TW200918619A - Powder coating composition for high temperature resistant coatings - Google Patents

Abstract

A powder coating composition is disclosed which comprises a resin component and a filler, wherein the resin component comprises a first silicone resin and a second silicone resin, said first and second silicone resins being characterized by having glass transition temperatures (Tg) that are different by at least 5 DEG C and / or having melt viscosities, as measured at 140 DEG C, that are different by at least 5, preferably 10 poise.

Description

200918619 IX. INSTRUCTIONS OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to a powder coating composition which is curable on a substrate to produce a high temperature resistant coating. More particularly, the present invention relates to a powder coating composition comprising at least two different polyoxo resins. [Prior Art] It is apparent that coatings applied to ovens, boilers, heat exchangers, automobile parts, cooking elements, cookware, and the like are required to exhibit high temperature resistance. Most organic coatings are not suitable for such applications. Because they are exposed to air at temperatures above 550 °C, they are easily consumed quickly. This has led to the development of coatings and lacquers incorporating poly-stone oxide resins, as described in U.S. Patent No. 5,9,514 (Eklund et al.). A mixture of a naphthenic resin, a mixture of Dow Corning 1-0543 and Dow Corning Z-6018, is mentioned in the examples. These resins have the following properties: - Dow Corning 1-0543 (now DC 220) Tg = 49 ° C, 140. (: The lower viscosity is 9.8 poise; _ Dow Corning Z-6018 Tg = 48 ° C, 14 (TC viscosity is 14.1 poise. The heat resistance is improved) but the coating containing polyoxyalkylene resin is still It was found to exhibit an adverse effect at the temperature of the horse. When the material coated with polyoxymethane powder was exposed to a temperature higher than 55 (rc, the coating will lose its constituent organic components by oxidation; the polyoxynized resin is therefore Rapid shrinkage and build-up of stress inside the coating. These stresses are relieved by cracking, causing the coating to peel or peel off from the material. 132713.doc 200918619 〇2004/076572 (Dupont de Nemours and Company) t Figure by polyoxyl The alkane resin contains at least one matrix material (preferably a low-melting inorganic glass) which softens and exhibits a constant flow in a temperature range in which the polyoxo resin undergoes shrinkage and embrittlement. European Patent No. 0950695 B1 (Mort〇n) proposes an alternative solution in which the powder coating composition is composed of a single polyoxynoxy resin combined with a filler of titanium dioxide and cloud and/or calcium metasilicate particles. Characterized by having a decane function (si_〇_H) and having only a small amount of organic moieties. In this reference, a single polyoxo oxy- sinter preferably has less than _ dynasty and -OH is included as the concentrating Oxygen oxime weight 2 〇 to 75 5% by weight. When = shixi oxygen burning self-curing at a temperature between 15G and 26 generations, limit the -0H to reduce the release of 4 water' and thus reduce the coating due to the above The formation of defects in water (such as pinholes), but it should be noted that this powder coating composition can be dry film in the range of U to 2.2 mils (45 to 55 μm). Cloth to substrate. When the powder coating is applied to the car body to protect and decorate the engineering product, the substrate: is relatively thin and has a smooth surface. However: when coating the coating is not: see the resistance to w temperature When the material is 'usually the surface of the substrate is shaped or uneven. To provide sufficient corrosion to the sprayed steel (four) and (beauty,) finish 'for example, the substrate must be coated enough dry Film thickness to compensate for: non-uniformity. Use of angled gravel, spherical, loaded abrasive sponge / / spray spray substrate Producing a pin surface exhibiting a distance between peaks σ of between 10 and 80 Mm (wherein the profile can be set by 132713.doc 200918619 for these uneven substrates, it has been found that there is a dry film thickness of the powder coating ( The actual upper limit of DFT) exceeds this upper limit and the coating will crack and peel off from the substrate. Obviously, the lower the upper limit, the less the ability of a given powder coating to compensate for the increased blow profile of the substrate surface. Therefore, there is a need in the art to provide a powder coating composition that exhibits high temperature resistance, but can also be applied to the surface of a two-type lock to provide such surface temperature resistance and preferably provide corrosion resistance. SUMMARY OF THE INVENTION According to a first aspect of the present invention, a powder coating composition comprising a resin component and a filler, wherein the resin component comprises a first polyoxyl resin and a second polyoxyl resin, The first and second polyoxyl resins are characterized by having a glass transition temperature (d) of at least 5 °C. According to a second aspect of the present invention, there is provided a powder coating composition comprising a resin component and a filler, wherein the resin component comprises a first polysulfide resin and a second (tetra) oxygen resin, the first and the Dimeric resin is characterized by a viscous viscosity measured under a thief with a difference of at least 5 poise, preferably 1 G poise. The difference between the two polyoxin resins in the powder coating composition means that each resin will respectively exhibit different flow lines at a temperature greater than 550 t: ,; and these different behaviors are synergistically combined to limit the inclusion of two kinds of poly amps & Resin coating shrinkage and embrittlement in this temperature range. The milk-first and second polyoxyl resins are preferably present in the resin component in a weight ratio of 2:1 to 1:2 (poly-oxygenated second polyoxyl resin). Similarly, the mth resin preferably has a 4Q. Between the — - the polyoxyl resin has at 55. To 8 (circle between rc. X 132713.doc 200918619 is not subject to the theory 'the first or the same may be due to the dioxane of the polymer, the higher the branch of the polymer, the difference in the degree of ▲ In addition, the shrinkage rate observed at the first and second temperatures is more than eight based on the type and content of the organic part of the knife and its collar content (ie, the functionality of the Shixi oxygenator). Regarding the filler component of the composition, the filler is preferably a heat-generating substance f in which one dimension is more than another dimension, and the filler is present in an amount of from 5 to 95% by weight based on the weight of the resin component.

According to a preferred embodiment of the present invention, the resin component of the powder coating further comprises from 1 to 25% by weight of the non-polyoxyl resin by weight of the resin component. The non-polyoxy resin is preferably an epoxy-polyester mixture. According to a second aspect of the present invention, there is provided a method of coating a substrate, wherein the powder coating composition described above is applied to a substrate, and then the powder coating composition is subjected to a curing step, wherein the powder coating composition is The dry powder thickness (DFT) of the cured powder coating is applied to a layer thickness of at least 65 microns. The cured powder coating has a DFT of from 7 Å to 13 Å, preferably from 75 to 1 Å. According to a fourth aspect of the present invention, there is provided a substrate coated with a cured layer of the above powder coating composition, the layer having a DFT of at least 65 microns, preferably 70 to 130 microns and more preferably 75 to 100 microns. . [Embodiment] Defined to describe the proportion of the components in the composition of the present invention, the term "resin" includes any resin or polymer itself, and a curing agent. 132713.doc 200918619 Regarding the polyxanthene resin of the present invention, the degree of substitution is The text is defined as the average number of organic substituent groups per fluorene atom, and is the sum of the mole percentage of each component multiplied by the number of substituents. This calculation is in Lawrence H. Brown's protective coating. Further elaboration in the silicones in protective coatings (in the coating, total dry "7" _ heart training Coai / « (4) Volume 1, Part III, film-forming composition (Film-Forming Compoisitioris), 1 5 13- 563 pages, RR Meyers and J. s. Long Editor · Marcel Dekker,

Inc. New York, 1972). As used herein, the "glass transition temperature" or Tg of any polymer can be as

Fox is calculated as described in 5w//_ Z Hall λ «Soc·, 1, 3, 123 (1956). Tg can also be measured experimentally using differential scanning calorimetry (at a heating rate of 2 〇 〇 / minute, where Tg is the midpoint of the inflection point). Unless otherwise stated, the Tg value indicated herein refers to the calculated Tg. The normative term 'toward temperature' is used herein to indicate that the cured powder coating composition of the present invention is intended to withstand the temperatures at which most of the organic components (including the organic portion of the polyoxynoxy resin) will be burned out. The cured powder coating of the present invention is subjected to a temperature of at least 550 °C. Powder coating composition Although the first and second polyoxyl resins of the present invention are characterized by different V melt viscosities, the two polyoxo resins should be solid at room temperature and both have greater than 45X: Surface transfer temperature (Tg). The lower limit of this & is to prevent improper adhesion (or sintering) of the coating powder. The organic portions of the first and second polyoxyl resins are aryl and/or short chain (6) to C5) alkyl groups. It is known that for good heat resistance, the methyl 'ethyl group and the phenyl group are 132713.doc 200918619 'The larger the number of phenyl groups, the better the anti-polyoxyl resin composition is provided, diphenyl, phenylene and benzene. The preferred organic portion of the propyl group, especially the higher the thermal conductivity of the phenyl group. Thus, the first and second methyl, ethyl, phenyl, dimethyl organic moieties and mixtures thereof. The dimeric 7-oxygen resin of the present invention more preferably comprises any mixture of bentonite and phenylmonomethyloxane and diphenylphosphonium alkyl groups, or phenylhydrazine azepine groups, wherein phenyl and The base ratio is (4) 1 · 5.1 Better system 7: 丨 to 丨丨: 〗. In any case, the first and second polyoxyphthalic resins are required to have an organic substitution of 1 > 5 or less, preferably from about 】 to about 1.5. The first and second polyoxyl resins will self-condense at high end-use temperatures and therefore have a stanol function (Si-〇_H). The dimeric oxime resin should have 2 to 7 = 5% by weight, more preferably 3 to 5% by weight of the condensable radical, but may be slightly deviated from these ranges depending on any catalyst in which f is present. The condensable hydroxyl group should not be too high to prevent water from escaping during the curing of the coating powder. On the other hand, the lower limit of the range of condensable hydroxyl groups is important because it is below this lower limit. I) #Coating powder will cure too slowly for commercial applications. Preferably, the first polyacetal resin comprises less than 0.2% by weight of the solvent, preferably less than 0.1% by weight. However, most of the commercially available polyoxime resins contain some residual compound due to the synthesis process of the polyoxin. The organic solvent tends to sink into the interior of the polyoxo resin, and when the oxygen resin is melt blended with other components to form a coating powder composition, the right side will be removed. Therefore, it may be necessary to substantially remove this residual φ^' agent which can be accomplished by melting the polyoxynoxy resin and removing the solvent from the molten resin by vacuuming the inert gas. 132713.doc 200918619 The key to the invention is that the first and second polyoxyxides according to the invention are characterized by having different cores and/or different melt viscosities measured at 15 (rc). It is achieved by using a polyoxyxene resin which differs in at least one of the following properties: degree of polymerization branching; type and degree of substitution of the organic moiety; and condensable hydroxyl group content. Thus, at least the polyoxyxylene resin is preferably at 14 〇. C has a viscosity of 5 to 1 Torr, preferably between 2 Torr and 5 Torr, to ensure that the resin imparts a proper melt flow to the molten coating powder at a temperature at which the coating powder is melted and solidified. Preferably, at least one of the first and second polyoxyl resins has a glass transition temperature (Tg) of more than 55, preferably more than 60 ° C. It can be used without peeling off one of the first preferred polyfluorene oxides. The resin was purchased from Wacker Chemie's SILRES® 604. This resin has a reactive hydroxyl content of 35 to 5%, between & 55 to 8 〇χ: and 140 卩Melt viscosity (which is equivalent to 1〇3 poise at 14〇.〇 Melt viscosity) (1 Pa.s~10 poise). It can also be used without flaking. One of the best second polyoxo resins is DC_233 from Dow Coming. This resin has 6% reactivity. The hydroxyl group contains a Tg of I, 45C and a melt viscosity of 2_13 Pa.s at 14 (rc equivalent to 21.3 poise at 140. (: melt viscosity below). According to the present invention, a filler is used to strengthen polyoxyl Coatings. As described in 950 695 A1 (Morton), suitable heat resistant fillers are characterized in that one dimension is at least four times greater than that of the dimension, and a dimension of at least four times will provide useful (four). Thus 'the same as described in the teachings. The method comprises glass, metal fiber, metal foil, mineral fiber, mica and calcium metasilicate, and the filler which meets the requirements of I327l3.doc 200918619 can be included in the powder coating composition of the invention. A preferred embodiment 'the filler comprises fibers of a mixed metal oxide of aluminum, lanthanum and magnesium. These specific fibers are preferably contained in the powder coating composition in an amount of from 20 to 60% by weight based on the weight of the resin component. Also preferably 'Filling can contain these fibers Blend with mica flakes. Important is to ensure that any filler is uniformly dispersed throughout the powder coating composition. The composition may be prepared and included with a suitable dispersing agent. The powder coating composition herein preferably comprises 〇5. The dispersant preferably comprises polyvinyl butyral to a weight of 2 parts by weight. According to a preferred embodiment of the present invention, the powder coating composition comprises from 1 to 25% by weight of the weight of the resin component. The non-polyoxyphthalocyanine is more preferably an epoxy-polyester mixture. As is known in the art, the polyester-epoxy mixture comprises an epoxy resin and a carbonyl-terminated polyester resin and may also comprise a The catalyst drives the curing reaction. In the present invention, the powder coating composition is preferably a mixture of such polyesters and epoxies based on a polyester/epoxy ratio of from 80/20 to 50/50. The polyester resin suitable for the above polyester-epoxy mixture should have an acid value of less than 12, preferably less than 5. These polyester resins should also be characterized by a hydroxyl number in the range of from about 20 to about 50 mg KOH per gram of polymer. The weight average molecular weight (Mw) of the polyphysic tree may range from about L000 to about ', preferably from about 1,500 to about 1 Torr. The radical functionality of the resin, i.e., the base (10) present in each molecule of the resin, is 2 or more and preferably 2, 2 or more, more preferably 3 5 or more. The upper limit of the radical functionality (molecular functionality) should correspond to the upper limit of the number of hydroxyl groups (molecular weight functionality). 132713.doc 200918619 The Tg of the polyester resin is preferably higher than 5 (rc 'more preferably higher than 55t) to prevent adhesion in the powder composition comprising the polyester resin. The poly-containing composition of the powder coating composition of the present invention The ester resin can be prepared from aromatic and/or saturated aliphatic acids and polyols using methods established in the art. The reactants can be heated to about 135 as needed in the presence of a catalyst such as p-toluenesulfonic acid. : to a temperature between 22 and rc, while spraying a stream of inert gas to remove water formed. Vacuum may be used at a suitable temperature or a solvent having a wide azeotrope may be formed to assist in the removal of water. Examples of aliphatic polycarboxylic acids include Diacid, pentane diacid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 3-oxoglutaric acid, 1,12-dodecanoic acid, tetrapropenyl succinic acid , maleic acid, fumaric acid, itaconic acid and malic acid. Examples of aromatic polycarboxylic acids are phthalic acid and its anhydride, isophthalic acid, benzophenone dicarboxylic acid, diphenyl phthalic acid 4,4_ bis-diphenyl diphenyl ether, 2,5-pyridine dicarboxylic acid and trimellitic acid. Suitable polyhydric alcohol is ethylene glycol . 1,3-propylene glycol, diethylene glycol, neopentyl glycol and trimethylol propane may be used a mixture of acids with polyols F, Commercially available powder coating compositions of the present invention is polyester comprising:. P_ 1407

LJ (Twin Hill), Uralac® P6505 (DSM), Morkote® 98HT (Rohm and Haas), Crylcoat® 820 (UCB), Alftalat® AN 745 (Solutia), Rucote® 625 (Bayer), and Sparkle® SP400 (Sun) Polymers). Examples of epoxy resins for epoxy-polyester blends are, but are not limited to, those obtained by reacting epigas alcohol with bisphenols such as bisphenol A and bisphenol F. The low melt viscosity of these resins facilitates their mixing with other components of the powder coating, preferably below 2 Torr. A suitable epoxy resin should also have a degree of marrying of 2 to · at 15 s s. 132713.doc • 14-200918619, preferably 3 to (4). The preferred f-epoxy (4) for the purpose of the present invention is a trademark.仏Essences from Qing 8 =^:7〇72, GT_6259 (H_smanLLc), Ep(10)8, and 陶ichemieals, In(10). It is known that zinc particles can be added to the powder coating composition for corrosion resistance. The present invention preferably comprises at least one of 1 to 50% by weight of the composition of the powder or the sample. Human zinc powder to improve resistance to microcracking, especially when the coating is to be exposed to temperatures above the zinc refining point (419. [). The composition preferably further comprises a total amount of 0.1% by weight of the powder coating composition to 2.0% by weight of zinc salt (such as octanoic acid, ethyl hexahydrate or zinc neodecanoate). These salts or substitutes (such as dibutyltin dilaurate and stannous octoate) catalyze the self-condensation of polyoxy 7 resin , thus reducing their clotting time. Flow control and leveling additives can be 2 to 10 weights of the weight of the composition The amount of % is present in the powder coating composition. These flow regulators which enhance the melt flow properties of the composition and assist in the removal of surface imperfections generally comprise acrylic and fluorine based polymers. Examples of commercially available flow regulators include: ^^丨8 Ρ-67, Xinxian (4) 8ρ_2〇〇 and clearfl〇w8 (both from Estr〇n)

Chemical Inc., Calvert City, KY); BYK® 361 and BYK® 3〇〇 (from YK Chemie, Wallingford, CONN); and —flow® 2000 (from Monsanto, St. Louis, MO). In one embodiment of the invention, the 'flow and leveling additive preferably comprises an acrylic resin', especially a difunctional acrylic resin, and more particularly a glycidyl group and a hydroxyl functional group and an epoxy equivalent (EEW). 132713.doc -15- 200918619 Acrylic resin, such as Fine CIad8A 241 (available from Reich〇id Inc.). To provide improved adhesion of the powder coating composition to a particular substrate, the composition may also comprise a tackifier in an amount of from 〇·丨 to 丨% by weight based on the total weight of the composition. As known in the art, tackifiers are characterized by having pendant or free functional groups or polar groups (e.g., carboxyl, anhydride, hydroxyl, hydroxyl, cyano, decyl or sulfonate groups) or It has inherent adhesive properties or a relatively small molecular size. In the present invention, a polymeric tackifier is preferably used and a suitable polymer comprises: Primacor ® 5990 (available from Dow Chemicals),

Surlyn ® 1855 and Nucrel ® 403 or 410 (available from DuPont), Hyvis 30 (speaking from BP Chemicals), Lithene N4 6000 (available from Doverstrand Ltd), and Soarnol D (EVAL·resin is purchased from British Trades & Shippers) The rhodium deaerator may also be used in the powder coating composition of the present invention in an amount of from 重量 to 5% by weight based on the weight of the composition. These deaerators facilitate the discharge of gases during the curing process. Examples of commercially available deaerators include: purchased from WeU w〇rth

Benzoin of Medicines and Uraflow® B from GCA Chemical Corporation (Brandenton, FLA). The powder coating composition may also preferably comprise a dry flow additive in an amount of from 至5 to 1.0% by weight based on the total weight of the composition. Examples of such additives include fuming stone, oxidized infusion, and mixtures thereof. In addition to the above components, the powder coating composition may contain other conventional additives. It comprises: a pigment, a gloss improving additive, a crater, a curing agent, a conditioning agent, a surfactant, a biological remover, and an organic plasticizer. 1327l3.doc -16· 200918619 A coloring agent or pigment suitable for use in the powder of the present invention may comprise carbon black (eg, W5 black of Engelhard Corporation), metal flakes and pigments (eg, various iron oxide pigments and mixed metal oxides) The content of the pigment: or the colorant or (4) may be as high as 2 parts per hundred parts of resin (calculated according to the weight) (-)' is preferably H15phr, more preferably 〇.5 to 1〇*. Preparation of powder coating composition

The powder coating composition of the present invention, which is a solid particle film-forming mixture, is prepared by a conventional production technique used in the powder coating industry. Usually, the components of the final coating composition are dry-mixed in an extruder. Sufficiently dazzling: the temperature of the two-component resin (preferably below 2 〇 (rc temperature) melt-mixed and then squeezed. The extrudate is then cooled to a solid, pulverized and ground to a fine powder: when dry blended Extrusion may potentially destroy the specific electrical fraction of the powder composition, or as such, when a particular abrasive component may damage the blender and extruder, it may be desirable to add such components to the formed powder. The powder coating composition of the powder coating composition is most often sprayed (especially by electrostatic spraying) or by fluidized bed coating. The powder coating composition can be applied in a single sweep or in several passes to provide the desired after curing. Thickness film. The powder coating composition of the present invention can be applied to a variety of substrates, including metallic and non-metallic substrates. After coating to a given thickness, the coated substrate is typically heated to 120 ° C and 260 °. Between C The composition is melted for a period of from i to 60 minutes to flow but also solidify to form a crosslinked matrix bonded to the substrate. The coated substrate is preferably heated to 200. (: temperature between 250 ° C and 250 ° C During the period of 20 to 40 knives, in one alternative of the method, the powder coating composition can be at least partially melted and cured by coating on a preheated substrate by 132713.doc 200918619; depending on the degree of curing, the powder can be Further heating after coating. The invention is further illustrated by, but not limited to, the following examples.

Silres-604: a hydroxy-functional fluorene phenyl polysiloxane resin sold by Wacker Chemie. The resin has a reactive hydroxyl group content of 3.5 to 7%, a Tg of between 55 and 80 ° C, and a melt viscosity of 140 ° C of 10.3 poise. DC233: A methylphenyl polyoxo resin sold by Dow Corning. The resin had a reactive hydroxyl content of 6%, a Tg of 45 ° C and a melt viscosity of 21.3 poise at 140 ° C. P-1407: Acid polyester hardener from Twin Hill Paints P_ Ltd (India).

Araldite® GT-7004: A solid, medium molecular weight epoxy resin based on two-year old A from Hunstman LLC.

Lanco TF-1780: PTFE modified polyethylene, micronized wax from Lubrizol Advanced Materials, Inc.

Resiflow® P-67: from Estron Chemical Inc., Calvert

City, KY's flow control agent.

Fine Clad ® A 241: an acrylic resin having a glycidyl group and a hydroxyl functional group and having an epoxy equivalent weight (EEW) of more than 3 Å from ReiehoId Inc.

Primacor ® 5990: Ethylene Acrylic Acid (EEA) Copolymer from Dow Chemicals 〇 132713.doc -18- 200918619 Benzoin: a getter from Well Worth Medicines. 9875 Black: A carbon black colorant from Engelhard Corporation, Ohio. Zinc powder: from the very fine grade of Transpek Silox Industry Ltd. Standart® AT: Zinc flakes from Eckart Effect Pigments. Coatforce CF10: — A synthetic metal, magnesium and cerium mixed metal oxide supplied by Lapinus Fibres.

Mica 1240: A dry milled muscovite from 20 Microns. f. 1 Mowital B_30H: Polyvinyl condensate supplied by Kuraray. Example 1 Preparation of a Powder Coating Composition A powder coating was prepared by blending the components provided in Table 1 to . The blended material is then passed through a twin screw extruder which melts and further mixes the feedstock. The extrudate is solidified by passing between the chill rolls, and then pulverized into flakes. (4) Mixing the sheets with the additive (component 14) and grinding them by (4) machine. The obtained powder is passed through the side mesh to "remove coarse particles. 132713.doc -19. 200918619 Table 1 Number of components (% by weight) 1 SILRES-604 17.5 2 DC-233 17.5 3 P-1407 5.6 4 ARALDITE GT-7004 2.4 5 LANCOTF-1780 1.5 6 RESIFLOW -67 1.2 7 Benzoin 0.3 8 ENGELHARD-9875 5.0 9 Zinc powder 34.0 10 STANDART AT 3.0 11 COATFORCE CF -10 8.0 12 MOWITAL B-30H 1.0 13 MICA 1240 2.8 14 AF Additive 0.2 Tests Use high pressure hoses in the near range and use S280 grade beads to spray multiple steel plates. Use Elcometer 233 digital surface profile and follow ASTM D4417 In the test method of B, the average peak-to-valley value of the steel sheet was measured to be 67 μm, and the standard deviation was 15 μm. The powder coating composition of Table 1 was applied to the steel sheet in a single layer by electrostatic rubbing to a film thickness of 70 to 100 μm. The coated powder coating composition was cured by heating the substrate to 230 ° C and maintaining the temperature for 30 minutes. The four panels were then exposed to different temperature conditions as shown in Table 2. Then according to ISO 09227 Each plate was subjected to another 500 hours of heat in 132713.doc -20- 200918619 salt spray. The results of these tests are also stated in Table 2. Table 2 Plate No. Temperature Treatment Observed/Failed (according to ISO 09227 1 Heat the plate to 550 ° C for 1 hour and then water quenching. Repeat 3 times. No peeling or cracking pass 2 Heat the plate to 600 t for 1 〇 min and then water quench. Repeat 5 times. No peeling or turtle Passing the pass 3 The plate was heated to 500 ° C for 5 hours and then air cooled. Repeated 3 times. No peeling or cracking qualified 4 The plate was heated to 550 ° C for 24 hours without peeling or cracking. Example 2 Powder coating combination Preparation of the powder A powder coating was prepared by blending the components 1 to 12 provided in Table 3. The blended material was then passed through a twin screw extruder which melted and further mixed the raw materials. The cold rolls were solidified and then pulverized into flakes. The sheets were then ground by a grinder. The resulting powder was passed through a 80 mesh screen to remove coarse particles. 132713.doc -21 - 200918619 Table 3 Number of component parts ( % by weight) 1 SILRES-604 14.5 2 DC-233 14.5 3 FINE CLAD A 241 8.0 4 PRIMACOR 5990 0.3 5 LANCOTF-1780 0.2 6 RESIFLOW -67 1.0 7 Benzoin 1.0 8 ENGELHARD-9875 5.0 9 Zinc Powder 31.5 10 STANDART AT 3.0 11 COATFORCE CF- 10 20.0 12 MOWITAL B-30H 1.0

The Tg of the powder thus formed was measured to be 56 °C. Tests A high pressure hose was used in the near range, and a plurality of steel sheets were sprayed using alumina grit of 120 to 2 micrometer order (purchased from Algrain Products P Ltd). The surface profile was measured between 30 and 30 meters using the Elcometer 233 digital surface profile. The powder composition of Table 3 was applied to the steel sheet in a single layer using an electrostatic gun. The coated powder coating composition was cured by heating the substrate to 230 ° C and maintaining the temperature for 30 minutes. The dry film thickness (DFT) of the coating on each plate is between 80 and 100 μm. The six panels were then exposed to different temperature conditions as shown in Table 4. Each plate is then subjected to a 500-hour hot neutral salt spray according to the procedure of ISO 09227. 132713.doc •22- 200918619 Fog. The undercreep of the coated coating was evaluated in accordance with the procedure of ASTM B-l 17. The results of these tests are also shown in Table 4. Table 4 Plate No. Temperature treatment Observed pass/fail (according to ISO 09227) Down dive (according to ASTM B-117) 1 Heat the plate to 200 ° C for 24 hours without peeling, some micro cracks qualified < 2 mm 2 Heat the plate to 350 ° C for 24 hours without peeling, some micro cracks qualified < 2 mm 3 heating plate to 400 ° C, no peeling for 24 hours, some micro cracks qualified < 2 mm 4 heating plate to 450 °C, for 24 hours without peeling or cracking qualified &lt; 2 mm 5 heating plate to 550 ° C for 24 hours without peeling or cracking qualified 0 mm 6 heating plate to 550 ° C for 1 hour, then water Quenching. Repeated 3 times without peeling or cracking qualified 0 mm. Since there is no microcracking at temperatures above 419 °C (ex-melting point) in this test, it is inferred that adding zinc powder to the formulation results in fewer or no microturtles. Cracking, and thus for systems exposed to high temperatures, results in better corrosion resistance over a longer period of time. 132713.doc -23-

Claims (1)

200918619, the scope of application of the patent: - a powder coating composition comprising - a resin component and a filler, wherein the tree component comprises - a poly-stone resin and a second poly-stone tree - and the second polyoxo resin is characterized by a glass transition temperature (dg) which differs by at least 5 °C. 2. A powder coating composition of a bismuth 3 lipid component and a filler, wherein the wax component comprises - a poly-stone resin and a second poly-stone resin and a second poly (tetra) resin The difference in the viscous viscosity measured at 14 generations differs by at least 5 poise. 3. A powder coating composition as claimed, wherein the first and second polyoxyn resins are characterized by a melting (four) degree difference of at least 5 poise measured at 14 generations. 4. The powder coating of claim 3, wherein the melt viscosities differ by at least poise. The powder coating composition according to any one of the preceding claims, wherein the glass transition temperature of the first polyoxyxylene resin is between 4 〇t: and 5 〇t:, and the first stone eve The glass transition temperature of the oxyresin is between 5 5 ° C and 80 ° C. 6. The powder coating composition according to any one of item 4, wherein the first - second polyoxyl resin is in a weight ratio of 2:1 to 1:2 (first polyoxygen tree month)曰·Second polyoxyl resin) is present in the composition. The powder coating composition of any one of items 1 to 4, wherein the filler is a heat resistant material which is at least four times larger than the other dimension, and the filler is 5 to 95 by weight of the resin component. The content of weight 存在 exists. The powder coating composition of the member 7, wherein the filler comprises the fiber of Ming, Shi Xi 132713.doc 200918619 and the mixed metal oxide of magnesium. 9. The composition comprises oxidation of a mixed metal of a resin group, a stone alloy and magnesium. The powder coating composition of claim 8 is 20 to 60% by weight of the fibers of the aluminum. The powder coating composition according to any one of the preceding claims, wherein the resin, and the knife progression comprises from 1 to 25 by weight based on the weight of the resin component. Non-polyoxy resin. 11. A powder coating composition according to claim 10, wherein the non-polylithite resin is an epoxy-polyester mixture. The powder coating composition according to any one of claims 4 to 4, which further comprises from 1 to 1 by weight, based on the total weight of the composition, of a polymeric tackifier. 13. The powder coating composition of any of claims 4 to 4, further comprising from 2 to 10% by weight, based on the total weight of the composition, of a flow additive comprising a difunctional acrylic resin. The powder coating composition of the present invention, wherein the first and second polyoxynoxy resins are in a weight ratio of 2:1 to 1:2 (first polyoxyl resin: second polyoxet a resin) is present in the composition, wherein the composition comprises from 20 to 60% by weight, based on the weight of the resin component, of a filler comprising fibers of a mixed metal oxide of aluminum, cerium and magnesium, and wherein the composition further comprises a combination The total weight of the object is 2 to 1 〇 by weight. /. A flow additive comprising a bifunctional acrylic resin. The powder coating composition according to any one of claims 1 to 4, which comprises zinc powder. A method of coating a substrate, wherein the powder coating composition as described in any one of claims 1 to 15 of 132713.doc 200918619 is applied to a substrate, after which the powder coating composition is subjected to a curing step. The powder coating composition is applied at a layer thickness such that the DFT of the cured powder coating is at least 65 microns. 17. The method of claim 16, wherein the cured powder coating is from 130 micrometers to preferably from 75 to 100 micrometers. r 18. A substrate coated with a cured layer of the powder coating composition of any one of claims 15 to 15, which layer has a dft of at least 65 microns, preferably 70 to 130 microns. 75 to 1 micron. 19. The coated substrate of claim 18, wherein the layer has a DFT between 65 and 1 micron, and wherein the cured coating composition meets when subjected to a hot neutral salt spray for a period of time Qualified requirements for the ISO 09227 program. 20. The coated substrate of claim 19, wherein the cured coating is subjected to a 500 hour hot neutral salt spray after undergoing 3 thermal cycles, meeting the eligibility requirements of the IS 〇 09227 procedure, wherein each of the thermal cycles It consists of 55 (continued for 1 hour at TC) and then water quenched. 132713.doc 200918619 VII. Designated representative map: (1) The representative representative of the case is: (none) (2) The symbol of the representative figure is simple Explanation: 8. If there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention: (none) 132713.doc