HK1179587B - Branched polyester polymers and coatings comprising the same, base material coated using the coatings - Google Patents
Branched polyester polymers and coatings comprising the same, base material coated using the coatings Download PDFInfo
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Description
Technical Field
The invention relates to branched polyesters prepared by free-radical polymerization of the double bonds of unsaturated polyester prepolymers. The invention further relates to a coating comprising said polyester and to a substrate coated with such a coating.
Background
Conventional linear and branched polyester resins produced by polycondensation of various combinations of polyols and polyacids have been widely used in the coating industry. They have been used to coat a variety of metallic and non-metallic substrates used in a number of different industries. These industries include in particular those requiring flexible coatings. Particularly suitable examples include substrates used in the packaging industry, coil coating, and certain industrial and automotive coatings. Certain coatings, particularly in the packaging industry, must withstand extreme stresses during the manufacture and use of packaging containers. In addition to flexibility, packaging coatings need to withstand chemicals, solvents and pasteurization processes employed in beer and beverage packaging, as well as retort conditions widely employed in food packaging. In the coil coating industry, coils are unwound, coated and rewound. Therefore, the coatings used must be sufficiently flexible to withstand the rolling process and subsequent stamping or other forming processes during which the coil is formed into the desired workpiece or end product; durability of the coating on the final workpiece or product is also a factor. Similarly, it is generally desirable for coatings used in the automotive industry to exhibit both flexibility and durability.
Typically high molecular weight polyesters with good flexibility and resistance to mechanical deformation can be prepared by controlling the ratio of polyol to polyacid and the extent of reaction. However, such polymers typically have a low average functionality per chain, which limits their further use in coatings. On the other hand, increasing the functionality can result in polyesters having lower molecular weights. The use of low molecular weight polyester resins in the coating can result in poor substrate adhesion, limited compatibility with other types of resins, and/or difficulty in achieving the desired balance of chemical resistance and flexibility.
Thus, polyesters having high levels of functionality without sacrificing molecular weight are desirable.
Disclosure of Invention
The present invention relates to a branched polyester polymer prepared by free radical polymerization of the double bonds of an unsaturated polyester polymer, said polymer comprising: a) a hard segment; b) a polyol segment; and c) an unsaturated polycarboxylic acid and/or anhydride and/or ester thereof. Coatings comprising said polyesters are also within the scope of the invention, such as substrates at least partially coated with said coatings.
Detailed Description
The present invention relates to branched polyester polymers generally comprising reaction products containing hard segments, polyol segments, and unsaturated polycarboxylic acids and/or anhydrides and/or esters thereof. The reaction product is an unsaturated polyester, which is sometimes referred to herein as an "unsaturated polyester prepolymer" or "reaction product" or the like. The polymerization is initiated by the unsaturation of the unsaturated polyester prepolymer using a free radical initiator to form a branched polyester.
Polyester prepolymers are prepared by reacting one or more monomers that contribute "hard segments" with one or more polyols and one or more unsaturated polycarboxylic acids/anhydrides/esters. As used herein, "hard segment" and like terms refer to a monomer or residue that contributes rigidity to the prepolymer rather than flexibility. The hard segment may be, for example, the residue of a polyacid. As used herein, the term "polyacid" and the like refers to a compound having two or more acid groups and includes esters and/or anhydrides of the acids. In certain embodiments, the polyacid is an aromatic or cycloaliphatic acid, suitable examples of which include, but are not limited to, phthalic acid, isophthalic acid, 5-tert-butylisophthalic acid, tetrachlorophthalic acid, tetrahydrophthalic acid, naphthalene polycarboxylic acids, terephthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, dimethyl terephthalate, cyclohexanedicarboxylic acid, chlorendic anhydride, 1, 3-cyclohexanedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, tricyclodecane polycarboxylic acid, endomethylenetetrahydrophthalic acid, endoethylenehexahydrophthalic acid, cyclohexanetetracarboxylic acid, cyclobutanetetracarboxylic acid and esters and anhydrides thereof, and/or combinations thereof. Monomers that contribute to the hard segment are sometimes referred to herein as "hard segment monomers".
In certain embodiments, one or more additional acids may also be used. Such acids may include, for example, other polybasic acids, monobasic acids, fatty acids, esters and/or anhydrides of any of these acids, and/or combinations thereof. Suitable polybasic acids include, but are not limited to, saturated polybasic acids such as adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, sebacic acid, dodecanedioic acid and their esters and anhydrides. Suitable monobasic acids include, but are not limited to, cycloaliphatic carboxylic acids including cyclohexane carboxylic acid, tricyclodecane carboxylic acid, camphoric acid, and aromatic monocarboxylic acids including benzoic acid and tert-butylbenzoic acid; c1-C18Aliphatic carboxylic acids such as acetic acid, propionic acid, butyric acid, caproic acid, oleic acid, linoleic acid, undecanoic acid, lauric acid, isononanoic acid, other fatty acids, and hydrogenated fatty acids of naturally occurring oils; and/or esters and/or anhydrides of any of these.
The unsaturated polyester prepolymer reaction product further comprises a polyol. As used herein, the term "polyol" and the like refers to a compound having two or more hydroxyl groups. The polyol used to form the polyol segment is sometimes referred to herein as the "polyol segment monomer". The polyol may also be selected to impart hardness to the prepolymer. Suitable polyols for use in the present invention may be any polyol known for use in the production of polyesters. Examples include, but are not limited to, alkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, hexylene glycol, polyethylene glycol, polypropylene glycol, and neopentyl glycol; hydrogenated bisphenol a; cyclohexanediol; propylene glycol including 1, 2-propylene glycol, 1, 3-propylene glycol, butylethylpropylene glycol, 2-methyl-1, 3-propylene glycol and 2-ethyl-2-butyl-1, 3-propylene glycol; butanediol, including 1, 4-butanediol, 1, 3-butanediol, and 2-ethyl-1, 4-butanediol; pentanediol, including trimethylpentanediol and 2-methylpentanediol; cyclohexanedimethanol; hexylene glycols, including 1, 6-hexanediol; caprolactone diol (e.g. -the reaction product of caprolactone with ethylene glycol); a hydroxyalkylated bisphenol; polyether glycols such as poly (butylene oxide) glycol; trimethylolpropane, pentaerythritol, dipentaerythritol, trimethylolethane, trimethylolbutane, dimethylolcyclohexane, glycerol, and the like. Suitable unsaturated polyols for use in the present invention can be any unsaturated alcohol containing two or more hydroxyl groups. Examples include, but are not limited to, trimethylolpropane monoallyl ether, trimethylolethane monoallyl ether, and prop-1-ene-1, 3-diol. The polyol segment may also include some monohydric alcohols, for example up to 10 or 5 weight percent based on the total weight of the polyol segment.
In certain embodiments, neither the hard segment nor the polyol segment contains unsaturation before or after the reaction product is formed.
The unsaturated polyester prepolymer further comprises an unsaturated polycarboxylic acid/anhydride/ester. The unsaturated polybasic acid suitable for use in the present invention may be any unsaturated carboxylic acid containing two or more carboxyl groups and/or an ester and/or anhydride thereof. Examples include, but are not limited to, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and mesaconic acid and/or esters and/or anhydrides thereof. When the unsaturated polybasic acid is in the form of an ester, these esters may be formed using any suitable alcohol, such as via C1-C18Alcohols (e.g., methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, isobutanol, 1-pentanol and 1-hexanol) with polyolsC formed by reaction of a polybasic acid1-C18An alkyl ester. Particularly suitable unsaturated polybasic acids are maleic acid, maleic anhydride or C of maleic acid1-C6An alkyl ester. In certain embodiments, the unsaturated polycarboxylic acid/anhydride/ester comprises from 3 to 10 weight percent, such as from 4 to 7 weight percent, of the polyester prepolymer, while in other embodiments it comprises 10% or more, or 15% or more, by weight of the polyester prepolymer.
The unsaturated polyester prepolymer may be prepared by any means known in the art. In one embodiment, the hard segments and polyol segments are pre-reacted to form what is sometimes referred to herein as a "polyol prepolymer" and then further reacted with an unsaturated polycarboxylic acid/anhydride/ester. In another embodiment, the hard segment, the polyol segment, and the unsaturated polycarboxylic acid/anhydride/ester are all reacted together. The polyol is typically in excess compared to the hard segments. For example, the ratio of reactive groups on the hard segment monomers to reactive groups on the polyol segment monomers may be 1:2, 2:3, or even higher. The higher the ratio, the higher the molecular weight of the reaction product. Due to the use of excess polyol, the reaction product has terminal hydroxyl functionality.
The unsaturated polyester prepolymer is then polymerized in the presence of a free radical initiator. In the radical polymerization, any radical initiator typically used for initiating polymerization of unsaturated compounds containing a double bond may be used. For example, the free radical initiator may be an azo initiator or a peroxide initiator, such as t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy benzoate or dibenzoyl peroxide. The ratio of initiator to unsaturated acid/anhydride/ester may vary depending on the degree of branching of the polyester chain desired. For example, the molar ratio of initiator to average number of double bonds per unsaturated acid/anhydride/ester chain may be from 0.001 to 1.0, such as from 0.01 to 0.9 or from 0.5 to 1.
Thus, the unsaturation from one acid/anhydride moiety reacts with the unsaturation of another in the reaction product. The result is a branched polyester polymer. At least some, if not all, of the branches have terminal hydroxyl groups. Depending on the starting materials used, pendant functionality may also be present in the branched polyester. Typically, when an initiator is used in conjunction with an unsaturated acid/anhydride/ester, a linear polymer is obtained. Thus, according to the present invention, it is very surprising and unexpected to obtain branched polyesters. It is to be understood that in the present invention, branching is primarily obtained by reaction of unsaturation. By using tri-or tetra-hydric alcohols, a small amount of branching can be contributed, but the amount of such compounds should be selected to avoid gelation. It will be appreciated that the present process of obtaining branching by polymerization of unsaturation using polycarboxylic acids and polyesters derived therefrom is very unique when compared to conventional branched polyesters such as those prepared by using trihydric or tetrahydric alcohols.
The initiator may be added in different portions at different times depending on the degree of polymerization control desired. For example, the entire free radical initiator may be added at the beginning of the reaction, the initiator may be divided into portions and the portions added at intervals during the reaction, or the initiator may be added in a continuous feed. It will be appreciated that adding initiator at set intervals or continuously fed will result in a more controlled process than adding all initiator initially.
Regardless of the manner in which the polyester prepolymer is produced, whether the polyol prepolymer is formed first, or the hard segment monomers and polyol segment monomers are reacted directly with the polycarboxylic acid/anhydride/ester, and how and when the initiator, etc., is added, the resulting branched polyester is actually a mixture of polyesters having a variety of degrees of unsaturation, chain lengths, branching, etc. Some of the resulting products are even monoesters, but are still encompassed by the term "polyester" as used herein.
The temperature at which the free radical polymerization reaction is carried out can vary depending on such factors as the unsaturated acid/anhydride/ester, polyol segment monomer, hard segment monomer, initiator, composition of the solvent, and desired properties in the polyester. Typically, free radical polymerization is carried out at a temperature of 50 ℃ to 150 ℃. In typical polymerizations, such as acrylics, higher temperatures result in higher free radical initiator concentrations, which in turn results in polymerization of more chains, each having a relatively lower molecular weight. In the system of the present invention, it has surprisingly been found that, in particular when maleic acid is used, the higher the initiator concentration, the higher the molecular weight of the resulting polymer. This is a surprising result, since the person skilled in the art would not have expected the polymerization of the invention to take place. However, too much initiator can lead to gelation. Thus, in certain embodiments, the polyesters of the present invention are ungelled.
Although the polymerization may be carried out in any manner, the radical polymerization may be carried out using a solution of an unsaturated acid/anhydride/ester and a polyol prepolymer (or a hard segment monomer and a polyol segment monomer) in view of ease of handling. Any solvent can be used as long as it can dissolve the components including the radical initiator to an extent sufficient for polymerization to effectively occur. Typical examples of suitable solvents include butylene glycol, propylene glycol monomethyl ether, methoxypropyl acetate, and xylene. The preparation of polyesters in a solvent is sometimes referred to herein as a "solvent-based system," meaning that more than 50% of the solvent, e.g., up to 100%, is organic, and less than 50% of the solvent, e.g., less than 20%, less than 10%, less than 5%, or less than 2% of the solvent is water.
Alternatively, the polyester may be prepared in a water-based system. A "water-based system" is a system in which more than 50%, such as up to 100%, of the solvent is water, and less than 50%, such as less than 20%, less than 10%, less than 5%, or less than 2%, of the solvent is an organic solvent. If the unsaturated polyester prepolymer has sufficient carboxylic acid groups, it can be converted to a water-dilutable material by neutralization or partial neutralization with a suitable base, followed by the addition of water. Non-limiting examples of suitable bases for neutralization include dimethylethanolamine, triethylamine, and 2-amino-2-methylpropanol. The aqueous material may then be polymerized using free radicals as described above. Alternatively, the unsaturated polyester prepolymer may be mixed with a surfactant and/or polymeric stabilizer material and then mixed with water prior to the aforementioned free radical polymerization. It will also be apparent to those skilled in the art that these aqueous mixtures may contain additional organic cosolvents, examples of which include, but are not limited to, butanediol, butyl diglycol, and propylene glycol monomethyl ether.
The resulting polyester may be solid or liquid in solvent-based or water-based systems.
As mentioned above, the polyesters of the present invention are formed by the double bond free radical polymerization of unsaturated polyester prepolymers containing terminal hydroxyl groups. In certain embodiments, two or more different unsaturated polyester prepolymers may be reacted together. As used herein, "different" means that one or more components used in the two or more unsaturated polyester prepolymers and/or the amount of one or more components used in the two or more unsaturated polyester prepolymers can be different. For example, polyesters according to the present invention may be prepared by reacting polyol components comprising the same components, while in other embodiments they may be prepared by reacting two or more polyol prepolymers formed from different components. That is, reacting a first polyol prepolymer comprising terminal hydroxyl groups and a second polyol prepolymer comprising terminal hydroxyl groups with an unsaturated acid/anhydride/ester; the components used to prepare the first and second prepolymers may be different or may have one or more different components. In this embodiment, the resulting polyester may have random units derived from the various types of prepolymers used. Thus, the present invention includes polyesters prepared from the same or different hard segment monomers, polyol segment monomers, and/or unsaturated acids/anhydrides/esters and/or the same or different amounts of any of these. The use of different polyol prepolymers, hard segment monomers, polyol segment monomers, unsaturated acids/anhydrides/esters and/or amounts can result in polyesters having different properties. In this manner, polyesters having desired properties can be formed by using specific components for the reaction product.
As noted above, free radical polymerization is employed to form the polyester, wherein the unsaturation in the polycarboxylic acid/anhydride/ester moiety in the reaction product is polymerized. In certain embodiments, the reaction is conducted such that substantially all of the unsaturation is reacted in the formation of the polyester, while in other embodiments, the resulting polyester also contains some unsaturation. For example, the resulting polyester may contain sufficient unsaturation to enable the polyester to react with other functional groups.
Since the branched polyesters according to the invention are formed primarily by free radical polymerization of the unsaturation in the unsaturated acid/anhydride/ester, the terminal hydroxyl groups will remain unreacted in the polyesters of the invention. These unreacted hydroxyl groups can then be crosslinked with another component. Thus, the present invention is distinct from techniques for forming gelled polyesters, i.e., a mass of networked polyesters. The polyesters of the present invention are thermosetting and thus also differ from the art taught for thermoplastic polyesters.
In certain embodiments, it may be desirable to convert some or all of the hydroxyl functionality on the unsaturated polyester prepolymer, e.g., before polymerization occurs, and/or some or all of the hydroxyl functionality on the branched polyester to another functionality. For example, hydroxyl groups can be reacted with a cyclic anhydride to provide acid functionality. Acid esters may also be formed.
In certain other embodiments, the unsaturated polyester prepolymer may comprise linkages other than ester linkages. For example, the polyester prepolymer may further comprise one or more urethane linkages. Urethane linkages can be introduced by reacting an excess of polyol prepolymer or unsaturated polyester polymer with a polyisocyanate. The resulting unsaturated polyester prepolymer will still have terminal functionality and unsaturation, but will also have urethane linkages in addition to the ester linkages. Other chemistries may also be introduced. Thus, in certain embodiments, the unsaturated polyester prepolymer further comprises one or more linkages in addition to ester linkages.
In certain other embodiments, unsaturated monomers other than the unsaturated polyacid/anhydride/ester of the reaction product are not used. For example, in certain embodiments, vinyl monomers such as (meth) acrylates, styrenes, and vinyl halides, and the like, are not used. Thus, it is to be understood that the branched polyesters of the present invention are not polyester/acrylic graft copolymers generally known in the art.
In certain embodiments, the polyesters of the present invention specifically exclude polyesters prepared from prepolymers formed by reaction with aldehydes; thus, in this embodiment, acyl succinic acid polyesters are specifically excluded. Similarly, in certain embodiments of the invention, the use of aldehydes in solvents is specifically excluded.
The polyesters of the present invention may have relatively higher molecular weight and functionality compared to conventional linear polyester resins. Typically, the ratio of the weight average molecular weight ("Mw") of the branched polyester of the present invention to the Mw of the unsaturated polyester prepolymer is from 1.2 to 100, such as from 4 or from 5 to 50, although in certain embodiments it may be as high as from 1.2 to 500.
In certain embodiments, the branched polyesters of the present invention may have a Mw as low as 600, or may have a Mw greater than 1000, for example greater than 5000, greater than 10,000, greater than 15,000, greater than 25,000, or greater than 50,000. In some embodiments, molecular weights of 80,000-100,000 are particularly suitable. Molecular weights above 100,000, up to 10,000,000 can be obtained. The molecular weight increase can be controlled by one or more factors, such as the type and/or amount of initiator used, the temperature, and the type and/or amount of solvent.
In addition to the above molecular weights, the branched polyesters of the present invention may also have relatively high functionality; in some cases, the functionality is higher than expected for conventional polyesters having the molecular weight range. The average functionality of the polyester may be 2.0 or higher, such as 2.5 or higher, 3.0 or higher, or even higher. As used herein, "average functionality" refers to the average number of functional groups on the branched polyester. The functionality of the branched polyester is measured by the number of unreacted hydroxyl groups remaining in the branched polyester, rather than by unreacted unsaturation. In certain embodiments, the branched polyesters of the present invention may have a hydroxyl number of from 10 to 500mgKOH/g, for example from 30 to 250 mgKOH/g. In certain embodiments, the branched polyesters of the present invention have high Mw and high functionality, e.g., Mw ≧ 15,000, such as 20,000-40,000 or greater than 40,000, and functionality ≧ 100 mgKOH/g.
Perhaps more significant with the branched polyesters of the present invention is the viscosity. The polyester can have a viscosity of Z or less at 60% total solids as measured by Gardner-Holt bubble method. This is the case even if the Mw is 40,000-50,000, or even above 50,000. The viscosity is typically not obtainable with predominantly linear polyesters having such high molecular weights.
Since the polyester of the present invention comprises functionality, it is suitable for use in coating formulations in which hydroxyl groups (and/or other functionality) are crosslinked with crosslinkers and/or other resins typically used in coating formulations. The present invention therefore further relates to a coating comprising a branched polyester according to the invention and a crosslinker for use therein. The crosslinking agent, or crosslinking resin or agent, may be any suitable crosslinking agent or resin known in the art and selected to be capable of reacting with one or more functional groups on the polyester. It will be appreciated that the coatings of the present invention cure to the extent that any of the noted unsaturations are present in the branched polyester by reaction of the hydroxyl and/or other functional groups with the crosslinking agent, rather than by reaction of the double bonds of the polycarboxylic acid/anhydride/ester residues.
Non-limiting examples of suitable crosslinking agents include phenolic resins, amino resins, epoxy resins, isocyanate resins, beta-hydroxy (alkyl) amide resins, alkylated urethane resins, polyacids, anhydrides, organometallic acid-functional materials, polyamines, polyamides, aminoplasts, and mixtures thereof. In certain embodiments, the crosslinking agent is a phenolic resin comprising an alkylated phenol/formaldehyde resin having a functionality of 3 or more and a difunctional ortho-cresol/formaldehyde resin. Such cross-linking agents are commercially available from Hexion as BAKELITE 6520LB and BAKELITE 7081 LB.
Suitable isocyanates include polyfunctional isocyanates. Examples of the polyfunctional polyisocyanate include aliphatic diisocyanates such as hexane diisocyanate and isophorone diisocyanate; and aromatic diisocyanates such as toluene diisocyanate and 4, 4' -diphenylmethane diisocyanate. The polyisocyanate may be blocked or unblocked. Examples of other suitable polyisocyanates include isocyanurate trimers, uretdiones of diisocyanates, and allophanates, as well as polycarbodiimides, such as those disclosed in U.S. patent application 12/056,304 filed 3.27.2008, incorporated herein by reference in its relevant part. Suitable polyisocyanates are well known in the art and are widely commercially available. For example, suitable polyisocyanates are disclosed in U.S. patent application No. 6,316,119 at column 6, lines 19-36, which is incorporated herein by reference. Examples of commercially available polyisocyanates include DESMODUR VP2078 and DESMODUR N3390 sold by Bayer Corporation, and TOLONATE HDT90 sold by Rhodia Inc.
Suitable aminoplasts include condensates of amines and/or amides with aldehydes. For example, condensates of melamine with formaldehyde are suitable aminoplasts. Suitable aminoplasts are well known in the art. Suitable aminoplasts are disclosed, for example, in U.S. Pat. No. 6,316,119 at column 5, lines 45-55, which is incorporated herein by reference.
In preparing the coatings of the present invention, the branched polyester and the crosslinking agent may be dissolved or dispersed in a single solvent or a mixture of solvents. Any solvent capable of applying the formulation to a substrate may be used and is well known to those skilled in the art. Typical examples include water, organic solvents and/or mixtures thereof. Suitable organic solvents include glycols, glycol ether alcohols, ketones or aromatics, such as xylene and toluene, acetates, petroleum ether, naphtha and/or mixtures thereof. "acetate" includes glycol ether acetates. In certain embodiments, the solvent is a non-aqueous solvent. By "non-aqueous solvent" and like terms is meant that less than 50% of the solvent is water. For example, less than 10% or even less than 5% or 2% of the solvent may be water. It is understood that solvent mixtures comprising less than 50% of the amount of water or no water may constitute "non-aqueous solvents". In other embodiments, the coating is aqueous or water-based. This means that 50% or more of the solvent is water. These embodiments have less than 50%, e.g., less than 20%, less than 10%, less than 5%, or less than 2% solvent.
In certain embodiments, the coating of the present invention further comprises a cure accelerator. Any cure accelerator typically used to catalyze the crosslinking reaction between polyester resins and crosslinkers such as phenolic resins may be used. Examples of such curing catalysts include phosphoric acid, alkaryl sulfonic acids, dodecylbenzene sulfonic acid, dinonyl naphthalene sulfonic acid, and dinonyl naphthalene disulfonic acid.
If desired, the coating composition may include in any of its components other optional materials known in the art for formulating coatings, such as colorants, plasticizers, abrasion resistant particles, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow control agents, thixotropic agents, fillers, organic cosolvents, reactive diluents, catalysts, grinding media, and other conventional adjuvants.
As used herein, the term "colorant" refers to any substance that imparts color and/or other opacity and/or other visual effect to the composition. The colorant can be added to the coating in any suitable form, such as discrete particles, dispersions, solutions, and/or flakes. A single colorant or a mixture of two or more colorants can be used in the coating of the present invention.
Examples of colorants include pigments, dyes and tints, such as those listed in the Dry Color Manufacturers Association (DCMA) and/or used in the paint industry, as well as special effect compositions. Colorants can include, for example, finely divided solid powders that are insoluble but wettable under the conditions of use. The colorant may be organic or inorganic and may be agglomerated or unagglomerated. The colorant can be incorporated into the coating by grinding or simple mixing. The tinting agent can be incorporated by grinding the coating using grinding media well known to those skilled in the art, such as acrylic grinding media.
Examples of pigments and/or pigment compositions include, but are not limited to, carbazoles, dioxazine crude pigments, azos, monoazos, disazos, naphthol AS, salt forms (lakes), benzimidazolones, coagulates, metal complexes, isoindolinones, isoindolines and polycyclic phthalocyanines, quinacridones, perylenes, diketopyrrolylpyrroles, thioindigoids, anthraquinones, indanthrones, anthrapyrimidines, flavanthrones, pyranthrones, anthanthrones, dioxazines, triarylcarboniums, quinophthalone (quinophthalone) pigments, diketopyrrolopyrrole red ("DPPBO red"), titanium dioxide, carbon black, carbon fibers, graphite, other conductive pigments and/or fibers, and mixtures thereof. The terms "pigment" and "colored filler" are used interchangeably.
Examples of dyes include, but are not limited to, those that are solvent-based and/or water-based, such as acid dyes, azo dyes, basic dyes, direct dyes, disperse dyes, reactive dyes, solvent dyes, sulfur dyes, mordant dyes such as bismuth vanadate, anthraquinone, perylene aluminum, quinacridone, thiazole, thiazine, azo, indigoid dyes, nitro, nitroso, oxazine, phthalocyanine, quinoline, stilbene, and triphenylmethane.
Examples of COLORANTS include, but are not limited to, pigments dispersed in a water-based or water-miscible carrier, such as AQUA-CHEM 896, commercially available from Degussa, inc, and MAXITONER absorbent COLORANTS, commercially available from the Accurate Dispersion division of Eastman Chemicals, inc.
As noted above, the colorant may be in the form of a dispersion, including but not limited to a nanoparticle dispersion. Nanoparticle dispersions can include 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 include a colorant, such as a pigment or dye having a particle size of less than 150nm, for example less than 70nm or less than 30 nm. Nanoparticles can be produced by comminuting a starting organic or inorganic pigment with a grinding media having a particle size of less than 0.5 mm. Examples of nanoparticle dispersions and methods for their production are described in U.S. Pat. No. 6,875,800B2, which is incorporated herein by reference. Nanoparticle dispersions can also be produced by crystallization, precipitation, gas phase coagulation and chemical attrition (i.e., partial dissolution). To minimize re-agglomeration of nanoparticles in the coating, a resin-coated nanoparticle dispersion may be used. As used herein, a "resin-coated nanoparticle dispersion" refers to a continuous phase in which are dispersed discrete "composite microparticles" comprising nanoparticles and a resin coating on the nanoparticles. Examples of resin-coated nanoparticle dispersions and methods for their production are described in U.S. patent provisional application publication No. 2005-0287348a1, filed 24.6.2004, U.S. provisional application serial No. 60/482,167, filed 24.6.2003, and U.S. patent application serial No. 11/337,062, filed 20.1.2006, which are also incorporated herein by reference.
Examples of special effect compositions that may be used include pigments and/or compositions that produce one or more appearance effects such as reflectance, pearlescence, metallic sheen, phosphorescence, fluorescence, photochromism, photosensitivity, thermochromism, goniochromism (goniochromism), and/or discoloration. Additional special effect compositions may provide other perceptible properties, such as opacity or texture. In one non-limiting embodiment, the special effect composition can produce a color shift such that the color of the coating changes when the coating is viewed at different angles. Examples of color effect compositions are described in U.S. Pat. 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 is produced by refractive index differences between materials rather than by refractive index differences between the surface of the material and air.
In certain non-limiting embodiments, photosensitive compositions and/or photochromic compositions that reversibly change their color upon exposure to one or more light sources can be used in the coatings of the present invention. Photochromic and/or photosensitive compositions can be activated by exposure to radiation of a particular wavelength. When the composition is excited, the molecular structure changes, and the changed structure exhibits a new color that is different from the original color of the composition. When the radiation exposure is removed, the photochromic and/or photosensitive composition can return to its rest state (state of rest), wherein the original color of the composition is restored. In one non-limiting embodiment, the photochromic and/or photosensitive composition can be colorless in a non-excited state and exhibit color in an excited state. Complete discoloration can occur in milliseconds to minutes, such as 20 seconds to 60 seconds. Examples of photochromic and/or photosensitive compositions include photochromic dyes.
In one non-limiting embodiment, the photosensitive composition and/or photochromic composition can be associated with and/or at least partially bonded to the polymeric material of the polymer and/or polymerizable component, such as by a covalent bond. In contrast to some coatings where the photosensitive composition may bleed out of the coating and crystallize into the substrate, according to a non-limiting embodiment of the present invention, the photosensitive composition and/or photochromic composition associated with and/or at least partially bonded to the polymer and/or polymerizable component has minimal bleed out of the coating. Examples of photosensitive and/or photochromic compositions and methods for their production are set forth in U.S. application serial No. 10/892,919 filed on 7, 16, 2004, which is incorporated herein by reference.
Generally, the colorant can be present in an amount sufficient to provide a desired visual and/or color effect. The colorant may comprise from 1 to 65 weight percent, such as from 3 to 40 weight percent, or from 5 to 35 weight percent of the composition of the present invention, as a weight percent based on the total weight of the composition.
"wear resistant particles" are materials that, when used in a coating, impart some wear resistance to the coating as compared to a coating lacking the particles. Suitable wear resistant particles include organic and/or inorganic particles. Examples of suitable organic particles include, but are not limited to, diamond particles such as diamond powder particles, and particles formed from carbide materials; examples of carbide particles include, but are not limited to, titanium carbide, silicon carbide, and boron carbide. Examples of suitable inorganic materials include, but are not limited to, silica, alumina, aluminum silicates, silica alumina, alkali metal aluminosilicates, borosilicate glasses, nitrides including boron nitride and silicon nitride, oxides including titanium dioxide and zinc oxide, quartz, nepheline syenite, e.g., zircon in the form of zirconia, baddeleyite, and xenolite. Particles of any size may be used, as may mixtures of different particles and/or different sized particles. For example, the particles may be microparticles having an average particle size of 0.1 to 50, 0.1 to 20, 1 to 12, 1 to 10, or 3 to 6 microns or any combination of any of these ranges. The particles may be nanoparticles having an average particle size of less than 0.1 micron, such as 0.8-500, 10-100 or 100-500 nm or any combination of these ranges.
In certain embodiments, the polyesters of the present invention are used as coating additives. For example, the polyesters of the present invention have been found to be useful in coating formulations comprising metal foils in place of all or part of sag control agents such as cellulose esters. With the coatings of the present invention, suitable orientation of the metal foil in the cured coating has been observed when the branched polymer comprises from 1.0 wt% to 80.0 wt%, for example from 20 to 60 wt% or from 45 to 55 wt%, based on the total weight of the coating solids. Particularly good results are observed when the Mw of the branched polyester is 80,000 or more, for example 90,000-100,000.
It is to be understood that the polyester and crosslinker of the invention may form a film-forming resin for full or partial coatings. In certain embodiments, one or more other film-forming resins may also be used in the coating. For example, the coating composition can comprise any of a variety of thermoplastic and/or thermosetting compositions known in the art. The coating composition may be a water-based or solvent-based liquid composition, or alternatively, may be in the form of solid particles, i.e. a powder coating.
Thermosetting or curable coating compositions typically comprise a film-forming polymer or resin having functional groups that can react with itself or with a crosslinking agent. Other film-forming resins can be selected from, for example, acrylic polymers, polyester polymers, polyurethane polymers, polyamide polymers, polyether polymers, polysiloxane polymers, copolymers thereof, and mixtures thereof. In general, these polymers may be any of these types of polymers prepared by any method known to those skilled in the art. The polymers may be solvent-based or water-dispersible, emulsified or of limited water solubility. The functional groups on the film-forming resin can be selected from any of a variety of reactive functional groups including, for example, carboxylic acid groups, amine groups, epoxy groups, hydroxyl groups, thiol groups, carbamate groups, amide groups, urea groups, isocyanate groups (including blocked isocyanate groups), mercapto groups, and combinations thereof. Suitable mixtures of film-forming resins can also be used in the preparation of the coating compositions of the present invention.
The thermosetting coating composition typically comprises a crosslinker that may be selected from any of the crosslinkers described above. In certain embodiments, the coatings of the present invention comprise a thermosetting film-forming polymer or resin, and a crosslinker therefor, which may be the same or different from the crosslinker used to crosslink the polyester. In certain other embodiments, a thermosetting film-forming polymer or resin having functional groups capable of reacting with itself is used in a manner that renders the thermosetting coating self-crosslinking.
The coating of the present invention may comprise from 1 to 100, for example from 10 to 90 or from 20 to 80% by weight of the polyester of the present invention, in% by weight based on the total weight of coating solids. The coating composition of the present invention may further comprise 0 to 90, such as 5 to 60 or 10 to 40 weight percent of a crosslinking agent for the branched polyester, based on the weight percent of the total coating solids. If used, other components comprise from 1 wt% up to 70 wt% or more, based on the total weight of the coating solids.
The coating formulations according to the invention can have a significant improvement in the cure response and/or bending flexibility, and/or a significant improvement in mechanical deformation and/or antibacterial properties, compared to conventional polyesters. Surprisingly, it was found that the durability of the coating of the invention is very high; namely, the gloss retention of the coating of the invention after 200 hours in a xenon arc aging tester is more than or equal to 70 percent. The coatings of the present invention also exhibit good flexibility and hardness. More specifically, the coatings of the present invention can have a flexibility of 20-25% multi-spot failure, or even 15-20% multi-spot failure, as measured by mandrel bending (sometimes referred to as wedge bending) according to ASTM method D522-93. The coating of the invention may also have a hardness of 80-140N/mm as measured by the Fischer-Micro hardness test2E.g. 110-140N/mm2The hardness of (2). Those skilled in the art will appreciate that achieving this level of flexibility and hardness in the same coating is a significant achievement. Typically, to obtain another shapeFormula (i) requires a sacrifice in one of flexibility or stiffness.
In certain embodiments of the present invention, the polyester and/or coating comprising the polyester is substantially free of epoxy groups. As used herein, the term "substantially epoxy-free" means that the polyester resin and/or coating comprising the same is substantially free of epoxy groups, epoxy residues, oxirane rings or oxirane ring residues, adducts of bisphenol A, BADGE or BADGE, adducts of bisphenol F, BFDGE or BFDGE. In certain other embodiments of the present invention, the polyester and/or coating comprising the same is substantially free of bisphenols or residues thereof, including bisphenol a, bisphenol F, BADGE and BFDGE. The polyester and/or coating comprising the same may also be substantially free of polyvinyl chloride or related halide-containing vinyl polymers. By "substantially free" it is meant that the polyester and/or coating comprises 10 wt.% or less, such as 5 wt.% or less, 2 wt.% or less, or 1 wt.% or less, based on the total weight of solids, of the compound described herein or otherwise known. Thus, it is to be understood that the polyesters and/or coatings according to the present invention may contain trace or small amounts of these components and still be "substantially free" of them. In yet other embodiments, the polyester and/or coating comprising the same is completely free of any of the above compounds or derivatives thereof.
The coatings of the present invention can be applied to any substrate known in the art, such as automotive substrates, industrial substrates, packaging substrates, wood flooring materials and furniture, apparel, electronic devices including housings and circuit boards, glass and transparencies, and sporting equipment including golf balls, and the like. These substrates may be metallic or non-metallic, for example. The metal substrate comprises tin, steel, tin-plated steel, chromium-passivated steel, galvanized steel, aluminum and aluminum foil. Non-metallic substrates include polymers, plastics, polyesters, polyolefins, polyamides, celluloses, polystyrenes, polyacrylics, poly (ethylene naphthalate), polypropylene, polyethylene, nylons, EVOH, polylactic acid, other "green" polymer substrates, poly (ethylene terephthalate) ("PET"), polycarbonate acrylonitrile butadiene styrene ("PC/ABS"), polyamides, wood, veneer, engineered wood materials, particle board, medium density fiberboard, cement, stone, glass, paper, cardboard, textiles, and synthetic and natural leathers, and the like. The substrate may be treated in some manner, for example to provide visual and/or color effects.
The coatings of the present invention can be applied by any process standard in the art, such as electrocoating, spraying, electrostatic spraying, dipping, rolling, brushing, and the like.
The coating may be applied to a dry film thickness of 0.04 mils to 4 mils, such as 0.3 to 2 or 0.7 to 1.3 mils. In other embodiments, the coating may be applied to a dry film thickness of 0.1 mils or greater, 0.5 mils or greater, 1.0 mils or greater, 2.0 mils or greater, 5.0 mils or greater, or even greater. The coatings of the present invention may be used alone or in combination with one or more other coatings. For example, the coatings of the present invention may or may not contain colorants and may be used as primers, basecoats, and/or topcoats. For substrates coated with multiple coatings, one or more of these coatings may be a coating as described herein. The coatings of the present invention may also be used as packaging "size" coatings, wash coats, spray coats, and end-coats, among others.
It is to be understood that the coatings described herein may be single component ("1K") or multi-component compositions such as two-component ("2K") or more. A 1K composition is understood to mean a composition which retains all coating components in the same container after production, during storage, etc. The 1K coating may be applied to the substrate and cured by any conventional means, such as heat and pressurized air, and the like. The coating of the present invention may also be a multi-component coating, which is understood to maintain the various components separately prior to application. As mentioned above, the coating of the present invention may be thermoplastic or thermosetting.
In certain embodiments, the coating is a clear coating. Transparent coatings are understood to be substantially transparent coatings. Thus, the clear coating can have a degree of chroma as long as it does not make the clear coating opaque to any significant degree or otherwise affect the ability to see the underlying substrate. The clearcoats of the invention can be used, for example, in conjunction with pigmented basecoats. The clearcoat layer can be formulated in a manner known in the coating art.
In certain embodiments, the coating is used as a primer, such as a chip resistant primer. Chipping primer coating compositions are known in the automotive OEM industry and are typically applied to various locations on a vehicle, such as the front door edge, the fender, the canopy and the a-pillar of the vehicle, prior to application of the primer-topcoat coating composition over the entire body of the vehicle. In certain embodiments, the chipping primer coating composition is not cured prior to application of one or more subsequent coatings. Instead, the chipping primer coating composition may be subjected to an ambient flash (ambient flash) step in which it is exposed to ambient air for a period of time to allow a portion of the organic solvent to evaporate from the chipping primer coating composition. The curing of the chipping primer coating composition is performed simultaneously with (co-curing) one or more other coating layers. Primers according to the present invention that include a chipping primer typically contain some colorant and are typically used with one or more other coating layers, such as after an electrocoat and before a primer top coat, a pigmented base coat, and a clear coat.
In certain embodiments, the coating comprises a colorant, such as a colored basecoat used in conjunction with a clearcoat, or a colored monocoat. The coatings are used, for example, in the automotive industry to impart decorative and/or protective finishes to coated substrates. Accordingly, the present invention further relates to a substrate at least partially coated with the coating of the present invention, wherein the substrate comprises a vehicle component. "vehicle" is used herein in its broadest sense to include a variety of vehicles such as, but not limited to, cars, trucks, buses, recreational vehicles, golf carts, motorcycles, bicycles, railroad cars, and the like. It should be understood that the portion of the vehicle coated according to the present invention may vary depending on the reason the coating is used. For example, the debris resistant primer may be applied to certain portions of the vehicle as described above. When used as a colored basecoat or monocoat, the coatings of the present invention are typically applied to the visible portions of the vehicle, such as the roof, hatch, door, etc., but may also be applied to other areas, such as the interior of the vehicle body and the interior of the door, etc. The clear coat is typically applied to the exterior of the vehicle.
Coil coatings having a wide range of applications in numerous industries are also within the scope of the invention; as mentioned above, the coating of the present invention is particularly suitable as a coil coating due to its unique combination of flexibility and hardness. Coil coatings also typically contain colorants.
The coatings of the present invention are also suitable for use as packaging coatings. The use of various pretreatment and packaging coatings has been well established. Such pretreatments and/or coatings may be used in the context of metal cans, where the treatments and/or coatings are used to retard or inhibit corrosion, provide a decorative coating, provide ease of handling during production, and the like. A coating may be applied to the interior of the can to prevent the contents from contacting the metal of the container. Contact between the metal and the food or beverage can, for example, lead to corrosion of the metal container, which can then contaminate the food or beverage. This is true when the contents of the canister are acidic. Coatings applied to the interior of the metal also help prevent corrosion of the can top, which is the area between the product filling line and the can lid; top corrosion is a significant problem for foods with high salt content. Coatings may also be applied to the exterior of metal cans, and certain coatings of the present invention are particularly suitable for use with coil metal stock, such as coil metal stock used to produce can ends ("can end stock"), and end caps (end caps) and closures ("cap/closure stock"). Since coatings designed for can end stock and cover/baffle stock are typically applied prior to cutting and stamping the coil metal stock into sheets, they are typically flexible and ductile. For example, the feedstock is typically double coated. The coated metal stock is then stamped. For can ends, a tab opening score is then formed in the metal and the tab is joined to a separately made pin. The ends are then attached to the can body by an edging process. A similar process is performed on an easy open can end. For easy open can ends, a score substantially around the circumference of the lid enables the lid to be easily opened and removed from the can, typically by pulling on a tab. For the cover/baffle, the cover/baffle stock is typically coated, such as by roll coating, and the cover and baffle are stamped from the stock; however, the cover/baffle may be applied after molding. Can coatings that implement relatively stringent temperature and/or pressure requirements should also be resistant to impact, corrosion, hazing, and/or blistering.
Accordingly, the present invention further relates to a package at least partially coated with any of the above coating compositions. In certain embodiments, the package is a metal can. The term "metal can" includes any type of metal can, container, or any type of receptacle or portion thereof for holding items. One example of a metal can is a food can; the term "food can" as used herein refers to a can, container or any type of receptacle or portion thereof for holding any type of food and/or beverage. The term "metal can" specifically includes food cans and also specifically "can ends" which are typically stamped from can end stock and used in conjunction with beverage packaging. The term "metal can" also includes in particular metal lids and/or closures, such as bottle caps, screw tops and lids of any size and pull-caps and the like. Metal cans can be used to hold other items as well as food and/or beverages including, but not limited to, personal care products, insecticidal sprayers, spray paint, and any other compound suitable for packaging in aerosol cans. These cans may include "two-piece cans" and "three-piece cans," as well as drawn and ironed one-piece cans; such unitary canisters are common in aerosol product applications. Packages coated according to the present invention may also include plastic bottles, plastic tubes, sheets and flexible packages such as those produced from PE, PP, PET and the like. The package may hold, for example, food, toothpaste, personal care products, and the like.
The coating may be applied to the interior and/or exterior of the package. For example, the coating may be roll coated onto metal used to produce two-piece food cans, three-piece food cans, can end stock, and/or lid/baffle stock. In certain embodiments, the coating may be applied to the coil or sheet by roll coating; the coating is then radiation cured and the can end is stamped to produce the final product, the can end. In other embodiments, the coating is applied to the can ends as an edge coating; the coating may be performed by roll coating. The edge coating acts to reduce friction to improve handling during continuous production and/or processing of the can. In certain embodiments, the coating is applied to the cover and/or baffle; the coating includes, for example, a colored finish applied to the lid at the lid/baffle and/or post, particularly those with score joints at the lid base, pre-and/or post-formed protective varnishes. The decorative can stock can also be partially coated externally with the coatings described herein, and the decorative coated can stock is used to form a variety of metal cans.
Substrates coated according to the present invention can be coated with any of the above compositions by any means known in the art such as spraying, rolling, dipping, brushing, flow coating, and the like; when the substrate is electrically conductive, the coating may also be applied by electrocoating. Suitable coating means can be determined by the person skilled in the art depending on the type of substrate to be coated and the effect of the coating used. If desired, the above-described coating may be applied to the substrate in single or multiple layers by multiple stages of heating between each layer application. After the substrate is coated, the coating composition can be cured by any suitable means.
As used herein, unless otherwise specified, all numbers such as those expressing values, ranges, amounts or percentages are to be considered as being preceded by the word "about", even if the term does not expressly appear. Moreover, any numerical range recited herein is intended to include all lower ranges subsumed therein. Singular encompasses plural and vice versa. For example, although "a" polyester, "a" unsaturated acid/anhydride/ester, "a" polyol prepolymer, "a" hard segment, "a" polyol segment, and "a" crosslinker, etc., are used herein, one or more of these components and any other components may be used. As used herein, the term "polymer" refers to oligomers as well as homopolymers and copolymers, and the prefix "poly" refers to two or more. The terms "include", "including" and the like mean including but not limited to. Where ranges have been given, ranges and/or numerical endpoints within these ranges can be incorporated within the scope of the present invention.
Examples
The following examples are intended to illustrate the invention and should not be construed as limiting it in any way.
Example 1
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| 2-methyl-1, 3-propanediol | 900 |
| Neopentyl glycol | 520 |
| Isophthalic acid | 1661 |
| Maleic anhydride | 245 |
| Butyl Stannoic acid | 3.33 |
| Phosphorous acid triphenyl ester | 1.66 |
A total of 900 grams of 2-methyl-1, 3-propanediol, 520 grams of neopentyl glycol, 1661 grams of isophthalic acid, 245 grams of maleic anhydride, 3.33 grams of butyl stannoic acid, and 1.66 grams of triphenyl phosphite are added to a suitable reaction kettle equipped with a stirrer, a temperature probe, a heated vapor reflux condenser with a distillation head, and a nitrogen sparge. The contents of the flask were heated to 90 ℃. At this temperature, the contents exothermed to 125 ℃. The reaction was then heated to 174 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 200 c, then 210 c and finally to 220 c and maintained at that temperature until 405 g of water was distilled off, and the acid value of the reaction mixture was measured to be 11.8. The reactor contents were cooled and discharged. The final material was a solid material having a measured solids of 99.5%, a hydroxyl number of 95.8 and a weight average molecular weight of 3144 as measured on a polystyrene standard.
Example 2
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| Example 1 | 1800 |
| Tert-butyl peroctoate (50% solution) | 18 |
| Tert-butyl peroctoate (50% solution) | 18 |
| Dowanol PM acetate | 596 |
| Dowanol PM | 596 |
A total of 1800 grams of polyester example 2a was placed in a suitable reaction kettle equipped with a stirrer, temperature probe, reflux condenser and nitrogen enclosure. A total of 596 grams of Dowanol PM acetate and 524 grams of Dowanol PM were added to the resin and mixed well. The flask contents were heated to 120 ℃. Over 15 minutes, a mixture of 18 grams of t-butyl peroctoate (50% solution) mixed with 36 grams of Dowanol PM was added dropwise to the reactor contents. The batch was held at 120 ℃ for 1 hour. A second mixture consisting of 18 grams of t-butyl peroctoate (50% solution mixed with 36 grams of Dowanol PM) was then added dropwise to the reactor contents over 15 minutes. The reactor contents were again held at 120 ℃ for 1 hour. The reactor contents were then cooled and discharged. The final resin had a measured solids of 60%, a Gardner-Holt viscosity of X, and a weight average molecular weight of 13833 as measured against a polystyrene standard.
Example 3a
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| 2-methyl-1, 3-propanediol | 810 |
| Neopentyl glycol | 468 |
| Isophthalic acid | 1495 |
| Benzoic acid | 158 |
| Maleic anhydride | 220 |
| Butyl Stannoic acid | 3.15 |
| Phosphorous acid triphenyl ester | 1.58 |
A total of 810 grams of 2-methyl-1, 3-propanediol, 468 grams of neopentyl glycol, 1495 grams of isophthalic acid, 158 grams of benzoic acid, 220 grams of maleic anhydride, 3.15 grams of butyl stannoic acid, and 1.58 grams of triphenyl phosphite are added to a suitable reaction kettle equipped with an agitator, a temperature probe, a heated vapor reflux condenser with a distillation head, and a nitrogen sparge. The flask contents were heated to 90 ℃. At this temperature, the material exothermed to 127 ℃. The reaction was then heated to 174 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 200 c, then to 210 c and finally to 220 c and maintained at that temperature until 356 g of water was distilled off, and the acid number of the reaction mixture was measured to be 9.2. The reactor contents were cooled and discharged. The final material was a solid material having a measured solids of 99.7%, a hydroxyl number of 66 and a weight average molecular weight of 3109 as measured based on polystyrene standards.
Example 3
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| Example 3a | 1800 |
| Tert-butyl peroctoate (50% solution) | 18 |
| Tert-butyl peroctoate (50% solution) | 18 |
| Dowanol PM acetate | 596 |
| Dowanol PM | 596 |
A total of 1800 grams of polyester example 3a was placed in a suitable reaction kettle equipped with a stirrer, temperature probe, reflux condenser and nitrogen blanker. A total of 596 grams of Dowanol PM acetate and 524 grams of Dowanol PM were added to the resin and mixed well. The flask contents were heated to 120 ℃. Over 15 minutes, a mixture of 18 grams of t-butyl peroctoate (50% solution) mixed with 36 grams of Dowanol PM was added dropwise to the reactor contents. The batch was held at 120 ℃ for 1 hour. A second mixture consisting of 18 grams of t-butyl peroctoate (50% solution mixed with 36 grams of Dowanol PM) was then added dropwise to the reactor contents over 15 minutes. The reactor contents were again held at 120 ℃ for 1 hour. The reactor contents were then cooled and discharged. The final resin had a measured solids of 61%, a Gardner-Holt viscosity of X, and a weight average molecular weight of 14584 as measured against a polystyrene standard.
Example 4
Table 1 lists the ingredients used to produce two clear coats (samples 1 and 2) and a pigmented base coat (sample 3) using the free radical ester resins of the present invention:
TABLE 1
| Components | Sample 1 | Sample 2 | Sample 3 |
| SOLVESSO 1001 | 32.35 | 31.81 | 32.68 |
| DOWANOL DPM2 | 32.35 | 31.81 | 22.68 |
| EVERSORB 743 | 2.50 | 2.50 | 2.50 |
| EVERSORB 934 | 0.50 | 0.50 | 0.50 |
| SETAMINE US 1385 | 42.86 | 42.86 | 42.86 |
| Polyester resin of example 26 | 116.09 | 0 | 88.91 |
| Polyester resin of example 37 | 0 | 114.75 | 0 |
| Flow additive8 | 0.83 | 0.83 | 0.83 |
| Dodecyl benzene sulfonic acid9 | 0.57 | 0.57 | 0.57 |
| White pigment paste10 | 0 | 0 | 97.01 |
1Aromatic solvents obtained from Exxon Corporation.
2Glycol ether solvents available from Dow Chemical Company.
3UV absorbers available from Everlight Chemical Industrial Corporation.
4Hindered amine light stabilizers available from Everlight Chemical Industrial Corporation.
5Melamine Resins obtained from Nuplex Resins.
6Polyester resin of example 2: 27.0% 2-methyl-1, 3-propanediol, 15.6% neopentyl glycol, 49.9% isophthalic acid and 7.4% maleic anhydride, Mw =13,833.
7Polyester resin of example 3: 25.7% 2-methyl-1, 3-propanediol, 14.8% neopentyl glycol, 5.0% benzoic acid47.4% isophthalic acid and 7.0% maleic anhydride, Mw =14,584.
8Poly (butyl acrylate) flow additive available from DuPont.
9Acid catalysts available from Cytec Industries.
10A white pigment paste was prepared in solvent using 67% of Tiona 595 titanium dioxide from MILLENIUM INORGANICS, 10.3% of PPG polyester resin and 4.4% of CYTEC INDUSTRIES FM 003V60 melamine resin to yield 83.9% solids by weight.
The clear coat was spray coated on a 4 inch x 12 inch steel panel coated with a cured ELECTROCOAT (ED6060)/PPG HP77224ER primer obtained from ACT Test Panels, Inc. of Hillsdale, Michigan using a SPRAYMATION machine. A water-based black coating available from PPGIndsdustries (HWH-9517) was sprayed on an E-Coat board at a total dry film thickness of 0.5 mils prior to clearcoat application. The water-based black coating was dehydrated at 176 ° f for 10 minutes before clear coating. After clear coat and 10 minutes room temperature flash, the entire stack was baked at 285 ° f for 30 minutes.
The white coating was sprayed on a 4 inch x 12 inch steel panel coated with a cured ELECTROCOAT (ED6060)/PPG HP77224ER primer obtained from ACT Test Panels, Inc. of Hillsdale, Michigan using a SPRAYMATION machine. After the white coating was applied to the substrate, a 10 minute room temperature flash was performed. The coating was baked at 285 ° f for 30 minutes.
Table 2 provides the appearance and physical properties obtained from each of the above samples.
TABLE 2
11Dry film thickness was measured using a fish DELTACOPE produced by inc, fisher techlology, CT., Windsor.
12NOVO GLOSS statistical 20 ℃ glossmeter available from Paul N.Gardner Company of Pompano Beach, Florida.
13DOI meter obtained from TRICOR System of Elgin, Illinois.
14Helmut Fischer GMBH from Sindelfingen, Germany&Microhardness instruments available from Company.
15Lab Car Wash tester available from AMTEC-KISTLER GmbH of Prattesching, Germany. 20 ° gloss was measured before and after 10 washes in the laboratory.
16400 ml of 38% sulfuric acid droplets were placed on each plate for three days and the resulting lesions were recorded. The rating scale is: 0= OK/1= light ring/2 = ring/3 = light white and/or blistering/4 = white&Swelling, matte, strong blistering/5 = overall damage.
The results shown in table 2 show that transparent and pigmented coatings with adequate properties can be obtained according to the invention.
Example 5
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| 1, 3-butanediol | 1218 |
| Isophthalic acid | 1495 |
| Maleic anhydride | 221 |
| Butyl Stannoic acid | 2.93 |
| Phosphorous acid triphenyl ester | 1.47 |
A total of 1218 grams of 1, 3-butanediol, 1495 grams of isophthalic acid, 221 grams of maleic anhydride, 2.33 grams of butyl stannoic acid, and 1.47 grams of triphenyl phosphite are added to a suitable reaction kettle equipped with an agitator, a temperature probe, a heated vapor reflux condenser with a distillation head, and a nitrogen sparge. The flask contents were heated to 90 ℃. At this temperature, the material exothermed to 115 ℃. The reaction was then heated to 181 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 200 c, then to 210 c and finally to 220 c and maintained at that temperature until 385 g of water was distilled off, and the acid value of the reaction mixture was found to be 11.4. The reactor contents were cooled and discharged. The final material was a solid material having a measured solids of 98%, a hydroxyl number of 82 and a weight average molecular weight of 3239 as measured on a polystyrene standard.
Example 6
A polyester resin was prepared from the following ingredients.
| Composition (I) | Parts by weight (gram) |
| Polyester of example 5 | 500 |
| Tert-butyl peroctoate (50% solution) | 5 |
| Tert-butyl peroctoate (50% solution) | 5 |
| Dowanol PM | 165 |
| Dowanol PM acetate | 165 |
A total of 500 grams of the polyester of example 6, 126 grams of Dowanol PM and 166 grams of Dowanol PM acetate were added to a suitable reaction kettle equipped with a stirrer, temperature probe, water cooled reflux condenser and flushed with nitrogen. The flask contents were heated to 120 ℃. At this point, 5 grams of t-butyl peroctoate mixed with 20 grams of Dowanol PM was added to the reactor over 15 minutes. The reactor contents were then held at 120 ℃ for 1 hour. At this point, 5 grams of t-butyl peroctoate additionally mixed with 20 grams of Dowanol PM was added to the reactor. The reactor contents were held at 120 ℃ for 2 hours, then cooled and the contents discharged. The final material was a solution having a measured solids of 61%, an acid number of 5.7 and a viscosity of Z1, with a weight average molecular weight of 67704 as measured against a polystyrene standard.
Example 7
Preparation of a polyester from
| Composition (I) | Parts by weight (gram) |
| 1, 3-butanediol | 460 |
| Isophthalic acid | 865 |
| Butyl Stannoic acid | 1.02 |
A total of 460 grams of 1, 3-butanediol, 565 grams of isophthalic acid and 1.02 grams of butyl stannoic acid were added to a suitable reaction kettle equipped with a stirrer, a temperature probe, a heated vapor reflux condenser with distillation head and a nitrogen sparge. The flask contents were heated to 90 ℃. At this temperature, the material exothermed to 126 ℃. The reaction was then heated to 201 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 211 ℃ and finally to 221 ℃ and maintained at this temperature until 122 g of water were distilled off, and the acid value of the reaction mixture was found to be 10.3. The reactor contents were cooled and discharged. The final material was a solid material with a measured solids of 96%, a hydroxyl number of 196 and a weight average molecular weight of 1448 as measured against a polystyrene standard.
Example 8
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| Polyester of example 7 | 532 |
| Maleic anhydride | 49 |
| 2, 6-di-tert-butyl-4-methylphenol | 0.17 |
A total of 532 grams of the polyester of example 7, 49 grams of maleic anhydride and 0.17 gram of 2, 6-di-tert-butyl-4-methylphenol were added to a suitable reaction kettle equipped with a stirrer, a temperature probe, a heated vapor reflux condenser with distillation head and a nitrogen sparge. The flask contents were heated to 92 ℃. The contents then exothermed to 138 ℃. The reaction was then heated to 201 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 203 ℃ and maintained at that temperature until 2 g of water was distilled off, and the acid value of the reaction mixture was found to be 8.2. The reactor contents were cooled and discharged. The final material was a solid material with a measured solids of 100%, a hydroxyl number of 65 and a weight average molecular weight of 4073 as measured on a polystyrene standard.
Example 9
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| Polyester of example 8 | 350 |
| Tert-butyl peroctoate | 21 |
| Tert-butyl peroctoate | 21 |
| Xylene | 176 |
A total of 350 grams of the polyester of example 8 and 155 grams of xylene were added to a suitable reaction kettle equipped with a stirrer, temperature probe, water cooled reflux condenser and flushed with nitrogen. The flask contents were heated to 120 ℃. At this point, 21 grams of t-butyl peroctoate mixed with 10.5 grams of xylene was added to the reactor. The reactor contents were then held at 120 ℃ for 1 hour. At this point, 21 grams of t-butyl peroctoate additionally mixed with 10.5 grams of xylene were added to the reactor. The reactor contents were held at 120 ℃ for 1 hour, then cooled and the material was removed. The final material was a solution having a measured solids of 61%, an acid number of 2.7, and a viscosity of Z3-Z4, and a weight average molecular weight of 120,432 as measured against a polystyrene standard.
Example 10
Coatings were produced using the polyesters prepared according to examples 6 and 9 above. All coating components shown in table 3 below were stirred from top to bottom.
TABLE 3
17Phenodur PR 16, commercially available from Cytec.
For the epoxy control (PPG2004877) and coatings produced according to the invention (10A and B), the coatings were made to 4 mg/square inch dry coating weight by using #14 and #12 wire wound bars. All coatings were applied on 0.2ETP (tin-plated steel) and TFS (tin-free steel) as received. All coated panels were baked at 410 ° F for 12.5 minutes and at 400 ° F peak metal temperature for 10 minutes. The coated panels were cut into 2 x 4.5 inch pieces to perform the wedge bend test, and 2 x 4 inch pieces to perform the test in a food simulant. After wedge bending the panels were soaked in 10% copper sulfate aqueous solution for 1 minute, the percent of spot failure was observed along the bend radius to evaluate the deflection of the coating. MEK rubs were performed with red cloth. As shown in table 4 below, pieces of the coated metal plate were dipped into a plurality of food simulants and autoclaved at 130 ℃ for 60 minutes.
TABLE 4
AWedge bending, a higher percentage of multi-spot failures indicates higher failures. The test was carried out according to STM0609, but with steel; after the steel test samples were wedge bent, they were immersed in 10% copper sulfate aqueous solution for 2 minutes instead of overnight.
BPencil hardness, higher numbers reflect harder coatings. Hardness of pencilThe test was performed according to ASTM D3363-92 a.
CDrying and adhering: 0-100(0=0% shrinkage, 100=100% coating shrinkage). The dry adhesion was tested by using a razor blade to cut 11 lines parallel and orthogonal to the length of the coated metal. The resulting reticle grid area is 0.50 "x 0.50" to 0.75 "x 0.75" square. Adhesion was evaluated using a 3M Scotch 610 tape, which was firmly attached to the delineated grid area by rubbing with a finger several times before tearing it open. After tearing the tape, adhesion was visually assessed on a scale of 0 (complete removal of coating) to 100% (no removal of coating).
DTurning red: scale 0-4 (0= no reddening, 4= opaque). For resistance to reddening and wet adhesion: the coated panels were cut into 2 "x 4" sample pieces and placed in jars containing deionized water or various food simulants at room temperature. The tank containing enough test liquid intentionally covered only half of the area of the total test coupon to evaluate the coating performance at the top of the vessel, the liquid level and the submerged area. The cans were then sealed with aluminum foil and placed in a sterilizer at 130 ℃ for 60 minutes (very harsh conditions). When the sterilizer was opened and cooled, the sealed test tank was immediately removed from the sterilizer and the hot deionized water or food simulant was drained from the test tank and replaced with hot tap water to completely submerge the test coupon. The test coupons were removed from the hot tap water and patted dry with a laboratory wipe, at which time redness and sticking were immediately assessed. Resistance to reddening was assessed by visually observing reddening in all three areas of the test coupon and recording only the ratings of the poorly reddened areas. The rating turned red on a 0 (no) to 4 (turbid) scale relative to the reddened sampling sheet standard. Coating adhesion was evaluated by taking the center of the bar at the liquid level using the procedure and scale described in dry adhesion.
Table 4 compares the performance of an epoxy-phenolic can coating commercially obtained from PPG with two coatings prepared according to the invention. The coatings of the present invention are very hard but still have relatively good flexibility. As previously mentioned, it is difficult to obtain hardness and flexibility in the same coating. Furthermore, better reddening and sticking results are unexpected. Polyesters that perform well in these areas are not known in the art. Thus, coatings prepared according to the present invention can provide results comparable to epoxy-phenolic coatings.
Example 11
Resin A-comparative example
(commercial polyester)
| Comparative example | Parts by weight (gram) |
| Neopentyl glycol | 39 |
| Isophthalic acid | 34 |
| Adipic acid | 17 |
| Trimethylolpropane | 10 |
| Molecular weight of resin | 10,900 |
Example B-1
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| 2-methyl-1, 3-propanediol | 338 |
| Neopentyl glycol | 390 |
| Isophthalic acid | 415 |
| Adipic acid | 365 |
| Maleic anhydride | 123 |
| Butyl Stannoic acid | 1.63 |
| Phosphorous acid triphenyl ester | 0.82 |
A total of 338 grams of 2-methyl-1, 3-propanediol, 390 grams of neopentyl glycol, 415 grams of isophthalic acid, 365 grams of adipic acid, 123 grams of maleic anhydride, 1.63 grams of butyl stannoic acid, and 0.82 grams of triphenyl phosphite were added to a suitable reaction kettle equipped with an agitator, a temperature probe, a heated vapor reflux condenser with a distillation head, and a nitrogen sparge. The flask contents were heated to 90 ℃ and allowed to exotherm to 141 ℃. The reaction was then heated to 176 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 200 c, then to 210 c and finally to 221 c and maintained at this temperature until 200 g of water was distilled off, and the acid value of the reaction mixture was measured to be 6.4. The reactor contents were cooled and discharged. The final material was a solid material having a measured solids of 99%, a hydroxyl number of 92.7 and a weight average molecular weight of 3440 as measured on a polystyrene standard.
Resin B
A polyester resin was prepared from the following ingredients:
| composition (I) | Weight average molecular weight (g) |
| Example B-1 | 500 |
| Tert-butyl peroctoate (50% solution) | 10 |
| Tert-butyl peroctoate (50% solution) | 10 |
| Tert-butyl peroctoate (50% solution) | 10 |
| Dowanol PM | 132 |
| Dowanol PM acetate | 145 |
A total of 500 grams of example B-1 and 132 grams of Dowanol PM were added to a suitable reaction kettle equipped with a stirrer, temperature probe, water cooled reflux condenser and flushed with nitrogen. The flask contents were heated to 120 ℃. At this point, 10 grams of t-butyl peroctoate mixed with 119 grams of Dowanol PM was added to the reactor over 15 minutes. The reactor contents were then held at 120 ℃ for 1 hour. At this point, a second 10 gram aliquot of t-butyl peroctoate mixed with 13 grams of Dowanol PM was added to the reactor. The reactor contents were held at 121 ℃ for 1 hour, then a third 10 gram aliquot of t-butyl peroctoate mixed with 13 grams of Dowanol PM was added to the reactor. The reaction mixture was again held at 120 ℃ for 1 hour. The contents were then cooled and discharged. The final material was a solution having a measured solids of 64%, an acid number of 7.2 and a viscosity of Z1+, with a weight average molecular weight of 91,529 measured based on polystyrene standards.
Resin C
A polyester resin was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| Example B-1 | 606 |
| Tert-butyl peroctoate (50% solution) | 12 |
| Tert-butyl peroctoate (50% solution) | 12 |
| Tert-butyl peroctoate (50% solution) | 12 |
| Dowanol PM | 210 |
| Dowanol PM acetate | 194 |
A total of 606 grams of example B-1 and 194 grams of Dowanol PM acetate were added to a suitable reaction kettle equipped with a stirrer, temperature probe, water cooled reflux condenser and flushed with nitrogen. The flask contents were heated to 120 ℃. At this point, 12 grams of t-butyl peroctoate mixed with 178 grams of Dowanol PM was added to the reactor over 15 minutes. The reactor contents were then held at 120 ℃ for 1 hour. At this point, a second 12 gram aliquot of t-butyl peroctoate mixed with 16 grams of Dowanol PM was added to the reactor. The reactor contents were held at 1226 ℃ for 1 hour, then a third 12 gram aliquot of t-butyl peroctoate mixed with 16 grams Dowanol PM was added to the reactor. The reaction mixture was again held at 125 ℃ for 1 hour. The mass is then cooled and discharged. The final material was a solution having a measured solids of 61%, an acid number of 5.9 and a Tviscosity, and a weight average molecular weight of 24,636 as measured against a polystyrene standard.
Example D-1
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| 2-methyl-1, 3-propanediol | 450 |
| Neopentyl glycol | 520 |
| Isophthalic acid | 1163 |
| Adipic acid | 146 |
| Maleic anhydride | 98 |
| Butyl Stannoic acid | 2.38 |
| Phosphorous acid triphenyl ester | 1.19 |
A total of 450 grams of 2-methyl-1, 3-propanediol, 520 grams of neopentyl glycol, 1163 grams of isophthalic acid, 146 grams of adipic acid, 98 grams of maleic anhydride, 2.38 grams of butyl stannoic acid, and 1.19 grams of triphenyl phosphite were added to a suitable reaction kettle equipped with an agitator, a temperature probe, a heated vapor reflux condenser with a distillation head, and a nitrogen sparge. The flask contents were heated to 90 ℃ and allowed to exotherm to 141 ℃. The reaction mixture was then heated to 179 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 200 c, then to 210 c and finally to 221 c and maintained at that temperature until 300 g of water was distilled off, and the acid value of the reaction mixture was found to be 9.5. The reactor contents were cooled and discharged. The final material was a solid material having a measured solids of 99%, a hydroxyl number of 54.6 and a weight average molecular weight of 4,903 as measured on a polystyrene standard.
Resin D
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| Example D-1 | 601 |
| Tert-butyl peroctoate (50% solution) | 6 |
| Dowanol PM | 160 |
| Dowanol PM acetate | 148 |
A total of 601 grams of example D-1 was added to a suitable reaction kettle equipped with a stirrer, temperature probe, water cooled reflux condenser and flushed with nitrogen, along with 160 grams of Dowanol PM and 136 grams of Dowanol PM acetate. The flask contents were heated to 120 ℃. At this point, 6 grams of t-butyl peroctoate mixed with 12 grams of Dowanol PM acetate was added to the reactor over 15 minutes. The reactor contents were then held at 120 ℃ for 1 hour. The mass is then cooled and discharged. The final material was a solution having a measured solids of 69%, an acid number of 7.1, and a viscosity of Z1-Z2, and a weight average molecular weight of 12,744 as measured against a polystyrene standard.
Example E-1
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| 1, 4-cyclohexanedimethanol | 1268 |
| Neopentyl glycol | 333 |
| Isophthalic acid | 333 |
| Hexahydrophthalic anhydride | 925 |
| Maleic anhydride | 196 |
| Butyl Stannoic acid | 3.05 |
| Phosphorous acid triphenyl ester | 1.53 |
A total of 1268 grams of 1, 4-cyclohexanedimethanol, 333 grams of neopentyl glycol, 333 grams of isophthalic acid, 924 grams of hexahydrophthalic anhydride, 196 grams of maleic anhydride, 3.05 grams of butylstannoic acid, and 1.53 grams of triphenyl phosphite are added to a suitable reaction kettle equipped with an agitator, a temperature probe, a heated vapor reflux condenser with a distillation head, and a nitrogen sparge. The flask contents were heated to 90 ℃ and allowed to exotherm to 161 ℃. The reaction mixture was then heated to 192 ℃. At this time, water begins to be produced from the reaction. The temperature of the reaction mixture was raised to 200 c, then to 210 c and finally to 221 c and maintained at that temperature until 210 g of water was distilled off, and the acid value of the reaction mixture was found to be 10.9. The reactor contents were cooled and discharged. The final material was a solid material having a measured solids of 99.9%, a hydroxyl number of 68.5, and a weight average molecular weight of 3,254 as measured on a polystyrene standard.
Resin E
A polyester was prepared from the following ingredients:
| composition (I) | Parts by weight (gram) |
| Example E-1 | 1503 |
| Tert-butyl peroctoate (50% solution) | 30 |
| Dowanol PM | 492 |
| Dowanol PM acetate | 453 |
A total of 1503 grams of example E-1 were added to a suitable reaction vessel equipped with a stirrer, temperature probe, water-cooled reflux condenser and flushed with nitrogen, along with 492 grams of Dowanol PM acetate. The flask contents were heated to 120 ℃. At this point, 30 grams of t-butyl peroctoate mixed with 453 grams of Dowanol PM was added to the reactor over 15 minutes. The reactor contents were then held at 120 ℃ for 1 hour. The reaction mixture was then cooled and the contents discharged. The final material was a solution having a measured solids of 61%, an acid number of 7.9 and a viscosity of Z2+, and a weight average molecular weight of 90,628 as measured against a polystyrene standard.
Example 12
Table 5 shows the compositions and molecular weights of the base polyester resins produced as alternative resins to CAB and standard polyester resins in the solvent primer layer, respectively. The standard resin was polyester resin a. Polyesters are produced with different levels of hard and soft monomers, with high and low molecular weights.
TABLE 5
Silver metal undercoats were prepared according to the examples in table 5. Free radical ester resin replaces CAB 381-0.5 resin and standard polyester resin A. The basecoat was applied to a 4 inch x 12 inch steel panel coated with cured ELECTROCOAT (ED 6060C) and a commercially available PPG primer (HP 77224ER) using a SPRAYMATION machine. These substrate boards are available from ACT Test Panels, inc.
The various coatings were applied using a SPRAYMATION machine. The base coat was applied with two coats and then a three minute room temperature flash was applied before two commercial PPG clearcoats (HIGH TECH) were applied by applying a1 minute room temperature flash between the coats. The composite coating was baked at 285 ° f for 30 minutes and then flashed at room temperature for 10 minutes.
TABLE 6
18Solvent obtained from EASTMAN CHEMICAL.
19Solvent obtained from EXXON Corporation.
20Solvent obtained from EASTMAN CHEMICAL.
21Acrylic microparticles as described in example II of US 4,147,688A.
22Cellulose acetate butyrate resin obtained from EASTMAN CHEMICAL, was dispersed in butyl acetate and butanol (77.4/13.6 ratio) to a 9% solution.
23Cellulose acetate butyrate resin, obtained from EASTMAN CHEMI CAL, was dispersed in butyl acetate as a 20% solution.
24Silicone fluid, available from DOW CORNING Corporation, was dispersed as a 10% solution in AROMATIC 100.
25Melamine-formaldehyde resins available from BASF Corporation.
26Butyl carbamate formaldehyde resin obtained from CYTEC SURFACTANE SPECIATILIES.
27ALUMINUM paste obtained from TOYO ALUMINUM k.k.
28Wax dispersed in solvent obtained from BYK-cer b.v.
Table 7 provides the appearance and physical properties obtained for each example. The examples were all baked in a vertical position. Example a is a standard primer coating using CAB 381-0.5 and a standard polyester resin. All other examples comprise free radical ester resins according to the present invention. The free radical ester resin with both hard monomer and highest molecular weight provides acceptable color, higher jetted solids, comparable hardness and superior appearance compared to example a. For the glossy (light face) effect provided by the aluminum-containing basecoat, a Higher dynamic Index (highher Flop Index) and a Higher color number of L15 are preferred. For dark dynamic color effects, lower L110 values are preferred. For a clear appearance on silver metal undercoats, higher gloss and DOI values are preferred. For a smooth transparent appearance, lower long and short wave values are preferred.
TABLE 7
29Dry film thickness measured by FISHER DELTACOPE produced by FISHER TECHNOLOGY, INC. of Windsor, CT.And (4) degree.
30From Helmut Fischer GMBH of Sindelfingen, Germany&Microhardness instruments available from Company.
31Model MA68II X-Rite Color Instrument, manufactured by X-Rite, Inc. of Grandville, Michigan.
32NOVO GLOSS statistical 20 ℃ glossometer, available from Paul N.Gardner Company, Inc. of Pompono Beach, Florida.
33DOI meter manufactured by TRICOR System, inc.
34BYK WAVESCAN DOI Instrument manufactured by BKY Gardner USA of Columbia, Maryland.
The results shown in table 7 show that coatings with higher molecular weights and low viscosities can be produced according to the invention, and that the coatings have a good appearance.
Although particular embodiments of the invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous modifications of the details of the present invention may be made without departing from the invention as defined in the appended claims.
Claims (21)
1. A crosslinkable branched polyester polymer prepared by free radical polymerization of the double bonds of a first unsaturated polyester prepolymer and the double bonds of a second unsaturated polyester prepolymer, wherein each prepolymer independently comprises:
a) a hard segment;
b) a polyol segment;
c) unsaturated polycarboxylic acids and/or anhydrides and/or esters thereof.
2. The polyester polymer of claim 1, wherein the hard segments of at least one prepolymer comprise aromatic and/or cycloaliphatic polyacid.
3. The polyester polymer of claim 2, wherein the hard segment of at least one prepolymer comprises isophthalic acid.
4. The polyester polymer of claim 3, wherein the hard segment of at least one prepolymer further comprises benzoic acid.
5. The polyester polymer of claim 1 wherein the polyol segments of at least one prepolymer comprise 2-methyl-1, 3-propanediol and/or neopentyl glycol.
6. The polyester polymer of claim 1 wherein the unsaturated polycarboxylic acid/anhydride/ester of at least one prepolymer comprises maleic acid/anhydride/ester.
7. The polyester polymer of claim 1 wherein the hard segments of at least one prepolymer comprise isophthalic acid, the polyol segments comprise 2-methyl-1, 3-propanediol and/or neopentyl glycol, and the unsaturated polycarboxylic acid/anhydride comprises maleic acid/anhydride/ester.
8. The polyester polymer of claim 1, wherein the Mw of the polyester is 15,000-50,000.
9. The polyester polymer of claim 1 wherein the Mw of the polyester is greater than 50,000.
10. The polyester polymer of claim 1 wherein the viscosity of the polyester is Z or less as measured by Gardner-Holt bubble method at 60% total solids.
11. The polyester polymer of claim 9 wherein the viscosity of the polyester is Z or less as measured by Gardner-Holt bubble method at 60% total solids.
12. A coating comprising the polyester of claim 1 and a crosslinking agent for use therein.
13. The coating of claim 12 wherein the hardness of the polyester polymer is 110-140N/mm as measured by the Fischer microhardness test2。
14. The coating of claim 12, wherein the polyester polymer has a mottle failure of 15-20% when measured by ASTM method D522-93.
15. The coating of claim 12, wherein for at least one prepolymer, the hard segments comprise isophthalic acid, the polyol segments comprise 2-methyl-1, 3-propanediol and/or neopentyl glycol, and the unsaturated polycarboxylic acid/anhydride comprises maleic acid/anhydride/ester.
16. The coating of claim 12, wherein the coating is a clear coating.
17. The coating of claim 12, wherein the coating comprises a colorant.
18. A substrate coated at least in part with the coating of claim 12.
19. The substrate of claim 18, wherein the substrate is a metal can.
20. The substrate of claim 18, wherein the substrate is a component of a vehicle.
21. The polyester of claim 1, wherein the only unsaturation in the reaction product is from component c).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US12/752,570 US9708504B2 (en) | 2010-04-01 | 2010-04-01 | Branched polyester polymers and coatings comprising the same |
| US12/752,570 | 2010-04-01 | ||
| PCT/US2011/030709 WO2011123632A1 (en) | 2010-04-01 | 2011-03-31 | Branched polyester polymers and coatings comprising the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK1179587A1 HK1179587A1 (en) | 2013-10-04 |
| HK1179587B true HK1179587B (en) | 2016-04-08 |
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