EP0572520A1 - Compositions d'enduits en poudre - Google Patents

Compositions d'enduits en poudre

Info

Publication number
EP0572520A1
EP0572520A1 EP19920906996 EP92906996A EP0572520A1 EP 0572520 A1 EP0572520 A1 EP 0572520A1 EP 19920906996 EP19920906996 EP 19920906996 EP 92906996 A EP92906996 A EP 92906996A EP 0572520 A1 EP0572520 A1 EP 0572520A1
Authority
EP
European Patent Office
Prior art keywords
coating
composition
linking
compoεition
powder coating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19920906996
Other languages
German (de)
English (en)
Inventor
Robert Boyd Barbee
Brian Steven Phillips
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eastman Chemical Co
Original Assignee
Eastman Kodak Co
Eastman Chemical Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eastman Kodak Co, Eastman Chemical Co filed Critical Eastman Kodak Co
Publication of EP0572520A1 publication Critical patent/EP0572520A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/40—High-molecular-weight compounds
    • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
    • C08G18/4202—Two or more polyesters of different physical or chemical nature
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/40—High-molecular-weight compounds
    • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
    • C08G18/4205—Polycondensates having carboxylic or carbonic ester groups in the main chain containing cyclic groups
    • C08G18/423—Polycondensates having carboxylic or carbonic ester groups in the main chain containing cyclic groups containing cycloaliphatic groups
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/80—Masked polyisocyanates
    • C08G18/8061—Masked polyisocyanates masked with compounds having only one group containing active hydrogen
    • C08G18/807—Masked polyisocyanates masked with compounds having only one group containing active hydrogen with nitrogen containing compounds
    • C08G18/8074—Lactams
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G2150/00—Compositions for coatings
    • C08G2150/20—Compositions for powder coatings

Definitions

  • This invention belongs to the field of powder coatings. More particularly, this invention relates to a novel blend of polyester-based powder coating compositions.
  • Plastic materials used in the manufacture of powde coatings are classified broadly as either thermosetting or thermoplastic.
  • heat is applied to the coating on the substrate to melt the particles of the powder coating and thereby permit the particles to flow together and form a smooth coating.
  • thermosetting coatings when compared to coatings derived from thermoplastic compositions, generally are tougher, more resistant to solvents and detergents, hav better adhesion to metal substrates and do not soften when exposed to elevated temperatures.
  • the curing of thermosetting coatings has created problems i obtaining coatings which have, in addition to the above stated desirable characteristics, good smoothness and flexibility.
  • Coatings prepared from thermosetting powder compositions upon the application of heat, may cure or set prior to forming a smooth coating, resultin in a relatively rough finish referred to as an "orange peel n surface.
  • Such a coating surface or finish lacks the gloss and luster of coatings typically obtained frc thermoplastic compositions.
  • the "orange peel" surface problem has caused thermosetting coalings to be applied from organic solvent systems which are inherently 2 -
  • Solvent-based coating compositions also suffer from the disadvantage of relatively poor percent utilization, i.e., in some modes of application, only 6 percent or less of the solvent-based coating compositio being applied contacts the article or substrate being coated. Thus, a substantial portion of solvent-based coatings can be wasted since that portion which does no contact the article or substrate being coated obviously cannot be reclaimed.
  • thermosetting coating compo ⁇ i- tions In addition to exhibiting good gloss, impact strength and resistance to solvents and chemicals, coatings derived from thermosetting coating compo ⁇ i- tions must possess good to excellent flexibility. For example, good flexibility is essential for powder coating compositions used to coat sheet (coil) steel which is destined to be formed or shaped into articles used in the manufacture of various household appliances and automobiles wherein the sheet metal is flexed or bent at various angles.
  • Powder coatings based on aromatic polyesters are well-known but generally suffer from poor weather- ability.
  • Figure 1 is a graph of QUV weathering of the powder coatings of Comparative Example 1, and Examples 2 and 3, all of which are described in the Experimental Section below.
  • "QUV" weathering is performed by exposing the coating to high intensity ultraviolet radiation, thereby simulating performance of the coating in the presence of sunlight, albeit on an accelerated basis.
  • the plot indicated by bold dots is the coating of Comparative Example 1; the plot indicated by open-circled points is the coating of Example 2; and the plot indicated by "triangle-points" is the coating of Example 3.
  • Percent gloss retention is plotted versus time.
  • the present invention provides a novel blend of polymers having free hydroxyl groups, which, when combined with a cross-linking agent and cured, provides coatings which have superior gloss retention when exposed to ultraviolet radiation.
  • the present invention provides powder coating compositions having good to excellent gloss, impact strength (toughness), flexibility, and weatherability superior to that of coatings based on aromatic poly- esters.
  • the time elapsed while subjecting powder coatings to QUV conditions which cause a 50% loss in gloss, is referred to herein as "GS Q " ' AS is evident from Figure 1, the powder coating compositions of the present invention are far superior, with regard to gloss retention, than coatings based on aromatic polyesters.
  • the present invention provides thermosetting powder coating compositions comprising:
  • Both the aromatic polyester and the all-aliphatic polyester may be produced using well known polycondensa- tion procedures. - 5
  • Poly(tetramethylene trans-1,4-cyclohexane- dicarboxylate) may be prepared from 1,4-butanediol and the acid or die ⁇ ter of trans-l,4-cyclohexane- dicarboxylic acid.
  • diester excess glycol is preferably used during ester interchange and is removed under reduced pressure until the desired viscosity is obtained.
  • the preferred all-aliphatic poly(tetramethylene trans-l,4-cyclohexanedicarboxylate) polyester of this invention has a Tm in the range of about 110 to 150 C C, a hydroxyl number in the range of about 25 to 65, an acid number of not more than 10 and an inherent viscosity of about 0.10 to 0.40.
  • This crystalline polyester component may also contain a branching agent, such as trimethylolpropane, to increase the cross-link density of the final coating in a concentration of up to 10 mol percent based on the total moles of polyol; i.e., up to 10 mole percent of trimethylolpropane residues and from 100 to 90 mole percent of 1,4-butanediol residues.
  • up to about 10 mole percent of the 1,4-butanediol residues may be replaced with diol residues containing from 2 to about 10 carbon atoms.
  • glycol residues include residues of ethylene glycol, propylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-l,3-diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl- -butyl-1,3- propanediol, 2-ethyl-2-i ⁇ obutyl-l,3-propanediol, 1,3- butanediol, 1,5-pentanediol, 1,6-hexanediol, thio- diethanol, 1,2-, 1,3- and 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-l,3-cyclobutane
  • trans-1,4- cyclohexanedicarboxylic acid is referred to herein, it is intended to mean at least 70% tran ⁇ -isomer. - 6 -
  • the aromatic polyester (Component 1(a)) will necessarily have a Tg of greater than 40°C.
  • the acceptably upper limit is generally dictated by th practicalities of the curing system; in other words, t upper limit could be as high as 150-180 ⁇ C, however, as the Tg of the aromatic polyester increase ⁇ , the performance limitations of the oven used for curing becomes more critical.
  • the preferred aromatic polyester component of the composition provided this invention has a Tg greater than 55°C, a hydroxyl number in the range of about 25 t 80, an acid number of not more than 15 and an inherent viscosity of about 0.15 to 0.4.
  • the aromatic polyester component preferably is comprised of (1) diacid residue of which at least 50 mole percent are terephthalic acid residues, (2) diol residues of which at least 50 mole percent are derived from 2,2-dimethyl-l,3-propanediol and (3) up to 10 mole percent, based on the total moles of (2) and (3), of trimethylolpropane residues.
  • These preferred aromatic polyesters are commercially avail ⁇ able, e.g., under the names Rucote® 107 brand resin sol by Ruco Polymer Corp. and Cargill Re ⁇ in 3000 sold by Cargill, Inc.
  • compositions of this invention comprise a blend cf about 10 to 80 weight percent of the aromatic polyester and 20 to 90 weight percent of the all-aliphatic poly ⁇ ester.
  • the blend of polymers containing free hydroxy groups provided by this invention preferably is comprised of about 20 to 75 weight percent of the aromatic polyester and 25 to 80 weight percent of the all-aliphatic polyester.
  • Suitable curing or cros ⁇ -linking agent ⁇ for u ⁇ e with hydroxyl-functional polyesters are well known in the art.
  • Preferred cross-linking agents include blocked isocyanates.
  • the blocked polyisocyanate compounds of the composition ⁇ of thi ⁇ invention are known compound ⁇ and can be obtained from commercial sources or may be prepared according to published procedures. Upon being heated to cure coatings of the compositions, the compounds are unblocked and the isocyanate groups react with hydroxy groups pre ⁇ ent on the amorphou ⁇ polye ⁇ ter and the all aliphatic polyester to cross-link the polymer chains and thus cure the compositions to form tough coatings.
  • the blocked polyisocyanate cross-linking component include those which are based on isophorone dii ⁇ ocyanate blocked with ⁇ -caprolactam, commercially available under the tradenames H ⁇ ls 1530 and Cargill 2400.
  • blocked polyisocyanate cros ⁇ -linking agents or compound ⁇ are those commonly referred to as ⁇ -caprolactam-blocked i ⁇ ophorone diisocyanate, e.g., those described in U.S. Patent Nos. 3,822,240 4,150,211 and 4,212,962, incorporated herein by reference.
  • the products marketed a ⁇ ⁇ -caprolactam-blocked i ⁇ ophorone dii ⁇ o ⁇ cyanate may consi ⁇ t primarily of the blocked, difunctional, monomeric i ⁇ ophorone diisocyanate, i.e., a mixture of the ci ⁇ and trans isomer ⁇ of 3-isocyanato- methyl-3,5,5-trimethylcyclohexyli ⁇ ocyanate, the blocked, difunctional dimer thereof, the blocked, trifunctional tri er thereof or a mixture of the monomeric, dimeric and/or trimeric form ⁇ .
  • the blocked, difunctional dimer thereof the blocked, trifunctional tri er thereof or a mixture of the monomeric, dimeric and/or trimeric form ⁇ .
  • the blocked polyisocyanate compound used as the cross- linking agent may be a mixture consisting primarily of the ⁇ -caprolactam-blocked , difunctional, monomeric isophorone diisocyanate and the ⁇ -caprolactam-blocked, trifunctional trimer of isophorone diisocyanate.
  • the description herein of the cross-linking agents as "polyisocyanates" refers to compounds which contain at least two isocyanato groups which are blocked with, i.e., reacted with, another compound, e.g., ⁇ -caprolactam.
  • the reaction of the isocyanato groups with the blocking compound is reversible at elevated temperatures, e.g., about 150°C, and above, at which temperature the isocyanato groups are available to react with the hydroxyl groups present on the free hydroxy groups of the polye ⁇ ter to form urethane linkages.
  • elevated temperatures e.g., about 150°C, and above, at which temperature the isocyanato groups are available to react with the hydroxyl groups present on the free hydroxy groups of the polye ⁇ ter to form urethane linkages.
  • the amount of the blocked diisocyanate cros ⁇ - linking compound pre ⁇ ent in the compo ⁇ ition ⁇ of this invention can be varied depending on several factors such as those mentioned hereinabove relative to the amount of components (l)(a) and (1) (b) which are utilized.
  • the amount of cross-linking compound which will effectively cross-link the hydroxy- containing polymers to produce coatings having a good combination of properties is in the range of about 5 to 30 weight percent, preferably 15 to 25 weight percent, based on the total weight of components (l)(a) and (l)(b) and the cros ⁇ -linking compound.
  • the powder coating compo ⁇ ition ⁇ of this invention may be prepared from the composition ⁇ de ⁇ cribed herein by dry-mixing and then melt-blending components (l)(a) and (1) (b) and the blocked polyi ⁇ ocyanate compound, along with other additives commonly used in powder coatings, and then grinding the solidified blend to a particle size, e.g., an average particle size in the range of about 10 to 300 microns, suitable for producing - 9 -
  • the ingredients of the powder coating compo ⁇ ition may be dry blended and then melt blended in a Brabender extruder at 90° to 130°C, granulated and finally ground.
  • the melt blending ⁇ houl be carried out at a temperature sufficiently low to prevent the unblocking of the polyisocyanate cross- linking compound and thus avoiding premature cros ⁇ - linking.
  • component ⁇ (l)(a) and (l)(b) may be blended prior to the incorporation therein of the blocked polyi ⁇ ocyanate compound.
  • Typical of the additive ⁇ which may be pre ⁇ ent in the powder coating compo ⁇ ition ⁇ include benzoin, u ⁇ ed t reduce entrapped air or volatile ⁇ , flow aid ⁇ or flow control agent ⁇ which aid the formation of a smooth, glos ⁇ y ⁇ urface, catalysts to promote the cross-linking reaction between the isocyanate groups of the cros ⁇ - linking agent and the hydroxyl group ⁇ on the polymers, stabilizers, pigments and dyes.
  • Suitable catalysts for promoting the cro ⁇ -linking include organo-tin compound ⁇ ⁇ uch a ⁇ dibutyltin dilaurate, dibutyltin di aleate, dibutyltin oxide, ⁇ tannous octanoate and ⁇ imilar compound ⁇ .
  • the powder coating compo ⁇ itions preferably contain a flow aid, also referred to as flow control or levelin agents, to enhance the surface appearance of cured coatings of the powder coating compositions.
  • flow aids typically comprise acrylic polymers and are avail- 10
  • a specific flow aid is an acrylic polymer having a molecular weight of about 17,000 and containing 60 mole percent 2-ethylhexy methacrylate residues and about 40 mole percent ethyl acrylate residue ⁇ .
  • the amount of flow aid pre ⁇ ent may preferably be in the range of about 0.5 to 4.0 weight percent, ba ⁇ ed on the total weight of component ⁇ (l)(a) and (l)(b) and the cro ⁇ -linking agent.
  • the powder coating compo ⁇ ition ⁇ may be depo ⁇ ited o variou ⁇ metallic and non-metallic ⁇ ub ⁇ trate ⁇ by known technique ⁇ for powder deposition such as by means of a powder gun, by electrostatic deposition or by depo ⁇ itio from a fluidized bed.
  • powder deposition such as by means of a powder gun, by electrostatic deposition or by depo ⁇ itio from a fluidized bed.
  • the particle size of the powder coating composition normally is in the range of 60 to 300 microns.
  • the powder i ⁇ maintained in su ⁇ pen ⁇ ion by pa ⁇ ing air through a porous bottom of the fluidized be chamber.
  • the articles to be coated are preheated to about 250° to 400°F (about 121° to 205 ⁇ C) and then brought into contact with the fluidized bed of the powder coating composition.
  • the contact time depends o the thickness of the coating that i ⁇ to be produced and typically is from 1 to 12 seconds.
  • the temperature of the substrate being coated cause ⁇ the powder to flow an thus fuse together to form a smooth, uniform, continuous, uncratered coating.
  • the temperature of the preheated article al ⁇ o affects cross-linking of the coating compo ⁇ ition and results in the formation of a tough coating having a good combination of properties.
  • Coating ⁇ having a thicknes ⁇ between 200 and 500 icron ⁇ may be produced by this method.
  • composition ⁇ al ⁇ o may be applied using an electrostatic proces ⁇ wherein a powder coating compo ⁇ i- tion having a particle size of less than 100 microns, preferably about 15 to 50 microns, is blown by means of compres ⁇ ed air into an applicator in which it i ⁇ charge with a voltage of 30 to 100 kV by high-voltage direct current.
  • the charged particle ⁇ then are sprayed onto the grounded article to be coated to which the particle adhere due to the electrical charge thereof.
  • the coate article is heated to melt and cure the powder particles.
  • Coatings of 40 to 120 microns thickness may be obtained.
  • Another method of applying the powder coating compositions is the electrostatic fluidized bed proce ⁇ which i ⁇ a combination of the two method ⁇ de ⁇ cribed above.
  • annular or partially annular electrode ⁇ are mounted over a fluidized bed so as to produce an electrostatic charge such as 50 to 100 kV.
  • the article to be coated either heated, e.g., 250° to 400°F, or cold, i ⁇ expo ⁇ ed briefly to the fluidized powder.
  • the coated article then can be heated to effec cro ⁇ -linking if the article wa ⁇ not preheated to a temperature sufficiently high to cure the coating upon contact of the coating particles with the article.
  • the powder coating composition ⁇ of thi ⁇ invention may be u ⁇ ed to coat article ⁇ of variou ⁇ shapes and size constructed of heat-re ⁇ i ⁇ tance aterial ⁇ such as glass, ceramic and various metal materials.
  • the compo ⁇ ition ⁇ are especially useful for producing coatings on article con ⁇ tructed of metals and metal alloy ⁇ , particularly ⁇ teel article ⁇ .
  • composition ⁇ according to thi ⁇ invention may be mixed by dry blending in a Henschel mixer, followed by compounding in a ZSK-30 Extruder (Werner & Pfleiderer) at 110-130 ⁇ C, grinding, and screening to obtain powder with average particle size of about 35 micron ⁇ .
  • the powdered compo ⁇ ition ⁇ were electo ⁇ tatically depo ⁇ ited on the substrate by use of a powder gun.
  • Coatings were prepared on 3 inch by 9 inch panels of 20-gauge, poli ⁇ hed, cold roll steel, the ⁇ urface of which ha ⁇ been zinc phosphated (Bonderite 37, The Parker Company).
  • the artificial weatherability of the coatings wa ⁇ determined by expo ⁇ ure of the coated panel ⁇ in a Cyclic Ultraviolet Weathering Tester (QUV) with 313 nm fluore ⁇ cent tube ⁇ .
  • the test condition wa ⁇ 8 hour ⁇ of light at 70°C and 4 hours of condensation at 45°C.
  • the flexibility of the coatings was determined in accordance with ASTM 4145-83 at ambient temperature by bending or folding a coated panel back against itself, using a hydraulic jack pre ⁇ surized at 20,000 pound ⁇ per square inch (psi), until the apex of the bend i ⁇ a ⁇ flat as can be reasonably achieved.
  • Thi ⁇ initial bend i ⁇ referred to a ⁇ OT meaning that there i ⁇ nothing (zero thickne ⁇ es) between the bent portions of the panel.
  • the bend is examined u ⁇ ing a 10X magnifying gla ⁇ and, if fracture ⁇ of the coating are ob ⁇ erved, the panel is bent a second time (IT) to form a three-layer sandwich.
  • each bend test i ⁇ the minimum thickness (minimum T-bend) of the bend which does not give any fractures of the coating.
  • the bend test used is excessively severe for most purposes for which coated articles are used, it provides a means to compare the flexibilities of different powder coating compo ⁇ ition ⁇ .
  • Impact strength was determined by using a Gardner Laboratory, Inc., Impact Tester. A weight is dropped within a slide tube from a specified height to hit a punch having a 5/8 inch diameter hemispherical nose which is driven into the front (coated face) or back of the panel. The highest impact which does not crack the coating is recorded in inch-pounds, front and reverse. Twenty degree and 60 degree glos ⁇ wa ⁇ mea ⁇ ured u ⁇ ing a glo ⁇ meter (Gardner Laboratory, Inc.) according to ASTM D-523.
  • Tm melting temperature
  • the pencil hardness of a coating is that of the hardest that will not cut into the coating according to ASTM 3363-74 (reapproved 1980).
  • the results are expres ⁇ ed according to the following ⁇ cale: ( ⁇ ofte ⁇ t) 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6K (hardest). 14 -
  • the conical mandrel is performed by bending the panel over 15 second ⁇ u ⁇ ing a Gardner Laboratory, Inc. conical mandrel of specified size according to ASTM-522-85. A pass or fail is recorded.
  • This example illu ⁇ trate ⁇ the typical procedure for preparing the all-aliphatic polyesters of this inven- tion.
  • the flask and contents were heated under nitrogen atmosphere to a temperature of 170 ⁇ C at which point methanol began to distill rapidly from the flask.
  • the temperature wa ⁇ increased to 200°C for 2 hours, raised to 215°C for 4 hours, and then to 235°C.
  • a vacuum of 10 mm of mercury wa ⁇ applied over a period of 12 minute ⁇ .
  • Stirring wa ⁇ continued under 10 mm of mercury at 235°C for about 3 hours to produce a low melt visco ⁇ ity, colorless polymer.
  • the resulting polymer has an inherent vi ⁇ co ⁇ ity of 0.30, a melting point of 130°C and a hydroxyl number of 30.
  • a powder coating composition was prepared from the following materials: 81.3 g Polyester of Example 1;
  • Ru ⁇ ote 107 a polyester based primarily on terephthalic acid and 2,2-dimethyl-l,3- propanediol;
  • Caprolacta -blocked isophorone poly ⁇ isocyanate Hul ⁇ 1530
  • 4.0 g Dibutyltin dilaurate 75.0 g Caprolacta -blocked isophorone poly ⁇ isocyanate (Hul ⁇ 1530); 4.0 g Dibutyltin dilaurate;
  • the above material ⁇ were melt-blended in an APV twin screw extruder at 110°C, ground in a Bantam mill to which a stream of liquid nitrogen is fed and classified through a 170 mesh screen on a KEK centrifugal sifter.
  • the finely-divided, powder coating composition obtained had an average particle size of about 50 microns.
  • Example 2 The powder coating composition prepared in Example 2 wa ⁇ applied electrostatically to one side of the 3 inch by 9 inch panels described above. The coating was then cured (cross-linked) by heating the coated panels at 177°C in an oven for 25 minutes. The cured coatings are about 50 microns thick.
  • the coatings on the panels had both front and back impact strengths of >160 inch-pounds, 20° and 60° gloss value ⁇ of 82 and 98, re ⁇ pectively, and a pencil hardness of HB.
  • the coated panel ⁇ pa ⁇ ed a 0.125 inch conical mandrel te ⁇ t and had a T-bend flexibility value of 1. After 780 hour ⁇ of QUV expo ⁇ ure, the coating retained 50% of the 60° glo ⁇ .
  • Example 2 panels were coated with thi ⁇ powder coating compo ⁇ ition and the coatings were cured and evaluated.
  • the coatings had both front and back impact strengths of >160 inch-pounds and 20° and 60° glos ⁇ value ⁇ of 72 and 91, respectively, and a pencil hardness of B.
  • the coated panels passed a 0.125 inch conical mandrel and had a T-bend flexibility value of 1. After 810 hours of QUV exposure, the coating retained 50% of the 60° glo ⁇ .
  • a powder coating compo ⁇ ition wa ⁇ prepared from the following materials: 816.60 g Rucote 107, a polye ⁇ ter described in Example 2;
  • Example 2 U ⁇ ing the procedure of Example 2, panel ⁇ were coated with thi ⁇ powder coating compo ⁇ ition and the coating ⁇ were cured and evaluated.
  • the coating ⁇ had both front and back impact ⁇ trength ⁇ of >160 inch-pound ⁇ and 20° and 60° glo ⁇ value ⁇ of 85 and 95, re ⁇ pectively, and a pencil hardne ⁇ of H.
  • the coated panel ⁇ pa ⁇ ed a 0.125 inch conical mandrel and had a T-bend flexibility value of 6.
  • the coating ⁇ of Examples 2 and 3 posses ⁇ a G 50 of 780 hours and 810 hour ⁇ , re ⁇ pectively.
  • the coating of Comparative Example 1 po ⁇ e ⁇ e ⁇ a G ⁇ of 280 hour ⁇ .

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Paints Or Removers (AREA)
  • Polyurethanes Or Polyureas (AREA)

Abstract

L'invention se rapporte à des compositions d'enduits en poudre thermodurcissables, qui sont constituées de mélanges de polyesters aromatiques et de tous les polyesters aliphatiques dérivés de l'acide 1,4-cyclohexane-dicarboxylique trans et du 1,4 butanediol, qui, avec un polyisocyanate bloqué, lors de leur application sur un substrat et après cuisson, forment un enduit de surface possédant de bonnes caractéristiques d'éclat, de résistance aux chocs, de flexibilité et de résistance aux intempéries.
EP19920906996 1991-02-19 1992-02-18 Compositions d'enduits en poudre Withdrawn EP0572520A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US656390 1984-10-01
US65639091A 1991-02-19 1991-02-19

Publications (1)

Publication Number Publication Date
EP0572520A1 true EP0572520A1 (fr) 1993-12-08

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EP19920906996 Withdrawn EP0572520A1 (fr) 1991-02-19 1992-02-18 Compositions d'enduits en poudre

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EP (1) EP0572520A1 (fr)
JP (1) JPH06505297A (fr)
CA (1) CA2103709A1 (fr)
WO (1) WO1992014770A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995001407A1 (fr) * 1993-07-01 1995-01-12 Eastman Chemical Company Compositions de revetement en poudre
MY139524A (en) * 2004-06-30 2009-10-30 Ciba Holding Inc Stabilization of polyether polyol, polyester polyol or polyurethane compositions
US20060041039A1 (en) 2004-08-20 2006-02-23 Gyorgyi Fenyvesi Fluorescent poly(alkylene terephthalate) compositions
WO2006041523A1 (fr) * 2004-10-08 2006-04-20 E.I. Dupont De Nemours And Company Compositions de poly(alkylene terephtalate) fluorescentes
GB2423770A (en) * 2005-02-01 2006-09-06 Ucn Know How Ltd Crystalline or semi-crystalline polyurethane

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4352924A (en) * 1981-06-29 1982-10-05 Eastman Kodak Company Thermosetting powder coating compositions
US4859760A (en) * 1987-12-07 1989-08-22 Eastman Kodak Company Polyurethane powder coating compositions
DE69006953T2 (de) * 1989-06-26 1994-09-22 Eastman Kodak Co Halbkristalline Polyester, deren Mischungen mit amorphen Polyestern sowie auf solchen Mischungen basierte Pulverlackzusammensetzungen.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9214770A1 *

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CA2103709A1 (fr) 1992-08-20
JPH06505297A (ja) 1994-06-16
WO1992014770A1 (fr) 1992-09-03

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