Electrodepositionable coating composition

Abstract

The present invention provides an electrodepositable coating composition, a coated substrate, and a method for coating a substrate. [Solution] An electrodepositable coating composition comprising an electrodepositable binder containing an ionic base-containing film-forming polymer and a curing agent, and at least one pigment, wherein the electrodepositable coating composition has a resin solids content of less than 30% by weight based on the total weight of the electrodepositable coating composition, and a viscosity of at least 15 cP at a shear rate of 0.1 / second as measured by a bath viscosity test method, and the pigment optionally includes a phyllosilicate pigment, and the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1 when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition.

Description

[Technical Field]

[0001] This disclosure relates to electrodepositable coating compositions, coated substrates, and methods for coating substrates. [Background technology]

[0002] Electrodeposition as a coating application method involves the deposition of a film-forming composition onto a conductive substrate under the influence of an applied potential. Compared to non-electrophoretic coating methods, electrodeposition has become the standard in the coating industry because it offers increased paint utilization with less waste, improved corrosion protection for substrates, and minimal environmental pollution. However, electrodepositable coating compositions with relatively high pigment levels may result in sedimentation in the bath and / or uneven or rough coating. Electrodepositable coating compositions with high pigment levels without sedimentation or appearance defects are desirable. [Overview of the project]

[0003] This disclosure provides an electrodepositable coating composition comprising an electrodepositable binder comprising an ionic base-containing film-forming polymer and a curing agent, and at least one pigment, wherein the electrodepositable coating composition has a resin solids content of less than 30% by weight based on the total weight of the electrodepositable coating composition, and a viscosity of at least 15 cP at a shear rate of 0.1 / second as measured by a bath viscosity test method, and the pigment optionally comprises a phyllosilicate pigment, and the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1 when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition.

[0004] The disclosure also provides a method for coating a substrate, comprising electrodepositing a coating derived from an electrodepositable coating composition comprising an electrodepositable binder comprising an ionic base-containing film-forming polymer and a curing agent, and at least one pigment, wherein the electrodepositable coating composition has a resin solids content of less than 30% by weight based on the total weight of the electrodepositable coating composition and a viscosity of at least 15 cP at a shear rate of 0.1 / second as measured by a bath viscosity test method, and the pigment optionally comprises a phyllosilicate pigment, wherein the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1 when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition.

[0005] The disclosure further provides a coating formed by depositing a coating from an electrodepositable coating composition comprising an electrodepositable binder comprising an ionic base-containing film-forming polymer and a curing agent, and at least one pigment, wherein the electrodepositable coating composition has a resin solids content of less than 30% by weight based on the total weight of the electrodepositable coating composition, and a viscosity of at least 15 cP at a shear rate of 0.1 / second as measured by a bath viscosity test method, and the pigment optionally comprises a phyllosilicate pigment, and the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1 when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition.

[0006] The disclosure further provides a substrate at least partially coated with a coating deposited from an electrodepositable coating composition comprising an electrodepositable binder comprising an ionic base-containing film-forming polymer and a curing agent, and at least one pigment, wherein the electrodepositable coating composition has a resin solids content of less than 30% by weight based on the total weight of the electrodepositable coating composition and a viscosity of at least 15 cP at a shear rate of 0.1 / second as measured by a bath viscosity test method, and the pigment optionally comprises a phyllosilicate pigment, and the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1 when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition.

[0007] The disclosure also provides a substrate comprising an electrodeposited coating layer containing an electrodepositable binder and a pigment, wherein the electrodeposited coating layer has a pigment-to-binder ratio of at least 0.3:1, and the electrodeposited coating layer has a horizontal surface roughness of less than 90 microinches as measured by an L-panel surface roughness test method. [Modes for carrying out the invention]

[0008] This disclosure relates to an electrodepositable coating composition comprising an electrodepositable binder comprising an ionic base-containing film-forming polymer and a curing agent, and at least one pigment, wherein the electrodepositable coating composition has a resin solids content of less than 30% by weight based on the total weight of the electrodepositable coating composition, and a viscosity of at least 15 cP at a shear rate of 0.1 / second as measured by a bath viscosity test method, and the pigment optionally comprises a phyllosilicate pigment, and the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1 when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition.

[0009] According to this disclosure, the term “electrodepositionable coating composition” refers to a composition that can be deposited on an electrically conductive substrate under the influence of an applied potential.

[0010] As used herein, the term “bath viscosity test method” refers to a test method such as those described in the Examples section of this specification.

[0011] According to this disclosure, an electrodepositable coating composition may have a resin solids content of less than 30% by weight, based on the total weight of the electrodepositable coating composition, and a viscosity of at least 15 cP, for example, at least 25 cP, for example, at least 35 cP, for example, at least 45 cP, for example, at least 55 cP, for example, at least 65 cP, for example, at least 75 cP, for example, at least 85 cP, for example, at least 95 cP, for example, at least 100 cP, based on the total weight of the electrodepositable coating composition, at a shear rate of 0.1 / second.

[0012] According to this disclosure, the electrodepositable coating composition has a resin solids content of less than 30% by weight, based on the total solids content of the electrodepositable coating composition, and a viscosity of less than 15 cP, for example less than 12 cP, for example less than 10 cP, for example less than 8 cP, for example less than 6 cP, when measured by a bath viscosity test method, at a shear rate of 100 / second.

[0013] According to this disclosure, the electrodepositable coating composition may have a pigment-to-binder ratio of at least 0.3:1, and the coating electrodeposited from the electrodepositable coating composition has a minimum complex viscosity during curing of 5,000 to 300,000 cP or less, as measured by a complex viscosity test method.

[0014] As used herein, “complex viscosity test method” refers to a procedure used to measure the viscosity of a coating film during a curing cycle, the method comprising: (a) setting up an Anton Paar MCR302 rheometer having a PPR25 / 23 spindle and a 0.1 mm gap; (b) applying tetrahydrofuran (THF) to an uncured electrodeposited coating sample, scraping the uncured electrodeposited coating sample from the panel using a metal spatula, and placing the sample on a Peltier plate; and (c) measuring the viscosity of the sample over time with the sample under a constant shear strain (vibration) of 5% and a frequency of 1 Hz, which is maintained throughout the entire length of the test, followed by a curing cycle of ambient flash at 40°C for 30 minutes, and then measuring the temperature rise from 40°C to 175°C over 41 minutes (3.3°C / min).

[0015] According to this disclosure, a coating deposited from an electrodepositable coating composition may have a horizontal surface roughness of less than 90 microinches, for example, less than 85 microinches, for example less than 80 microinches, for example less than 75 microinches, for example less than 60 microinches, for example less than 50 microinches, for example less than 45 microinches, for example less than 40 microinches, for example less than 35 microinches, for example less than 30 microinches, as measured by the L-panel surface roughness test method.

[0016] As used herein, the term “L panel surface roughness test method” refers to a test method such as that described in the Examples section of this specification.

[0017] According to this disclosure, a coating deposited from an electrodepositable coating composition has a vertical surface roughness of less than 75 microinches, e.g., less than 60 microinches, e.g., less than 50 microinches, e.g., less than 40 microinches, e.g., less than 30 microinches, e.g., less than 25 microinches, e.g., less than 20 microinches, e.g., less than 15 microinches, e.g., less than 10 microinches, as measured by the L-panel surface roughness test method.

[0018] According to the present disclosure, an electrodepositable coating composition can have a relative sedimentation of 90 mg / P:B or less, for example, 85 mg / P:B or less, for example, 80 mg / P:B or less, for example, 50 mg / P:B or less, for example, 40 mg / P:B or less, for example, 35 mg / P:B or less, for example, 25 mg / P:B or less, for example, 20 mg / P:B or less when measured by the relative sedimentation test method.

[0019] As used herein, the term "relative sedimentation test method" refers to the test method as described in the Examples section of this specification.

[0020] According to the present disclosure, an electrodepositable coating composition can have a VOC of less than 1.5 lb / gallon (179.7 g / L), for example, less than 1.3 lb / gallon (155.8 g / L), for example, less than 1.1 lb / gallon (131.8 g / L), for example, less than 1.0 lb / gallon (119.8 g / L), for example, less than 0.8 lb / gallon (95.9 g / L). As used herein, the term "volatile organic content" or "VOC" refers to an organic solvent that does not chemically react with the components of an electrodepositable binder or curing agent and is present in a composition having a boiling point of less than 250°C. As used herein, the term "boiling point" refers to the boiling point of a substance at a standard atmospheric pressure of 101.325 kPa (1.01325 bar or 1 atmosphere), which is also commonly referred to as the normal boiling point. Volatile organic content includes volatile organic solvents. As used herein, the term "volatile organic solvent" refers to an organic compound having a boiling point of less than 250°C, for example, less than 200°C. VOC can be calculated according to the following formula.

Number

[0021] According to the present disclosure, an electrodepositable binder includes an ionic base-containing film-forming polymer.

[0022] According to this disclosure, ionic base-containing film-forming polymers may include cationic base-containing film-forming polymers. Cationic base-containing film-forming polymers may be used in cationic electrodepositable coating compositions. As used herein, the term “cationic base-containing film-forming polymer” refers to a polymer containing at least partially neutralized cationic groups, such as positively charged sulfonium and ammonium groups. As used herein, the term “polymer” includes, but is not limited to, oligomers, as well as homopolymers and copolymers. Cationic base-containing film-forming polymers may contain active hydrogen functional groups. As used herein, the term “active hydrogen functional group” refers to these groups that are reactive with isocyanates, as determined by the Zerewittnoff test, as described in the JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol. 49, page 3181 (1927), and includes, for example, hydroxyl groups, primary or secondary amine groups, and thiol groups. A film-forming polymer containing a cationic base and an active hydrogen functional group may be referred to as an active hydrogen-containing cationic base-containing film-forming polymer.

[0023] Examples of polymers suitable for use as cationic base-containing film-forming polymers in this disclosure include, but are not limited to, alkyd polymers, acrylics, polyepoxides, polyamides, polyurethanes, polyureas, polyethers, and polyesters.

[0024] More specific examples of suitable active hydrogen-containing cationic base-containing film-forming polymers include polyepoxide-amine adducts, for example, adducts of polyglycidyl ethers of polyphenols such as bisphenol A with primary and / or secondary amines, such as those described in U.S. Patent No. 4,031,050, column 3, lines 27 to 50; U.S. Patent No. 4,452,963, column 5, lines 58 to 6, line 66; and U.S. Patent No. 6,017,432, column 2, lines 66 to 6, line 26, which are incorporated herein by reference. The portion of the amine that reacts with the polyepoxide may be a polyamine ketimine, as described in U.S. Patent No. 4,104,147, column 6, lines 23 to 7, line 23 (this quoted portion is incorporated herein by reference). Non-gelling polyepoxide-polyoxyalkylene polyamine resins, for example, those described in column 2, line 60 to column 58 of U.S. Patent No. 4,432,850, are also preferred, and this quoted portion is incorporated herein by reference. In addition, cationic acrylic resins, for example, those described in column 2, line 18 to column 3, line 61 of U.S. Patent No. 3,455,806 and in column 2, line 29 to column 3, line 21 of U.S. Patent No. 3,928,157, can be used, and both portions of these are incorporated herein by reference.

[0025] In addition to amine base-containing resins, quaternary ammonium base-containing resins may also be used as cationic base-containing film-forming polymers in this disclosure. Examples of these resins are formed by reacting organic polyepoxides with tertiary aminates. Such resins are described in U.S. Patent No. 3,962,165, columns 2, line 3 to 11, line 7; U.S. Patent No. 3,975,346, columns 1, line 62 to 17, line 25; and U.S. Patent No. 4,001,156, columns 1, line 37 to 16, line 7, which are incorporated herein by reference. Other suitable examples of cationic resins include ternary sulfonium base-containing resins, for example, those described in U.S. Patent No. 3,793,278, columns 1, line 32 to 5, line 20, which are incorporated herein by reference. Furthermore, cationic resins that cure via a transesterification mechanism, such as those described on page 2, line 1 to page 6, line 25 of European Patent Application No. 12463B1, can also be used, and this portion is incorporated herein by reference.

[0026] Other suitable cationic base-containing film-forming polymers include those capable of forming photodegradable electrodepositable coating compositions. Such polymers include those containing cationic amine bases derived from pendant and / or terminal amino groups, disclosed in paragraphs

[0064] to

[0088] of U.S. Patent Application Publication 2003 / 0054193A1, which are incorporated herein by reference. Also suitable are active hydrogen-containing cationic base-containing resins derived from polyglycidyl ethers of polyhydric phenols that are essentially free of aliphatic carbon atoms to which two or more aromatic groups are bonded, described in paragraphs

[0096] to

[0123] of U.S. Patent Application Publication 2003 / 0054193A1, which are incorporated herein by reference.

[0027] The active hydrogen-containing cationic base-containing film-forming polymer becomes cationic and water-dispersible by at least partial neutralization with a resin-neutralizing acid. Suitable resin-neutralizing acids include organic and inorganic acids. Non-limiting examples of suitable organic acids include formic acid, acetic acid, methanesulfonic acid, and lactic acid. Non-limiting examples of suitable inorganic acids include phosphoric acid and sulfamic acid. "Sulfamic acid" means sulfamic acid itself or its derivatives such as those having the following formula: [ka] In the formula, R is hydrogen or an alkyl group having 1 to 4 carbon atoms. Mixtures of the acids described above may also be used in this disclosure.

[0028] The degree of neutralization of cationic base-containing film-forming polymers may vary depending on the specific polymer involved. However, the cationic base-containing film-forming polymer should be sufficiently neutralized using a sufficient amount of resin neutralizing acid so that it can be dispersed in an aqueous dispersion medium. For example, the amount of resin neutralizing acid used may provide at least 20% of the total theoretical neutralization. It is also possible to use an excess of acid exceeding the amount required for 100% total theoretical neutralization. For example, the amount of resin neutralizing acid used to neutralize a cationic base-containing film-forming polymer may be ≥0.1% based on the total amines in the active hydrogen-containing cationic base-containing film-forming polymer. Alternatively, the amount of resin neutralizing acid used to neutralize an active hydrogen-containing cationic base-containing film-forming polymer may be ≤100% based on the total amines in the active hydrogen-containing cationic base-containing film-forming polymer. The total amount of resin neutralizing acid used to neutralize a cationic base-containing film-forming polymer may be in the range of any combination of the values ​​described in the preceding sentence, including the values ​​described. For example, the total amount of resin neutralizing acid used to neutralize an active hydrogen-containing cationic base-containing film-forming polymer may be 20%, 35%, 50%, 60%, or 80%, based on the total amines in the cationic base-containing film-forming polymer.

[0029] According to this disclosure, the cationic base-containing film-forming polymer may be present in the cationic electrodepositable coating composition in an amount of at least 40% by weight, for example, at least 50% by weight, for example, at least 60% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. The cationic base-containing film-forming polymer may be present in the cationic electrodepositable coating composition in an amount of 90% by weight or less, for example, 80% by weight or less, for example, 75% by weight or less, based on the total weight of the resin solids of the electrodepositable coating composition. The cationic base-containing film-forming polymer may be present in the cationic electrodepositable coating composition in amounts of 40% to 90% by weight, for example, 40% to 80% by weight, for example, 40% to 75% by weight, for example, 50% to 90% by weight, for example, 50% to 80% by weight, for example, 50% to 75% by weight, for example, 60% to 90% by weight, for example, 60% to 80% by weight, for example, 60% to 75% by weight, based on the total weight of the resin solids content of the electrodepositable coating composition.

[0030] As used herein, “resin solids” includes an ionic base-containing film-forming polymer, a curing agent, and any additional water-dispersible, uncolored components present in the electrodepositable coating composition.

[0031] According to this disclosure, ionic base-containing film-forming polymers may include anionic base-containing film-forming polymers. As used herein, the term “anionic base-containing film-forming polymer” refers to an anionic polymer containing at least partially neutralized anionic functional groups, such as carboxylic acid groups and phosphate groups that impart a negative charge. As used herein, the term “polymer” includes, but is not limited to, oligomers, as well as homopolymers and copolymers. Anionic base-containing film-forming polymers may contain active hydrogen functional groups. As used herein, the term “active hydrogen functional group” refers to these groups that are reactive with isocyanates, as determined by the Zerewitinoff test as described above, and include, for example, hydroxyl groups, primary or secondary amine groups, and thiol groups. Anionic base-containing film-forming polymers containing active hydrogen functional groups may be referred to as active hydrogen-containing anionic base-containing film-forming polymers. Anionic base-containing film-forming polymers may be used in anionic electrodepositionable coating compositions.

[0032] Anionic base-containing film-forming polymers may include base-solubilized carboxylic acid group-containing film-forming polymers, such as reaction products or adducts of drying oils or semi-drying fatty acid esters with dicarboxylic acids or their anhydrides, as well as reaction products of fatty acid esters, unsaturated acids or their anhydrides, and any additional unsaturated modifying materials that further react with polyols. Also preferred are at least partially neutralized interpolymers of hydroxy-alkyl esters of unsaturated carboxylic acids, unsaturated carboxylic acids, and at least one other ethylenically unsaturated monomer. Another preferred anionic electrodepositable resin includes alkyd-aminoplast vehicles, i.e., vehicles containing alkyd resins and amine-aldehyde resins. Another preferred anionic electrodepositable resin composition includes mixed esters of resinous polyols. Other acid-functional polymers, such as phosphorylated polyepoxides or phosphorylated acrylic polymers, may also be used. Exemplary phosphorylated polyepoxides are disclosed in U.S. Patent Application Publication 2009-0045071, paragraphs

[0004] to

[0015] and U.S. Patent Application 13 / 232,093, paragraphs

[0014] to

[0040] , the portions of which are incorporated herein by reference. Resins containing one or more pendant carbamate functional groups, such as those described in U.S. Patent No. 6,165,338, are also preferred.

[0033] According to this disclosure, an anionic base-containing film-forming polymer may be present in a cationic electrodepositable coating composition in an amount of at least 50% by weight, for example, at least 55% by weight, for example, at least 60% by weight, based on the total weight of the resin solids content of the electrodepositable coating composition. An anionic base-containing film-forming polymer may be present in an anionic electrodepositable coating composition in an amount of 90% by weight or less, for example, 80% by weight or less, for example, 75% by weight or less, based on the total weight of the resin solids content of the electrodepositable coating composition. The anionic base-containing film-forming polymer may be present in the anionic electrodepositable coating composition in amounts of 50% to 90% by weight, for example, 50% to 80% by weight, for example, 50% to 75% by weight, for example, 55% to 90% by weight, for example, 55% to 80% by weight, for example, 55% to 75% by weight, for example, 60% to 90% by weight, for example, 60% to 80% by weight, for example, 60% to 75% by weight, based on the total weight of the resin solids content of the electrodepositable coating composition.

[0034] According to this disclosure, the ionic base-containing film-forming polymer may be present in the electrodepositable coating composition in an amount of at least 40% by weight, for example, at least 50% by weight, for example, at least 55% by weight, for example, at least 60% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. The ionic base-containing film-forming polymer may be present in the electrodepositable coating composition in an amount of 90% by weight or less, for example, 80% by weight or less, for example, 75% by weight or less, based on the total weight of the resin solids of the electrodepositable coating composition. The ionic base-containing film-forming polymer may be present in the electrodepositable coating composition in an amount of 40% to 90% by weight, for example, 40% to 80% by weight, for example, 40% to 75% by weight, for example, 50% to 90% by weight, for example, 50% to 80% by weight, for example, 50% to 75% by weight, for example, 55% to 90% by weight, for example, 55% to 80% by weight, for example, 55% to 75% by weight, for example, 60% to 90% by weight, for example, 60% to 80% by weight, for example, 60% to 75% by weight, based on the total weight of the electrodepositable coating composition.

[0035] According to this disclosure, the electrodepositable coating compositions of this disclosure further comprise a curing agent. The curing agent may react with reactive groups, such as active hydrogen groups, of an ionic base-containing film-forming polymer to curing the coating composition and form a coating. As used herein, the terms “curing,” “cured,” or similar terms, when used in relation to the electrodepositable coating compositions described herein, mean that at least a portion of the components forming the electrodepositable coating composition are crosslinked to form a coating. Additionally, curing of an electrodepositable coating composition refers to subjecting the composition to curing conditions (e.g., high temperature) to induce a reaction of reactive functional groups of the components of the electrodepositable coating composition, resulting in crosslinking of the components of the composition and the formation of at least partially cured coatings. Non-limiting examples of suitable curing agents include phenol-formaldehyde condensates, at least partially blocked polyisocyanates, aminoplast resins, and phenoplast resins, e.g., their allyl ether derivatives.

[0036] Suitable at least partially blocked polyisocyanates include aliphatic polyisocyanates, aromatic polyisocyanates, and mixtures thereof. The curing agent may include at least partially blocked aliphatic polyisocyanates. Suitable at least partially blocked aliphatic polyisocyanates include, for example, fully blocked aliphatic polyisocyanates, e.g., as described in U.S. Patent No. 3,984,299, column 1, line 57 to column 3, line 15 (this portion is incorporated herein by reference), or partially blocked aliphatic polyisocyanates that react with the polymer backbone, e.g., as described in U.S. Patent No. 3,947,338, column 2, line 65 to column 4, line 30 (this portion is also incorporated herein by reference). "Blocked" means that the isocyanate groups have reacted with the compound such that the resulting blocked isocyanate groups are stable to active hydrogen at ambient temperature but reactive with active hydrogen in the film-forming polymer at high temperatures, such as 90°C to 200°C. The polyisocyanate curing agent may be a completely blocked polyisocyanate that is substantially free of free isocyanate groups.

[0037] Polyisocyanate curing agents may include diisocyanates, polyisocyanates with higher functionality, or combinations thereof. For example, polyisocyanate curing agents may include aliphatic and / or aromatic polyisocyanates. Aliphatic polyisocyanates include (i) alkylene isocyanates, e.g., trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate ("HDI"), 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, ethylidene diisocyanate, and butylidene diisocyanate, and (ii) cycloalkylene isocyanates, e.g., 1,3-cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,2-cyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexyl isocyanate) ("HMDI"), 1,6-hexmethylene diisocyanate (1,6-hexmethylene Examples include cyclotrimers of diisocyanate (also known as isocyanurate trimers of HDI, and commercially available from Convestro AG as Desmodur N3300), and meta-tetramethylxylylene diisocyanate (commercially available from Allnex SA as TMXDI®). Aromatic polyisocyanates include (i) arylene isocyanates, e.g., m-phenylene diisocyanate, p-phenylene diisocyanate, 1,5-naphthalene diisocyanate, and 1,4-naphthalene diisocyanate, and (ii) alkali-rene isocyanates, e.g., 4,4'-diphenylenemethane ("MDI"), 2,4-toleylene diisocyanate or 2,6-toleylene diisocyanate ("TDI"), or mixtures thereof, 4,4-toluidine diisocyanate, and xylylene diisocyanate.Triisocyanates, such as triphenylmethane-4,4',4''-triisocyanate, 1,3,5-triisocyanatobenzene, and 2,4,6-triisocyanatotoluene, tetraisocyanates, such as 4,4'-diphenyldimethylmethane-2,2',5,5'-tetraisocyanate, and polymerized polyisocyanates, such as tolylene diisocyanate dimers and trimers, may also be used. The curing agent may include blocked polyisocyanates selected from polymerized polyisocyanates, such as polymerized HDI, polymerized MDI, and polymerized isophorone diisocyanate. The curing agent may also include blocked trimers of hexamethylene diisocyanate, available from Covestro AG as Desmodur N3300®. Mixtures of polyisocyanate curing agents may also be used.

[0038] The polyisocyanate curing agent may be at least partially blocked with at least one blocking agent selected from 1,2-alkanediols, e.g., 1,2-propanediol; 1,3-alkanediols, e.g., 1,3-butanediol; benzyl alcohols, e.g., benzyl alcohol; allyl alcohols, e.g., allyl alcohol; caprolactam; dialkylamines, e.g., dibutylamine; and mixtures thereof. The polyisocyanate curing agent may be at least partially blocked with at least one 1,2-alkanediol having three or more carbon atoms, e.g., 1,2-butanediol.

[0039] Other suitable blocking agents include aliphatic, alicyclic, or aromatic alkyl monoalcohols or phenol compounds, such as lower aliphatic alcohols like methanol, ethanol, and n-butanol; alicyclic alcohols like cyclohexanol; aromatic alkyl alcohols like phenylcarbinol and methylphenylcarbinol; and phenol compounds such as phenol itself and substituted phenols whose substituents do not affect the coating operation, such as cresol and nitrophenol. Glycol ethers and glycolamines can also be used as blocking agents. Suitable glycol ethers include ethylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol methyl ether, and propylene glycol methyl ether. Other suitable blocking agents include oximes such as methyl ethyl ketoxime, acetone oxime, and cyclohexanone oxime.

[0040] For example, the blocking agent may include an ether or polyether containing a hydroxyl group and a terminal group having structure-OR, where R is a C1-C8 alkyl group, e.g., a C1-C4 alkyl group, e.g., a C1-C3 alkyl group, or two terminal hydroxyl groups. The polyether may include a homopolymer, a block copolymer, or a random copolymer. For example, the polyether may include a homopolymer of ethylene oxide or propylene oxide, or the polyether may include a block or random copolymer containing a combination of ethylene oxide and propylene oxide in a block or random pattern. Such a blocking agent may include the following structure: [ka] In the formula, R1 and R2 are each hydrogen, or one of R1 and R2 is hydrogen and the other is a methyl group, R3 is H or a C1-C8 alkyl group, e.g., a C1-C4 alkyl group, e.g., a C1-C3 alkyl group, and n is an integer from 1 to 50, e.g., 1 to 40, e.g., 1 to 30, e.g., 1 to 20, e.g., 1 to 12, e.g., 1 to 8, e.g., 1 to 6, e.g., 1 to 4, e.g., 2 to 50, e.g., 2 to 40, e.g., 2 to 30, e.g., 2 to 20, e.g., 2 to 12, e.g., 2 to 8, e.g., 2 to 6, e.g., 2 to 4, e.g., 3 to 50, e.g., 3 to 40, e.g., 3 to 30, e.g., 3 to 20, e.g., 3 to 12, e.g., 3 to 8, e.g., 3 to 6, e.g., 3 to 4.

[0041] For example, the blocking agent may include ethoxylated bisphenol. Such a blocking agent may include the following structure: [ka] In the expression, n is an integer and m is an integer between 1 and 20. For example, m and n may be equal, and each may be independently 2, 3, 4, 5, 6, 7, 8, 9, or 10. In other examples, m and n may not be equal, and may be any combination of integers that add up to 20.

[0042] The curing agent may optionally contain high molecular weight volatile groups. As used herein, the term “high molecular weight volatile groups” refers to blocking agents and other organic by-products generated and volatilized during the curing reaction of an electrodepositable coating composition having a molecular weight of at least 70 g / mol, e.g., at least 125 g / mol, e.g., at least 160 g / mol, e.g., at least 195 g / mol, e.g., at least 400 g / mol, e.g., at least 700 g / mol, e.g., at least 1000 g / mol, or greater, and may range from 70 to 1,000 g / mol, e.g., 160 to 1,000 g / mol, e.g., 195 to 1,000 g / mol, e.g., 400 to 1,000 g / mol, e.g., 700 to 1,000 g / mol. For example, organic by-products may include alcoholic by-products resulting from the reaction of the film-forming polymer with an aminoplast or phenoplast curing agent, and blocking agents may include alcohol-containing organic compounds used to block isocyanate groups of polyisocyanates that are not blocked during curing. For clarity, high molecular weight volatile groups explicitly exclude any organic solvents that may be covalently bonded to the curing agent before curing and may be present in the electrodepositable coating composition. Upon curing, the pigment-to-binder ratio of the deposited film may increase in the cured film compared to the deposited uncured pigment-to-binder ratio in the electrodepositable coating composition due to the greater mass loss of blocking agents and other organic by-products derived from the curing agent that volatilize during curing. High molecular weight volatile groups may constitute 5% to 50% by weight of the film-forming binder, e.g., 7% to 45% by weight, e.g., 9% to 40% by weight, e.g., 11% to 35% by weight, e.g., 13% to 30% by weight of the film-forming binder, based on the total weight of the film-forming binder.High molecular weight volatile groups and other low molecular weight volatile organic compounds generated during curing, such as low molecular weight blocking agents and organic by-products generated during curing, may be present in amounts such that the relative weight loss of the film-forming binder deposited on the substrate relative to the weight of the film-forming binder after curing is 5% to 50% by weight of the film-forming binder, for example, 7% to 45% by weight, for example, 9% to 40% by weight, for example, 11% to 35% by weight, for example, 13% to 30% by weight, based on the total weight of the film-forming binder before and after curing.

[0043] The curing agent may include an aminoplast resin. The aminoplast resin is a condensation product of an aldehyde with a substance that carries an amino or amide group. Condensation products obtained from the reaction of alcohols and aldehydes with melamine, urea, or benzoguanamine can be used. However, aldehyde condensates of other amine and amide condensation products, such as triazine, diazine, triazole, guanidine, guanamine, as well as alkyl-substituted ureas and aryl-substituted ureas, and alkyl-substituted and aryl-substituted derivatives of such compounds, including alkyl-substituted melamine and aryl-substituted melamine, can also be employed. Some examples of such compounds include N,N'-dimethylurea, benzourea, dicyandiamide, formguanamine, acetoganamine, ammeline, 2-chloro-4,6-diamino-1,3,5-triazine, 6-methyl-2,4-diamino-1,3,5-triazine, 3,5-diaminotriazole, triaminopyrimidine, 2-mercapto-4,6-diaminopyrimidine, and 3,4,6-tris(ethylamino)-1,3,5-triazine. Suitable aldehydes include formaldehyde, acetaldehyde, crotonaldehyde, acrolein, benzaldehyde, furfural, and glyoxal.

[0044] The aminoplast resin may contain methylol or similar alkylol groups, and at least a portion of these alkylol groups may be etherified by reaction with an alcohol to provide an organic solvent-soluble resin. Any monohydric alcohol can be used for this purpose, including alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, and heptanol, as well as benzyl alcohol and other aromatic alcohols, cyclic alcohols such as cyclohexanol, monoethers of glycols such as cellosolve and carbitol, and halogen-substituted or other substituted alcohols such as 3-chloropropanol and butoxyethanol.

[0045] Non-limiting examples of commercially available aminoplast resins include those available under the trademark CYMEL® from Allnex Belgium SA / NV, such as CYMEL 1130 and 1156, and those available under the trademark RESIMENE® from INEOS Melamines, such as RESIMENE 750 and 753. Examples of suitable aminoplast resins are also described in U.S. Patent No. 3,937,679, column 16, line 3 to column 17, line 47, which is incorporated herein by reference. As disclosed in the aforementioned portion of this '679 patent, aminoplasts may be used in combination with methylolphenol ethers.

[0046] Phenoplast resins are formed by the condensation of an aldehyde and a phenol. Suitable aldehydes include formaldehyde and acetaldehyde. Methylene-releasing agents and aldehyde-releasing agents such as paraformaldehyde and hexamethylenetetramine can also be used as aldehyde agents. Various phenols can be used, such as phenol itself, cresol, or substituted phenols in which hydrocarbon radicals having a linear, branched, or cyclic structure substitute for hydrogen in the aromatic ring. Mixtures of phenols can also be employed. Some specific examples of suitable phenols are unsaturated hydrocarbon-substituted phenols such as p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, cyclopentylphenol, and monobutenylphenol, which contains a butenyl group at the ortho, meta, or para position and in which the double bond occurs at various positions in the hydrocarbon chain.

[0047] The aminoplast resins and phenoplast resins described above are described in U.S. Patent No. 4,812,215, column 6, line 20 to column 7, line 12, which is incorporated herein by reference.

[0048] The curing agent may be present in the cationic electrodepositable coating composition in an amount of at least 10% by weight, for example, at least 20% by weight, for example, at least 25% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. The curing agent may be present in the cationic electrodepositable coating composition in an amount of 60% by weight or less, for example, 50% by weight or less, for example, 40% by weight or less, based on the total weight of the resin solids of the electrodepositable coating composition. The curing agent may be present in the cationic electrodepositable coating composition in an amount of 10% to 60% by weight, for example, 10% to 50% by weight, for example, 10% to 40% by weight, for example, 20% to 60% by weight, for example, 20% to 50% by weight, for example, 20% to 40% by weight, for example, 25% to 60% by weight, for example, 25% to 50% by weight, for example, 25% to 40% by weight, based on the total weight of the resin solids of the electrodepositable coating composition.

[0049] The curing agent may be present in the anionic electrodepositable coating composition in an amount of at least 10% by weight, for example, at least 20% by weight, for example, at least 25% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. The curing agent may be present in the anionic electrodepositable coating composition in an amount of 50% by weight or less, for example, 45% by weight or less, for example, 40% by weight or less, based on the total weight of the resin solids of the electrodepositable coating composition. The curing agent may be present in the anionic electrodepositable coating composition in an amount of 10% to 50% by weight, for example, 10% to 45% by weight, for example, 10% to 40% by weight, for example, 20% to 50% by weight, for example, 20% to 45% by weight, for example, 20% to 45% by weight, for example, 20% to 40% by weight, for example, 25% to 50% by weight, for example, 25% to 45% by weight, for example, 25% to 40% by weight, based on the total weight of the resin solids of the electrodepositable coating composition.

[0050] The curing agent may be present in the electrodepositable coating composition in an amount of at least 10% by weight, for example, at least 20% by weight, for example, at least 25% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. The curing agent may be present in the electrodepositable coating composition in an amount of 60% by weight or less, for example, 50% by weight or less, for example, 45% by weight or less, for example, 40% by weight or less, based on the total weight of the resin solids of the electrodepositable coating composition. The curing agent may be present in the electrodepositable coating composition in an amount of 10% to 60% by weight, for example, 10% to 50% by weight, for example, 10% to 45% by weight, for example, 10% to 40% by weight, for example, 20% to 60% by weight, for example, 20% to 50% by weight, for example, 20% to 45% by weight, for example, 20% to 40% by weight, for example, 25% to 60% by weight, for example, 25% to 50% by weight, for example, 25% to 45% by weight, for example, 25% to 40% by weight, based on the total weight of the resin solids content of the electrodepositable coating composition.

[0051] According to this disclosure, the electrodepositable coating composition further comprises a pigment. The pigment may include iron oxide, lead oxide, strontium chromate, carbon black, charcoal dust, titanium dioxide, barium sulfate, coloring pigments, phyllosilicate pigments, metallic pigments, thermally conductive electrical insulating fillers, flame retardant pigments, or any combination thereof.

[0052] As used herein, the term "phyllosilicate" refers to SiO4 extending outward in an infinite sheet. -4 This refers to a group of minerals that have silicate sheets with a basic structure based on interconnected tetrahedrons forming 6-membered rings, where 3 of the 4 oxygen atoms from each tetrahedron form Si2O5. -2 The basic structural unit is shared with other tetrahedra that give rise to phyllosilicates. The phyllosilicate is formed by a hydroxide ion located at the center of the tetrahedron and / or, for example, Fe +2 Mg +2 , or Al +3 These pigments may contain cations such as , which form a cation layer between silicate sheets where the cations can cooperate with oxygen and / or hydroxide ions in the silicate layer. The term "phylrosilicate pigment" refers to pigment materials containing phylrosilicates. Non-limiting examples of phylrosilicate pigments include mica, chlorite, serpentine, talc, and clay minerals. Examples of clay minerals include kaolin clay and smectite clay. The sheet-like structure of phylrosilicate pigments tends to result in pigments having a plate-like structure, but pigments can be manipulated (through mechanical means, etc.) to have other particulate structures. When exposed to a liquid medium, these pigments may or may not swell, and may or may not have leaching components (e.g., ions that can be attracted toward an aqueous medium).

[0053] Phyllosilicate pigments may include plate-shaped pigments. For example, phyllosilicate pigments may include plate-shaped mica pigments, plate-shaped chlorite pigments, plate-shaped serpentine pigments, plate-shaped talc pigments, and / or plate-shaped clay pigments. Plate-shaped clay pigments may include kaolin clay, smectite clay, or a combination thereof.

[0054] As described above, when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition, the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1.

[0055] If the electrodepositable coating composition is a cationic electrodepositable coating composition and contains a pigment dispersing agent, the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1.

[0056] If the cationic electrodepositionable coating composition contains a pigment-dispersing acid, the cationic electrodepositionable coating composition may be substantially free of, essentially free of, or completely free of phyllosilicate pigments.

[0057] If the cationic electrodepositionable coating composition contains a pigment dispersant, the cationic electrodepositionable coating composition may be substantially free of, essentially free of, or completely free of phyllosilicate pigments.

[0058] As used herein, the term “thermally conductive electrical insulating filler” refers to a pigment, filler, or inorganic powder having a thermal conductivity of at least 5 W / m·K at 25°C (measured according to ASTM D7984) and a volume resistivity of at least 10 Ω·m (measured according to ASTM D257, C611, or B193), or “TC / EI filler” means such. TC / EI filler materials may include organic or inorganic materials, may include particles of a single type of filler material, or may include particles of two or more types of TC / EI filler materials. That is, a TC / EI filler material may include particles of a first TC / EI filler material and may further include particles of at least a second (i.e., second, third, fourth, etc.) TC / EI filler material different from the first TC / EI filler material. As used herein with respect to types of filler materials, references to “first,” “second,” etc., are for convenience only and do not refer to the order of addition, etc.

[0059] TC / EI filler materials may have a thermal conductivity of at least 5 W / m·K at 25°C (measured according to ASTM D7984), for example, at least 18 W / m·K, for example, at least 55 W / m·K. TC / EI filler materials may have a thermal conductivity of 3,000 W / m·K or less at 25°C (measured according to ASTM D7984), for example, 1,400 W / m·K or less, for example, 450 W / m·K or less. TC / EI filler materials may have a thermal conductivity of 5 W / m·K to 3,000 W / m·K at 25°C (measured according to ASTM D7984), for example, 18 W / m·K to 1,400 W / m·K, for example, 55 W / m·K to 450 W / m·K.

[0060] The TC / EI filler material may have a volume resistivity of at least 10 Ω·m (measured according to ASTM D257, C611, or B193), for example, at least 20 Ω·m, for example, at least 30 Ω·m, for example, at least 40 Ω·m, for example, at least 50 Ω·m, for example, at least 60 Ω·m, for example, at least 60 Ω·m, for example, at least 70 Ω·m, for example, at least 80 Ω·m, for example, at least 80 Ω·m, for example, at least 90 Ω·m, for example, at least 100 Ω·m.

[0061] Suitable non-limiting examples of TC / EI filler materials include nitrides, metal oxides, metalloid oxides, metal hydroxides, arsenides, carbides, minerals, ceramics, and diamonds. For example, TC / EI filler materials include, essentially consist of, or may consist of, boron nitride, silicon nitride, aluminum nitride, boron arsenide, aluminum oxide, magnesium oxide, calcined magnesium oxide, beryllium oxide, silicon dioxide, titanium oxide, zinc oxide, nickel oxide, copper oxide, tin oxide, aluminum hydroxide, magnesium hydroxide, boron arsenide, silicon carbide, agate, emery, ceramic microspheres, diamond, or any combination thereof. Non-limiting examples of commercially available boron nitride TC / EI filler materials include, for example, CarboTherm from Saint-Gobain, CoolFlow and PolarTherm from Momentive, and hexagonal boron nitride powder available from Panadyne; examples of aluminum nitride include, for example, aluminum nitride powder available from Micron Metals Inc. and Toyalnite from Toyal; examples of aluminum oxide include, for example, Microgrit from Micro Abrasives, Nabalox from Nabaltec, Aeroxide from Evonik, and Alodur from Imerys; examples of calcined magnesium oxide include, for example, MagChem® P98 from Martin Marietta Magnesia Specialties; examples of aluminum hydroxide include, for example, APYRAL from Nabaltec GmbH and aluminum hydroxide from Sibelco; and examples of ceramic microspheres include, for example, ceramic microspheres from Zeeospheres Ceramics or 3M. These fillers can also be surface modified. For example, surface-modified magnesium oxide, available as PYROKISUMA 5301K from Kyowa Chemical Industry Co., Ltd. Alternatively, TC / EI filler materials may not contain any surface modifiers.

[0062] TC / EI filler materials may have any particle shape or geometric shape. For example, TC / EI filler materials may have regular or irregular shapes, such as spherical, elliptical, cubic, plate-like, needle-like (elongated or fibrous), rod-like, disc-like, prismatic, flake-like, irregular, rock-like, aggregates thereof, and any combination thereof.

[0063] The particles of the TC / EI filler material may have a reported average particle diameter of at least 0.01 microns, e.g., at least 2 microns, e.g., at least 10 microns, in at least one dimension, as reported by the manufacturer. The particles of the TC / EI filler material may have a reported average particle diameter of at least 100 microns or more, e.g., 100 microns or less, e.g., 50 microns or less, e.g., 40 microns or less, e.g., 25 microns or less, in at least one dimension. The particles of the TC / EI filler material may have reported average particle diameters of 0.01 to 100 microns, e.g., 0.01 to 50 microns, e.g., 0.01 to 40 microns, e.g., 0.01 to 25 microns, e.g., 2 to 100 microns, e.g., 2 to 50 microns, e.g., 2 to 40 microns, e.g., 2 to 25 microns, e.g., 10 to 100 microns, e.g., 10 to 50 microns, e.g., 10 to 40 microns, e.g., 1025 microns, e.g., 10 to 100 microns, e.g., 10 to 100 microns, e.g., 0.01 to 50 microns, e.g., 0.01 to 40 microns, e

[0064] The particles of the TC / EI filler material in the electrodepositable coating composition may have a reported Mohs hardness of at least 1 (based on the Mohs hardness scale), for example, at least 2, for example, at least 3. The particles of the TC / EI filler material in the electrodepositable coating composition may have a reported Mohs hardness of 10 or less, for example, 8 or less, for example, 7 or less. The particles of the TC / EI filler material in the electrodepositable coating composition may have a reported Mohs hardness of 1 to 10, for example, 2 to 8, for example, 3 to 7.

[0065] As used herein, “flame retardant” refers to a material that slows or stops the spread of fire or reduces its intensity. Flame retardants may be available as a powder that can be mixed with a composition, foam, or gel. For example, if a composition of the present disclosure contains a flame retardant, such a composition may form a coating on a substrate surface, and such a coating may function as a flame retardant.

[0066] As described in detail below, flame retardants may include minerals, organic compounds, organic halogen compounds, organophosphorus compounds, or combinations thereof.

[0067] Suitable examples of minerals include huntite, hydromagnesite, various hydrates, red phosphorus, boron compounds such as borates, carbonates such as calcium carbonate and magnesium carbonate, and combinations thereof.

[0068] Suitable examples of organic halogen compounds include organochlorines such as chlorendic acid derivatives and chlorinated paraffins, organic bromines such as decabromodiphenyl ether (decaBDE) and decabromodiphenylethane (a substitute for decaBDE), and polymer brominated compounds such as brominated polystyrene, brominated carbonate oligomers (BCO), brominated epoxy oligomers (BEO), tetrabromophthalic anhydride, tetrabromobisphenol A (TBBPA), and hexabromocyclododecane (HBCD). Such halogenated flame retardants can be used in combination with synergists to enhance their efficiency. Other suitable examples include antimony trioxide, antimony pentoxide, and sodium antimonate.

[0069] Suitable examples of organophosphorus compounds include triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP), bisphenol A diphenyl phosphate (BADP), and tricresyl phosphate (TCP); phosphonates such as dimethylmethyl phosphonate (DMMP); and phosphinates such as aluminum diethyl phosphate. In one important class of flame retardants, compounds contain both phosphorus and halogens. Such compounds include tris(2,3-dibromopropyl) phosphate (brominated tris), and chlorinated organic phosphates such as tris(1,3-dichloro-2-propyl) phosphate (chlorinated tris or TDCPP) and tetrakis(2-chloroethyl(2-chlorethyl))dichloroisopentyl diphosphate (V6).

[0070] Suitable examples of organic compounds include carboxylic acids, dicarboxylic acids, melamines, and organic nitrogen compounds.

[0071] Other suitable flame retardants include ammonium polyphosphate and barium sulfate.

[0072] According to this disclosure, pigments may have any particle shape or geometric shape. For example, pigments may have regular or irregular shapes, such as spherical, elliptical, cubic, plate-like, needle-like (elongated or fibrous), rod-like, disc-like, prismatic, flake-like, irregular, rock-like, aggregates thereof, and any combination thereof.

[0073] The pigment may have a reported average particle size of at least 0.01 microns, e.g., at least 2 microns, e.g., at least 10 microns, in at least one dimension, as reported by the manufacturer. The pigment may have a reported average particle size of at least 100 microns or more, e.g., 100 microns or less, e.g., 50 microns or less, e.g., 40 microns or less, e.g., 25 microns or less, in at least one dimension. The pigments may have reported average particle sizes of 0.01 to 100 microns, e.g., 0.01 to 50 microns, e.g., 0.01 to 40 microns, e.g., 0.01 to 25 microns, e.g., 2 to 100 microns, e.g., 2 to 50 microns, e.g., 2 to 40 microns, e.g., 2 to 25 microns, e.g., 10 to 100 microns, e.g., 10 to 50 microns, e.g., 10 to 40 microns, e.g., 1025 microns, e.g., 10 to 25 microns, e.g., 10 to 25 microns, e.g., 10 to 25 microns, e.g., 10 to 100 microns, e.g., 0.01 to 50 micro

[0074] According to this disclosure, the electrodepositable coating composition is substantially free of, essentially free of, or completely free of metallic pigments.

[0075] According to this disclosure, the electrodepositable coating composition is substantially free of, essentially free of, or completely free of electrically conductive pigments.

[0076] According to this disclosure, the electrodepositable coating composition may optionally further include pigment dispersion additives that function to improve pigment dispersion and increase the viscosity of the electrodepositable binder and the electrodepositable coating composition. The improvement in pigment dispersion can be demonstrated by a reduction in the pigment grinding time or energy required to achieve a Hegman reading of at least 5.

[0077] As used herein, the terms “dispersed pigment” or “pigment dispersion” refer to a pigment that has been deaggregated in a liquid medium. The degree of pigment dispersion and / or deaggregation can be measured using a Hegman gauge.

[0078] Pigment dispersion additives may optionally include phyllosilicate pigment dispersants. As used herein, the term “phyllosilicate pigment dispersant” refers to a material that can form a chemical complex with a phyllosilicate pigment and may help to promote the dispersion of the phyllosilicate pigment. The complex may be referred to as a phyllosilicate pigment dispersant-phyllosilicate pigment complex.

[0079] Alternatively, an electrodepositable coating composition may be substantially free of, essentially free of, or completely free of phylrosilicate pigment dispersants. As used herein, an electrodepositable coating composition is substantially free of phylrosilicate pigment dispersants if, if present, they are present in an amount of less than 1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is essentially free of phylrosilicate pigment dispersants if, if present, they are present in an amount of less than 0.1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is completely free of phylrosilicate pigment dispersants if they are not present in the composition, i.e., 0.00% by weight based on the total solids weight of the composition.

[0080] Alternatively, the electrodepositable coating composition may be substantially free of, essentially free of, or completely free of phylrosilicate pigment dispersant-phylrosilicate pigment complexes. As used herein, the electrodepositable coating composition is substantially free of phylrosilicate pigment dispersant-phylrosilicate pigment complexes if, at all, they are present in an amount of less than 1% by weight based on the total solids weight of the composition. As used herein, the electrodepositable coating composition is essentially free of phylrosilicate pigment dispersant-phylrosilicate pigment complexes if, at all, they are present in an amount of less than 0.1% by weight based on the total solids weight of the composition. When used herein, an electrodepositable coating composition is completely free of the phylrosilicate pigment dispersant-phylrosilicate pigment complex if the phylrosilicate pigment dispersant-phylrosilicate pigment complex is not present in the composition, i.e., if it is 0.00% by weight based on the total solids weight of the composition.

[0081] As used herein, the dispersion additive may include a material capable of forming a chemical complex with the pigment, and the pigment dispersion additive may optionally include a material capable of forming a chemical complex with the pigment, or a material that has physical interactions with the pigment, and may optionally form a pigment dispersion additive-pigment complex.

[0082] Pigment dispersion additives may include pigment dispersion acids. In cationic electrodepositable coating compositions, pigment dispersion acids are present in addition to any solubilizing acids used to disperse and / or solubilize the resin component of the electrodepositable binder and / or the acid added to adjust the pH of the composition, and the pigment dispersion acids may form chemical complexes or physical interactions with the pigment. Pigment dispersion acids may be monobasic or polybasic acids. As used herein, the term "polybasic acid" refers to a chemical compound having two or more acidic protons. As used herein, the term "acidic proton" refers to a proton that forms part of an acid group, including, but not limited to, phosphorus oxyacids, carboxylic acids, and sulfur oxyacids.

[0083] The pigment dispersing acid may contain a first acidic proton having a pKa of at least 1.1, for example, at least 1.5, for example, at least 1.8. The pigment dispersing acid may contain a first acidic proton having a pKa of 4.6 or less, for example, 4.0 or less, for example, 3.5 or less. The pigment dispersing acid may contain a first acidic proton having a pKa of 1.1 to 4.6, for example, 1.5 to 4.0, for example, 1.8 to 3.5.

[0084] The pigment dispersing acid may include carboxylic acids, phosphorus oxyacids (such as phosphoric acid or phosphonic acid), or combinations thereof.

[0085] The weight ratio of pigment to pigment dispersion additive to moles may be at least 0.25 g / mmol, for example, at least 0.5 g / mmol, for example, at least 1.0 g / mmol, for example, at least 1.5 g / mmol, for example, at least 1.75 g / mmol. The weight ratio of pigment to pigment dispersion additive to moles may be 25 g / mmol or less, for example, 15 g / mmol or less, for example, 10 g / mmol or less, for example, 8.25 g / mmol or less, for example, 6.5 g / mmol or less, for example, 5.0 g / mmol or less. The weight ratio of pigment dispersion additive to moles of pigment is 0.25~25 g / mmol, for example, 0.25~15 g / mmol, for example, 0.25~10 g / mmol, for example, 0.25~8.25 g / mmol, for example, 0.25~6.5 g / mmol, for example, 0.25~5.0 g / mmol, for example, 0.5~25 g / mmol, for example, 0.5~15 g / mmol, for example, 0.5~10 g / mmol, for example, 0.5~8.25 g / mmol, for example, 0.5~6.5 g / mmol, for example, 0.5~5.0 g / mmol, for example, 1~25 g / mmol, for example, 1~15 g / mmol, for example, 1~10 g / The amount can be mmol, for example, 1-8.25 g / mmol, for example, 1-6.5 g / mmol, for example, 1-5.0 g / mmol, for example, 1.5-25 g / mmol, for example, 1.5-15 g / mmol, for example, 1.5-10 g / mmol, for example, 1.5-8.25 g / mmol, for example, 1.5-6.5 g / mmol, for example, 1.5-5.0 g / mmol, for example, 1.75-25 g / mmol, for example, 1.75-15 g / mmol, for example, 1.75-10 g / mmol, for example, 1.75-8.25 g / mmol, for example, 1.75-6.5 g / mmol, for example, 1.75-5.0 g / mmol.

[0086] The pigment-to-binder (P:B) ratio as described herein may refer to the weight ratio of pigment to binder in an electrodepositable coating composition, and / or the weight ratio of pigment to binder in a deposited wet film, and / or the weight ratio of pigment to binder in a dry, uncured deposited film, and / or the weight ratio of pigment to binder in a cured film. The pigment-to-binder (P:B) ratio of the pigment to the electrodepositable binder may be at least 0.30:1, e.g., at least 0.35:1, e.g., at least 0.40:1, e.g., at least 0.50:1, e.g., at least 0.60:1, e.g., at least 0.75:1, e.g., at least 1:1, e.g., at least 1.25:1, e.g., at least 1.5:1. The pigment-to-binder (P:B) ratio of the electrodepositable binder for the pigment may be 2.0:1 or less, for example, 1.75:1 or less, for example, 1.5:1 or less, for example, 1.25:1 or less, for example, 1:1 or less, for example, 0.75:1 or less, for example, 0.70:1 or less, for example, 0.60:1 or less, for example, 0.55:1 or less, for example, 0.50:1 or less. The pigment-to-binder ratio (P:B) of the pigment to the electrodepositable binder is 0.3:1 to 2.0:1, for example, 0.3:1 to 1.75:1, for example, 0.3:1 to 1.50:1, for example, 0.3:1 to 1.25:1, for example, 0.3:1 to 1:1, for example, 0.3:1 to 0.75:1, for example, 0.3:1 to 0.70:1, for example, 0.3:1 to 0.60:1, for example, 0.3:1 to 0.55:1, for example, 0.3:1 to 0.50:1, for example, 0.35:1 to 2.0:1, for example, 0.35:1 to 1.75:1, for example, 0.35:1 to 1.50:1, for example, 0.35 :1~1.25:1, for example, 0.35:1~1:1, for example, 0.35:1~0.75:1, for example, 0.35:1~0.70:1, for example, 0.35:1~0.60:1, for example, 0.35:1~0.55:1, for example, 0.35:1~0.50:1, for example, 0.4:1~2.0:1, for example, 0.4:1~1.75:1, for example, 0.4:1~1.50:1, for example, 0.4:1~1.25:1, for example, 0.4:1~1:1, for example, 0.4:1~0.75:1, for example, 0.4:1~0.70:1, for example, 0.4:1~0.60:1, for example, 0.4:1~0.55:1, for example, 0.4:1~0.50:1, for example, 0.5:1~2.0:1, for example, 0.5:1~1.75:1, for example, 0.5:1~1.50:1, for example, 0.5:1~1.25:1, for example, 0.5:1~1:1, for example, 0.5:1~0.75:1, for example, 0.5:1~0.70:1, for example, 0.5:1~0.60:1, for example, 0.5:1~0.55:1, for example, 0.6:1~2.0:1, for example, 0.6:1~1.75:1, for example, 0.6:1~1.50:1, for example, 0.6:1~1.25:1, for example, 0.6:1~1:1, for example, 0.6 Possible values ​​include: 1~0.75:1, for example, 0.6:1~0.70:1, for example, 0.75:1~2.0:1, for example, 0.75:1~1.75:1, for example, 0.75:1~1.50:1, for example, 0.75:1~1.25:1, for example, 0.75:1~1:1, for example, 1:1~2.0:1, for example, 1:1~1.75:1, for example, 1:1~1.50:1, for example, 1:1~1.25:1, for example, 1.25:1~2.0:1, for example, 1.25:1~1.75:1, for example, 1.25:1~1.50:1, for example, 1.50:1~2.0:1, for example, 1.50:1~1.75:1.

[0087] The pigment dispersion additive may be present in an amount of at least 0.1% by weight, for example, at least 0.3% by weight, for example, at least 0.5% by weight, for example, at least 0.7% by weight, for example, at least 0.8% by weight, for example, at least 1% by weight, based on the total solids weight of the composition. The pigment dispersion additive may be present in an amount of 10% by weight or less, for example, 7.5% by weight or less, for example, 5% by weight or less, for example, 3% by weight or less, for example, 2% by weight or less, for example, 1.5% by weight or less, for example, 1% by weight or less, for example, 0.8% by weight or less, based on the total solids weight of the composition.The pigment dispersion additive is present in amounts of 0.1% to 10% by weight, for example, 0.1% to 7.5% by weight, for example, 0.1% to 5% by weight, for example, 0.1% to 3% by weight, for example, 0.1% to 2% by weight, for example, 0.1% to 1.5% by weight, for example, 0.1% to 1% by weight, for example, 0.1% to 0.8% by weight, for example, 0.3% to 10% by weight, for example, 0.3% to 7.5% by weight, for example, 0.3% by weight. ~5% by weight, e.g., 0.3% by weight ~ 3% by weight, e.g., 0.3% by weight ~ 2% by weight, e.g., 0.3% by weight ~ 1.5% by weight, e.g., 0.3% by weight ~ 1% by weight, e.g., 0.3% by weight ~ 0.8% by weight, e.g., 0.5% by weight ~ 10% by weight, e.g., 0.5% by weight ~ 7.5% by weight, e.g., 0.5% by weight ~ 5% by weight, e.g., 0.5% by weight ~ 3% by weight, 0.5% by weight ~ 2% by weight, e.g., 0.5% by weight ~ 1.5% by weight, e.g., 0.5% by weight ~ 1% by weight Amount in percent, for example, 0.5% by weight to 0.8% by weight, for example, 0.7% by weight to 10% by weight, for example, 0.7% by weight to 7.5% by weight, for example, 0.7% by weight to 5% by weight, for example, 0.7% by weight to 3% by weight, for example, 0.7% by weight to 2% by weight, for example, 0.7% by weight to 1.5% by weight, for example, 0.7% by weight to 1% by weight, for example, 0.7% by weight to 0.8% by weight, for example, 0.8% by weight to 10% by weight, for example, 0.8% by weight to 7.5% by weight, for example, 0.8% by weight It can exist in quantities of %~5% by weight, for example, 0.8%~3% by weight, for example, 0.8%~2% by weight, for example, 0.8%~1.5% by weight, for example, 0.8%~1% by weight, for example, 1%~10% by weight, for example, 1%~7.5% by weight, for example, 1%~5% by weight, for example, 1%~3% by weight, for example, 1%~2% by weight, for example, 1%~1.5% by weight, for example, 1%~1% by weight, for example, 1%~0.8% by weight.

[0088] According to this disclosure, an electrodepositable coating composition may be substantially free of, essentially free of, or completely free of a pigment dispersant. As used herein, an electrodepositable coating composition is substantially free of a pigment dispersant if, if present, it is present in an amount of less than 1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is essentially free of a pigment dispersant if, if present, it is present in an amount of less than 0.1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is completely free of a pigment dispersant if, i.e., it is not present in the composition, i.e., it is 0.00% by weight based on the total solids weight of the composition.

[0089] According to this disclosure, an electrodepositable coating composition may be substantially free of, essentially free of, or completely free of pigment-dispersing acids. As used herein, an electrodepositable coating composition is substantially free of pigment-dispersing acids if, if present, they are present in an amount of less than 1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is essentially free of pigment-dispersing acids if, if present, they are present in an amount of less than 0.1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is completely free of pigment-dispersing acids if they are not present in the composition, i.e., they are present in an amount of 0.00% by weight based on the total solids weight of the composition.

[0090] According to this disclosure, an electrodepositable coating composition may be substantially free of, essentially free of, or completely free of a silane dispersant. As used herein, an electrodepositable coating composition is substantially free of a silane dispersant if, if present, it is present in an amount of less than 1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is essentially free of a silane dispersant if, if present, it is present in an amount of less than 0.1% by weight based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is completely free of a silane dispersant if it is not present in the composition, i.e., it is present in an amount of 0.00% by weight based on the total solids weight of the composition.

[0091] According to this disclosure, the electrodepositable coating composition may be substantially free of, essentially free of, or completely free of electrically conductive particles. Electrically conductive particles may include any particles capable of conducting electricity. As used herein, electrically conductive particles are defined as materials having at least 1 × 10⁻⁶ particles. 5 Conductivity of S / m and 1 × 10 at 20°C 6A material is "capable of conducting electricity" if it has a resistivity of Wm or less. Electrically conductive particles may include carbonaceous materials such as activated carbon, carbon black such as acetylene black and furnace black, graphene, carbon nanotubes including single-walled carbon nanotubes and / or multi-walled carbon nanotubes, carbon fibers, fullerenes, metal particles, and combinations thereof. As used herein, an electrodepositable coating composition is substantially free of electrically conductive particles if the electrically conductive particles are present in an amount of less than 5% by weight based on the total weight of the pigments in the composition. As used herein, an electrodepositable coating composition is essentially free of electrically conductive particles if the electrically conductive particles are present in an amount of less than 1% by weight based on the total weight of the pigments in the composition. As used herein, an electrodepositable coating composition is completely free of electrically conductive particles if the electrically conductive particles are not present in the composition, i.e., 0.00% by weight based on the total weight of the pigments in the composition.

[0092] According to this disclosure, an electrodepositable coating composition may be substantially free of metal particles, essentially free of them, or not at all free of them. As used herein, the term “metal particles” refers to metal pigments and metal alloy pigments consisting primarily of metals in their elemental (zero-valent) state. Examples of metal particles include zinc, aluminum, cadmium, magnesium, beryllium, copper, silver, gold, iron, titanium, nickel, manganese, chromium, scandium, yttrium, zirconium, platinum, tin, and their alloys, as well as various grades of steel. As used herein, an electrodepositable coating composition is substantially free of metal particles if the metal particles are present in an amount less than 5% by weight based on the total weight of the pigments in the composition. As used herein, an electrodepositable coating composition is essentially free of metal particles if the metal particles are present in an amount less than 1% by weight based on the total weight of the pigments in the composition. As used herein, an electrodepositable coating composition is completely free of metal particles if the metal particles are not present in the composition, i.e., 0.00% by weight based on the total weight of the pigments in the composition.

[0093] According to this disclosure, an electrodepositable coating composition may be substantially free of, essentially free of, or completely free of lithium-containing compounds. As used herein, a lithium-containing compound refers to a lithium-containing compound or complex, such as LiCoC, LiNiC, LiFePO4, LiCoPCO4, LiMnO2, LiMn2O4, Li(NiMnCo)O2, and Li(NiCoAl)O2. As used herein, an electrodepositable coating composition is "substantially free" of lithium-containing compounds if the lithium-containing compound is present in the electrodepositable coating composition in an amount of less than 1% by weight, based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is "essentially free" of lithium-containing compounds if the lithium-containing compound is present in the electrodepositable coating composition in an amount of less than 0.1% by weight, based on the total solids weight of the composition. As used herein, an electrodepositable coating composition is "completely lithium-free" if the lithium-containing compound is not present in the electrodepositable coating composition, i.e., <0.001% based on the total solids weight of the composition.

[0094] According to this disclosure, an electrodepositable coating composition may optionally be substantially free of, essentially free of, or completely free of pulverized resin. As used herein, the term “pulverized resin” refers to a resin that is chemically distinct from the main film-forming polymer used in grinding the pigment to form a pigment paste, apart from the main film-forming polymer of the binder. For example, the pulverized resin may contain a quaternary ammonium base and / or a tertiary sulfonium group. As used herein, an electrodepositable coating composition is substantially free of pulverized resin if, if present, it is present in an amount of 5% by weight or less based on the total resin solids weight of the composition. As used herein, an electrodepositable coating composition is essentially free of pulverized resin if, if present, it is present in an amount of 3% by weight or less based on the total resin solids weight of the composition. As used herein, an electrodepositable coating composition is completely free of pulverized resin if, i.e., it is not present in the composition, i.e., it is present in an amount of 0.00% by weight based on the total resin solids weight of the composition.

[0095] The electrodepositable coating compositions according to this disclosure may optionally comprise one or more further components in addition to the ionic base-containing film-forming polymer and curing agent described above.

[0096] According to this disclosure, electrodepositable coating compositions may optionally include a catalyst for catalyzing the reaction between the curing agent and the polymer. Examples of catalysts suitable for cationic electrodepositable coating compositions include, but are not limited to, organotin compounds (e.g., dibutyltin oxide and dioctyltin oxide) and their salts (e.g., dibutyltin diacetate); other metal oxides (e.g., oxides of cerium, zirconium, and bismuth) and their salts (e.g., bismuth sulfamate and bismuth lactate); or cyclic guanidines as described in U.S. Patent No. 7,842,762, column 1, line 53 to column 4, line 18 and column 16, line 62 to column 19, line 8 (these cited portions are incorporated herein by reference). Examples of catalysts suitable for anionic electrodepositionable coating compositions include latent acid catalysts, specific examples of which are specified in WO2007 / 118024

[0031] , and include, but are not limited to, ammonium hexafluoroantimonate, quaternary salts of SbF6 (e.g., NACURE® XC-7231), t-amine salts of SbF6 (e.g., NACURE® XC-9223), Zn salts of trifluic acid (e.g., NACURE® A202 and A218), quaternary salts of trifluic acid (e.g., NACURE® XC-A230), and diethylamine salts of trifluic acid (e.g., NACURE® A233) (all commercially available from King Industries), and / or mixtures thereof. Latent acid catalysts can be formed by preparing derivatives of acid catalysts such as p-toluenesulfonic acid (pTSA) or other sulfonic acids. For example, a well-known group of blocked acid catalysts are amine salts of aromatic sulfonic acids, such as pyridinium-p-toluenesulfonate. Such sulfonates have lower activity than free acids in promoting crosslinking. During curing, the catalyst can be activated by heating.

[0097] According to this disclosure, the electrodepositable coating composition may optionally include a rheological modifier. As used herein, the term “rheological modifier” refers to a material that, when added to an electrodepositable coating composition, modifies the rheological properties of a fluid, such as imparting shear-thinning properties, shear-thickening properties, thixotropic properties, etc. Rheological modifiers can help prevent the settling of the electrodepositable coating composition, and they can further improve the uniformity of the electrodeposited coating produced by electrodepositing the electrodepositable coating composition. Rheological modifiers may include, for example, one or more cellulose derivatives, one or more alkali-swelling rheological modifiers, one or more acid-swelling rheological modifiers, one or more hydrophobic-modified urethane-ethoxylate (HEUR)-associating thickeners, colloidal layered silicates, smectite clay, fumed silica, and the like.

[0098] Cellulose derivatives may include any known in the art for modifying the rheology of electrodepositable coating compositions. For example, cellulose derivatives may include carboxymethylcellulose and its salts, microcrystalline cellulose, nanocrystalline cellulose, and other cellulosic compounds. A non-limiting example of a suitable commercially available cellulosic compound is CRYSTOcellulose, available from Renmatix, Inc., which is a highly crystalline cellulose derivative with a particle size in the range of 0.5 to 1.5 pm, providing properties of both microcrystalline cellulose and highly nanocrystalline cellulose in parallel.

[0099] Rheology modifiers may include alkali-swelling rheology modifiers. Non-limiting examples of alkali-swelling rheology modifiers include alkali-swelling emulsions (ASEs), hydrophobic-modified alkali-swelling emulsions (HASEs), ATRP star polymers, and other materials that provide pH-triggered rheological changes at low pH. Commercially available alkali-swelling rheology modifiers include alkali-swelling emulsions (ASEs) such as ACRYSOL® ASE60, hydrophobic-modified alkali-swelling emulsions (HASEs) such as ACRYSOL® HASE TT-615 and ACRYSOL® DR-180 HASE (each of which is available from Dow Chemical Company), and ATRP star polymers such as fracASSIST® Prototype 2. ACRYSOL ASE alkali-swelling rheology modifiers contain copolymers of (meth)acrylic acid and acrylate esters in a ratio of approximately 2:1 to 1:2, for example, 1.5:1 to 1:1.5, for example, approximately 1.1:1 to 1:1.1, for example, approximately 1:1. ACRYSOL ASE alkali-swelling rheology modifiers contain tertiary polymers containing (meth)acrylic acid and acrylate ester copolymers used in the ASE family modified with hydrophobic acrylic ester monomers. When the acid is not neutralized at a low pH, the rheology modifier is insoluble in water and does not thicken the composition; however, when the acid is completely neutralized at a higher pH, the rheology modifier becomes soluble and thickens the composition.

[0100] Rheology modifiers may include hydrophobic group-modified urethane-ethoxylate (HEUR)-associating thickeners. Non-limiting examples of hydrophobic group-modified urethane-ethoxylate (HEUR)-associating thickeners include, but are not limited to, products sold by Borchers Americas Inc. under the BORCHI Gel mark.

[0101] The rheology modifier may include a colloidal layered silicate. Examples of colloidal layered silicates suitable for use in the electrodepositable coating compositions described herein include, for example, LAPONITE RD, LAPONITE RDS, LAPONITE XL21, and LAPONITE JS, including combinations thereof. LAPONITE RD is a free-flowing synthetic layered silicate having a bulk density of 1,000 kg / m 3 and a surface area (BET) of 370 m 2 / g and a pH of 9.8 for a 2% suspension in water. The composition is 59.5% SiO2, 27.5% MgO, 0.8% Li2O, and 2.8% Na2O on a dry weight basis. LAPONITE RDS is also a free-flowing synthetic layered silicate having a bulk density of 1,000 kg / m 3 and a surface area (BET) of 330 m 2 / g and a pH of 9.7 for a 2% suspension in water. The composition is 54.5% SiO2, 26.0% MgO, 0.8% Li2O, 5.6% Na2O, and 4.1% P2O5 on a dry weight basis. LAPONITE XL21 is magnesium sodium fluorosilicate. The particle size of the colloidal layered silicate such as those described above can be 1 nm to 2 μm in average diameter. Suitable methods for measuring the particle sizes disclosed herein include, for example, transmission electron microscopy (TEM). A suitable method for measuring the clay particle size by TEM includes suspending the particles in a solvent and then drop-casting the suspension onto a TEM grid dried under ambient conditions. For example, the clay particles may be diluted with water for drop-casting, and measurements can be obtained from images acquired from a Tecnai T20 TEM operating at 200 kV and analyzed using ImageJ software, or equivalent solvents, equipment, and software.

[0102] As used herein, the term "smectite clay" refers to a clay having a variable net negative charge balanced by a positive charge adsorbed externally on the interlayer surface.

[0103] As used herein, the term "acid-swelling rheological modifier" refers to a rheological modifier that is insoluble at high pH and does not thicken the composition, and is soluble at low pH and thickens the composition.

[0104] Rheological modifiers may include fumed silica. Fumed silica is produced by flame decomposition of silicon tetrachloride or from quartz sand and evaporated by an electric arc at 3000°C. Non-limiting examples of suitable fumed silica are those available from Evonik Resource Efficiency GmbH (marketed under the name AEROSIL), Cabot Corporation (Cab-O-Sil), Wacker Chemie (HDK), Dow Corning, Heraeus (Zandosil), Tokuyama Corporation (Reolosil), OCI (Konasil), Orisil (Orisil), and Xunyuchem (XYSIL).

[0105] The rheological modifier may be present in an amount of 0.5% by weight, for example, at least 1% by weight, for example, at least 2% by weight, for example, at least 2.5% by weight, based on the total weight of the resin solids in the electrodepositable coating composition. The rheological modifier may be present in an amount of 15% by weight or less, for example, 10% by weight or less, for example, 8% by weight or less, for example, 5% by weight or less, based on the total weight of the resin solids in the electrodepositable coating composition. The rheological modifier may be present in amounts of 0.5% to 15% by weight, for example, 0.5% to 10% by weight, for example, 0.5% to 8% by weight, for example, 0.5% to 5% by weight, for example, 1% to 15% by weight, for example, 1% to 10% by weight, for example, 1% to 8% by weight, for example, 1% to 5% by weight, for example, 2% to 15% by weight, for example, 2% to 10% by weight, for example, 2% to 8% by weight, for example, 2% to 5% by weight, for example, 2.5% to 15% by weight, for example, 2.5% to 10% by weight, for example, 2.5% to 8% by weight, for example, 2.5% to 5% by weight, based on the total weight of the resin solids content of the electrodepositable coating composition.

[0106] According to this disclosure, the electrodepositable coating compositions of this disclosure may optionally include crater control additives that can be incorporated into the coating composition, such as polyalkylene oxide polymers which may contain copolymers of butylene oxide and propylene oxide. According to this disclosure, the molar ratio of butylene oxide to propylene oxide may be at least 1:1, for example, at least 3:1, for example, at least 5:1, and may optionally be 50:1 or less, for example, 30:1 or less, for example, 20:1 or less. According to this disclosure, the molar ratio of butylene oxide to propylene oxide may be 1:1 to 50:1, for example, 3:1 to 30:1, for example, 5:1 to 20:1.

[0107] Polyalkylene oxide polymers may contain at least two hydroxyl functional groups and may be monofunctional, difunctional, trifunctional, or tetrafunctional. As used herein, “hydroxyl functional group” includes an -OH group. For clarity, polyalkylene oxide polymers may contain additional functional groups in addition to hydroxyl functional groups. As used herein, “monofunctional” means a monomer or polymer containing one (1) hydroxyl functional group per molecule when used in relation to the number of hydroxyl functional groups contained in a particular monomer or polymer. As used herein, “difunctional” means a monomer or polymer containing two (2) hydroxyl functional groups per molecule when used in relation to the number of hydroxyl functional groups contained in a particular monomer or polymer. As used herein, “trifunctional” means a monomer or polymer containing three (3) hydroxyl functional groups per molecule when used in relation to the number of hydroxyl functional groups contained in a particular monomer or polymer. As used herein, "tetrafunctional" means a monomer or polymer containing four (4) hydroxyl functional groups per molecule, when used in relation to the number of hydroxyl functional groups contained in a particular monomer or polymer.

[0108] The hydroxyl equivalent of a polyalkylene oxide polymer may be at least 100 g / mol, for example, at least 200 g / mol, for example, at least 400 g / mol, and may be 2,000 g / mol or less, for example, 1,000 g / mol or less, for example, 800 g / mol or less. The hydroxyl equivalent of a polyalkylene oxide polymer may be between 100 g / mol and 2,000 g / mol, for example, between 200 g / mol and 1,000 g / mol, for example, between 400 g / mol and 800 g / mol. As used herein, with respect to a polyalkylene oxide polymer, "hydroxyl equivalent" is determined by dividing the molecular weight of the polyalkylene oxide polymer by the number of hydroxyl groups present in the polyalkylene oxide polymer.

[0109] The polyalkylene oxide polymer has a z-average molecular weight (M) of at least 200 g / mol, for example, at least 400 g / mol, for example, at least 600 g / mol. z ) may have a z-average molecular weight of 5,000 g / mol or less, for example, 3,000 g / mol or less, for example, 2,000 g / mol or less. According to this disclosure, polyalkylene oxide polymers may have a z-average molecular weight of 200 g / mol to 5,000 g / mol, for example, 400 g / mol to 3,000 g / mol, for example, 600 g / mol to 2,000 g / mol. When used herein, a z-average molecular weight of less than 900,000 (M z Regarding polyalkylene oxide polymers having ) "z average molecular weight (M z The term ) refers to the z-average molecular weight (M) determined by a Waters 2695 separation module with a Waters 410 differential refractometer (RI detector), polystyrene standards with molecular weights of approximately 500 g / mol to 900,000 g / mol, tetrahydrofuran (THF) with 0.05 M lithium bromide (LiBr) as the eluent at a flow rate of 0.5 mL / min, and one Asahipak GF-510 HQ column for separation. z ) means.

[0110] Polyalkylene oxide polymers may be present in the electrodepositable coating composition in an amount of at least 0.1% by weight, e.g., at least 0.5% by weight, e.g., at least 0.75% by weight, based on the total weight of the resin blend solids, and may optionally be present in the electrodepositable coating composition in an amount of 10% by weight or less, e.g., 4% by weight or less, e.g., 3% by weight or less, based on the total weight of the resin blend solids. Polyalkylene oxide polymers may be present in the electrodepositable coating composition in an amount of 0.1% to 10% by weight, e.g., 0.5% to 4% by weight, e.g., 0.75% to 3% by weight, based on the total weight of the resin blend solids.

[0111] According to this disclosure, the electrodepositable coating composition may include other optional components such as a pigment composition, and, if desired, various additives, such as fillers, plasticizers, antioxidants, biocides, UV light absorbers and stabilizers, hindered amine light stabilizers, defoamers, fungicides, dispersants, flow control agents, surfactants, wetting agents, or combinations thereof. Alternatively, the electrodepositable coating composition may not contain any of the optional components at all, i.e., the optional components are not present in the electrodepositable coating composition. The other additives described above may be present in the electrodepositable coating composition in amounts of 0.01% to 3% by weight, based on the total weight of the resin solids content of the electrodepositable coating composition.

[0112] According to this disclosure, the electrodepositable coating composition comprises an aqueous medium containing water and, optionally, one or more organic solvents. The aqueous medium is present in an amount of, for example, 40% to 90% by weight, or 50% to 75% by weight, based on the total weight of the electrodepositable coating composition. Examples of suitable organic solvents include oxygenated organic solvents, such as ethylene glycol, diethylene glycol, propylene glycol, and monoalkyl ethers of dipropylene glycol containing 1 to 10 carbon atoms in the alkyl group, such as monoethyl and monobutyl ethers of these glycols. Examples of other at least partially water-miscible solvents include alcohols such as ethanol, isopropanol, butanol, and diacetone alcohol. When used, the organic solvent may typically be present in an amount of less than 10% by weight, or less than 5% by weight, based on the total weight of the electrodepositable coating composition. The electrodepositable coating composition may be provided in particular in the form of a dispersion, such as an aqueous dispersion.

[0113] For example, the organic solvent may include an ether or polyether containing a hydroxyl group and a terminal group having structure-OR, where R is a C1-C8 alkyl group, e.g., a C1-C4 alkyl group, e.g., a C1-C3 alkyl group, or two terminal hydroxyl groups. The polyether may include homopolymers, block copolymers, or random copolymers. For example, the polyether may include a homopolymer of ethylene oxide or propylene oxide, or the polyether may include a block or random copolymer containing combinations of ethylene oxide and propylene oxide in a block or random pattern. Such an organic solvent may include the following structures: [ka] In the formula, R1 and R2 are each hydrogen, or one of R1 and R2 is hydrogen and the other is a methyl group, R3 is H or a C1-C8 alkyl group, e.g., a C1-C4 alkyl group, e.g., a C1-C3 alkyl group, and n is an integer from 1 to 50, e.g., 1 to 40, e.g., 1 to 30, e.g., 1 to 20, e.g., 1 to 12, e.g., 1 to 8, e.g., 1 to 6, e.g., 1 to 4, e.g., 2 to 50, e.g., 2 to 40, e.g., 2 to 30, e.g., 2 to 20, e.g., 2 to 12, e.g., 2 to 8, e.g., 2 to 6, e.g., 2 to 4, e.g., 3 to 50, e.g., 3 to 40, e.g., 3 to 30, e.g., 3 to 20, e.g., 3 to 12, e.g., 3 to 8, e.g., 3 to 6, e.g., 3 to 4.

[0114] According to this disclosure, the total solids content of the electrodepositable coating composition may be at least 1% by weight, for example, at least 5% by weight, and may be 50% by weight or less, for example, 40% by weight or less, for example, 20% by weight or less, based on the total weight of the electrodepositable coating composition. The total solids content of the electrodepositable coating composition may be 1% to 50% by weight, for example, 5% to 40% by weight, for example, 5% to 20% by weight, based on the total weight of the electrodepositable coating composition. As used herein, “total solids” refers to the non-volatile content of the electrodepositable coating composition, i.e., the material that does not volatilize when heated at 110°C for 15 minutes.

[0115] According to this disclosure, electrodepositable coating compositions can be applied to a substrate electrophoretically. Cationic electrodepositable coating compositions can be deposited electrophoretically on any electrically conductive substrate. Suitable substrates include metal substrates, metal alloy substrates, and / or metallized substrates such as nickel-plated plastics. In addition, substrates may include non-metallic conductive materials, such as composite materials including carbon fibers or materials containing conductive carbon. According to this disclosure, metals or metal alloys may include cold-rolled steel, hot-rolled steel, zinc-coated steel, zinc compounds, or zinc alloys, such as electro-galvanized steel, hot-dip galvanized steel, galvanized steel, and zinc alloy-plated steel. Aluminum alloys of the 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, or 7XXX series, as well as clad aluminum alloys and cast aluminum alloys of the A356 series, can also be used as substrates. Magnesium alloys of the AZ31B, AZ91C, AM60B, or EV31A series can also be used as substrates. Substrates used in this disclosure may also include titanium and / or titanium alloys. Other suitable non-ferrous metals include copper and magnesium, as well as alloys of these materials. Suitable metal substrates for use in this disclosure often include those used in the assembly of components for vehicle bodies (e.g., doors, body panels, trunk deck lids, roof panels, hoods, roofs and / or stringers, rivets, landing gear components, and / or body panels used in aircraft), vehicle frames, vehicle parts, motorcycles, wheels, industrial structures, and electrical appliances including washing machines, dryers, refrigerators, stoves, dishwashers, etc., agricultural equipment, lawn and garden equipment, air conditioning units, heat pump units, lawn furniture, and other articles. As used herein, “vehicle” or variations thereof include, but are not limited to, civil, commercial, and military aircraft, and / or land vehicles such as cars, motorcycles, and / or trucks. Metal substrates may also be, for example, in the form of metal sheets or fabricated parts.It will also be understood that the substrate may be pretreated with zirconium containing a pretreatment solution, such as a zinc phosphate pretreatment solution as described in U.S. Patent Nos. 4,793,867 and 5,588,989, or a pretreatment solution as described in U.S. Patent Nos. 7,749,368 and 8,673,091.

[0116] The Disclosure also relates to a method for coating a substrate, such as one of the conductive substrates described above. According to the Disclosure, such a method may include the steps of: electrophoretically depositing an electrodepositable coating composition as described above onto at least a portion of a substrate; and curing the coating composition to form at least a partially cured coating on the substrate. According to the Disclosure, the method may include (a) electrophoretically depositing an electrodepositable coating composition of the Disclosure onto at least a portion of a substrate; and (b) heating the coated substrate to a temperature and time sufficient to cure the electrodeposited coating on the substrate. According to the Disclosure, the method may optionally further include (c) directly applying one or more pigment-containing coating compositions and / or one or more pigment-free coating compositions to the at least partially cured electrodeposited coating to form a topcoat on at least a portion of the at least partially cured electrodeposited coating; and (d) heating the coated substrate of step (c) to a temperature and time sufficient to cure the topcoat.

[0117] According to this disclosure, the cationic electrodepositable coating composition of this disclosure may be deposited on an electrically conductive substrate by placing the composition in contact with an electrically conductive cathode and an electrically conductive anode, the surface to be coated being the cathode. After contact with the composition, when a sufficient voltage is applied between the electrodes, an adhesive film of the coating composition is deposited on the cathode. The conditions under which electrodeposition is carried out are generally the same as those used for electrodeposition of other types of coatings. The applied voltage can vary, from low voltages such as 1 volt to high voltages such as several thousand volts, e.g., 50 to 500 volts. The current density can be 0.5 to 15 amperes per square foot and tends to decrease during electrodeposition, indicating the formation of an insulating film.

[0118] Once a cationic electrodepositable coating composition is electrodeposited onto at least a portion of a conductive substrate, the coated substrate is heated to a temperature and time sufficient to at least partially cure the electrodeposited coating on the substrate. As used herein, the term “at least partially cured” with respect to a coating means a coating formed by subjecting the coating composition to curing conditions such that a chemical reaction occurs in which at least a portion of the reactive groups of the components of the coating composition to form the coating. The coated substrate may be heated to temperatures in the range of 250°F to 450°F (121.1°C to 232.2°C), for example, 275°F to 400°F (135°C to 204.4°C), for example, 300°F to 360°F (149°C to 180°C). The curing time may depend on the curing temperature and other variables, such as the film thickness of the electrodeposited coating, the level and type of catalyst present in the composition, etc. For the purposes of this disclosure, all that is required is a time sufficient to cure the coating on the substrate. For example, the curing time may be in the range of 10 to 60 minutes, for instance, 20 to 40 minutes. The thickness of the resulting cured electrodeposited coating may be in the range of 15 to 50 microns.

[0119] According to this disclosure, the anionic electrodepositable coating composition of this disclosure can be deposited on an electrically conductive substrate by placing the composition in contact with an electrically conductive cathode and an electrically conductive anode, the surface to be coated being the anode. After contact with the composition, when a sufficient voltage is applied between the electrodes, an adhesive film of the coating composition is deposited on the anode. The conditions under which electrodeposition is carried out are generally the same as those used for electrodeposition of other types of coatings. The applied voltage can vary, from low voltages such as 1 volt to high voltages such as several thousand volts, e.g., 50 to 500 volts. The current density can be 0.5 to 15 amperes per square foot and tends to decrease during electrodeposition, indicating the formation of an insulating film.

[0120] Once a cationic electrodepositable coating composition is electrodeposited onto at least a portion of a conductive substrate, the coated substrate may be heated to a temperature and time sufficient to at least partially cure the electrodeposited coating on the substrate. As used herein, the term “at least partially cured” with respect to a coating means a coating formed by subjecting the coating composition to curing conditions such that a chemical reaction occurs in which at least a portion of the reactive groups of the components of the coating composition to form the coating. The coated substrate may be heated to temperatures in the range of 200°F to 450°F (93°C to 232.2°C), for example, 275°F to 400°F (135°C to 204.4°C), for example, 300°F to 360°F (149°C to 180°C). The curing time may depend on the curing temperature and other variables, such as the film thickness of the electrodeposited coating, the level and type of catalyst present in the composition, etc. For the purposes of this disclosure, all that is required is that there is sufficient time to cure the coating on the substrate. For example, the curing time may be in the range of 10 to 60 minutes, for instance, 20 to 40 minutes. The thickness of the resulting cured electrodeposited coating may be in the range of 15 to 50 microns.

[0121] The electrodepositable coating compositions of this disclosure may also be applied to substrates using non-electrophoretic coating techniques such as flow coating, dip coating, spray coating, and roll coating, if desired. For non-electrophoretic coating, the coating compositions may be applied to conductive and non-conductive substrates such as glass, wood, and plastic.

[0122] This disclosure further relates to coatings formed by at least partially curing the electrodepositable coating compositions described herein.

[0123] This disclosure further relates to substrates at least partially coated with an electrodepositable coating composition described herein, at least in a partially cured state. The coated substrate may include a coating comprising an ionic base-containing film-forming polymer and a curing agent.

[0124] This disclosure also relates to a substrate comprising an electrodeposited coating layer containing an electrodepositable binder and a pigment, wherein the electrodeposited coating layer has a pigment-to-binder ratio of at least 0.3:1, and the electrodeposited coating layer has a horizontal surface roughness of less than 90 microinches as measured by the L-panel surface roughness test method.

[0125] The electrodepositable coating compositions of this disclosure may be used as electrocoating layers that are part of a multilayer coating composite including a substrate having various coating layers. The coating layers may include a pretreatment layer such as a phosphate layer (e.g., a zinc phosphate layer), an electrocoating layer resulting from the aqueous resin dispersion of this disclosure, and a suitable topcoat layer (e.g., a basecoat, a clearcoat layer, a colored monocoat, and a color-plus-clear composite composition). The suitable topcoat layer includes any of those known in the art, each independently being in the form of an aqueous system, a solvent system, a solid particulate form (i.e., a powder coating composition), or a powder slurry. The topcoat typically includes a film-forming polymer, a crosslinking material, and, in the case of a colored basecoat or monocoat, one or more pigments. According to this disclosure, a primer layer is disposed between the electrocoating layer and the basecoat layer. According to this disclosure, one or more of the topcoat layers are applied onto a substantially uncured substrate. For example, a clear coat layer can be applied over at least a portion of a substantially uncured base coat layer (wet-on-wet), and both layers can be cured simultaneously in a downstream process.

[0126] Furthermore, the topcoat layer may be applied directly onto the electrodepositable coating layer. In other words, the substrate lacks a primer layer. For example, the basecoat layer may be applied directly onto at least a portion of the electrodepositable coating layer.

[0127] It will also be understood that a topcoat layer can be applied on top of a base coat, even if the base coat layer has not fully cured. For example, a clear coat layer can be applied on top of a base coat layer even if the base coat layer has not undergone a curing step. Both layers can then be cured during the subsequent curing step, thereby eliminating the need to cure the base coat and clear coat layers separately.

[0128] According to this disclosure, additional compounding components such as colorants and fillers may be present in various coating compositions that give rise to a topcoat layer. Any suitable colorant and filler may be used. For example, a colorant can be added to the coating in any suitable form such as individual particles, dispersions, solutions, and / or flakes. The coatings of this disclosure may use a single colorant or a mixture of two or more colorants. In general, a colorant can be present in any amount sufficient to impart the desired properties, appearance, and / or color effect in a layer of a multilayer composite.

[0129] Examples of colorants include pigments, dyes, and tints, for example, those used in the paint industry and / or those described by the Dry Color Manufacturers Association (DCMA), as well as special effect compositions. Colorants may include, for example, finely divided solid powders that are insoluble under the conditions of use but wettable. Colorants may be organic or inorganic and may be aggregated or non-aggregated. Colorants can be incorporated into coatings by grinding or simple mixing. Colorants can be incorporated into coatings by grinding using a grinding vehicle such as an acrylic grinding vehicle, a use that will be well known to those skilled in the art.

[0130] Examples of pigments and / or pigment compositions include, but are not limited to, crude carbazole dioxazine pigments, azo, monoazo, disazo, naphthol AS, salts (lake), benzimidazolone, condensates, metal complexes, isoindolinone, isoindoline and polycyclic phthalocyanines, quinacridone, perylene, perinone, diketopyrrolopyrrole, thioindigo, anthraquinone, indanthron, anthrapyrimidine, flavanthron, pyrantron, antantron, dioxazine, triarylcarbonium, quinophthalone pigments, diketopyrrolopyrrole red ("DPP Red BO"), titanium dioxide, carbon black, zinc oxide, antimony oxide, as well as organic or inorganic UV opaque pigments such as iron oxides, transparent red or yellow iron oxides, phthalocyanine blue, and mixtures thereof. The terms "pigment" and "coloring filler" can be used interchangeably.

[0131] Examples of dyes include, but are not limited to, acid dyes, azo dyes, basic dyes, direct dyes, disperse dyes, reactive dyes, solvent dyes, sulfur dyes, mordant dyes, and solvent-based and / or aqueous dyes such as bismuth vanadate, anthraquinone, perylene, aluminum, quinacridone, thiazole, thiazine, azo, indigoid, nitro, nitroso, oxazine, phthalocyanine, quinoline, stilbene, and triphenylmethane.

[0132] Examples of tints include, but are not limited to, pigments dispersed in aqueous or water-miscible carriers, such as AQUA-CHEM 896, commercially available from Degussa, Inc., and CHARISMA COLORANTS and MAXITONER INDUSTRIAL COLORANTS, commercially available from the Accurate Dispersions division of Eastman Chemical, Inc.

[0133] The colorants may, but are not limited to, be in the form of a dispersion containing nanoparticle dispersions. The nanoparticle dispersion may contain one or more highly dispersed nanoparticle colorants and / or colorant particles that produce a desired visible color and / or opacity and / or visual effect. The nanoparticle dispersion may contain colorants such as pigments or dyes having particle sizes less than 150 nm, e.g., less than 70 nm, or less than 30 nm. Nanoparticles can be produced by the step of pulverizing a raw material organic or inorganic pigment in a grinding medium having a particle size less than 0.5 mm. Exemplary nanoparticle dispersions and methods for producing them are specified in U.S. Patent No. 6,875,800B2, which is incorporated herein by reference. Nanoparticle dispersions can also be produced by crystallization, precipitation, gas-phase condensation, and chemical friction (i.e., partial dissolution). To minimize re-aggregation of nanoparticles within the coating, resin-coated nanoparticle dispersions can be used. As used herein, “resin-coated nanoparticle dispersion” refers to a continuous phase in which inconspicuous “composite material microparticles,” including nanoparticles and a resin coating on the nanoparticles, are dispersed. Exemplary dispersions of resin-coated nanoparticles and methods for producing them are specified in U.S. Patent Application No. 10 / 876,031, filed June 24, 2004, incorporated herein by reference, and U.S. Provisional Patent Application No. 60 / 482,167, filed June 24, 2003, also incorporated herein by reference.

[0134] According to this disclosure, special effect compositions that can be used in one or more layers of a multilayer coating composite include pigments and / or compositions that produce one or more appearance effects such as reflectance, pearlescent luster, metallic luster, phosphorescence, fluorescence, photochromism, photosensitivity, thermochromism, goniochromism, and / or color change. Additional special effect compositions may provide other perceptible properties such as reflectance, opacity, or texture. For example, a special effect composition may produce a color shift such that the color of the coating changes when viewed at different angles. Exemplary color effect compositions are specified in U.S. Patent No. 6,894,086, which is incorporated herein by reference. Additional color effect compositions may include transparent coated mica and / or synthetic mica, coated silica, coated alumina, transparent liquid crystal pigments, liquid crystal coatings, and / or any composition in which interference arises from differences in refractive index within the material, and not from differences in refractive index between the surface of the material and air.

[0135] According to this disclosure, photosensitive compositions and / or photochromic compositions that reversibly change color when exposed to one or more light sources can be used for any number of layers in a multilayer composite. Photochromic compositions and / or photosensitive compositions can be activated by exposure to radiation of a specified wavelength. When the composition is excited, its molecular structure changes, and the altered structure exhibits a new color different from the composition's original color. When exposure to radiation is removed, the photochromic composition and / or photosensitive composition can return to a dormant state in which the composition's original color returns. For example, a photochromic and / or photosensitive composition may be colorless in an unexcited state and exhibit color in an excited state. The full color change may occur within milliseconds to several minutes, such as 20 to 60 seconds. Exemplary photochromic and / or photosensitive compositions include photochromic dyes.

[0136] According to this disclosure, photosensitive compositions and / or photochromic compositions can be associated with polymeric materials of polymers and / or polymerizable components, and / or can be at least partially bonded to them, such as by covalent bonds. In contrast to some coatings, in which the photosensitive composition may migrate from the coating and crystallize in the substrate, the photosensitive compositions and / or photochromic compositions associated with and / or partially bonded to polymers and / or polymerizable components according to this disclosure have minimal migration from the coating. Exemplary photosensitive compositions and / or photochromic compositions and methods for producing them are specified in U.S. Patent Application No. 10 / 892,919, filed July 16, 2004, which is incorporated herein by reference.

[0137] As used herein, unless otherwise defined, the term “substantially absent” means that, if any, the component is present in an amount less than 1% by weight based on the total resin solids weight of the composition.

[0138] As used herein, unless otherwise defined, the term “essentially not present” means that the component, if present at all, is present in an amount less than 0.1% by weight based on the total resin solids weight of the composition.

[0139] As used herein, unless otherwise defined, the term “completely absent” means that the component is not present in the composition, i.e., 0.00% by weight based on the total resin solids weight of the composition.

[0140] For the purposes of this detailed description, it should be understood that alternative variations and step sequences may be conceivable, unless expressly designated to be contrary to this disclosure. Furthermore, except in any embodiment or unless otherwise indicated, all numbers representing quantities of formulation ingredients used herein and in the claims should be understood to be modified in all cases by the term “approximately.” Thus, unless shown to be contrary to this, the numerical parameters described in the following specification and the appended claims are approximations that may vary depending on the desired properties obtained by this disclosure. At the very least, and without attempting to limit the application of the equivalent view to the claims, each numerical parameter should be interpreted in light of at least the reported significant number of digits and by applying the usual rounding technique.

[0141] While the numerical ranges and parameters representing the broad scope of this disclosure are approximations, the figures shown in specific examples are reported as accurately as possible. However, any given figure inherently contains a certain degree of error that inevitably arises from the standard deviation observed in each of its test measurements.

[0142] Furthermore, it should be understood that any numerical range described herein is intended to include all subranges contained within it. For example, the range "1 to 10" is intended to have all subranges between (and including) the stated minimum value of 1 and the stated maximum value of 10, i.e., the minimum value equal to or greater than 1 and the maximum value equal to or less than 10.

[0143] As used herein, “including,” “containing,” and similar terms are understood to be synonymous with “comprising” in the context of this application, and are therefore open-ended and do not exclude the presence of additional undescribed or unmentioned elements, materials, components, or method steps. As used herein, “consisting of” is understood in the context of this application to exclude the presence of any unspecified elements, components, or method steps. As used herein, “essentially consisting of” is understood in the context of this application to include specific elements, materials, components, or method steps, and those described that “do not significantly affect the basic and novel features.”

[0144] In this application, unless otherwise specified, the use of the singular includes the plural, and the plural includes the singular. For example, this specification refers to "one (an)" ionic base-containing film-forming polymer and "one (a)" curing agent, but combinations of these components (i.e., plural) can be used. In addition, in this application, "and / or" may be explicitly used in certain cases, but unless otherwise specified, the use of "or" means "and / or".

[0145] While certain aspects of this disclosure are described in detail, it will be understood by those skilled in the art that, in light of the overall teachings of this disclosure, various modifications and alternatives to those details can be developed. Therefore, the specific configurations disclosed are illustrative only and are not intended to be limitations on the scope of this disclosure, which would give the entirety of the appended claims and any and all equivalents thereof.

[0146] The following examples illustrate the present disclosure, but should not be considered as limiting the disclosure to those details. Unless otherwise indicated, all parts and percentages in the following examples, and throughout this specification, are by weight. [Examples]

[0147] Preparation of resin system: Resin system I Preparation of Crosslinking Agent I: A blocked polyisocyanate crosslinking agent suitable for use in electrodepositable coating resins was prepared in the following manner. Components 2, 3a, and 3b, listed in Table 1 below, were added to a flask set for total reflux under nitrogen with stirring. The contents of the flask were heated to 35°C, and component 1 was added dropwise so that the temperature would rise due to the exothermic reaction and be maintained below 100°C. After the addition of component 1 was complete, component 4 was added to establish a temperature of 100°C in the reaction mixture. The reaction mixture was held at that temperature until no residual isocyanate was detected by IR spectroscopy. Components 5a and 5b were then added, the reaction mixture was stirred for 30 minutes, and then cooled to ambient temperature. [Table 1]

[0148] Preparation of Cationic Amine-Functionalized Polyepoxide Resin (Resin System I): A cationic amine-functionalized polyepoxide polymer resin suitable for use in formulating electrodepositable coating compositions was prepared in the following manner. Components 1-4 listed in Table 2 below were combined in a flask set for total reflux under nitrogen with stirring. The mixture was heated to a temperature of 130°C, generating exothermic reaction (maximum 175°C). A temperature of 145°C was established in the reaction mixture, and the reaction mixture was then held for 1 hour. Next, component 5, followed by components 6-7, were introduced into the flask, and a temperature of 100°C was established in the reaction mixture. Next, pre-mixed components 8 and 9 were rapidly added to the reaction mixture, generating exothermic reaction. A temperature of 110°C was established, and the reaction mixture was held for 1 hour. Next, component 10 was added and mixed for 15 minutes. After holding, the contents of the flask were poured out and cooled to room temperature. [Table 2]

[0149] Resin-based preparation: Resin-based: Resin-based II Preparation of Crosslinking Agent II: A blocked polyisocyanate crosslinking agent suitable for use in electrodepositable coating resins was prepared in the following manner. Components 1a, 1b, 1c, 1d, and 1e, listed in Table 3 below, were added to a flask set for total reflux under nitrogen with stirring. The contents of the flask were heated to 35°C, and component 2 was added dropwise so that the temperature would rise due to the exothermic reaction and be maintained below 110°C. After the addition of component 2 was complete, component 3 was added to establish a temperature of 110°C in the reaction mixture. The reaction mixture was held at that temperature until no residual isocyanate was detected by IR spectroscopy. Then, component 4 was added, and the reaction mixture was stirred for 30 minutes and cooled to ambient temperature. [Table 3]

[0150] Preparation of Cationic Amine-Functionalized Polyepoxide Resins (Resin Type II): Cationic amine-functionalized polyepoxide polymer resins suitable for use in formulating electrodepositable coating compositions were prepared in the following manner. Components 1-4 listed in Table 4 below were combined in a flask set for total reflux under nitrogen with stirring. The mixture was heated to a temperature of 130°C, generating exothermic reaction (maximum 175°C). A temperature of 145°C was established in the reaction mixture, and the reaction mixture was then held for 1 hour. Next, component 5, followed by components 6-7, were introduced into the flask, and a temperature of 100°C was established in the reaction mixture. Next, pre-mixed components 8 and 9 were rapidly added to the reaction mixture, generating exothermic reaction. A temperature of 110°C was established, and the reaction mixture was held for 1 hour. Next, component 10 was added and mixed for 15 minutes. After holding, the contents of the flask were poured out and cooled to room temperature. [Table 4]

[0151] Preparation of electrodepositable coating compositions Sources of pigments, additives, and chemicals used in the formulation: Chemicals used in the formulation of the electrocoat bath were obtained from various suppliers. Solvent DOWANOL PM was obtained from Dow Chemical Company at 98% purity. Sulfamic acid was obtained from PPG Industries. TIONA595 titanium dioxide pigment can be obtained from Tronox Inc. Barium sulfate pigment can be obtained from Venator Materials PLC. ASP-200 clay pigment can be obtained from BASF.

[0152] Control Composition 1: This electrocoat is commercially available from PPG Industries under the name FRAMECOAT® II and is supplied as a two-component composition. An electrocoat bath was prepared by mixing 1801 grams of CR681 resin (available from PPG), 243.8 grams of CP524 paste (available from PPG), and 1755.2 grams of deionized water. The P:B ratio of this coating was 0.1:1.0. Composition 1 was used in accordance with the technical notification.

[0153] Composition 2: 593 grams of resin system I, heated to 80°C using a thermocouple and heating mantle, were placed in a stainless steel beaker (3 liters). The resin was stirred at 1500 RPM using a 3-inch propeller blade powered by a Fawcett air motor (Model 103A). The following components were added in the order listed. 57.5 grams of deionized water were added to the resin and mixed for 5 minutes. Next, 300 grams of ASP-200 were added to the resin over 5 minutes. This mixture was stirred for 20 minutes. In another stainless steel beaker (1 liter), 7.41 grams of sulfamic acid were added to 387.4 grams of deionized water and mixed for 15 minutes under gentle stirring. After sufficient dispersion was achieved in the resin mixture, the acid solution was slowly poured into the resin mixture while continuing to stir. The acidified resin mixture was held for 1 hour while continuing to stir. After holding for 1 hour, the resin mixture was diluted with 448.6 grams of deionized water over 20 minutes, allowing the temperature to fluctuate naturally. Then, a tin catalyst was added by adding 21.2 grams of E6165 (dibutyltin oxide [DBTO] paste available from PPG Industries) to provide a 0.7 wt% Sn input relative to the resin solids. Finally, an additional 1435.4 grams of deionized water was added to prepare a finished electrocoat bath with 25 wt% solids. The pH of the final bath was 5.89, and the conductivity was 960 μS.

[0154] Composition 3: 593 grams of resin system I, heated to 80°C using a thermocouple and heating mantle, were placed in a stainless steel beaker (3 liters). The resin was stirred at 1500 RPM using a 3-inch propeller blade powered by a Fawcett air motor (Model 103A). The following components were added in the order listed. 57.5 grams of deionized water were added to the resin and mixed for 5 minutes. Next, 95 grams of ASP-200 were added to the resin over 5 minutes, followed by 55 grams of barium sulfate pigment, and then 150 grams of TIONA595 titanium dioxide pigment. This mixture was stirred for 20 minutes. In another stainless steel beaker (1 liter), 7.41 grams of sulfamic acid were added to 387.4 grams of deionized water and mixed for 15 minutes under gentle stirring. After sufficient dispersion was achieved in the resin mixture, the acid solution was slowly poured into the resin mixture while continuing to stir. The acidified resin mixture was held for 1 hour while continuing to stir. After holding for 1 hour, the resin mixture was diluted with 448.6 grams of deionized water over 20 minutes, allowing the temperature to fluctuate naturally. Then, a tin catalyst was added by adding 21.2 grams of E6165 (dibutyltin oxide [DBTO] paste available from PPG Industries) to provide a 0.7 wt% Sn input relative to the resin solids. Finally, an additional 1435.4 grams of deionized water was added to prepare a finished electrocoat bath with 25 wt% solids. The final bath had a pH of 5.78 and a conductivity of 974 μS.

[0155] Composition 4: 807.9 grams of resin system II, heated to 80°C using a thermocouple and heating mantle, were placed in a stainless steel beaker (4 liters). The resin was stirred at 1500 RPM using a 3-inch propeller blade powered by a Fawcett air motor (Model 103A). The following components were added in the order listed. 80.5 grams of deionized water were added to the resin and mixed for 5 minutes. Next, 420 grams of ASP-200 were added to the resin over 5 minutes. This mixture was stirred for 20 minutes. In another stainless steel beaker (1 liter), 10.57 grams of sulfamic acid were added to 736.7 grams of deionized water and mixed for 15 minutes under gentle stirring. After sufficient dispersion was achieved in the resin mixture, the acid solution was slowly poured into the resin mixture while continuing to stir. The acidified resin mixture was held for 1 hour while continuing to stir. After holding for 1 hour, the resin mixture was diluted with 456.8 grams of deionized water over 20 minutes, allowing the temperature to fluctuate naturally. Then, a tin catalyst was added by adding 29.6 grams of E6165 (dibutyltin oxide [DBTO] paste available from PPG Industries) to provide a 0.7 wt% Sn input relative to the resin solids. Finally, an additional 2009.9 grams of deionized water was added to prepare a finished electrocoat bath with 25 wt% solids. The final bath had a pH of 5.72 and a conductivity of 1085 μS.

[0156] Composition 5: Rheology additive solution was prepared by adding deionized water (945 g), BORCHI Gel 0620 (150 g), commercially available from Borchers Americas Inc., and ethylene glycol butyl ether (405 g) to a steel beaker (3 liters), and stirred at 500 RPM for 1 hour with a high-lift impeller blade powered by a Fawcett air motor (Model 103A).

[0157] In a separate stainless steel beaker (4 liters), 807.9 grams of resin system II, heated to 80°C using a thermocouple and heating mantle, were added. The resin was stirred at 1500 RPM using a 3-inch propeller blade powered by a Fawcett air motor (Model 103A). The following components were added in the order listed. 80.5 grams of deionized water were added to the resin and mixed for 5 minutes. Next, 420 grams of ASP-200 were added to the resin over 5 minutes. This mixture was stirred for 20 minutes. In a separate stainless steel beaker (1 liter), 10.57 grams of sulfamic acid were added to 577.8 grams of deionized water and mixed for 15 minutes under gentle stirring. After sufficient dispersion was achieved in the resin mixture, the acid solution was slowly poured into the resin mixture while continuing to stir. The acidified resin mixture was held for 1 hour while continuing to stir. After holding for 1 hour, the resin mixture was diluted over 20 minutes with 175 grams of rheological additive solution and 461.3 grams of deionized water, allowing the temperature to fluctuate naturally. Then, a tin catalyst was added by adding 29.8 grams of E6165 (dibutyltin oxide [DBTO] paste available from PPG Industries) to provide a 0.7 wt% Sn input relative to the resin solids. Finally, an additional 2029.8 grams of deionized water was added to prepare a finished electrocoat bath with 25 wt% solids. The pH of the final bath was 5.85, and the conductivity was 1101 μS.

[0158] Composition 6: 534 grams of resin system I, heated to 80°C using a thermocouple and heating mantle, were placed in a stainless steel beaker (3 liters). The resin was stirred at 1500 RPM using a 3-inch propeller blade powered by a Fawcett air motor (Model 103A). The following components were added in the order listed. 51.8 grams of deionized water were added to the resin and mixed for 5 minutes. Next, 382.5 grams of ASP-200 were added to the resin over 5 minutes. This mixture was stirred for 20 minutes. In another stainless steel beaker (1 liter), 6.67 grams of sulfamic acid were added to 423.7 grams of deionized water and mixed for 15 minutes under gentle stirring. After sufficient dispersion was achieved in the resin mixture, the acid solution was slowly poured into the resin mixture while continuing to stir. The acidified resin mixture was held for 1 hour while continuing to stir. After holding for 1 hour, the resin mixture was diluted with 466.2 grams of deionized water over 20 minutes, allowing the temperature to fluctuate naturally. Then, a tin catalyst was added by adding 19 grams of E6165 (dibutyltin oxide [DBTO] paste available from PPG Industries) to provide a 0.7 wt% Sn input relative to the resin solids. Finally, an additional 932.4 grams of deionized water was added to prepare a finished electrocoat bath with 30 wt% solids. The pH of the final bath was 5.7, and the conductivity was 928 μS.

[0159] Test method Sedimentation Test Method: The amount of sedimentation over a set time was determined using a Biolin Scientific Attension Force Tensiometer (Model: Sigma 703) equipped with a platinum pan. A small sample of the electrodepositable coating composition was placed in a 4-ounce glass vial. The glass vial containing the electrodepositable coating composition was placed on the tension meter platform, and the platinum pan was inserted into the coating below the liquid surface. The instrument was zeroed out, and data acquisition was started. The amount of sedimentation of the composition components (reported in mg) was monitored for 30 minutes.

[0160] Sedimentation was also evaluated against the P:B ratio of the electrodepositable coating composition. This was determined by dividing the total amount of settled components of the composition by the P:B ratio of the composition. This is referred to herein as the "relative sedimentation test method."

[0161] Bath Viscosity Test Method: The flow curve of the liquid bath was determined by measuring viscosity as a function of shear rate. Viscosity was measured using an Anton-Paar MCR302 rheometer with a temperature-controlled concentric cylinder (cup and bob) setup. The temperature was kept constant at 32°C. First, to stabilize the coating system in a steady state, the viscosity of the electrocoat bath was measured for 21 data points at a duration set by the device, for 0.1 s. -1 Measurements were taken at a constant shear rate of 0.1 to 1000 s. -1 Viscosity was measured using a logarithmic gradient of the shear rate, varying the shear rate at point intervals of 5 points per decade over a duration set by the device. Low shear viscosity was 0.1 s. -1 This is the shear rate, and high shear viscosity is 100 s. -1 The shear rate is reported. This test method is referred to herein as the bath viscosity test method.

[0162] L-panel surface roughness test method: A metal substrate was formed into a panel (optionally pre-treated with a pre-treatment composition (e.g., zinc phosphate pre-treatment composition)), cut in half to obtain a 4-inch x 6-inch panel. Then, 0.25 inches was removed from each side of the panel to obtain a 3.5-inch x 6-inch panel, which was bent into an "L" shape to obtain a 4-inch vertical surface and a 2-inch horizontal surface. This panel was immersed in an electrocoat bath under stirring, and stirring could be stopped. After standing in the unstirred bath for 3 minutes, electrodeposition of the composition was allowed to proceed. The substrate was coated by applying current to the electrodepositable coating bath using a rectifier. The target film construct was 0.5–0.7 mil (12.7–17.8 microns) on the vertical surface of the substrate. This film thickness was deposited by using voltage / temperature / current conditions for a 25.4 micron DFT (2-minute conditions), but was deposited in 1 minute. The exact coating conditions may vary depending on the composition. After electrocoating the panels, they were rinsed with deionized water and baked in an electric oven at 350°F for 30 minutes. The surface roughness of the horizontal and vertical surfaces was measured using a Precision Surtronic 25 surface roughness meter available from Taylor Hobson. This instrument was referenced using a 3-inch silicon wafer (product number 16013) available from Ted Pella Inc., which had a roughness of 1.0 ± 0.7 microinches after 10 repeated measurements. This test method is referred to herein as the L-panel surface roughness test method.

[0163] Complex viscosity test method: The viscosity of the deposited coating during the curing cycle was measured by the following steps: (a) setting up an Anton Paar MCR302 rheometer with a PPR25 / 23 spindle and a 0.1 mm gap; (b) applying tetrahydrofuran (THF) to the uncured electrodeposited coating sample, scraping the uncured electrodeposited coating sample from the panel using a metal spatula, and placing the sample on a Peltier plate; (c) measuring the viscosity of the sample over time under a constant shear strain (vibration) of 5% and a frequency of 1 Hz, which is maintained throughout the length of the test, followed by a curing cycle of ambient flash at 40°C for 30 minutes, and then measuring the temperature rise from 40°C to 175°C over 41 minutes (3.3°C / min). This test method is referred to herein as the complex viscosity test method.

[0164] Example A: Evaluation of bath stability CRS panels, pre-treated with zinc phosphate (C700 item:28630, available from ACT (Hillsdale, MI)), were prepared in the manner described in the L-panel surface roughness test method. Electrodepositionable coatings were applied using a DC-powered rectifier (Xantrax model XFR600-2 (Elkhart, Indiana) or Sorensen XG300-5.6 (Ameteck, Berwyn, Pennsylvania)). This film thickness was deposited using voltage / temperature / current conditions for 2 minutes. The exact coating conditions for each coating are shown in Table 5. After electrocoating the panels, they were rinsed with deionized water and baked in an electric oven (Despatch model LFD-1-42) at 350°F for 30 minutes. After baking, the panels were cooled at ambient temperature for 20 minutes. Results from the L-panel surface roughness test method and the corresponding bath viscosity test method performed on the electrodepositionable coating bath are shown in Table 6 below. [Table 5] [Table 6]

[0165] The results in Table 6 demonstrate that the rheological properties of electrodepositable coating compositions can be used to stabilize them against sedimentation. For example, compositions 2, 3, and 5 each have a P:B ratio of 0.6:1 and a low shear viscosity of at least 15, demonstrating good relatively low sedimentation, low sedimentation relative to the total P:B ratio of the composition, and good horizontal surface roughness of the resulting coated coating. This is particularly true for compositions 2 and 3, which include a polyisocyanate curing agent containing a polyether blocking agent. In contrast, composition 4 did not have a low shear viscosity sufficient to prevent significant sedimentation and resulted in a rough horizontal surface. However, as shown in composition 5, the addition of a thickener to composition 4 increased the low shear viscosity, significantly reduced sedimentation and sedimentation per P:B ratio, and resulted in less rough horizontal surface.

[0166] The results in Table 6 also show a comparison with control composition 1, a commercially available composition with a lower P:B ratio of 0.1:1. Although control composition 1 did not have a very high low shear viscosity, the composition was still stable and did not result in high horizontal surface roughness due to its relatively low pigment content. In contrast, compositions 2 and 3, despite having six times higher pigment content which would be expected to result in more sedimentation, provide slightly rougher but comparable horizontal surface roughness. Similarly, the compositions had less sedimentation relative to composition P:B than control composition 1.

[0167] Application B: Curing viscosity and appearance To measure the minimum complex viscosity as described in the complex viscosity test method, an electrodeposited film was coated onto a bare, unwashed 3003 H14 aluminum substrate provided by Q-Lab Corporation. The coating was applied at a bath temperature of 90°F for 120 seconds with a current limit of 1 ampere at 285V. The uncured deposited coating was then handled as described in the complex viscosity test method.

[0168] To measure the appearance of the cured film, CRS panels pre-treated with zinc phosphate (C700 item:28630, available from ACT (Hillsdale, MI)) were prepared by cutting the panels in half to obtain 4-inch x 6-inch panels. The electrodepositable composition was then applied at a bath temperature of 90°F for 120 seconds with a current limit of 1 ampere at 285 volts. After electrodeposition, the panels were rinsed with deionized water and baked in an electric oven at 350°F for 30 minutes. After baking, the panels were cooled for 30 minutes. The roughness of the cured coated surface was then measured using a Precision Surtronic 25 surface roughness meter, available from Taylor Hobson.

[0169] The results of the complex viscosity test method and the appearance of the cured film can be seen in Table 7. [Table 7]

[0170] The results in Table 7 show that increased pigment deposition can lead to an increase in the viscosity profile during the curing process, which affects the appearance of the final cured coating. A reduction in the minimum complex viscosity can result in a decrease in the surface roughness of the cured coating.

[0171] It will be understood by those skilled in the art that numerous modifications and variations are possible in light of the above disclosure without departing from the broad concept of the present invention described and illustrated herein. Accordingly, it should be understood that the above disclosure is merely an example of various exemplary embodiments of this application, and that numerous modifications and variations can be readily made by those skilled in the art within the spirit and scope of this application and the appended claims.

Claims

1. An electrodepositable coating composition, An electrodepositable binder comprising an ionic base-containing film-forming polymer and a curing agent, A compound comprising at least one pigment, The electrodepositable coating composition has a resin solids content of less than 30% by weight, based on the total weight of the electrodepositable coating composition, and a viscosity of at least 15 cP at a shear rate of 0.1 / second, as measured by the bath viscosity test method. An electrodepositable coating composition wherein the pigment optionally comprises a phyllosilicate pigment, and the pigment-to-binder ratio of the phyllosilicate pigment to the electrodepositable binder is less than 0.2:1 when the electrodepositable coating composition is a cationic electrodepositable coating composition and a pigment-dispersing acid is present in the cationic electrodepositable coating composition.

2. The electrodepositable coating composition according to claim 1, wherein the electrodepositable coating composition has a resin solid content of less than 30% by weight, based on the total solid content of the electrodepositable coating composition, and a viscosity of less than 15 cP at a shear rate of 100 / second, as measured by the bath viscosity test method.

3. The electrodepositable coating composition according to claim 1, wherein the electrodepositable coating composition has a pigment-to-binder ratio of at least 0.3:1, and the coating electrodeposited from the electrodepositable coating composition has a minimum complex viscosity during curing of 5,000 to 300,000 cP or less, as measured by a complex viscosity test method.

4. The electrodepositable coating composition according to any one of the prior claims, wherein the composition has a VOC of less than 1.5 lb / gallon.

5. The electrodepositable coating composition according to any one of the prior claims, wherein the electrodepositable coating composition has a pigment-to-binder (P:B) ratio of 0.3:1 to 2.0:

1.

6. The electrodepositable coating composition according to any one of the prior claims, wherein the coating deposited from the electrodepositable coating composition has a horizontal surface roughness of less than 90 microinches when measured by the L-panel surface roughness test method.

7. The electrodepositable coating composition according to any one of the prior claims, wherein the coating deposited from the electrodepositable coating composition has a vertical surface roughness of less than 75 microinches when measured by the L-panel surface roughness test method.

8. An electrodepositable coating composition according to any one of the prior claims, further comprising a pigment-dispersing acid.

9. The electrodepositable coating composition according to any one of the prior claims, wherein the pigment comprises iron oxide, lead oxide, strontium chromate, carbon black, charcoal dust, titanium dioxide, barium sulfate, coloring pigments, phyllosilicate pigments, metallic pigments, thermally conductive electrical insulating fillers, flame retardant pigments, or any combination thereof.

10. The electrodepositable coating composition according to any one of the prior claims, wherein the electrodepositable coating composition is an anionic electrodepositable coating composition.

11. The electrodepositable coating composition according to any one of claims 1 to 9, wherein the electrodepositable coating composition is a cationic electrodepositable coating composition.

12. The electrodepositable coating composition according to claim 11, wherein the cationic electrodepositable coating composition substantially does not contain a pigment dispersing acid or a silane dispersant.

13. The electrodepositable coating composition according to claim 11, wherein, if the cationic electrodepositable coating composition contains a pigment-dispersing acid, the cationic electrodepositable coating composition substantially does not contain a phyllosilicate pigment.

14. The electrodepositable coating composition according to any one of the prior claims, wherein the electrodepositable coating composition substantially, essentially, or completely lacks a metallic pigment and / or an electrically conductive pigment.

15. The electrodepositable coating composition according to any one of the prior claims, wherein the curing agent comprises at least partially blocked polyisocyanate, aminoplast resin, phenoplast resin, or a combination thereof.

16. The curing agent comprises a polyisocyanate that is at least partially blocked by a blocking agent having the following structure: 【Chemistry 1】 wherein R １ and R ２ are each hydrogen or one of R １ and R ２ is hydrogen and the other is a methyl group, R ３ is H or C １ to C ８ alkyl group, for example, C １ to C ４ alkyl group, for example, C １ to C ３ alkyl group, and n is an integer of 1 to 50. The electrodepositable coating composition according to any one of claims 1 to 14.

17. The curing agent comprises a polyisocyanate that is at least partially blocked by a blocking agent having the following structure: 【Chemistry 2】 An electrodepositable coating composition according to any one of claims 1 to 14, wherein n is an integer and m is an integer from 1 to 20.

18. An electrodepositable coating composition according to any one of the prior claims, further comprising water and optionally an aqueous medium containing one or more organic solvents.

19. The aforementioned organic solvent comprises the following structure: 【Transformation 3】 In the formula, R １ and R ２ However, each is either hydrogen or R １ and R ２ One of them is hydrogen, and the other is a methyl group, R ３ However, H or C １ ~C ８ Alkyl alkyl groups, for example, C １ ~C ４ Alkyl alkyl groups, for example, C １ ~C ３ The electrodepositable coating composition according to claim 18, wherein the alkyl group is an integer from 1 to 50.

20. An electrodepositable coating composition according to any one of the prior claims, further comprising a rheological modifier.

21. The electrodepositable coating composition according to any one of the prior claims, wherein the ionic base-containing film-forming polymer is present in the electrodepositable coating composition in an amount of 40% to 90% by weight, and the curing agent is present in the electrodepositable coating composition in an amount of 10% to 60% by weight, based on the total weight of the resin solids in the electrodepositable coating composition.

22. The electrodepositable coating composition according to any one of the prior claims, wherein the electrodepositable coating composition has a relative sedimentation of 90 mg / P:B or less when measured by a relative sedimentation test method.

23. A method for coating a substrate, comprising electrodepositing a coating derived from an electrodepositable coating composition according to any one of claims 1 to 22 onto at least a portion of the substrate.

24. A coating formed by depositing a coating from an electrodepositable coating composition according to any one of claims 1 to 22 onto a substrate.

25. A substrate at least partially coated with a coating deposited from an electrodepositable coating composition according to any one of claims 1 to 22.

26. The substrate according to claim 25, wherein the substrate further comprises a pretreatment layer beneath the coating deposited from the electrodepositable coating composition.

27. The substrate according to claim 25 or 26, wherein the substrate further comprises a topcoat layer on top of the coating deposited from the electrodepositable coating composition.

28. The substrate according to claim 25, wherein the substrate does not contain an intervening coating layer and / or a pretreatment layer between the coating deposited from the electrodepositable coating composition and the substrate.

29. A substrate comprising an electrodeposited coating layer containing an electrodepositable binder and a pigment, wherein the electrodeposited coating layer has a pigment-to-binder ratio of at least 0.3:1, and the electrodeposited coating layer has a horizontal surface roughness of less than 90 microinches when measured by an L-panel surface roughness test method.

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