Mixed powder composition and method for producing a mixed powder composition

Abstract

The mixed powder composition forms a layered single coating. The mixed powder composition includes (A) a functionalized fluorinated polymer and (B) a non-fluorinated polymer. The functionalized fluorinated polymer (A) includes hydroxyl and / or carboxylic acid functional groups and has a complex viscosity at 200 DEG C of 10 to 100 Pa-sec, measured according to ASTM D4440-15. The non-fluorinated polymer (B) has a complex viscosity of 0.1 to 35 Pa-sec at 200 DEG C, measured according to the same ASTM standard. The weight ratio of the functionalized fluorinated polymer (A) and the non-fluorinated polymer (B) in the mixed powder composition is from 60 / 40 to 30 / 70. A layered cured single coating is formed from the mixed powder composition.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and all benefits to U.S. Provisional Patent Application No. 63 / 467,616, filed May 19, 2023, which is expressly incorporated herein by reference in its entirety.

[0003] Public content area

[0004] The subject matter disclosure generally relates to mixed powder compositions that form layered single coatings. The subject matter disclosure also generally relates to cured single coatings formed from said mixed powder compositions, and to extrusion methods for producing the mixed powder compositions. Background Technology

[0005] Powder coating systems are commonly used to coat various substrates to achieve aesthetic properties and a wide range of functional performance characteristics, including, for example, corrosion resistance, scratch resistance, impact resistance, and weather resistance. A powder coating system may comprise one or more layers and utilizes fluorinated polymers in combination with other unfluorinated polymers to achieve the desired aesthetic and functional performance characteristics. Whether a powder coating system comprises one or more layers, fluorinated polymers are used to establish fluorine dominance in the outermost layer of the powder coating system and achieve the desired properties.

[0006] The conventional effort to use multiple layers in powder coating systems is cumbersome, time-consuming, and costly because it requires separate layers, such as intermediate or intermediate coatings, and a separate topcoat as the outermost layer to achieve the fluorine advantage in the outermost layer. These separate layers are formed from compositions with different chemical compositions and require multiple preparation and application steps (e.g., surface preparation, separate spraying, and / or separate curing steps), which is undesirable. Figure 1A The Chinese government has disclosed an example of such a routine effort.

[0007] Powder coating systems, even with only one or a single layer, remain cumbersome, time-consuming, and costly compared to other conventional efforts. With only one layer, the powder composition applied to form that layer must include both fluorinated and non-fluorinated polymers to achieve the desired properties. In other words, because in this example with only one layer, the powder coating system does not include a separately sprayed, dedicated fluorine-dominant topcoat, the powder composition applied to form the single layer must include both fluorinated and non-fluorinated polymers. However, conventional methods for producing powder compositions containing both fluorinated and non-fluorinated polymers are not ideal. [Reference] Figure 1BThese conventional methods typically require extruding the powder composition containing the fluorinated polymer separately from the powder composition containing the unfluorinated polymer, and then post-blending, i.e., dry blending the two resulting extrudates in an additional step, to establish a powder composition containing both the fluorinated and unfluorinated polymers. This approach, including the additional step of post-blending the two extrudates, obviously increases complexity, time, and cost. Furthermore, as... Figure 1C For example, it is generally understood that current powder coating systems with a single layer formed from such a powder composition have too little fluorine present at or near the top (or outermost) of the powder coating system, and inconsistent dispersion of fluorine throughout the powder coating system. In other words, conventional powder coating systems do not have sufficient layering after the powder composition is applied and cured, and without sufficient layering, the fluorine dominance in the outermost layer is insufficient, and the desired fluorine-dependent properties cannot be achieved.

[0008] Therefore, there are still opportunities to improve the mixed powder compositions and the methods for producing them.

[0009] Overview of Public Content

[0010] The mixed powder composition forms a layered, cured single coating, i.e., a layered single coating. The mixed powder composition comprises (A) a functionalized fluorinated polymer and (B) an unfluorinated polymer. The functionalized fluorinated polymer (A) includes hydroxyl and / or carboxylic acid functional groups and has a complex viscosity of 10 to 100 Pa-sec at 200°C, as measured according to ASTM D4440-15. The unfluorinated polymer (B) has a complex viscosity of 0.1 to 35 Pa-sec at 200°C, as measured according to the same ASTM standard. The weight ratio of the functionalized fluorinated polymer (A) to the unfluorinated polymer (B) in the mixed powder composition is 60 / 40 to 30 / 70. The layered, cured single coating is formed by the mixed powder composition. The functionalized fluorinated polymer (A) and the unfluorinated polymer (B), including their respective complex viscosities and the functionality of the fluorinated polymer (A), result in the formation of a layered powder coating system (e.g., a layered single coating) when the mixed powder composition is applied to a substrate and cured.

[0011] In one embodiment, an extrusion method for producing a mixed powder composition is disclosed. In this embodiment, the mixed powder composition comprises a fluorinated polymer and an unfluorinated polymer. The method includes extruding the fluorinated polymer and the unfluorinated polymer through an extrusion process having a feed length L. f The feed section is supplied to an extruder with a screw. Fluorinated and unfluorinated polymers are passed through the extruder at a kneading length L. k The mixture is kneaded in the kneading zone to form a mixed powder composition. From the extruder with a discharge length L... dThe discharge zone discharges the mixed powder composition. For this extrusion method, the kneading length L of the kneading zone... k The effective length L of the screw s From more than 50% to 60%, as long as the feed length L f and kneading length L k and emission length L d The total percentage is 100%. In this extrusion method, the kneading length L of the kneading zone is... k (where L is the effective length of the screw) s The content of the mixed powder composition (from more than 50 to 60%) results in a powder coating system with layering (e.g., a cured single coating) when the mixed powder composition is applied to a substrate and cured.

[0012] Brief description of the attached diagram

[0013] The advantages of the invention will be readily apparent when considered in conjunction with the accompanying drawings, and will become even more apparent by referring to the following detailed description of the advantages of the invention.

[0014] Figure 1A This is a side view of a prior art powder coating system that includes an intermediate layer and a separate top coating as the outermost layer containing fluorine.

[0015] Figure 1B This is a general illustration of a prior art method in which a powder composition having a fluorinated polymer is extruded separately from another powder composition having an unfluorinated polymer, and then the two resulting extrudates are mixed in an additional step, i.e., dry-blended, to establish a powder composition having both fluorinated and unfluorinated polymers.

[0016] Figure 1C The images are digital images of the cross-section of a conventional single-layer powder coating system, produced by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy, illustrating the inconsistent dispersion of fluorine within the single layer and the insufficient fluorine dominance in the outermost layer.

[0017] Figure 2 This is a side view of a single-layer powder coating system according to the present disclosure, which is a layered, cured single coating such that the top film phase of the cured single coating is fluorine-dominant. Figure 2 It is essentially illustrative and not to scale.

[0018] Figure 3AThe image shown is a digital image of a cross-section of a monolayer powder coating system according to the present disclosure, produced by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX). The monolayer powder coating system is a layered, cured single-coat layer such that the top film phase of the cured single-coat layer is fluorine-dominant. The cured single-coat layer is formed from a mixed powder composition comprising a 50 / 50 weight ratio of a functionalized fluorinated polymer (A) and a first unfluorinated polymer (B), wherein the fluorinated polymer (A) is Lumiflon. ® LF710F and the first unfluorinated polymer (B) is the polyester Uralac ® P 1685.

[0019] Figure 3B yes Figure 3A Digital images of cured single-coat layers with dimpled / dotted rectangles, EDX illustrating the fluorine dominance in the top film phase.

[0020] Figure 4A The image shown is a digital image of a cross-section of a single-layer powder coating system according to the present disclosure, produced by SEM with EDX. The single-layer powder coating system is a layered, cured single-coat system such that the top film phase of the cured single-coat is fluorine-dominant. The cured single-coat is formed from a mixed powder composition comprising titanium dioxide (TiO2) and a functionalized fluorinated polymer (A) in a 50 / 50 weight ratio, and a second unfluorinated polymer (B). The fluorinated polymer (A) is Lumiflon. ® LF710F and the second unfluorinated polymer (B) is polyester SP-400.

[0021] Figure 4B is Figure 4A A schematic diagram of a cured single coating, with EDX illustrating the fluorine dominance in the top film phase, where fluorine is represented by the symbol "+".

[0022] Figure 4C is Figure 4A A schematic diagram of the cured single coating, EDX illustrates the titanium from TiO2 concentrated in the middle and bottom film phases, such that fluorine protects the titanium in the top film phase shown in Figure 4B, where titanium is represented by the symbol "". ° "express.

[0023] Figure 5AThe image shown is a digital image of a cross-section of a single-layer powder coating system according to the present disclosure, produced by an EDX-equipped SEM. This single-layer powder coating system is a cured single coating formed from a mixed powder composition comprising a functionalized fluorinated polymer (A) and a third unfluorinated polymer (B) (unfluorinated polymer 3, polyester SP-500), wherein the cured single coating has a total cured film thickness of 25 to 100 micrometers (µm) and is layered between a top film phase, a bottom film phase adjacent to the substrate and opposite the top film phase, and an intermediate film phase between the top and bottom film phases, wherein the top film phase is fluorine-dominant relative to both the bottom and intermediate film phases, and has a film thickness of at least 8 µm.

[0024] Figure 5B This is a digital image of a cross-section of a single-layer powder coating system according to the present disclosure, generated by SEM with EDX, the single-layer powder coating system comprising a functionalized fluorinated polymer (A) and a fourth unfluorinated polymer (B) (unfluorinated polymer 4, polyester Desmophenene). ® A cured single coating formed from a mixed powder composition of 1700, wherein the cured single coating has a total cured film thickness of 25 to 100 micrometers and is layered between a top film phase, a bottom film phase adjacent to the substrate opposite to the top film phase, and an intermediate film phase between the top film phase and the bottom film phase, wherein the top film phase is fluorine-dominant relative to both the bottom film phase and the intermediate film phase, and has a film thickness of at least 8 µm.

[0025] Figure 5C The image shown is a digital image of a cross-section of a single-layer powder coating system according to the present disclosure, produced by an EDX-equipped SEM. This single-layer powder coating system is a cured single coating formed from a mixed powder composition comprising a functionalized fluorinated polymer (A) and a fifth unfluorinated polymer (B) (unfluorinated polymer 5, polyester SP-1300), wherein the cured single coating has a total cured film thickness of 25 to 100 micrometers and is layered between a top film phase, a bottom film phase adjacent to the substrate and opposite the top film phase, and an intermediate film phase between the top and bottom film phases, wherein the top film phase is fluorine-dominant relative to both the bottom and intermediate film phases, and has a film thickness of at least 8 µm.

[0026] Figure 6A This is a schematic diagram of the screw of an extruder used in the extrusion method according to this disclosure, specifically illustrating a kneading length L. k The effective length L of the screw s The kneading zone is greater than 50% to 60%.

[0027] Figure 6B yes Figure 6AA schematic diagram of the screw illustrates the mixing and melting stages of the kneading zone, and the specific operating temperature in the kneading zone of the extrusion method according to this disclosure.

[0028] Detailed description of the publicly available content

[0029] General reference Figure 2 -6, The mixed powder composition of this disclosure ultimately forms a layered single coating. The layered single coating is further described below and is also referred to throughout as the cured single coating 10. The mixed powder composition is a “powder” because the mixed composition is typically a collection of dry particles (e.g., 96% by weight solids or higher). The dry particles may have any particle size and / or particle size distribution. For example, the dry particles of the mixed powder composition may have an average particle size or particle size distribution of 10 to 200, 50 to 200, more specifically 50 to 150 micrometers, as determined by any technique known in the art (including, but not limited to, the use of a Malvern particle size analyzer, filters, etc.).

[0030] The term "mixed powder composition" is used because the powder composition comprises both fluorinated polymers and unfluorinated polymers. Various embodiments of the mixed powder compositions disclosed throughout this specification exist. In some embodiments, the mixed powder composition comprises (A) a functionalized fluorinated polymer and (B) an unfluorinated polymer. Alternatively, the mixed powder composition may consist substantially of a functionalized fluorinated polymer (A) and an unfluorinated polymer (B), or of a functionalized fluorinated polymer (A) and an unfluorinated polymer (B). In other embodiments further described below, the mixed powder composition may, but does not necessarily, comprise a functionalized fluorinated polymer. The polymers described herein may be polymers, copolymers, and terpolymers, and are most commonly macromolecules. For the purposes of this specification, the term polymer should be understood to also include low molecular weight polymers, i.e., oligomers. Additionally, for the purposes of this specification, an unfluorinated polymer should be understood to be any polymer that is not a fluoropolymer, or any polymer that does not contain fluorine atoms.

[0031] The functionalized fluorinated polymer (A) includes hydroxyl and / or carboxylic acid functional groups. In other words, regarding hydroxyl and / or carboxylic acid functional groups, the functionalized fluorinated polymer (A) may include hydroxyl-only functional groups, carboxylic acid-only functional groups, or both hydroxyl and carboxylic acid functional groups. It may also be described that the functionalized fluorinated polymer (A) has functional groups selected from hydroxyl, carboxylic acid, and combinations thereof. It is understood that, in addition to hydroxyl and / or carboxylic acid functional groups, the functionalized fluorinated polymer (A) may also include other functional groups, such as thiol or amine functional groups.

[0032] Generally, the most common functionalized fluorinated polymer (A) is a thermosetting polymer. The functionalized fluorinated polymer (A) can be any fluorinated polymer, provided it includes hydroxyl and / or carboxylic acid functionality. The functionalized fluorinated polymer (A) can be selected from copolymers of trichlorotrifluoroethylene (e.g., ethylene trichlorotrifluoroethylene (ECTFE)), copolymers of tetrafluoroethylene (e.g., ethylene tetrafluoroethylene (ETFE)), polymers of tetrafluoroethylene, copolymers of fluoroethylene vinyl ethers (FEVE), polymers of FEVE, copolymers of fluoroethylene vinyl esters, polymers of fluoroethylene vinyl esters, and combinations thereof. Of course, regardless of the material chosen for the functionalized fluorinated polymer (A), the polymer must be functionalized, i.e., include hydroxyl and / or carboxylic acid functionality.

[0033] More specifically, the functionalized fluorinated polymer (A) is preferably a fluorinated polymer containing hydroxyl groups, having units derived from fluoroolefins, units derived from monomers containing hydroxyl groups that can copolymerize with fluoroolefins (hereinafter also referred to as "monomers (a1)"), and units derived, as needed, from another monomer other than fluoroolefins and monomers (a1) (hereinafter also referred to as "monomers (a2)").

[0034] The functionalized fluorinated polymer (A) may be a fluorinated polymer containing hydroxyl groups, which are introduced through the conversion of the polymer's reactive groups. Preferred fluorinated polymers containing hydroxyl groups are those obtained by reacting a fluorinated polymer having units derived from fluoroolefins, units derived from monomers having reactive functional groups other than hydroxyl groups, and (if desired) units derived from the aforementioned monomer (a2) with a compound having a second reactive functional group that reacts with the said reactive functional groups and the hydroxyl groups.

[0035] The monomers to be copolymerized with fluoroolefins (monomers (a1), (a2), etc.) can be monomers that have fluorine atoms other than fluoroolefins, but preferably monomers that do not have fluorine atoms.

[0036] Monomer (a1) is a monomer having a hydroxyl group. Monomers having a hydroxyl group can be, for example, allyl alcohol, hydroxyethyl vinyl ether (e.g., 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, cyclohexanediol monovinyl ether, etc.), hydroxyalkyl allyl ether (e.g., 2-hydroxyethyl allyl ether, etc.), hydroxyalkyl vinyl esters (e.g., hydroxypropionic acid vinyl ester), or (meth)acrylate hydroxyalkyl esters (e.g., (meth)acrylate hydroxyethyl ester, etc.). For monomer (a1), one type can be used alone, or two or more types can be used in combination.

[0037] The monomer (a2) may be, for example, a vinyl ether, allyl ether, vinyl ester of carboxylic acid, allyl ester of carboxylic acid, olefin, etc., without a reactive group. Vinyl ethers may be, for example, cycloalkyl vinyl ethers (e.g., cyclohexyl vinyl ether (hereinafter also referred to as "CHVE")) or alkyl vinyl ethers (e.g., nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether, tert-butyl vinyl ether, etc.). Allyl ethers may be, for example, alkyl allyl ethers (e.g., ethyl allyl ether, hexyl allyl ether, etc.). Vinyl esters of carboxylic acid may be, for example, vinyl esters of carboxylic acids (e.g., acetic acid, butyric acid, neopentanoic acid, benzoic acid, or propionic acid). Furthermore, as vinyl esters of carboxylic acids having branched alkyl groups, commercially available VeoVa-9 or VeoVa-10 (each manufactured by Shell Chemical Co., trade name) may be used. Allyl esters of carboxylic acid may be, for example, allyl esters of carboxylic acids (e.g., acetic acid, butyric acid, neopentanoic acid, benzoic acid, or propionic acid). The olefin may be, for example, ethylene, propylene, or isobutylene. The monomer (a2) is preferably a cycloalkyl vinyl ether, particularly CHVE. The monomer (a2) is preferably a monomer having a linear or branched alkyl group having three or more carbon atoms. For the monomer (a2), one type may be used alone, or two or more types may be used in combination.

[0038] The combination of monomers constituting the functionalized fluorinated polymer (A) and more specifically the fluorinated polymer containing hydroxyl groups is preferred (1), and particularly preferred (2) or (3).

[0039] Combination (1):

[0040] Fluoroolefins: TFE or CTFE;

[0041] Monomer (a1): hydroxyalkyl vinyl ether; and

[0042] Monomer (a2): Selected from at least one member of cycloalkyl vinyl ethers, alkyl vinyl ethers and vinyl carboxylic acids.

[0043] Combination (2):

[0044] Fluoroolefins: TFE;

[0045] Monomer (a1): hydroxyalkyl vinyl ether; and

[0046] Monomer (a2): CHVE or tert-butyl ether.

[0047] Combination (3)

[0048] Fluoroolefins: CTFE;

[0049] Monomer (a1): hydroxyalkyl vinyl ether; and

[0050] Monomer (a2): CHVE or tert-butyl ether.

[0051] The proportion of fluoroolefin units is preferably 30-70 mol%, particularly preferably 40-60 mol%, based on the total units (100 mol%) in the functionalized fluoropolymer (A). The proportion of monomer (a1) units is preferably 0.5-20 mol%, particularly preferably 1-15 mol%, based on the total units (100 mol%) in the functionalized fluoropolymer (A). The proportion of monomer (a2) units is preferably 20-60 mol%, particularly preferably 30-50 mol%, based on the total units (100 mol%) in the functionalized fluoropolymer (A).

[0052] FEVE polymers including carboxylic acid functional groups or FEVE polymers including hydroxyl functional groups are particularly suitable for use in subject-mixed powder compositions. One such FEVE polymer including hydroxyl functional groups is Lumiflon, commercially available from AGC Chemicals Americas, Inc., Exton, Pennsylvania. ® LF710F. Exemplary FEVE polymers including hydroxyl functionalities are typically represented in the following formula I.

[0053]

[0054] In Formula I, R1, R2, and R3 are each independently selected from hydrogen or straight-chain or branched, substituted or unsubstituted, cyclic or acyclic C1-C18 alkyl groups, and each X is any halogen, preferably fluorine, provided that at least one X is fluorine. Most typically, all X are fluorine.

[0055] The functionalized fluorinated polymer (A) has a complex viscosity of 10 to 100, typically 20 to 80, more typically 25 to 70, and most typically 35 to 50 Pa-sec at 200°C, measured according to ASTM D4440-15. For measurements according to ASTM D4440-15, a polished conical plate (not a parallel plate) is used as the instrument / test fixture in this specification. The geometry of each sample is approximately 25 mm in diameter by approximately 4 mm in thickness. Alternatively, the geometry of each sample is 25 mm in diameter by 3 mm in thickness. The complex viscosity is measured according to ASTM D4440-15 using samples typically 1 to 5 g, more typically 1 to 3 g, and most typically approximately 1 g (or practically 1 g). The same information described above regarding measurements according to ASTM D4440-15 applies to the measurement of the complex viscosity of the unfluorinated polymer (B) described separately below. Complex viscosity is also commonly referred to as melt viscosity in the polymer industry.

[0056] Unrestricted by any particular theory, it is believed that this complex viscosity of the functionalized fluorinated polymer (A), together with the unfunctionalized polymer (B), enables delamination within the single coating during the curing of the mixed powder composition to form the cured single coating 10. This complex viscosity of the functionalized fluorinated polymer (A) in the mixed powder composition also enables the cured single coating 10 formed from the mixed powder composition to achieve desired aesthetic and functional properties. The unfluorinated polymer (B) and the cured single coating are further described below.

[0057] Other relevant physical properties of the functionalized fluorinated polymer (A) in this mixed powder composition include number-average molecular weight, OH value, and glass transition temperature (T). g While ranges of these other physical properties of the functionalized fluorinated polymer (A) as described below are not required, such ranges can further facilitate the realization of layering in the single coatings described herein. The functionalized fluorinated polymer (A) may have a number average molecular weight of 3,000-50,000, or more particularly 5,000-30,000. The functionalized fluorinated polymer (A) may also have an OH value of 10 to 100, more typically 10 to 80 or 30 to 80, and most typically 40 to 50 mgKOH / g polymer. The functionalized fluorinated polymer (A) may also have a To of 10 to 90, more typically 30 to 80, and most typically 40 to 60 °C. g Particularly preferred FEVE polymers of the functionalized fluorinated polymer (A) include hydroxyl functional groups, have a complex viscosity of 35 to 50 Pa-sec at 200°C, and an OH value of 40-50 mg KOH / g polymer. When a FEVE polymer including carboxylic acid functional groups is used as the functionalized fluorinated polymer (A), this carboxylated FEVE polymer may have an acid value of 1 to 60 mg KOH / g polymer.

[0058] The mixed powder composition also includes an unfluorinated polymer (B). As further described below, the unfluorinated polymer (B) may be functionalized or unfunctionalized, and may be a thermosetting polymer or a thermoplastic polymer. In other words, the unfluorinated polymer (B) may be a functionalized thermosetting polymer, an unfunctionalized thermosetting polymer (i.e., a thermosetting polymer without functional groups), a functionalized thermoplastic polymer, or an unfunctionalized thermoplastic polymer (i.e., a thermoplastic polymer without functional groups). The unfluorinated polymer may be substantially any polymer, as long as it is not a fluoropolymer, i.e., it does not contain fluorine atoms.

[0059] Most commonly, the unfluorinated polymer (B) is a functionalized thermosetting polymer (B1). Of course, the functionalized thermosetting polymer (B1) is unfluorinated. The functional groups of the functionalized thermosetting polymer (B1) are selected from hydroxyl functional groups, carboxylic acid functional groups, epoxy functional groups, and combinations thereof. In other words, regarding the functional groups of the functionalized thermosetting polymer (B1), the functionalized thermosetting polymer (B1) can include hydroxyl-only functional groups, carboxylic acid-only functional groups, epoxy-only functional groups, hydroxyl and carboxylic acid functional groups, hydroxyl and epoxy functional groups, carboxylic acid and epoxy functional groups, or all three of the following: hydroxyl, carboxylic acid, and epoxy functional groups. It can also be described that the functionalized thermosetting polymer (B1) has hydroxyl and / or carboxylic acid and / or epoxy functional groups. It is understood that, in addition to hydroxyl and / or carboxylic acid and / or epoxy functional groups, the functionalized thermosetting polymer (B1) may also include other functional groups, such as thiol functional groups, amine functional groups, etc.

[0060] The functionalized thermosetting polymer (B1) may be any thermosetting polymer, provided that the polymer is not a fluoropolymer, i.e., does not contain fluorine atoms, and includes functional groups selected from hydroxyl, carboxylic acid, epoxy, and combinations thereof. The functionalized thermosetting polymer (B1) may be selected from polyesters, polyurethanes, acrylics, epoxy resins, and combinations thereof. Regardless of the material chosen for the functionalized thermosetting polymer (B1), the thermosetting polymer is functionalized, i.e., includes hydroxyl and / or carboxylic acid and / or epoxy functionality. Polyesters including hydroxyl functional groups are particularly suitable as functionalized thermosetting polymers (B1) for use in the main mixed powder compositions. Suitable polyesters including hydroxyl functional groups include, but are not limited to, SP-400, SP-500, and SP-1300, commercially available from Sun Polymers International, Inc., Mooresville, Indiana, and Uralac, commercially available from Covestro LLC, Pittsburgh, Pennsylvania. ® P 1680 and P1685, and Desmophen, also available from Covestro LLC in Pittsburgh, Pennsylvania. ® 1700.

[0061] As noted above, the unfluorinated polymer (B) can also be a thermoplastic polymer, which can be functionalized or unfunctionalized. When the unfluorinated polymer (B) is a thermoplastic polymer, the most common is a non-functionalized thermoplastic polymer (B2). Exemplary non-functionalized thermoplastic polymers (B2) include, but are not limited to, thermoplastic polymers selected from: polyvinyl chloride, polyalkylene, polyalkylene terephthalate, polyvinylbutyrate, polyamides, and combinations thereof. Polyvinylbutyrate is particularly suitable for the unfluorinated polymer (B) when a non-functionalized thermoplastic polymer (B2) is desired.

[0062] Regardless of whether the unfluorinated polymer (B) is functionalized, and regardless of whether the unfluorinated polymer (B) is a thermosetting or thermoplastic polymer, the unfluorinated polymer (B) has a complex viscosity of 0.1 to 35, more typically 0.3 to 20, and most typically 0.5 to 10 Pa-sec at 200 °C, as measured according to ASTM D4440-15. Without being limited by any particular theory, it is believed that this complex viscosity of the unfluorinated polymer (B) works in conjunction with the functionalized fluorinated polymer (A) to achieve delamination within the single coating during the curing of the mixed powder composition to form the cured single coating 10. This complex viscosity of the unfluorinated polymer (B) in the mixed powder composition also enables the cured single coating 10 formed from the mixed powder composition to achieve desired aesthetic and functional properties. The cured single coating 10 is further described below.

[0063] Other relevant physical properties of the unfluorinated polymer (B) in this mixed powder composition include OH value and glass transition temperature (T). g While ranges of these other physical properties of the unfluorinated polymer (B) as described below are not required, such ranges can further facilitate the realization of layering in the single coating described herein. The unfluorinated polymer (B) may have an OH value of 5 to 200, more typically 10 to 180, and most typically 20 to 140 mg KOH / g polymer. The unfluorinated polymer (B) may also have a To of 30 to 90, more typically 40 to 80, and most typically 50 to 70 °C. g The particularly preferred polyester of the unfluorinated polymer (B) is thermosetting, includes hydroxyl functional groups, has a complex viscosity of 0.5 to 10 Pa-sec at 200°C, and an OH value of 20 to 140 mg KOH / g polymer.

[0064] The weight ratio of the functionalized fluorinated polymer (A) to the unfluorinated polymer (B) is 60 / 40 to 30 / 70, more typically 60 / 40 to 35 / 65, 60 / 40 to 40 / 60, 60 / 40 to 45 / 55, and most typically 55 / 45 to 45 / 55. At this weight ratio of functionalized fluorinated polymer (A) to unfluorinated polymer (B), the mixed powder composition forms a cured single coating 10 with desired aesthetic and functional properties. This weight ratio of functionalized fluorinated polymer (A) to unfluorinated polymer (B) of 60 / 40 to 30 / 70 (including a more specific weight ratio between 60 / 40 and 30 / 70) drives layering in the cured single coating 10 and achieves the desired aesthetic and functional properties. The specific weight ratio of 60 / 40 to 30 / 70 of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B) makes the mixed powder composition "self-stratifying," thereby driving stratification in the cured single coating 10. In fact, using a weight ratio of functionalized fluorinated polymer (A) and unfluorinated polymer (B) outside the range of 60 / 40 to 30 / 70, the mixed powder composition is not "self-stratifying." Thus, the cured single coating formed from such a mixed powder composition is not stratified, as illustrated in more detail below in the examples.

[0065] The functionalized fluorinated polymer (A) may be present in the mixed powder composition in an amount of 15-60, more typically 20-50, and most typically 25-40 parts by weight, based on the total weight of the mixed powder composition. Similarly, the unfluorinated polymer (B) may be present in the mixed powder composition in an amount of 15-60, more typically 20-50, and most typically 25-40 parts by weight, based on the total weight of the mixed powder composition.

[0066] As described above, the functionalized fluorinated polymer (A) has a complex viscosity of 10 to 100, typically 20 to 80, more typically 25 to 70, and most typically 35 to 50 Pa-sec at 200°C, as measured according to ASTM D4440-15, and the unfluorinated polymer (B) has a complex viscosity of 0.1 to 35, more typically 0.3 to 20, and most typically 0.5 to 10 Pa-sec at 200°C. Additionally, although not required, it is advantageous if the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the unfluorinated polymer (B) is at least 20, more typically at least 25 Pa-sec at 200°C. Alternatively, this difference between the complex viscosity of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B) is 20-80, more typically 20-60 Pa-sec at 200°C. To further describe in detail the embodiment in which the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the unfluorinated polymer (B) is at least 20 Pa·sec at 200°C, in these embodiments, the minimum complex viscosity of the functionalized fluorinated polymer (A) must necessarily be 20.1 Pa·sec or greater at 200°C, because the minimum possible complex viscosity of the unfluorinated polymer (B) is 0.1 Pa·sec at 200°C. In other words, in these particular embodiments, a wide range of complex viscosities of the functionalized fluorinated polymer (A) of 10 to 100 Pa·sec at 200°C and a wide range of complex viscosities of the unfluorinated polymer (B) of 0.1 to 35 Pa·sec at 200°C remain applicable to a certain extent, or as long as the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the unfluorinated polymer (B) remains at least 20 Pa·sec at 200°C.

[0067] Similar to a weight ratio of 60 / 40 to 30 / 70 for functionalized fluorinated polymer (A) and unfluorinated polymer (B), the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the unfluorinated polymer (B) drives stratification in the cured single coating 10 and achieves the desired aesthetic and functional properties. This difference in complex viscosity also makes the mixed powder composition “self-stratifying,” thereby driving stratification in the cured single coating 10.

[0068] In a preferred embodiment of the mixed powder composition, the functionalized fluorinated polymer (A) has an OH value of 10 to 100 mg KOH / g polymer, and the unfluorinated polymer (B) has an OH value of 5 to 200 mg KOH / g polymer. In another preferred embodiment of the mixed powder composition, the functionalized fluorinated polymer (A) has a glass transition temperature T of 10 to 90 °C.g Furthermore, the unfluorinated polymer (B) has a glass transition temperature T ranging from 30 to 90°C. g In another preferred embodiment of the mixed powder composition, the functionalized fluorinated polymer (A) has a complex viscosity of 25 to 70 Pa-sec at 200°C and an OH value of 30 to 80 mg KOH / g polymer, and the unfluorinated polymer (B) has a complex viscosity of 0.3 to 20 Pa-sec at 200°C and an OH value of 10 to 180 mg KOH / g polymer. Although not required, it is further advantageous in the embodiments selected in this paragraph if the weight ratio of the functionalized fluorinated polymer (A) to the unfluorinated polymer (B) is 55 / 45 to 45 / 55, more typically 50 / 50.

[0069] Although not required, the mixed powder composition may also include titanium dioxide (TiO2). Titanium dioxide is not particularly limited and may be any known in the art. For example, titanium dioxide may have any particle size and an average particle size distribution known in the art. If present, titanium dioxide may also be surface-treated with one or more treatments of one or more metal oxides such as alumina, silicon oxide, etc. In various embodiments, titanium dioxide is present in the mixed powder composition in an amount of 1-40, 2-20, or 5-15% by weight, based on the total weight of the mixed powder composition. The amount of titanium dioxide used in the mixed powder composition can influence other aesthetic and functional performance properties of the cured single coating 10, including color and gloss retention over time due to weathering, as well as impact resistance and corrosion resistance.

[0070] Regarding impact resistance, conventional powder coating systems formed from conventional powder compositions containing titanium dioxide are known to fail impact tests due to cracking within the powder coating system. In contrast, when the mixed powder composition of this disclosure includes titanium dioxide, the cured single coating 10 formed from such a mixed powder composition containing titanium dioxide typically passes at least one of a direct impact test and a reverse (or indirect) impact test measured at 30 cm according to ASTM D2794-93, i.e., no cracking occurs in the cured single coating 10 during the test. In other words, the cured single coating 10 of this disclosure may pass the direct impact test only, may pass the reverse impact test only, or may pass both direct and reverse impact tests. For the direct impact test, the test plate includes the cured single coating 10 on top, or upward toward the indenter, so that the indenter directly impacts the cured single coating 10, causing a bulge test area in the cured single coating 10 used for evaluation. For reverse or indirect impact testing, the test plate is "flipped" so that the cured single coating 10 is at the bottom or facing downwards away from the indenter, so that the indenter impacts the cured single coating 10 opposite the test plate, i.e., the indenter does not directly impact the cured single coating 10. Here, when the indenter impacts the cured single coating 10 opposite the test plate, a recessed test area is formed in the cured single coating 10 used for evaluation. From this ASTM, the indenter used is a steel punch with a hemispherical head having a diameter of 0.500 inches (or 12.7 mm).

[0071] Examples of titanium dioxide that can be used in mixed powder compositions include, but are not limited to: Ti-Pure™ R-101, Ti-Pure™ R-103, Ti-Pure™ R-104, Ti-Pure™ R-105, Ti-Pure™ R-350, TS-6200, Ti-Pure™ Select TS-6300, Ti-Pure™ R-706, Ti-Pure™ R-741, Ti-Pure™ R-746, Ti-Pure™ R-796+, Ti-Pure™ R-900, Ti-Pure™ R-902+, Ti-Pure™ R-931, Ti-Pure™ R-942P, Ti-Pure™ R-960 for plastics, Ti-Pure™ R-960 for coatings, Ti-Pure™ TS-6200, Biasill™, cross-grain sand, Starblast™, Starblast™ Ultra, staurolite, zircon sand, Zircore™, Kyasill™, and combinations thereof. Exemplary titanium dioxide is often described in the art as “ultra-durable” titanium dioxide and is commercially available from The Chemours Company of Wilmington, Delaware. Regardless of the specific titanium dioxide selected for inclusion in the mixed powder composition, any surface treatment on the titanium dioxide may contribute to further resistance to aesthetic and / or functional performance degradation due to weathering.

[0072] In the broadest sense, a mixed powder composition need not include a curing agent; that is, the mixed powder composition may be free of a curing agent. However, mixed powder compositions typically do include a curing agent that is reactive with at least one of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B). In other words, the curing agent is reactive only with the functionalized fluorinated polymer (A), only with the unfluorinated polymer (B), or with both the functionalized fluorinated polymer (A) and the unfluorinated polymer (B), even if their reactivity differs. The curing agent reacts with the functionalized fluorinated polymer (A) and / or with the unfluorinated polymer (B) to crosslink. More specifically, if present, the curing agent chemically reacts with the hydroxyl and / or carboxylic acid functional groups of the functionalized fluorinated polymer (A) and / or with the functional groups of the unfluorinated polymer (B) (when the unfluorinated polymer (B) is functionalized), and crosslinks with the functionalized fluorinated polymer (A) and / or with the unfluorinated polymer (B). As is known in the art, in the context of powder compositions, curing agents are also often referred to as crosslinking agents or crosslinking reagents.

[0073] The curing agent can be any curing agent suitable for chemically reacting with the functional groups of the functionalized fluorinated polymer (A) and / or with the functional groups of the unfluorinated polymer (B) (when the unfluorinated polymer (B) is functionalized). Most typically, the curing agent is selected from capped isocyanates, triglycidyl isocyanurate, hydroxyalkylamides, and combinations thereof. Regarding isocyanates as suitable curing agents, both uncapped and capped isocyanates can be included in the mixed powder composition; however, it should be understood that capped isocyanates are preferred over uncapped isocyanates. A suitable curing agent, the capped isocyanate, is VESTAGON, commercially available from Evonik Industries AG of Essen, Germany. ® B 1530. As an example, when the mixed powder composition includes the following, a FEVE polymer including hydroxyl functional groups as a functionalized fluorinated polymer (A), a polyester including hydroxyl functional groups as an unfluorinated polymer (B), and a capped isocyanate as a curing agent, the isocyanate reacts with the hydroxyl functional groups of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B) during the curing of the mixed powder composition and the decapsulation generated by the capped isocyanate to establish a thermosetting cured single coating 10 including urethane bonds or linkers.

[0074] In addition to the functionalized fluorinated polymer (A), the unfluorinated polymer (B), titanium dioxide (if present), and the curing agent (if present), the mixed powder composition may also include other components, such as additives. Exemplary additives include, but are not limited to, flow additives, matting agents, degassing agents, extender pigments, major pigments other than titanium dioxide, surfactants, extreme ultraviolet (UV) absorbers, hindered amine light stabilizers (HALS), antistatic agents, etc.

[0075] For specific references Figure 2 The cured single coating 10 is formed from a mixed powder composition and disposed on a substrate 12. The cured single coating 10 of this disclosure may also be referred to as a powder coating system 10 and may be distributed on any substrate 12. The cured single coating 10 of this specification may be formed from any mixed powder composition. It is noteworthy that the mixed powder composition forming the cured single coating 10 of this specification may be the same as or different from the mixed powder composition described above.

[0076] Common substrates for which the mixed powder composition is applied to form a cured single coating 10 include, but are not limited to, wood substrates, carbon fiber substrates, polyvinyl chloride (PVC) substrates, aluminum substrates, and glass fiber substrates. Aluminum substrate 12 is a particularly preferred substrate 12 for the mixed powder composition. Although not required, substrate 12 may have its outermost surface prepared prior to the application of the mixed powder composition for the formation of the cured single coating 10 on substrate 12. During surface preparation, degreasing and etching of substrate 12 are typically considered. Chromate surface preparation is most typical for the mixed powder composition and substrate 12 described herein. Figure 2 As best represented, the surface preparation method or technique establishes a surface preparation layer 14 between the substrate 12 and the applied mixed powder composition (and ultimately between the substrate 12 and the cured single coating 10). This surface preparation layer 14 can vary in composition and thickness to affect several physical properties, including but not limited to overall corrosion protection and adhesion.

[0077] The mixed powder composition can be applied to the substrate 12 using a variety of powder application techniques, including but not limited to impregnating or immersing the substrate 12 in the mixed powder composition, or electrostatically spraying the mixed powder composition onto the substrate 12. Once the mixed powder composition has been applied to the substrate 12, the substrate 12 with the mixed powder composition is cured to form a cured single coating 10. Curing the mixed powder composition requires a curing temperature and curing time to heat and melt the mixed powder composition and maintain it in a molten state for a predetermined period of time. The curing temperature and curing time are typically established based on various factors, including, for example, the type and amount of components in the mixed powder composition, the desired cured film thickness, etc. The curing temperature and curing time are also established based on the reaction temperature of a particular curing agent. For example, when the curing agent is a capped isocyanate, the curing temperature is typically 170-210°C (at a temperature at which the capped isocyanate is uncapped), and the curing time is typically 5-120 minutes, more typically 10-60 minutes. During curing, a single coating has an overall cured film thickness of 25-100, more typically 30-80, and most typically 50-60 micrometers.

[0078] refer to Figure 2-5. The cured single coating 10 is layered between a top film phase 16, a bottom film phase 18 adjacent to the substrate 12 and opposite to the top film phase 16, and an intermediate film phase 20 between the top and bottom film phases 16 and 18. The top film phase 16 of the cured single coating 10 is adjacent to the top or outermost (environmentally facing) surface 17 of the cured single coating 10. Because the cured layer 10 is a single coating, i.e., only one or a single layer, the outermost portion or outermost layer of the cured single coating 10 is not itself a separate layer. Instead, the outermost portion or layer is the top film phase 16, and there is no separating boundary between this top film phase 16 and the intermediate film phase 20 adjacent to the top film phase 16. Any boundaries within the cured single coating 10 are blurred. For example, the boundary between the intermediate film phase 20 and the bottom film phase 18 is also blurred.

[0079] The stratification between the top, bottom, and intermediate film phases 16, 18, and 20 is also considered a gradient or phase separation within the cured single coating 10. This gradient is specifically caused by... Figure 2 The gradient or grayscale of the shading is represented by different degrees. Now generally referring to Figures 3-5, with this layering, the top film phase 16 is fluorine-dominant (i.e., fluorine-rich) compared to both the bottom film phase 18 and the intermediate film phase 20. The fluorine dominance in the top film phase 16 means that the top film phase 16 has more fluorine than the bottom film phase and the intermediate film phases 18, 20. The fluorine dominance in the top film phase 16 is generally consistent across the cured single coating 10, i.e., the fluorine dominance is not sporadic. It is noteworthy that, as by Figure 3B The presence of fluorine in 4B is optimally represented, with fluorine dispersed throughout the cured single coating 10. A certain amount of fluorine remains in the intermediate and bottom film phases 20 and 18, and the top film phase 16 remains fluorine-dominant, provided that the concentration of fluorine in the top film phase 16 is greater than that in the intermediate and bottom film phases 20 and 18. This fluorine dominance in the top film phase 16 results in the cured single coating 10 exhibiting the desired weather-resistant functional properties. It is noteworthy that regarding... Figure 3A and 3B The understanding is that these digital SEM images do not necessarily have to be to scale with each other. Thus, Figure 3A The thicknesses of the various film phases 16, 20, and 18 represented in the figure cannot be relative to... Figure 3B The thicknesses of the various film phases 16, 20, and 18 are compared.

[0080] General reference Figures 5A-5C The cured single coating 10 is formed from a functionalized fluorinated polymer (A) and three different unfluorinated polymers (B). The cured single coating 10 has an overall film thickness of 25 to 100 micrometers, specifically for... Figure 5A The cured single coating is 57.8 micrometers, for Figure 5B The cured single coating is 10 for 57.0 micrometers and for Figure 5C The cured single coating 10 has a thickness of 58.6 micrometers. Furthermore, as illustrated in these specific figures, when the cured single coating 10 is fluorine-dominant, the top film phase 16 can vary in film thickness. The top film phase 16 preferably has a fluorine-dominant film thickness of at least 8 micrometers. Alternatively, the film thickness of the top film phase can be at least 10 micrometers or in the range of 8-50, 10-50, 10-35, 15-35, 15-30, and 17-30 micrometers. Figures 5A-5C It is specifically shown in the text that Figure 5A The thickness of the top phase 16 is 26.7 micrometers. Figure 5B The thickness of the top phase 16 is 21.7 micrometers. Figure 5C The thickness of the top film phase 16 is 26.4 micrometers. The thickness of the top film phase 16 can also be understood as a percentage of the total cured film thickness of the cured single coating 10. In this context, non-limiting examples of the thickness of the top film phase 16 include examples where the thickness of the top film phase 16 is 25 to 55%, optionally 35 to 55%, and further optionally 40 to 50% of the total cured film thickness of the cured single coating 10.

[0081] While not required in all implementations, the intermediate film phase 20 may be fluorine-dominant relative to the bottom film phase 18, meaning the intermediate film phase 20 may have more fluorine than the bottom film phase 18. In this case, where the intermediate film phase 20 is fluorine-dominant relative to the bottom film phase 18, the cured single coating 10 comprises a gradient in which the concentration of fluorine in the cured single coating 10 decreases consistently from the top film phase 16 downwards through the intermediate film phase 20 to the bottom film phase 18.

[0082] General reference Figure 4A -4C, the mixed powder compositions of this disclosure are particularly suitable for protecting cured single-coat 10 with titanium dioxide from aesthetic and / or functional performance degradation caused by weathering, such as exposure to ultraviolet (UV) radiation from the sun, exposure to UVA lamps commonly used in QUV accelerated weathering tests, and exposure to moisture from elements. More specifically, it is generally understood that titanium dioxide is readily degraded due to photocatalytic reactions promoted by UV radiation and moisture. Fluorine in the top film phase 16 of the cured single-coat 10 predominantly blocks aesthetic and / or functional performance degradation caused by weathering. More specifically, the bond strength, i.e., the bond dissociation energy, of the fluorine-carbon (FC) bond can exceed 500 kJ / mol, and this amount is sufficient to block energy in the UV region (primarily UV-A) of sunlight, typically ranging from 315 to 400 kJ / mol. Due to the dominance of fluorine in the top phase 16 of the cured single coating 10, FC bonds are prevalent in the top phase 16 (which is closest to the sun), and these FC bonds are stronger than other chemical bonds such as C-C bonds.

[0083] As a result, it is understood that the cured single coatings 10 of this disclosure exhibit improved weathering compared to prior art cured single coatings that do not have a fluorine advantage in their respective top or outermost (environmentally facing) surfaces. As an example, such prior art cured single coatings that do not have a fluorine advantage in their respective top or outermost surfaces are typically formed from powder compositions comprising only polyester and unfunctionalized fluorinated polymers (A). It is also understood that the cured single coatings 10 of this disclosure, compared to conventional efforts using multiple separate layers in powder coating systems (e.g., prior art), exhibit improved weathering. Figure 1A Compared to those conventional efforts (represented in the text), it exhibits at least the same and possibly even improved weathering. For the purposes of this disclosure, the term improved weathering refers to gloss properties (e.g., gloss retention) over time.

[0084] For details, please refer to the following: Figure 4A The cured single coating 10 at -4C comprises a functionalized fluorinated polymer (A), an unfluorinated polymer (B), and titanium dioxide (TiO2). In the schematic diagram of Figure 4B, SEM / EDX imaging illustrates the fluorine dominance in the top film phase 16, where fluorine is indicated by the symbol "+". As clearly shown, + (fluorine) or a high concentration of + (fluorine) is prevalent in the top film phase 16. Furthermore, the symbol "+" is used... ° The schematic diagram in Figure 4C illustrates that titanium from TiO2 does not aggregate in the top phase 16, but rather in the middle phase 20 and the bottom phase 18. This allows the fluorine in the top phase 16 (shown in Figure 4B) to protect the titanium from the aforementioned aesthetic and / or functional performance degradation. Notably, titanium, along with most of the unfluorinated polymer (B) (e.g., polyesters containing hydroxyl functional groups), is primarily present in the middle and bottom phases 20 and 18. In other words, due to stratification, the unfluorinated polymer (B) is primarily in the middle and bottom phases 20 and 18, while the fluorinated polymer (A), such as FEVE polymers containing hydroxyl functional groups, is primarily in the top phase 16. It is understood that the schematic diagrams in Figures 4B and 4C are relative to... Figure 4A The scale in the digital SEM images is not proportional. Therefore, the thicknesses of the various film phases 16, 20, and 18 shown in Figures 4B and 4C cannot be relative to the actual thickness. Figure 4A The thicknesses of the various film phases 16, 20, and 18 are compared.

[0085] As noted above, the cured single coating 10 of this specification can be formed from any mixed powder composition. More specifically, the cured single coating 10 of this specification can be formed from any mixed powder composition, provided that the formed cured single coating 10 has an overall cured film thickness of 25 to 100 micrometers and has a fluorine advantage relative to the bottom film phase 18 and the intermediate film phase 20 as described above. Although not required, the cured single coating 10 of this specification is most commonly formed from the mixed powder composition described above, particularly wherein the mixed powder composition comprises a functionalized fluorinated polymer (A) (which includes hydroxyl and / or carboxylic acid functional groups and has a complex viscosity of 10 to 100 Pa-sec at 200°C, measured according to ASTM D4440-15) and an unfluorinated polymer (B) (which has a complex viscosity of 0.1 to 35 Pa-sec at 200°C, measured according to the same ASTM standard), in a weight ratio of 70 / 30 to 30 / 70.

[0086] General reference Figure 6A and 6B The extrusion method produces a mixed powder composition. The mixed powder composition produced according to the subject extrusion method may be the same as or different from the mixed powder composition described above. The main difference is that the extrusion method of this disclosure does not require the functionalization of the fluorinated or unfluorinated polymer used. The fluorinated and unfluorinated polymers used in this extrusion method may be functionalized, but they do not have to be.

[0087] refer to Figure 6A The extrusion method involves passing a fluorinated polymer and an unfluorinated polymer through a feed length L. f The feed zone is supplied to an extruder with a screw, where the fluorinated polymer and the unfluorinated polymer are kneaded together in the extruder at a kneading length L. k The powder is kneaded in the kneading zone to form a mixed powder composition, and discharged from the extruder with a discharge length L. d The emission zone emits a mixed powder composition.

[0088] Regarding the supply of fluorinated and unfluorinated polymers to the extruder, the fluorinated and unfluorinated polymers, along with any other components such as additives, may be supplied to the extruder individually or together. When the fluorinated polymer, unfluorinated polymer, and any other components are supplied to the extruder individually, these components are first mixed in the extruder. In another, more preferred embodiment of the extrusion method of this disclosure, the fluorinated polymer, unfluorinated polymer, and any other components are already mixed together to some extent (premixed) before being supplied to the extruder. When the fluorinated polymer, unfluorinated polymer, and any other components are supplied to the extruder together, all components are typically premixed outside the extruder or independently of the extruder, thereby first forming a premixed composition, which is then typically supplied to the extruder via a feed hopper.

[0089] The extruder has a total volumetric capacity in the feed zone, and although not required, it is preferred that the fluorinated and unfluorinated polymers be fed into the extruder at 10 to 30%, optionally 10 to 25%, and further optionally 15 to 25% of the total volumetric capacity in the feed zone during the feeding of the fluorinated and unfluorinated polymers. It is also preferred that the screw speed of the extruder be set to 150 to 600 RPM. Alternatively, the screw speed of the extruder may be set to 300 to 600 RPM. Without being limited by any particular theory, it is believed that this feed rate of fluorinated and unfluorinated polymers into the extruder facilitates the production of the mixed powder composition, which achieves stratification in the single coating 10 formed from the mixed powder composition.

[0090] It is understood that the screw of the extruder in this extrusion method may include a single screw or multiple screws, including two or more screws. It is noteworthy that the extruder and the screws (one or more) are... Figure 6A and 6B The information is clearly and explicitly disclosed, although these components are not specifically numbered in these drawings. Regarding the number of screws, the kneading length L of the kneading zone... k The effective length L of the screw (one or more) s From more than 50% to 60%, as long as the feed length L f and kneading length L k and emission length L d The total percentage is 100%.

[0091] Continue to refer to Figure 6A Although it's not required, but as L k / L s For replenishment of more than 50 to 60%, it is advantageous if the feed length L f The effective length L of the screw s 30% to 40%, and emission length L dFor the effective length L s 6% to 16%. In a preferred embodiment of the extrusion method, the feed length L... f For L s 32% to 38%, kneading length L k For L s 52% to 58%, and emission length L d For L s 9% to 14%.

[0092] Now for reference Figure 6B During kneading, the fluorinated and unfluorinated polymers can be kneaded at temperatures ranging from 35 to 115°C, more typically 40 to 80°C, and most typically 45 to 70°C. These temperature ranges represent the temperature of the polymers. To achieve such temperatures for the fluorinated and unfluorinated polymers during kneading, the temperature throughout the kneading zone of the extruder (often referred to as the barrel temperature) is typically set between 40 and 140°C, more typically 48 to 120°C. The kneading step involves melting the fluorinated and unfluorinated polymers and mixing them to form a mixed powder composition. Furthermore, although not required, it is preferred that the kneading zone of this extrusion method does not contain, i.e., has no neutral zone. In other words, it is preferred that one or more screws run along the kneading length L. k The neutral kneading section is excluded. The fluorinated and unfluorinated polymers are melted and mixed via the screw of an extruder. In the kneading step, the melting of the fluorinated and unfluorinated polymers typically occurs at 51°C or lower, more typically at 45 to 51°C. Then, in the kneading step, the mixing of the fluorinated and unfluorinated polymers typically occurs at a temperature greater than 51°C, more typically at a temperature greater than 51 to 57°C.

[0093] As noted above, the fluorinated and unfluorinated polymers used in this extrusion method may be functionalized, but they need not be. The particular fluorinated polymer used in this extrusion method is the functionalized fluorinated polymer (A) described above, i.e., a functionalized fluorinated polymer comprising hydroxyl and / or carboxylic acid functional groups and having a complex viscosity of 10 to 100 Pa-sec at 200°C as measured according to ASTM D4440-15, such as FEVE polymers containing hydroxyl functional groups. The particular unfluorinated polymer used in this extrusion method is the unfluorinated polymer (B) described above, i.e., an unfluorinated polymer having a complex viscosity of 0.1 to 35 Pa-sec at 200°C as measured according to ASTM D4440-15. More particularly, it is advantageous if the unfluorinated polymer used in this extrusion method is a functionalized thermosetting polymer (B1) containing functional groups selected from hydroxyl, carboxylic acid, epoxy, and combinations thereof, such as polyesters containing hydroxyl functional groups. The mixed powder composition produced by this extrusion method may further include the curing agent described above. If a curing agent is included, at least one of the fluorinated polymer and the unfluorinated polymer is functionalized for reaction with the curing agent.

[0094] Although not required, this extrusion method and the resulting mixed powder composition are advantageous if the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the unfluorinated polymer (B) is at least 20, more typically at least 25 Pa-sec at 200°C. Alternatively, the difference between the complex viscosity of this functionalized fluorinated polymer (A) and the unfluorinated polymer (B) used in the main extrusion method is 20-80, more typically 20-60 Pa-sec at 200°C. Example

[0095] The following examples also illustrate the mixed powder compositions and cured single coatings 10 of this disclosure, and are intended for illustrative purposes and not for limitation. Those skilled in the art will recognize that equivalents of the following components and suppliers exist. Therefore, the components of the following mixed powder compositions should not be construed as limiting.

[0096] In Example 1, where the weight ratio of the functionalized fluorinated polymer (A) to the unfluorinated polymer (B) is 50 / 50, the components listed in Table 1 below were weighed separately and added to a sample bag of sufficient size / volume.

[0097]

[0098] The functionalized fluorinated polymer (A) is Lumiflon, commercially available from AGC Chemicals Americas, Inc., Exton, Pennsylvania.® LF710F.

[0099] The unfluorinated polymer (B) is SP-500, which is commercially available from Sun Polymers International, Inc. in Mooresville, Indiana.

[0100] The curing agent is VESTAGON, which is commercially available from Evonik Industries AG in Essen, Germany. ® B1530.

[0101] Flow Additive 1 is Resinflow PL-200, which is commercially available from Estron Chemical, Inc., Calvert City, Kentucky.

[0102] Flow Additive 2 is Resinflow PL-67, which is commercially available from Estron Chemical, Inc., Calvert City, Kentucky.

[0103] The degassing agent is benzoin, which is commercially available from Estron Chemical, Inc. in Calvert City, Kentucky.

[0104] MINEX pigment No. 1 is available from Sibelco Specialty Minerals in Antwerp, Belgium. ® 10.

[0105] Titanium dioxide is Ti-Pure™ TS-6200, which is commercially available from Ti-Pure™, The Chemours Company in Wilmington, Delaware.

[0106] The second type of body pigment is FP-480 OpacityPigment™, which is commercially available from FP-Pigments Oy in Espoo, Finland.

[0107] The UV absorber is Tinuvin® PA 144, which is commercially available from BASF Corporation in Florham Park, New Jersey.

[0108] HALS is Tinuvin® 460, available from BASF Corporation in Florham Park, New Jersey.

[0109] After weighing the components in Table 1 and adding them to the sample bags, the contents of the powdered sample bags were then added to a laboratory grinder for premixing. The contents were premixed in the grinder for approximately 4 seconds to grind the powder into a premixed composition with a smaller particle size.

[0110] The premixed composition is then collected in a sample bag for use and processing via an extruder having a feed zone, a kneading zone, and a discharge zone. For Example 1, the extruder is an MP24PC integrated extruder with integrated cooling rollers, commercially available from Baker Perkins. The extruder is heated, and the screw is set to rotate at 300 RPM. The premixed composition is poured from the sample bag into the feed hopper or trough of the extruder. From here, the premixed composition is conveyed and fed into the opening of the extruder. More specifically, the screw of the feed hopper is set to 20% of the total volumetric capacity at the feed zone for feeding the premix into the extruder, and includes a fluoropolymer (Lumiflon). ® A premixed composition of LF710F and an unfluorinated polymer (SP-500) is fed via a screw into the feed zone of an extruder. For Example 1, the feed length L of the feed zone is... f The effective length L of the screw s 34.62%.

[0111] In an extruder, contents comprising fluorinated and unfluorinated polymers are kneaded in a kneading zone, and more specifically melted and mixed to form a mixed powder composition. For Example 1, the kneading length L of the kneading zone... k The effective length L of the screw s The content is 53.85%, and the kneading temperature is 35 to 115°C, more particularly 48 to 104°C, and most particularly 85 to 100°C. The mixed powder composition of Example 1 is then discharged from the discharge zone of the extruder. For Example 1, the discharge length L of the discharge zone is... d The effective length L of the screw s 11.53%. It is noteworthy that, as exemplified in Example 1, the feed length L... f and kneading length L k and emission length L d The total percentage is 100%. The mixed powder composition of Example 1 is then poured into the cooling roller of an extruder, compressed into a sheet, and collected in a discharge tray. The mixed powder composition of Example 1 is collected into a finished bag, which is now in the physical form of a sheet, wherein the contents of Example 1 are compounded in the sheet.

[0112] From the finished product bag, the composite sheet of Example 1 was then sieved using a Retsch AS 200 vibrating screen for subsequent application by spraying and then curing to form a cured single coating 10. For spraying, the mixed powder composition of Example 1 was used with Encore, commercially available from Nordson Corporation in Westlake, Ohio. ® LT manual powder coating system (Encore) ® The system (or manual spraying) forms a single coating on the substrate. For Example 1, Encore ® The system controller is configured as follows: (i) intelligent flow mode; (ii) classic / standard electrostatic mode at 60 kV; (iii) powder flow rate / flowing air % set to "9"; and (iv) total flow set to "50". Using these configurations, the operator sprays back and forth on the substrate for a total of one pass, achieving single-coat film formation in one pass for subsequent curing. For curing, the substrate, including the sprayed single-coat, is cured in an oven at 200°C in a vertical orientation for 20 minutes to form a cured single coating 10.

[0113] For Examples 2A-2W, refer now to Table 2 below, which includes comparative examples and inventive examples. Specifically, Examples 2A-2H and 2T-2W are comparative examples, and Examples 2I-2S are inventive examples. All Examples 2A-2W are loaded (whether comparative or inventive) according to the description of Example 1 above. Therefore, Example 2L in Table 2 below is equivalent to Example 1 in Table 1 above.

[0114] For the mixed powder coating compositions of Examples 2A-2W, all individual components are the same as those described above with respect to Example 1. The only variation in the mixed powder coating compositions is the change in the weight ratio of the functionalized fluorinated polymer (A) to the unfluorinated polymer (B) (Column [3]). Finally, Examples 2A-2W were extruded, sprayed, and cured as described above with respect to Example 1.

[0115]

[0116]

[0117] The data presented in Table 2 above establishes a weight ratio of 60 / 40 to 30 / 70 (including a more specific weight ratio between 60 / 40 and 30 / 70) of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B) of the present invention (see Examples 2I-2S) that drives stratification in the cured single coating 10. In Examples 2I-2S, stratification exists, wherein the fluorine-dominant top film phase 16 has a thickness ranging from 9.5 to 26.7 micrometers. Furthermore, referring to column [6] in Table 2, Examples 2I-2S result in a thickness of the top film phase 16 ranging from 26 to 52% of the total cured film thickness of the cured single coating 10. This particular weight ratio of 60 / 40 to 30 / 70 of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B) makes the mixed powder composition “self-stratifying,” thereby driving stratification in the cured single coating 10.

[0118] In contrast, using a weight ratio of functionalized fluorinated polymer (A) to unfluorinated polymer (B) outside the range of 60 / 40 to 30 / 70 (see Examples 2A-2H and 2T-2W), the mixed powder composition is not “self-stratified.” As a result, the cured single coating formed from such a mixed powder composition is not stratified, i.e., there is no top film phase at all, as in Examples 2A-2H and 2T-2W by the thickness of 0 micrometers in column [4] and the 0% example in column [6] of Table 2.

[0119] It should be understood that the appended claims do not limit the expression of any particular compound, composition, or method described in the detailed description, which may vary among specific embodiments falling within the scope of the appended claims. Regarding any Markush group upon which this document relies to describe a particular feature or aspect of the various embodiments, different, specific, and / or unexpected results may be obtained from each member of the respective Markush group, independent of all other Markush members. Each member of the Markush group may be individually or in combination reliable and provide sufficient support for the specific embodiments within the scope of the appended claims.

[0120] Furthermore, any scopes and subscopes relied upon in independently and collectively describing various embodiments of this disclosure fall within the scope of the appended claims and are to be understood as describing and considering all ranges including integer values ​​and / or fractional values, even if such values ​​are not explicitly stated herein. Those skilled in the art will readily recognize that the enumerated scopes and subscopes adequately describe and implement various embodiments of this disclosure, and that such scopes and subscopes may be further divided into relevant halves, thirds, quarters, fifths, etc. By way of example only, the range “0.1-0.9” may be further divided into the lower third (0.1-0.3), the middle third (0.4-0.6), and the upper third (0.7-0.9), which are individually and collectively within the scope of the appended claims and are individually and / or collectively reliable and provide sufficient support for specific embodiments within the scope of the appended claims. Additionally, regarding language used to define or modify scopes, such as “at least,” “greater than,” “less than,” “not greater than,” etc., it should be understood that such language includes subscopes and / or upper or lower limits. As another example, the scope of "at least 10" inherently includes sub-scopes from at least 10 to 35, from at least 10 to 25, and from 25 to 35, etc., and each sub-scope can be individually and / or collectively relied upon to provide sufficient support for specific embodiments within the scope of the appended claims. Finally, individual digits within the disclosed scope can be relied upon to provide sufficient support for specific embodiments within the scope of the appended claims. For example, the scope of "1-9" includes individual integers such as 3, and individual digits including decimal points (or fractions) such as 4.1, which are reliable and provide sufficient support for specific embodiments within the scope of the appended claims.

[0121] This disclosure has been described in an illustrative manner, and it should be understood that the terminology used is intended to be descriptive rather than limiting. Many modifications and variations of this disclosure are possible based on the above teachings. This disclosure may be implemented in a manner different from that specifically described. The subject matter of all combinations of independent and dependent claims (both single and multiple dependents) is expressly contemplated herein.

Claims

1. A mixed powder composition for forming a layered, single-coat, the composition comprising: (A) a functionalized fluorinated polymer comprising hydroxyl and / or carboxylic acid functional groups and having a complex viscosity at 200°C of 10 to 100 Pa-sec as measured by ASTM D4440-15; and (B) a non-fluorinated polymer having a complex viscosity at 200°C of 0.1 to 35 Pa-sec as measured by ASTM D4440-15, wherein the weight ratio of the functionalized fluorinated polymer (A) and the non-fluorinated polymer (B) is 60 / 40 to 30 / 70.

2. The mixed powder composition of claim 1, wherein the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the non-fluorinated polymer (B) is at least 20 Pa-sec at 200°C.

3. The mixed powder composition of either of claims 1 or 2, wherein the functionalized fluorinated polymer (A) has an OH value of 10 to 100 mg KOH / g polymer and the non-fluorinated polymer (B) has an OH value of 5 to 200 mg KOH / g polymer.

4. The mixed powder composition according to any one of claims 1 to 3, wherein the functionalized fluorinated polymer (A) has a glass transition temperature Tg of 10 to 90 °C g and the non-fluorinated polymer (B) has a glass transition temperature Tg of 30 to 90 °C g .

5. The mixed powder composition of any of claims 1-4, wherein the functionalized fluorinated polymer (A) has a complex viscosity at 200°C of 25 to 70 Pa-sec and an OH value of 30 to 80 mg KOH / g polymer and the non-fluorinated polymer (B) has a complex viscosity at 200°C of 0.3 to 20 Pa-sec and an OH value of 10 to 180 mg KOH / g polymer.

6. The mixed powder composition of any of claims 1-5, wherein the functionalized fluorinated polymer (A) is selected from the group consisting of copolymers of tetrafluoroethylene, polymers of tetrafluoroethylene, copolymers of fluoroethylenyl vinyl ether (FEVE), polymers of FEVE, copolymers of fluoroethylenyl vinyl ester, polymers of fluoroethylenyl vinyl ester, and combinations thereof.

7. The mixed powder composition of any of claims 1-6, wherein the functionalized fluorinated polymer (A) comprises a FEVE polymer comprising hydroxyl functional groups.

8. The mixed powder composition of claim 7, wherein the FEVE polymer has a complex viscosity at 200°C of 35 to 50 Pa-sec and an OH value of 40 to 50 mg KOH / g polymer.

9. The mixed powder composition of any of claims 1, 2, 4, and 6, wherein the functionalized fluorinated polymer (A) comprises a FEVE polymer comprising carboxylic acid functional groups, wherein the FEVE polymer comprising carboxylic acid functional groups optionally has an acid value of 1 to 60 mg KOH / g polymer.

10. The hybrid powder composition of any one of claims 1-9, wherein the non-fluorinated polymer (B) comprises a functionalized thermoset polymer (Bl) comprising functional groups selected from hydroxyl functional groups, carboxylic acid functional groups, epoxy functional groups, and combinations thereof.

11. The hybrid powder composition of claim 10, wherein the functionalized thermoset polymer (Bl) is selected from polyesters, polyurethanes, acrylics, epoxy resins, and combinations thereof.

12. The hybrid powder composition of claim 10 or 11, wherein the functionalized thermoset polymer (Bl) comprises a polyester comprising hydroxyl functional groups.

13. The hybrid powder composition of claim 12, wherein the polyester has a complex viscosity at 200°C of 0.5 to 10 Pa-sec and an OH number of 20 to 140 mg KOH / g polymer.

14. The hybrid powder composition of any one of claims 1-9, wherein the non-fluorinated polymer (B) comprises a non-functional thermoplastic polymer (B2).

15. The hybrid powder composition of claim 14, wherein the non-functional thermoplastic polymer (B2) is selected from polyvinyl chloride, polyolefins, polyalkylene terephthalate, polyvinyl butyrate, polyamides, and combinations thereof.

16. The hybrid powder composition of claim 14 or 15, wherein the non-functional thermoplastic polymer (B2) comprises polyvinyl butyrate.

17. The hybrid powder composition of any one of claims 1-16, wherein the weight ratio of the functionalized fluorinated polymer (A) and the non-fluorinated polymer (B) is 60 / 40 to 35 / 65, optionally 60 / 40 to 40 / 60, further optionally 60 / 40 to 45 / 55, and yet further optionally 55 / 45 to 45 / 55.

18. The hybrid powder composition of any one of claims 1-17, further comprising titanium dioxide (Ti02).

19. The hybrid powder composition of any one of claims 1-18, further comprising a curing agent reactive with at least one of the functionalized fluorinated polymer (A) and the non-fluorinated polymer (B).

20. The hybrid powder composition of claim 19, wherein the curing agent is selected from blocked isocyanates, isocyanurate triglycidyl esters, hydroxyalkyl amides, and combinations thereof.

21. A cured monocoat disposed on a substrate and formed from a hybrid powder composition, wherein the cured monocoat has a total cured film thickness of 25 to 100 micrometers and is stratified between a top film phase, a bottom film phase adjacent to the substrate opposite the top film phase, and an intermediate film phase between the top film phase and the bottom film phase, and wherein the top film phase is fluorine-dominant relative to both the bottom film phase and the intermediate film phase.

22. The cured monocoat of claim 21, wherein the intermediate film phase is fluorine-dominant relative to the bottom film phase.

23. The cured monocoat of claim 21 or 22, wherein the top film phase has a film thickness of at least 8 microns, optionally 10 to 35 microns, and further optionally 15 to 30 microns.

24. The cured monocoat of any one of claims 21-23, wherein the thickness of the top film phase is 25 to 55%, optionally 35 to 55%, and further optionally 40 to 50% of the total cured film thickness of the cured monocoat.

25. The cured monocoat of any one of claims 21-24, comprising titanium dioxide (Ti02), and which passes at least one of a direct impact test and a reverse impact test each measured at 30 cm according to ASTM D2794-93.

26. The cured monocoat of any one of claims 21-25, wherein the mixed powder composition from which the cured monocoat is formed comprises (A) a functionalized fluorinated polymer comprising hydroxyl and / or carboxylic acid functional groups and having a complex viscosity at 200°C of 10 to 100 Pa-sec measured according to ASTM D4440-15, and (B) an unfluorinated polymer having a complex viscosity at 200°C of 0.1 to 35 Pa-sec measured according to ASTM D4440-15.

27. The cured monocoat of claim 26, wherein the weight ratio of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B) is 60 / 40 to 30 / 70; and / or wherein the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the unfluorinated polymer (B) is at least 20 Pa-sec at 200°C.

28. The cured monocoat of claim 26 or 27, wherein the mixed powder composition from which the cured monocoat is formed further comprises a curing agent reactive with at least one of the functionalized fluorinated polymer (A) and the unfluorinated polymer (B).

29. An extrusion method for producing a mixed powder composition comprising a fluorinated polymer and an unfluorinated polymer, the method comprising: The fluorinated polymer and the non-fluorinated polymer are fed into an extruder having a screw, in a feed zone having a feed length L f of 0.5 to 5 meters. kneading zone of the extruder having a kneading length L k of from 1 to 3 kneading blocks, each kneading block having a kneading length Lk of from 0.1 to 0.5 m, and from the discharge zone of the extruder having a discharge length L d of the mixed powder composition, The kneading length L k The effective length L of the screw s The percentage is greater than 50% to 60%, provided that the feed length L is... f and the kneading length L k and the emission length L d The total percentage is 100%.

30. The extrusion process of claim 29, wherein the feed length L f is from 30 to 40% of the effective length L s of the screw, and the discharge length L d is from 6 to 16% of the effective length L s of the screw.

31. The extrusion process according to claim 29 or 30, wherein the feed length L f is from 32 to 38% of the effective length L s of the screw, the kneading length L k is from 52 to 58% of the effective length L s , and the discharge length L d is from 9 to 14% of the effective length L s .

32. The extrusion method of one of claims 29-31, wherein the fluorinated polymer and the unfluorinated polymer are kneaded at a temperature of 35 to 115°C.

33. The extrusion method of any one of claims 29-32, wherein the fluorinated polymer and the unfluorinated polymer are kneaded at a temperature of 40 to 80°C, optionally 45 to 70°C.

34. The extrusion method of any one of claims 29-33, wherein the step of kneading comprises melting the fluorinated polymer and the unfluorinated polymer and mixing the fluorinated polymer and the unfluorinated polymer to form a mixed powder composition.

35. The extrusion method of claim 34, wherein the fluorinated polymer and the unfluorinated polymer are melted at a temperature of 51°C or less and then mixed at a temperature greater than 51°C.

36. The extrusion process of any one of claims 29-35, wherein the extruder has a total volume capacity at the feed zone, and the fluorinated polymer and the non-fluorinated polymer are fed into the extruder at the feed zone at 10 to 30%, optionally 10 to 25%, and further optionally 15 to 25% of the total volume capacity at the feed zone.

37. The extrusion process of any one of claims 29-36, wherein the fluorinated polymer comprises (A) a functionalized fluorinated polymer comprising hydroxyl and / or carboxylic acid functional groups and having a complex viscosity at 200 °C of 10 to 100 Pa-sec, measured according to ASTM D4440-15, and the non-fluorinated polymer comprises (B) a non-fluorinated polymer having a complex viscosity at 200 °C of 0.1 to 35 Pa-sec, measured according to ASTM D4440-15.

38. The extrusion process of claim 37, wherein the weight ratio of the functionalized fluorinated polymer (A) and the non-fluorinated polymer (B) is 60 / 40 to 30 / 70.

39. The extrusion process of claim 37 or 38, wherein the non-fluorinated polymer (B) comprises a functionalized thermoset polymer (B1) comprising functional groups selected from the group consisting of hydroxyl functional groups, carboxylic acid functional groups, epoxy functional groups, and combinations thereof.

40. The extrusion process of any one of claims 37-39, wherein the difference between the complex viscosity of the functionalized fluorinated polymer (A) and the complex viscosity of the non-fluorinated polymer (B) is at least 20 Pa-sec at 200 °C, the functionalized fluorinated polymer (A) comprises a FEVE polymer containing hydroxyl functional groups, and the non-fluorinated polymer (B) comprises a polyester containing hydroxyl functional groups.

41. The extrusion process of any one of claims 29-40, wherein the mixed powder composition further comprises a curing agent reactive with at least one of the fluorinated polymer and the non-fluorinated polymer.

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