Abstract: There are described compositions and methods for the laser marking of products or their packaging. The compositions comprise transition metal oxides, saccharides and/or flame-retardant agents, optionally with other additives, dispersed in a carrier.

Abstract: A multifunctional aromatic amine hardener composition including the reaction condensation product of (a) at least one aniline and (b) at least one non-aromatic cyclic dicarboxaldehyde; and a reactive thermosettable resin composition including (i) at least one multifunctional aromatic amine hardener composition curing agent, (ii) at least one thermoset resin, and optionally (c) at least one catalyst; and a process for preparing a thermoset product from the thermosettable composition. The hardener composition above and a thermoset resin may be used to prepare a thermoset product with improved thermo-mechanical behavior.

Abstract: Disclosed is an improved coating composition for food containers that is resistant to high pH processing environments. The improved coating composition is based upon an epoxy-amino resin coating composition that has been modified with other components to improve its performance in high pH environments balanced with flexibility, formability and abrasion resistance. Typically, the coating composition includes an epoxy resin, an amino resin cross-linking agent, a blocked polyisocyanate and a saturated polyester.

Abstract: Partially hydrogenated bisphenol-A based polymers. Coating compositions for food or beverage containers and medical devices, including a partially hydrogenated bisphenol-A based polymer. Food or beverage containers and medical devices coated with partially hydrogenated bisphenol-A based polymers. Food or beverage containers and medical devices made from partially hydrogenated bisphenol-A based polymers.

Abstract: The present invention provides a thermosetting and photocurable coating composition comprising: (A) at least one compound selected from the group consisting of radical-polymerizable unsaturated monomers, resins containing radical-polymerizable unsaturated groups, and resins containing radical-polymerizable unsaturated groups and thermosetting functional groups; (B) a hydroxyl-containing polyester resin produced by esterifying a polybasic acid (a) and a polyhydric alcohol (b), wherein an alicyclic polybasic acid (a1) and/or an alicyclic polyhydric alcohol (b1) are included in a ratio of 20% or more based on the total weight of polybasic acid (a) and polyhydric alcohol (b); (C) a crosslinking agent; and (D) a photopolymerization initiator; and a method of forming a coating film using the coating composition.

Abstract: Compositions are described comprising a) polyoxymethylene, b) thermoplastic elastomer having active hydrogen atoms, c) polyoxymethylene which differs from component a) and contains active hydrogen atoms, d) reagent for covalent coupling of components b) and c), and e) if appropriate, another impact modifier, which differs from component b). The compositions feature improved toughness and can be used for production of moldings.

Abstract: The present invention relates to basecoat materials comprising one or more water soluble, fatty acid modified epoxy esters and/or one or more fatty acid modified alkyd resins, to processes for preparing them, and to their use.

Abstract: A reactive fluorinated polymer having polyester and polyether segments is mixed with a reactive melamine resin to form a coating composition. The polyether segment can include monomeric units from an oxetane monomer having pendant fluorine groups that are linked to the oxetane via an ether group. The melamine resin can be a lower alkyl etherified melamine-formaldehyde. The composition can be disposed on a substrate and treated to form a laminate.

Abstract: In the process of the present invention, a polyamide A1 and an organized clay B are mixed mainly by dispersive mixing, and after added with a polyamide A2, mixed mainly by distributive mixing in a corotating intermeshing twin-screw extruder so designed as to effect the dispersive mixing and the distributive mixing. The organized clay B is completely and finely dispersed and distributed throughout the resultant polyamide composite material. Shaped articles such as films and sheets made of the polyamide composite material exhibit excellent gas barrier properties and transparency with little malodor mainly attributable to the decomposed products of the organizing agent for preparing the organized clay B.

Abstract: A coating composition is produced by forming an aqueous dispersion of a crosslinking agent and a resin that comprises the reaction product of an alkyd polymer, an optional surfalkyd, diacetone acrylamide, another acrylate monomer and optionally aromatic monomers wherein the reaction product is neutralized with either ammonia or an amine. A coating of the aqueous dispersion on wood exhibits at least some of the following desired properties: rapid dry time, good tannin blocking, good resistance to picking up dirt, good hot box stability and good exterior durability. Additionally, the inventive coatings appear to provide improved crosslinking compared to coatings comprising resins not neutralized with an amine or ammonia and/or not containing a surfalkyd.

Abstract: A coating composition comprising components A, B and optionally C, wherein component A comprises at least one hydroxy-terminated polyarylate. Component B is an organic species which can react with the hydroxy terminal groups of component A, and component C is a catalyst or mixture of catalysts. The hydroxy-terminated polyarylates are prepared by a solution polymerization method.

Abstract: The present invention relates to a thermoplastic elastomer resin which has good melt viscosity, melt tension, and thermal resistance, wherein it is prepared by introducing a chain extender and a stabilizer for hydrolysis to a thermoplastic elastomer resin produced through melt polymerization in the presence of hydroxy carboxylic acid compound and subjecting the mixture to reactive extrusion to increase the molecular weight and crosslinking degree of the elastomer resin. The thermoplastic elastomer resin according to the present invention has good properties for automobile parts, particularly constant velocity joint boots and bellows.

Abstract: A crosslinking agent that is an ungelled reaction product of (a) at least one aminoplast resin and (b) at least one aromatic heterocycle containing at least one nitrogen atom wherein the crosslinking agent is essentially free of active hydrogen functional groups and has a glass transition temperature of at least 10° C. is disclosed. Methods for preparing crosslinking agents are also disclosed. Further provided is a curable powder coating composition including a polymer having a glass transition temperature of at least 30° C. containing reactive functional groups and the present crosslinking agent; a multilayer composite coating composition and substrates coated therewith are also disclosed.

Abstract: A water-dilutable polyester resin ABCD having a mass fraction of from 1 to 10% of units derived from unsaturated cocondensed building blocks, an olefinic double bond content of from 10 to 2 000 mmol/kg, and a sulfonic acid group content of from 20 to 300 mmol/kg, modified if desired by copolymerizing olefinically unsaturated monomers in the presence of the polyester resin, a process for preparing them, and their use in particular in one-component coating compositions in combination with amino resin curatives.

Abstract: A crosslinking agent that is an ungelled reaction product of (a) an aminoplast resin and (b) a compound having active hydrogen groups reactive with the aminoplast resin such that the crosslinking agent is essentially free of functional groups reactive with an aminoplast resin and has a glass transition temperature of at least 10° C. is disclosed. Compound (b) is, more specifically, a monofunctional sulfonamide having only one active hydrogen. Methods for preparing crosslinking agents are also disclosed. Further provided is a curable powder coating composition including a polymer having a glass transition temperature of at least 30° C. containing reactive functional groups and the present crosslinking agent; a multilayer composite coating compositions and substrates coated therewith are also disclosed. Methods for modifying aminoplasts are also disclosed.

Abstract: Branched, amorphous, polyester-based macropolyols having a narrow molecular weight distribution and a process for making the macropolyol.

Abstract: The present invention provides a resin composition suitable for molding a microscopic structure that has small cure shrinkage, good mold transfer properties and excellent properties for post-processing such as polishing processing and laser processing. Such a resin is a thermosetting resin composition comprising 95 to 35 wt % of a thermosetting resin and 5 to 65 wt % of organic filler having a particle size of 10 ?m or less. From such a resin, an ink ejecting apparatus having a microscopic structure, for example, a nozzle of a diameter of 30 ?m, is integrally molded.

Abstract: A powder coating composition comprising at least about 0.1% by weight of a reaction product of an aminoplast and a compound having one carbamate group has improved smoothness.

Abstract: A polyurethane composition comprising: A) from 3 to 35% by weight of a polymeric composition comprising 1) at least one polymer and 2) at least one thermoset in amounts of from 0.5 to 50% by weight, based on the sum of A1) and A2), prepared by reaction in the polymer matrix A1) of a) at least one starting component containing NH2 groups and b) at least one starting component containing NCO groups, a) and b) having simultaneously or independently a functionality of ?2 and at least one starting component having a functionality of >2 being present in amounts of from 0.5 to 100% by weight, based on the weight of A2); B) from 15 to 45% by weight in the polymeric composition A), based thereon, of at least one amorphous and/or crystalline polyester having an OH number of from 10 to 250 mg KOH/g; C) from 7 to 25% by weight in the polymeric composition A), based thereon, of at least one curing agent based on blocked polyisocyanates, isocyanurates and/or uretdiones having a functionality of at least 1.

Abstract: Coating compositions comprising: A) least one hydroxy-functional polyester with at least two hydroxyl groups per molecule, wherein at least one of which hydroxyl groups is a tertiary hydroxyl group, and the polyester has a number average molecular weight Mw of 200 to 5000, and contains as a structural element 10-90 wt-%, relative to the total quantity of polyester, of at least one acid ester group comprising a tertiary hydroxyl group and of the following general formula I ?wherein R1 is a single bond or a C1-C6 alkyl group, R2 and R3 mutually independently mean a C1-C4 alkyl group, B) optionally, at least one additional hydroxy-functional binder other than A) and C) at least one cross-linking agent which is capable of entering into a cross-linking reaction with the OH-groups of components A) and B.

Abstract: A process for the manufacture of glycidylester compositions by (a) reacting: (i) at least one cyclohexyl anhydride compound A; (ii) at least one di-secondary or di-primary hydroxyl compound B containing two (cyclo)aliphatic hydroxyl groups; (iii), at least one di-secondary carboxylic acid or anhydride compound C; and (iv) a mono-glycidyl ester of an ?,?-branched carboxylic acid compound D containing from 5 to 19 carbon atoms; and (b) reacting the carboxyl functional polyester from step (a) with an excess epihalohydrin in the presence of a base.

Abstract: The aromatic polyurethane elastomers of the present invention are particularly suited for methods of making objects in a mold cavity. The objects generally include an elastomeric layer formed from an aromatic polyurethane and a foam layer which is subsequently applied to the elastomer. The aromatic elastomer of the present invention lends itself to being precoated with an in-mold coating or being painted after demolding the resulting part.

Abstract: Hydroxyl group-containing polymers which comprise moieties of polyesters and of addition polymers formed from olefinically unsaturated monomers, the polyesters containing units from aliphatic cyclic or polycyclic dihydroxy or polyhydroxy compounds or diepoxy or polyepoxy compounds A and aliphatic cyclic dicarboxylic or polycarboxylic acids B and the addition polymers containing units from olefinically unsaturated alkyl esters G of aliphatic, linear, branched or cyclic olefinically unsaturated monocarboxylic and/or dicarboxylic acids, olefinically unsaturated hydroxyalkyl esters H of one of the acids specified under G, at least one further olefinically unsaturated monomer I selected from vinylaromatics, vinyl esters, halogenated monomers, unsaturated nitriles, amides or diamides of unsaturated monocarboxylic acids, vinyl ethers, and allyl ethers, and also, where appropriate, carboxylic acids J, selected from the monocarboxylic acids specified under G or dicarboxylic acids specified under G in unesterified or m

Abstract: A random polytrimethylene ether ester prepared by polycondensation of 1,3-propanediol reactant and about 10 to about 0.1 mole % of aliphatic or aromatic diacid or diester, as well as its manufacture and use thereof.

Abstract: A crosslinking agent is provided which is an ungelled reaction product of (a) an aminoplast resin and (b) a compound having active hydrogen groups reactive with the aminoplast resin (a) such that the crosslinking agent is essentially free of functional groups reactive with aminoplast resin and has a glass transition temperature of at least 10° C. Also provided is a method for preparing the crosslinking agent. Further provided is a curable powder coating composition including (A) a polymer having a glass transition temperature of at least 30° C. containing reactive functional groups and (B) the previously described crosslinking agent. Additionally provided is a multilayer composite coating composition including a base coat deposited from a film-forming composition and a top coat over the base coat deposited from the previously described powder coating composition. Coated substrates are also provided.

Abstract: A coating composition comprising at least one hydroxyl functional polymer, a crosslinker capable of crosslinking with said hydroxyl functional polymer (a) to form a film, and a reactive diluent comprising 1,3-cyclohexane dimethanol and 1,4-cyclohexane dimethanol.

Abstract: A composition comprises a curing agent or coreactant and a glycidyl ester produced by reacting a carboxyl-functional polyester having an acid value of less than 280 mg KOH/gram with excess epihaloydrin in the presence of a base and, optionally, a catalyst, wherein the carboxyl-functional polyester is produced by reacting (a) at least on cyclohexyl anhydride A; (b) at least one di-secondary or di-primary hydroxyl compound B containing two (cyclo)aliphatic hydroxyl groups; (c) at least one di-secondary carboxylic acid or anhydride C; and (d) a monoglycidyl ester of an alpha,alpha-branched carboxylic acid D containing from 5 to 19 carbon atoms.

Abstract: Polyester fibers comprising a copolyester which simultaneously satisfies the following respective requirements (a) to (c), (a) a terephthalic acid component in an amount of 0 to 100 mol % and a 2,6-naphthalenedicarboxylic acid component in an amount of 100 to 0 mol % respectively based on the whole dicarbxylic acid component, wherein the total amount, of the terephthalic acid component and the 2,6-naphthalenedicarboxylic acid component, accounts for 90 mol % or more based on the whole dicarboxylic acid component, (b) a trimethylene glycol component accounts for 0 to 100 mol % and a 1,4-cyclohexanedimethanol component accounts for 100 to 0 mol % respectively based on the whole glycol component, wherein the total amount, of the trimethylene glycol component and the 1,4-cyclohexanedimethanol component, accounts for 90 mol % or more based on the whole glycol component and (c) the sum total value of mol % of the 2,6-naphthalenedicarboxylic acid component and mol % of the 1,4-cyclohexanedimethanol component is 2

Abstract: A graft polymer, which is obtained by grafting a branch polymer having a fluoroalkyl group onto a trunk polymer through a linkage having a —C(═O)NH— group, gives a solvent-based water- and oil-repellent composition having high water- and oil-repellency, high product stability and high dilution stability.

Abstract: Resin for a binder suitable for mineral fibers such as glass or stone wool, said resin comprising the reaction product of a polymer free mixture of an amine with a first anhydride and a second anhydride, characterized in that the first and second anhydrides are different anhydrides.

Abstract: Monofunctional polyfluorooxetane oligomers and polymers are prepared by the cationic polymerization of fluorooxetane monomers with a monoalcohol. The fluorooxetane oligomers or polymers can be copolymerized with generally cyclic ethers. Alternatively, the polyfluorooxetane oligomer or polymer having a single hydroxyl end group can be functionalized with a variety of compounds so as to yield a functional end group such as an acrylate, a methacrylate, an allylic, an amine, etc., with the functionalized oligomer or polymer being suitable for use in radiation curable or thermal curable coating compositions. These functionalized polymers can be copolymerized and cured to provide improvements in wetting and surface properties that have previously been provided by migratory chemicals such as waxes and oils.

Abstract: Provided is a crosslinking agent which is the ungelled reaction product of a polyester polyol and an aminotriazine compound having one or less non-alkylated NH bond per triazine ring. The polyester polyol is the reaction product of a cycloaliphatic polyol and a cyclic polycarboxylic acid or anhydride. The crosslinking agent is essentially free of hydroxyl functionality and has a glass transition temperature of at least 10° C. Further provided is a powder coating composition including a solid particulate film-forming mixture of a polymer containing reactive functional groups and having a Tg of at least 30° C., and the crosslinking agent. Additionally provided is a multi-layer composite coating composition having a basecoat layer deposited from a basecoat film-forming composition and a topcoat over the basecoat deposited from the previously described powder coating composition. Coated substrates are also provided.

Abstract: The aromatic polyurethane elastomers of the present invention are particularly suited for methods of making objects in a mold cavity. The objects generally include an elastomeric layer formed from an aromatic polyurethane and a foam layer which is subsequently applied to the elastomer. The aromatic elastomer of the present invention lends itself to being precoated with an in-mold coating or being painted after demolding the resulting part.

Abstract: The present invention provides compositions comprising a graphite, binder precursor and low polarity solvent that upon hardening form layers of an electrically conductive material. The compositions of the present invention are sprayable by an internally charged electrostatic sprayer.

Abstract: A polyester polymer includes at least one hydroxyl terminated polyoxetane block containing repeat units derived from polymerizing at least one oxetane monomer having a pendant —CH2—O—(CH2)n—Rf group wherein said Rf group is partially or fully fluorinated. A preferred process for forming said polymer is by reacting a hydroxyl terminated polyoxetane with a polycarboxylic acid under appropriate conditions to form an ester linkage and then adding and reacting that product with polyester forming reactants. The polyester polymer containing at least one polyoxetane block therein when reacted with an amino resin curative can be used as a coating on a substrate wherein the coating has dry erase properties. The coated substrate can be used as prepared or applied to yet other substrates.

Abstract: In an intermediate coating composition comprising high-acid-value polyester resin, low-acid-value polyester resin, melamine resin containing an imino group and pigments, a ratio (AV1/AV2) of acid value (AV1) of high-acid-value polyester resin to that (AV2) of low-acid-value polyester resin is adjusted to be 1.25-5. A method for forming multilayered coating films using this intermediate coating composition and multilayered coating films prepared using said method are provided, wherein, by specifying the acid value of resins and type of cross-linking agents in the intermediate coating, said multilayered coating films formed even under short-time baking conditions is excellent in its appearance and adhesiveness to the top coating, and said intermediate coating composition is able to maintain its storage stability excellent so as to be capable of shortening the coating processes.

Abstract: The present invention relates to a new liquid, storage-stable coating composition, which is suitable for the production of coatings which have an outstanding resistance to external weathering, and binders thereof which are composed of a hardener component comprising an aminoplast resin and/or a blocked polyisocyanate and a specific polyol component of selected units, and to its use for the production of weathering-resistant coatings on any desired heat-resistant substrates.

Abstract: A polyester resin composition comprising 50 equivalents/ton or more of an aromatic ring in the resin and at least one thermosetting resin selected from the group consisting of melamine resin, urea resin, benzoguanamine resin and phenol resin. The aromatic ring in the polyester resin has a phenolic hydroxyl group and at least one of ortho-position and para-position of the aromatic ring to the phenolic hydroxyl group is a hydrogen atom. The resin composition has excellent toughness at ambient temperature and heat resistance.

Abstract: Improved anti-reflective coating compositions for use in integrated circuit manufacturing processes and methods of forming these compositions are provided. Broadly, the compositions are formed by heating a solution comprising a compound including specific compounds (e.g., alkoxy alkyl melamines, alkoxy alkyl benzoguanamines) under acidic conditions so as to polymerize the compounds and form polymers having an average molecular weight of at least about 1,000 Daltons. The monomers of the resulting polymers are joined to one another via linkage groups (e.g., —CH2—, —CH2—O—CH2—) which are bonded to nitrogen atoms on the respective monomers. The polymerized compound is mixed with a solvent and applied to a substrate surface after which it is baked to form an anti-reflective layer. The resulting layer has high k values and can be formulated for both conformal and planar applications.

Abstract: The aromatic polyurethane elastomers of the present invention are particularly suited for methods of making objects in a mold cavity. The objects generally include an elastomeric layer formed from an aromatic polyurethane and a foam layer which is subsequently applied to the elastomer. The aromatic elastomer of the present invention lends itself to being precoated with an in-mold coating or being painted after demolding the resulting part.

Abstract: A binder for a coating composition is formed using a principal resin polyol, in combination with a hyper-branched polyol as a reactive intermediate, and at least one crosslinker. The principal resin polyol is at least one of a polyester polyol, a polyether polyol, and a polyacrylate. Hyper-branched polyester polyols may be used as reactive diluents, which will cross-link with isocyanates, isocyanurates, epoxides, anhydrides or their corresponding polyacids and/or aminoplasts to form a binder having particular properties, to help control the rheology of a coating system. The hyperbranched polyol, the principal resin polyol, or both may, optionally, include a carbamate functional group in the structure thereof. Coating compositions may be made using the binders together with additional components.

Abstract: A crosslinking agent is provided which is an ungelled reaction product of (a) an aminoplast resin and (b) a compound having active hydrogen groups reactive with the aminoplast resin (a) such that the crosslinking agent is essentially free of functional groups reactive with aminoplast resin and has a glass transition temperature of at least 10° C. Also provided is a method for preparing the crosslinking agent. Further provided is a curable powder coating composition including (A) a polymer having a glass transition temperature of at least 30° C. containing reactive functional groups and (B) the previously described crosslinking agent. Additionally provided is a multilayer composite coating composition including a base coat deposited from a film-forming composition and a top coat over the base coat deposited from the previously described powder coating composition. Coated substrates are also provided.

Abstract: A crosslinking agent which is an ungelled reaction product of (a) at least one aminoplast resin, (b) at least one polyfunctional polymer having functional groups reactive with aminoplast resin (a) and having a glass transition temperature of at least 15° C.; and (c) at least one compound different from (b) having active hydrogen groups reactive with aminoplast resin (a) is provided. Also provided is a method for preparing the crosslinking agent. Further provided is a powder coating composition which includes the crosslinking agent. Additionally provided is a multi-layer composite coating composition having a base coat layer and a top coat over the base coat deposited from the previously described powder coating composition. Coated substrates are also provided.

Abstract: A random polytrimethylene ether ester prepared by polycondensation of 1,3-propanediol reactant and about 10 to about 0.1 mole % of aliphatic or aromatic diacid or diester, as well as its manufacture and use thereof.

Abstract: A crosslinking agent which is an ungelled reaction product of (a) at least one aminoplast resin, (b) at least one polyfunctional polymer having functional groups reactive with aminoplast resin (a) and having a glass transition temperature of at least 15° C.; and (c) at least one compound different from (b) having active hydrogen groups reactive with aminoplast resin (a) is provided. Also provided is a method for preparing the crosslinking agent. Further provided is a powder coating composition which includes the crosslinking agent. Additionally provided is a multi-layer composite coating composition having a base coat layer and a top coat over the base coat deposited from the previously described powder coating composition. Coated substrates are also provided.

Abstract: Low molar mass polyester polyols having a weight average molar mass Mw of up to 3500 g/mol, hydroxyl numbers of from 80 to 280 mg/g and acid numbers of from 5 to 40 mg/g, comprising structural units derived from aliphatic monocyclic or polycyclic compounds containing at least two hydroxyl and/or epoxide groups and at least one heteroatom, aliphatic acyclic or cyclic polyhydroxy compounds containing three or more hydroxyl groups per molecule, linear or branched aliphatic dihydroxy compounds and aliphatic cyclic polycarboxylic acids, alone or in a mixture with low molar mass acrylate copolymers, may be processed to give coating materials which dry rapidly, and result in defect-free surfaces.

Abstract: A polyester polymer includes at least one hydroxyl terminated polyoxetane block containing repeat units derived from polymerizing at least one oxetane monomer having a pendant —CH2—O—(CH2)n—Rf group wherein said Rf group is partially or fully fluorinated. A preferred process for forming said polymer is by reacting a hydroxyl terminated polyoxetane with a polycarboxylic acid under appropriate conditions to form an ester linkage and then adding and reacting that product with polyester forming reactants. The polyester polymer containing at least one polyoxetane block therein when reacted with an amino resin curative can be used as a coating on a substrate wherein the coating has dry erase properties. The coated substrate can be used as prepared or applied to yet other substrates.

Abstract: A crosslinking agent that is an ungelled reaction product of (a) an aminoplast resin and (b) a compound having active hydrogen groups reactive with the aminoplast resin such that the crosslinking agent is essentially free of functional groups reactive with an aminoplast resin and has a glass transition temperature of at least 10° C. is disclosed. Compound (b) is, more specifically, a monofunctional sulfonamide having only one active hydrogen. Methods for preparing crosslinking agents are also disclosed. Further provided is a curable powder coating composition including a polymer having a glass transition temperature of at least 30° C. containing reactive functional groups and the present crosslinking agent; a multilayer composite coating compositions and substrates coated therewith are also disclosed. Methods for modifying aminoplasts are also disclosed.

Abstract: The invention relates to a method for producing polyesters with a reduced content of free acetaldehyde from terephthalic acid and ethylene glycol via a catalyzed polycondensation in the melt and also the use of this method. The method is based thereby on the usage of highly active polycondensation catalysts, on the deactivation of these catalysts by the addition of phosphorous-containing inhibitors and the addition of acetaldehyde-bonding substances. The entire polycondensation is thereby implemented at temperatures beneath 280° C.

Abstract: The combination of powder coatings usable in a coating method comprising mixing two or more powder coatings of which each color is different, wherein each of the powder coatings fuses with each other and is heat-cured, to thereby give a coating film having a homogenous hue. A powder coating composition comprising two or more powder coatings of which each color is different, wherein each of the powder coatings fuses with each other and is heat-cured, to thereby give a coating film having a homogenous hue. A coating method comprising the steps of (a) applying to a substrate two or more powder coatings, of which each color is different; (b) heating to fuse with each other each of the two or more powder coatings applied in step (a); and (c) curing the resulting fused product in step (b), to give a coating film having a homogeneous hue.