PRO GEL CAP STYLE MULTIFUNCTIONAL COMPOSITION

Abstract

A method for creating a multi-functional additive for fusion powder coating compositions that is made from a binder system platform so as to replace the need for multiple conventional additives. The method calls for the multi-functional additive to be provided to fusion powder coating compositions by way of a carrier system selected from (3-aminopropyl) trimethoxysilane (TMS), silicon dioxide (at 45 to 55% active levels), and a flow aid comprising a polyethylene resin, a polyester hydroxyl resin, a polymeric curative, degassing agent, ricinoleic acid, and glass flake.

Claims

1. A method of preparing a multifunctional additive for fusion powder coating compositions, the method comprising: selecting a binder system platform to impart a final powder coating formulation with at least two of the following functions: flow modifier, flexibility agent, wetting agent, curing agent, gloss control, mar/scratch resistance, impact resistance, and/or rheology modifier; extruding the binder system platform to form an extrudate; and grinding the extrudate to a predetermined particle size range to produce an additive powder; and mixing the additive powder with a silica carrier to form a multifunctional additive, wherein the silica carrier is at least one selected from (3-aminopropyl) trimethoxysilane (TMS), silicon dioxide, and a flow aid, said flow aid comprising a polyethylene resin, a polyester hydroxyl resin, a polymeric curative, degassing agent, ricinoleic acid, and glass flake.

2. The method of claim 1 wherein the predetermined particle size range is between 100 nanometers and 5 micrometers for all particles of extrudate.

3. The method of claim 1 wherein a weight ratio of the carrier to additive powder is between 5:95 and 55:45.

4. The method of claim 3 wherein the weight ratio is between 20:80 and 25:75.

5. The method of claim 3 wherein the binder system platform includes at least one polyester resin.

6. The method of claim 3 wherein the weight ratio is greater than 25:75.

7. The method of claim 1 wherein the binder system platform includes at least one polyester resin.

8. A method of making a fusion powder coating composition comprising: selecting a finished coating formulation having at least one thermosetting resin selected from the group consisting of epoxy resin, epoxy-polyester resin, acrylic resin, hydroxyl polyester resin, TGIC polyester, TGIC-free polyester resin, and any combination of two or more thereof; and providing an additive made according to the method of claim 1 to form a fusion powder coating composition, wherein the fusion powder coating composition consists of between 0.06 to 1.5 wt. % of the additive.

9. The method of claim 8 wherein no other additives, excepting the thermosetting resin(s) and appropriate curatives therefore, are provided to the powder coating composition.

Description

DETAILED DESCRIPTION

[0031] Reference will now be made in detail to exemplary embodiments of the present invention. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the respective scope of the invention. Moreover, features of the various embodiments may be combined or altered without departing from the scope of the invention. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the invention.

[0032] Any elements described herein as singular can be pluralized (i.e., anything described as “one” can be more than one). Any species element of a genus element can have the characteristics or elements of any other species element of that genus. The described configurations, elements or complete assemblies and methods and their elements for carrying out the invention, and variations of aspects of the invention can be combined and modified with each other in any combination. As used herein, the words “example” and “exemplary” mean an instance, or illustration. The words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment. The word “or” is intended to be inclusive rather an exclusive, unless context suggests otherwise. As an example, the phrase “A employs B or C,” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles “a” and “an” are generally intended to mean “one or more” unless context suggest otherwise.

[0033] As noted above, the inventors endeavored to create a multi-functional binder system which could serve as an additive to simultaneously address issues and irregularities such as surface tension, surface cracking, delayed curing, loss of gloss/color, taber abrasion, impact fading, etc. These added benefits could include a lower viscosity during the curing process (whether for powder or liquid applied coatings), improved mar and scratch resistance for the final fused/cured coating, improved flexibility, improved surface tension, improved weathering resistance, increased curing mechanism, improved slip resistance, improved impact fading, improved substrate wetting and increased flow in surface rheology with minimal effect on the gloss of the final, fused/cured coating.

[0034] Specific examples of binder system platforms according to the invention are included in Tables 1 through 4 below. While these are provided as discrete formulations, these may be selectively combined, reordered, or omitted to form still other combinations and permutations, all of which form separate aspects of the invention.

[0035] As previously stated, while the binder system disclosed herein nominally includes components that are common to conventional coatings, the ancillary components (i.e., the non-resin components, such as anti-corrosion pigments, curative/hardeners, degassing agents, anti-oxidants, and the like) are not necessarily selected so as to make the flow modifier a viable, stand-alone finished coating composition in its own right. That is, while the additives appear to have the same constituents as a conventional, finished powder coating, it is irrelevant whether these components would themselves be useful as a coating. Indeed, the curatives proposed for some embodiments do not sufficiently act as curatives for the disclosed resins of the binder system.

[0036] Instead, the binder systems are formulated to be combined with a separate stand-alone coating composition and to deliver the desired effects with respect to surface tension, viscosity, flow, etc. as that finished coating composition (including the additives created using the inventive method) cures. This holistic approach to formulating an additive—by considering a combination of resins and ancillary components that deliver a synergistic effect—is, in the inventors' view, a stark departure from previous additives. Whereas past additives identified one or two chemicals as “active” or important contributors to its efficacy—with the additive itself then formulated to maximize the amount(s) of those active ingredients, the disclosed aspects of this invention acknowledge the significance of providing an entire binder system that itself melts and integrates with finished coating composition to which it is added and, eventually, cured.

[0037] Further, by relying on a carrier system, the additives created using the inventive method can be integrated seamlessly during the curing process. That is, the micronized additive(s) (i.e, particle sizes between 100 nanometers and 5 microns) can be introduced to the finished coating composition by way of an inert carrier that will simply become part of the final, cured coating. Further, when delivered on a carrier system, the finished coating's storage life is increased and its handling is simplified. In this manner, the inventors refer to the binder system additives as a “platform” through which any number of goals or aims to improve coatings can be achieved (of course, in conventional coatings, these goals or aims were only fulfilled by separate and discrete components, many of which were introduced in pure form and at significant cost).

[0038] Thus, one aspect of the disclosed formulations is that the amounts of each multi-functional additive component are selected relative to ratio of multi-functional additive to the carrier system. That is, the additive adheres to the silica carrier in known amounts, so that the combination additive-carrier is provided to the finished coating composition at the relatively low weight percentages contemplated herein. Further, given the aforementioned synergistic effects of the constituents of the additive, the relative (or “stoichiometric”) amounts of the constituents and the carrier system are important to the efficacy of the final additive.

[0039] In some aspects, the multifunctional additive, after initial extrusion and grinding, can be added at 55 wt. % or greater in comparison to the silica carrier. That is, the weight ratio of extruded additive to silica is 55:45 or more. In other aspects, ratios of 5:95, 10:90; 15:85; 20:80; 25:75; 30:70; 35:65; 40:60; and 45:55 are contemplated. Carriers of particular interest include (3-aminopropyl) trimethoxysilane and/or a silicone dioxide-precipitated amorphous silicate (45-55% active). The flow aid disclosed in U.S. Pat. No. 9,353,254 (which includes polyethylene resin, polyester hydroxyl resin, polymeric curative(s), degassing agent, ricinoleic acid, and glass flake) has also proven to serve as a useful carrier in its own right.

[0040] The platforms contemplated herein can be cured 10 min. @ 375° F. or 20 min. @ 350° F., using a convection oven such as laboratory oven (e.g., Blue M made in White Deer, Pa.). The multi-functional additive is then milled or ground to a particle size that is appropriate for powder coating applications, with micronized sizes being most ideal when a carrier system is used. In this manner, as little as 0.5 to 150 grams of additive per 1000 grams of finished coating powder can be effective when blending a finished powder coating composition, post extrusion (of the finished coating composition), according to certain aspects of the invention. Alternatively, as noted above, 0.05 to 1.5 wt. % of the multi-functional additive can be blended and extruded with/as part of the finished coating composition.

[0041] At ambient temperature and pressure, the components forming the additive extrudate are admixed in a tumbler for 40-55 minutes or a high speed mixer for 45-50 seconds until fully blended. The admixed material is then placed in the extruder hopper via the screw mechanism at 300 RPM to the extruder dye, preferably with three temperature zones at a feed rate of 400 g/min. Any suitable extruder utilizing a single or twin screw mechanism may be used to form an extrusion product. The zone settings may be, respectively 60/60/100° C. The extrusion sheet product is then ground into particles (e.g., via a Retch mill grinder or coffee grinder) for 1-5 minutes at ambient temperature and pressure to form a powder having a most or substantially all of the particles preferably between about 30 to 50 μm in size.

[0042] The silica carrier is then blended with the particulates of this additive extrudate. This may occur via a high speed system (e.g., Henschel) for a period of time sufficient to further micronize the components and adhere them to the carrier.

[0043] In identifying appropriate resins for the multi-functional additive (selected from one more of the groups of epoxy, epoxy-polyester, hydroxyl polyester, acrylic, TGIC polyester and TGIC-free polyester), alternatives can be identified so long as they have the same chemical composition and similar characteristics, such as the viscosity, T.sub.g temperature, differential scanning calorimetry, and Hegman gage test, as the exemplary grades of material identified herein.

[0044] Coating platforms appropriate for the multifunctional additives made according to this invention preferably include a conventional thermosetting powder coating resin material selected from one or more of the groups of epoxy, epoxy-polyester, hydroxyl polyester, acrylic, TGIC polyester and TGIC-free polyester resins. Conventional additives, such as hardeners, tetramethoxy glycoluril, pigments, waxes, catalysts, flow aids, degassing agents and gloss modifiers may be included, although many of these additives will be unnecessary in view of the multifunctional hardness composition's capabilities. In these cases, only about 0.5% to about 1.5% by weight of a finished powder coating platform will be comprised of the multifunctional additive.

[0045] Representative and suitable epoxy resins include Kukdo Epoxy resin KD-242H. KD-242H, is a bisphenol-A type solid epoxy resin which has excellent flow characteristics. KD-242H has an epoxy equivalent weight specification of 660-720 (g/eq), a softening point of about 85 to 95° C., and a melt viscosity of specification of about 2200 to 2800 cps at 150° C. Suitable hardeners include Kukdo KD-410J, Epikure 101 and Dyhard 100.

[0046] Dow Chemical's D.E.R 663U is a solid epoxy resin and is a standard medium molecular weight epoxy resin for powder coating applications. The resin has an epoxy equivalent weight specification of 730-820 (g/eq), a softening point specification of 92°−102° C. and a melt viscosity specification of 2000-4000 cps at 150° C. Suitable hardeners include Kukdo KD-401, KD-41, KD-410J, Epikure 101 and Dyhard 100.

[0047] Representative examples of epoxy-polyester resins useful in one embodiment include: Crylcoat 2401-2 and Crylcoat 2471-4 from Allnex; SP-100 and SP-400 from Sun Polymers; and Rucote 102, 106, and Rucote 118 from Stepan Company. The table below shows one example of a multifunctional hardness composition formulation in accordance with one embodiment of the invention (column 2) and approximated weight ranges covering other embodiments of the invention.

[0048] The multifunctional additives herein can be added to liquid as well as powder coating formulations. The formulation may be combined with liquids such as water (preferably de-ionized and/or distilled), acetone, methyl-ethyl ketone (butanone), ethanol, and other, similar common industrial solvents, as well as combinations thereof. When the multifunctional hardness composition is combined with such a liquid carrier, the formulation volatilizes after the initial coating.

[0049] Further, coating compositions having the binder system platform (i.e., multifunctional) additive can be applied on various substrate types such as plastic, metal, aluminum, wood, concrete, paper, cloth, stucco and a host of other materials to act as a coating. Additional, exemplary resins and additives, suitable for such coating compositions, as disclosed in any the references identified herein are also incorporated by reference. Still other components that may be mixed into or formed as part of the extruded powder.

[0050] Unless specifically noted, all tests and measurements are conducted in ambient conditions according to commonly accepted measurement protocols (e.g., such as those regularly published by ASTM International) and relying upon commercially available instruments according to the manufacturer-recommended operating procedures and conditions. Specific tests and regimens identified in the military and other specifications noted above may be particularly informative in characterizing the performance of coatings contemplated herein, including ASTM B117, D476 (type III or IV), D522, D523, D1849, D2794, D2805, D3271, D3335, D3359, D3363, D3451, D3723, D4060, D5767, D7027, D7187, E308, E1331, G90, G154, and G171. Unless noted to the contrary (explicitly or within the context of a given disclosure), all measurements are in grams and all percentages are based upon weight percentages.

[0051] Unless otherwise stated, all percentages stated herein are weight percentages based on the total powder coating composition or, in the context of the multifunctional additive component itself, the composition of the additive.

Examples

[0052] In addition to the disclosures of the applications invoked in the priority claim, additional aspects of the invention are provided in the tables below. The percentages cited are with respect to the total mass/weight of the formulation for the additive to be extruded, prior to mixing that extrudate with the silica carrier and/or introduction of the silica-carried additive into a final fusion powder coating composition. Further, these weight percentages may be adjusted appropriately within the stated ranges, such that the specific example provided for each additive should not be deemed as limiting.

[0053] With reference to the tables below, representative examples of polyester hydroxyl resins useful in some embodiments of the multifunctional hardness composition include: Crylcoat 2401-2 and Crylcoat 2471-4 from Allnex; SP-100 and SP-400 from Sun Polymers; and Rucote 102, 108 and Rucote 121 from Stepan Company.

[0054] Representative curatives useful in one embodiment include, Crelan NI2 blocked cycloaliphatic polyisocynate, Dow Chemical TGIC, (triglycidyllisocyanurate), Epikure 101 Imidazole Adduct, Epikure P-108 DICY Imidazole Adduct, aliphatic and cycloaliphatic amine multifunctional hardness composition from Momentive Industries and phenolic hardener DEH84 from Dow Chemical.

[0055] In the tables below, exemplary acrylic resins case be selected from

TABLE-US-00001 TABLE 1 Mutli-functional surface tension additive. Exemplary Component (in g) Minimum wt. % Maximum wt. % Polyester resin 700 65.0 75.0 Acrylic resin 150 10.0 20.0 Degassing agent 10 0.5 1.5 Anti-oxidant 8 0.2 1.2 Catalysts 10 0.2 1.8 Glass flakes 122 11.5 12.5 Functionalities delivered by this additive include improved surface tension, catalyst delivery (to the final composition), improved substrate wetting and leveling without influencing surface slip, improved flow, improved mar and scratch resistance, improved hardness, and chemical resistance. Preferred blending ratio by weight (additive:silica) is between 55:45 and 65:35.

TABLE-US-00002 TABLE 2 Mutli-functional gloss control/matting, scratch resistance, and surface hardness additive. Exemplary Maximum Component (in g) Minimum wt. % wt. % Polyester resin 665 62.0 72.0 TGIC polyester resin 222 17.0 27.0 Acrylic resin 35 3.0 4.0 Flow aid (e.g., Pison Stream 10 0.5 1.5 Solutions PF-45) Surfactant 8 0.5 1.5 Catalyst 5 0.1 1.0 Glass flakes 40 3.5 4.5 Flow modifier 15 1.0 2.0 Functionalities delivered by this additive include uniform matting, improved surface tension via lower viscosity during endothermic reactions, improved scratch resistance, improved mar and scratch resistance, improved hardness, and chemical resistance. Preferred blending ratio by weight (additive:silica) is between 25:75 and 35:65.

TABLE-US-00003 TABLE 3 Mutli-functional flow aid and appearance additive. Exemplary Component (in g) Minimum wt. % Maximum wt. % Polyester resins 800 70.0 80.0 Acrylic resin 50 4.5 5.5 Degassing agent 10 0.5 1.5 Flow Modifier 15 1.0 2.0 Anti-oxidant 10 0.5 1.5 Glass flakes 122 11.5 12.5 Functionalities delivered by this additive includes improves resistance to fading, increases flow and surface tensions during endothermic reaction and cross-linking period via lower viscosity, improved flexibility and impact strength, and chemical resistance. Preferred blending ratio by weight (additive:silica) is between 15:85 and 25:75.

TABLE-US-00004 TABLE 4 Mutli-functional curing agent additive. Exemplary Maximum Component (in g) Minimum wt. % wt. % Polyester resins 899 84.5 95.5 Curatives (as masterbatch) 80 7.5 8.5 Flow modifier 15 1.0 2.0 Catalysts 6 0.6 10.0 Functionalities delivered by this additive includes increased gel time, improved strength, promotion of cross-linking as induced by radiation, heat, and/or chemical additives, improved resistance to weathering, and chemical resistance. Preferred blending ratio by weight (additive:silica) is between 5:95 and 15:85.

[0056] Although the embodiments of this disclosure have been disclosed, it is to be understood that the present disclosure is not to be limited to just the described embodiments, but that the embodiments described herein are capable of numerous rearrangements, modifications and substitutions without departing from the scope of the claims hereafter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present specification, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present specification are possible. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.