer which is a silicate or silicate derivative, then mineral dispersants or graphene oxide and / or boron nitride, - particles of water-insoluble thermoplastic polymers or polyaryletherketones to an aqueous solution with mechanical stirring, said mechanical stirring preferably being carried out at at least 2000 rpm and / or for at least 1 hour.

11. 10. A method of applying a composition according to any one of claims 1 to 9, comprising spraying the composition onto a substrate, optionally at room temperature, and thereafter curing the coated substrate, preferably for at least 5 minutes and / or at a temperature above the melting point of the thermoplastic polymer, preferably from 170 to 450°C, preferably from 400 to 430°C, for example around 420°C, to fix the coating on the substrate.

12. The method of claim 11 , wherein the substrate is a metal or a ceramic.

13. A substrate selected from metals and ceramics, coated with a coating comprising a water-insoluble thermoplastic polymer or a polyaryletherketone, and obtainable by the method according to any one of claims 10 to 12.

14. 14. The substrate according to claim 11 or 12 or 13, coated, wherein the coating comprises at least 30% by weight of a water-insoluble thermoplastic polymer or polyaryletherketone, and / or at least 0.01%, preferably at least 1%, of a silicate derivative, and / or at least 0.01%, preferably at least 0.1%, of a mineral dispersant or graphene oxide and / or boron nitride.

15. 15. The substrate of claim 14, comprising either at least 60% by weight of a water-insoluble thermoplastic polymer or polyaryletherketone, or at least 30% by weight of a water-insoluble thermoplastic polymer or polyaryletherketone and at least 30% by weight of another polymer, preferably selected from fluoropolymers, natural fibers, and nylon.

16. 10. An article of manufacture comprising a composition according to any one of claims 1 to 9; a kitchen utensil comprising a coating comprising a water-insoluble thermoplastic polymer or polyaryletherketone, a silicate derivative (preferably an aluminosilicate and / or sodium or potassium silicate) and a mineral dispersant or graphene oxide and / or boron nitride, wherein said water-insoluble thermoplastic polymer or said polyaryletherketone is present in the coating in an amount of at least 30% by weight.

17. 17. The kitchen utensil of claim 16, wherein the coating further comprises a fluoropolymer, preferably in an amount of at least 30% by weight, or an inorganic material with a low coefficient of friction selected from the group consisting of boron nitride, tungsten sulfide, molybdenum sulfide, silicon carbide, and tungsten carbide.

18. 18. The kitchen appliance of claim 16 or 17, which is free of perfluorooctanoic acid (PFOA) and / or per- and polyfluoroalkyl substances (PFAS).

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