AU2005223685A1 - Activation method - Google Patents

Description

WO 2005/089480 PCT/US2005/009091 ACTIVATION METHOD FIELD The present writing relates to a method of 5 activating an organic coating, a coated substrate having an activated coating and an activation treatment for an organic coating. In particular, the activation method improves the adhesion of the organic coating to further coating layers and/or to other entities. 10 BACKGROUND Organic coatings are generally used to protect the surface of materials from incidental damage, abrasion, chemical attack and from environmental or in-service 15 degradation. Organic coatings are also used to enhance the aesthetics and/or optical properties of an object or component. The surface properties of many coatings dramatically change on drying, curing and/or aging to become more inert ,20 than might be predicted based on the chemistry of their individual components alone. Whilst this phenomenon in part provides the coating with chemical resistance, impact strength and abrasion resistance, it also complicates the process of applying additional coating layers, 25 particularly when they are not applied within a predetermined reapplication window. The same problem arises with applying other entities such as sealants, fillers, stickers and the like, to such coatings. In cases which require the application of additional coating layers 30 and/or other entities, a mechanical or stripping process of the coating is generally necessary before the re application procedure can take place. In the specific example of aircraft coatings, it is well known that adhesion will not meet in-service 35 performance requirements when fresh layers of coating are applied over layers which have aged beyond the acceptable reapplication window. The acceptable window may be of the WO2005/089480 PCT/US2005/009091 2 order of days under ambient conditions or hours under conditions of high temperature and/or humidity. Once the reapplication window has been exceeded, the standard practice for applying additional coating layers on 5 aircraft involves mechanical abrasion of the aged coating. Both chemical stripping and mechanical abrasion have limitations. Mechanical abrasion is labor intensive, the reproducibility is variable, and it is ergonomically costly due to the highly repetitive and vibratory nature 10 of the work. As such there is a pressing need for the development of a surface treatment to improve the adhesion of aged or inert industrial organic coatings towards additional coating layers or other entities, for example, adhesives, sealants, fillers, stickers and the like. 15 Haack (Surface and Interface Anal, (2000), 29, p829) investigated the interaction of automotive polyurethane coatings using UV light to generate ozone. Promising results in terms of improved adhesion and reduced water contact angles were produced when paint formulations 20 incorporating TiO 2 were subjected to H 2 0 2 and UV light. However, there are obvious practical difficulties associated with this strategy, particularly in terms of its commercial viability for application in areas susceptible to corrosion and for treating larger surfaces. 25 Also the occupational health and safety issues make it less suited to commercial application. Coating manufacturers have developed a method of improving the procedure of coating stripping through the development of barrier layers which, for example, protect 30 the primer and conversion coating of metal structures from the chemical stripping agents (US 6,217,945). Although this procedure would inevitably improve the rate of paint stripping and reduce the amount of infrastructure down time it still relies on paint removal to provide a surface 35 which will accept a fresh coating layer with acceptable adhesion.

WO2005/089480 PCT/US2005/009091 3 In the biological field, Park et al. (Biomaterials, (1998), 19, p851) employed the surface urethane NH group to graft chemical species onto polyurethane rubber, whilst Levy et al. (Biomaterials (2001) 22, p2683) employed a 5 strong base to remove the surface urethane NH proton to accelerate such nucleophilic grafting reactions. Both strategies are unsuitable for activating organic coatings. The chemical reaction kinetics of the first strategy would be too slow to be practical, particularly since, 10 considering the low surface energy and inertness to bonding of such coatings, the urethane NH groups may not be oriented towards the air-coating interface. The use of very strong bases, as per the second strategy, may degrade existing paint layers, resulting in a mechanically weak 15 foundation for fresh coatings to adhere to. Furthermore, the latter strategy is also unacceptable for activating large areas due to corrosion and health and safety considerations. Other strategies in the biological field have 20 employed free radical techniques to graft molecules onto the surface of biomedical polyurethane surfaces (Matuda et al, J. Biomed. Res., (2002), 59, p386; Eaton et al, Biomaterials, (1996), 17, p1977). Although commercially viable, the main difficulty with this strategy lies in 25 promoting actual grafting of the substrate. Controlled glycolysis or aminolysis as described in Polymer Engineering & Science (1978), 18, p 8 4 4 , and J. Applied Polymer Science (1994), 51, p675) has very slow kinetics at room temperature and as such is not a 30 practical solution. The use of reagents such as dimethyl phosphonate (Polymer Degradation and Stability, (2000), 67, p159) is also not appropriate since they are highly toxic and act too slowly at room temperature. The strategies disclosed above do not adequately 35 address the need for the development of a surface treatment to improve the adhesion of aged or inert organic coatings to additional coating layers and/or other WO2005/089480 PCT/US2005/009091 4 entities. The problems of commercial viability, health and safety considerations, viable kinetics, applicability to small and large surface areas still remain and need to be resolved. 5 SUMMARY We have now found a method which allows the activation of organic coatings to improve their adhesive properties towards further coating layers of the same or 10 different type, and/or other entities without compromising coating integrity, via the use of mild reagents and conditions. The term "mild" in this context refers to chemicals which are not known to be excessively corrosive, acidic, 15 basic or toxic and are applicable for use in highly regulated industrial environments. One example of such an environment is a commercial aircraft paint hangar. Advantageously, this method no longer requires the traditional methods of mechanical abrasion or chemical 20 stripping of an organic coating to improve its adhesive properties towards additional coatings and/or other entities. In a first aspect, the present invention provides a method of activating an organic coating to enhance 25 adhesion of the coating to a further coating and/ or other entities comprising applying a solvent and an adhesion promoter to a surface of the organic coating, wherein contact of the organic coating with the solvent or the solvent and adhesion promoter combination results in 30 swelling of the organic coating. In another aspect, the present invention provides a coated substrate having an activated organic coating, wherein the adhesion of the activated coating to a further coating and/or other entities has been enhanced by 35 application of a solvent and an adhesion promoter to the surface of the activated coating, such that contact of the organic coating with the solvent or the solvent and WO2005/089480 PCT/US2005/009091 5 adhesion promoter combination results in swelling of the organic coating. The solvent and the adhesion promoter may be applied either simultaneously, sequentially or separately. 5 Advantageously, the solvent and adhesion promoter are combined and applied to the organic coating in the form of an activation treatment. In a further aspect, the present invention provides an activation treatment for an organic coating to enhance 10 adhesion of the coating to a further coating and/or other entities comprising an adhesion promoter and a solvent, wherein contact of the organic coating with solvent or the solvent and adhesion promoter combination results in swelling of the organic coating. 15 In a further aspect, the present invention provides a method for the preparation of the activation treatment defined above comprising the step of mixing the solvent with the adhesion promoter. 20 DETAILED DESCRIPTION In this specification, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, 25 i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. As used in the specification the singular forms " a" "an" and "the" include plural references unless the 30 context clearly dictates otherwise. Thus, for example, reference to "a solvent" includes mixtures of solvents, reference to "an adhesion promoter" includes mixtures of two or more such adhesion promoters, and the like. The method of the present invention involves 35 activating an organic coating so as to enhance the adhesive properties of at least the surface of the coating towards additional coating layers and/or other entities, WO2005/089480 PCT/US2005/009091 6 for example, adhesives, sealants, fillers, stickers andcl the like. The term 'activating' is used in this context to mean the improvement of the adhesive properties of the organic coating relative to the adhesive properties of 5 that coating, prior to application of the solvent and adhesion promoter. The word "coating" is used herein its broadest sense and describes decorative topcoats; undercoats; intermediate coatings; primers; sealers; lacquers; 10 coatings which are pigmented or clear; coatings designed for specific purposes, such as, corrosion prevention, temperature resistance, or camouflage; coatings which are high gloss, matte, textured, or smooth in finish; or coatings containing specialty additives, such as, metaL 15 flakes. In general, organic coatings which are cured, dried or aged beyond a certain time period develop resistance to forming strong adhesive linkages towards other entities. Their surface properties become more inert than might be 20 predicted, based on the chemistry of their individual components alone. Without wishing to be limited by theory, it is believed that this phenomena may result from a reduction in coating surface energy and amount of reactive surface functional chemical groups in conjunction with a 25 higher cross-link density as a function of cure time/aging which makes chemical interaction and/or the formation of strong adhesive linkages with other entities difficult The organic coatings which may be activated include, but are not limited to, fully or partially cross-linkedc 30 organic coatings. Examples of organic coatings include, polyurethane, epoxy, polyester, polycarbonate and/or acrylic coatings, more preferably polyurethane coatings. Due to their superior mechanical properties and resistance to abrasion, chemical attack, and environmental 35 degradation, such organic coatings are widely used to protect infrastructure in the aerospace, marine, military, automotive, and construction industries. Many of these WO2005/089480 PCT/US2005/009091 7 coatings show a marked reduction in adhesion to other entities, such as additional coating layers, adhesives, sealants, pressure sensitive decals or logos and the like, with increased time of curing and/or aging. 5 The activation method involves applying the solvent and the adhesion promoter to a surface of the organic coating., The surface treatment is not a primer coating but rather a chemical method of modifying the surface of the existing coating so that it is more receptive to forming 10 adhesive interactions with further coatings and/or other entities. Without wishing to be limited by theory, it is believed that a suitable choice of solvent(s) and/or solvent(s)-adhesion promoter(s) combinations allows the 15 coating to be reversibly swollen (expanded). This allows the adhesion promoter(s) to penetrate the highly chemically-resistant coating surface and engage in attractive interactions with the existing coating, for example molecular entanglement, physiochemical 20 interactions such as hydrogen bonding, or chemical linkages such as covalent or ionic bonds. Upon evaporation or partial evaporation of the solvent(s) and/or adhesion promoter(s), the coating surface is left disordered, with at least some of the securely-tethered 25 functional adhesion promoters protruding from the surface and hence available to form adhesive linkages with separate entities through molecular entanglement, physiochemical, or chemical interactions. Preferably the solvent and/or adhesion promoter only 30 swell the surface of the organic coating so that the integrity of the first or lower coatings or the underlying substrate are not compromised. The solvent may be a single solvent or a combination of two or more solvents. Preferably the solvent is an 35 organic solvent. Suitable organic solvents or solvent combinations include: WO2005/089480 PCT/US2005/009091 8 Ester based solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate and tertiary butyl acetate, acetates based on glycols such as ethylene and propylene glycol repeat units 5 for example glycoletheracetates such as ethyleneglycol monoetheracetate and diethylene glycol- monoetheracetate and dipropylene glycol monoether acetate where the ether residue may be aliphatic (methyl, ethyl, butyl etc) or optionally aromatic (benzene derivatives); 10 Ketones such as methyl ethyl ketone, methyl amyl ketone, methyl isoamyl ketone, methyl propyl ketone, methyl isobutyl ketone and acetone; Alcohols such as benzyl alcohol; tertiary butanol; isopropanol; and mono and dihydroxy glycols based on 15 ethylene and propylene glycol repeat units such as ethylene glycol, diethylene glycol, ethylene glycol monoether, diethylene glycol monoether dipropylene glycol and dipropylene glycol monoether, where the ether residue may be aliphatic (e.g. methyl, ethyl, butyl etc.) or 20 optionally aromatic (e.g. benzene derivatives); Ethers based on ethylene and propylene glycol repeat units such as ethylene glycol diether, diethylene glycol diether, triethylene glycol diether and dipropylene glycol diether where, the ether residue may be aliphatic (methyl, 25 ethyl, butyl etc) or optionally aromatic (benzene derivatives)(tetrahydrofuran); Amides such as N-methyl pyrrolidinone and dimethylacetaminde; Aromatics such as toluene and xylene; and 30 Halogenated solvents such as dichloromethane and tetrachloroethylene. However, in view of the toxicity and negative environmental impact of halogenated solvents, it will be understood that they should be used within the constraints 35 of environmental, health, and safety regulations. More preferred solvents are ester based solvents such as ethyl acetate, isopropyl acetate tertiary butyl acetate WO2005/089480 PCT/US2005/009091 9 and glycoletheracetates; ketone solvents such as methyl amyl ketone and methyl isoamyl ketone; alcohols such as benzyl alcohol, isopropylalcohol and glycolmonoethers; ether solvents gylcoldiethers; amide solvents such as N 5 methyl pyrrolidinone; chlorinated solvents such as dichloromethane and dichloroethylene. More preferred solvent combinations include high and low boiling point solvent combinations such as N-methyl pyrrolidinone: ethyl acetate; dichloromethane: benzyl 10 alcohol; ethyl acetate: benzyl alcohol; ethyl acetate: diglycol ether dimethyl ether; and isopropylalcohol:ethoxyethylacetate. Particularly preferred solvents are ester based solvents such as ethyl acetate and isopropyl acetate, 15 t-butylacetate and glycoletheracetates based on ethyleneglycol and propyleneglycol repeat units; and ketone solvents such as methyl amyl ketone and methyl isoamyl ketone and ether based solvents such as glycoldiethers. 20 The solvent(s) are generally present in the activation treatment in an amount of less than about 99.9%, preferably greater than about 50%, most preferably in an amount of about 50 to about 99.9% based on the total weight of the combination of solvent(s), adhesion 25 promoter(s) and any optional additive(s). The adhesion promoter is preferably a compound having at least one functional group. More preferably, two or more functional groups are present and under these circumstances they can be of the same or different 30 functionality. Examples of such functional groups include but are not limited to amine, alcohol, carboxylic acid, amide, ester, thiol, ether, epoxy, isocyanate, isothiocyanate and anhydride groups. Adhesion promoters with nucleophilic functional groups are preferred. 35 Particularly preferred are adhesion promoters with functional groups based on amines and/or alcohols.

WO2005/089480 PCT/US2005/009091 10 The adhesion promoter may take the form of a linear molecule, or alternatively it may take a branched, hyperbranched or dendritic structure. It may be a discrete molecule or a polymer with a molecular weight 5 distribution. Adhesion promoters with molecular weights less than about 100,000 have been found to be suitable. Preferably, the molecular weight is less than about 10,000 to achieve suitable activation kinetics. 10 Suitable adhesion promoters include linear and branched polyethylene imines (PEI); amine, epoxy, isocyanate and/or hydroxyl terminated polyether glycols such as polyethylene glycol, polypropylene glycol and/or polyethylene oxide; dendrimers such as polypropylene imine 15 octamine dendrimer and/or polypropylene imine tetraamine dendrimer; and low molecular weight amines such as ethylene diamine, diethylene tetraamine, triethylene tetraamine (TETA), tetraethylene pentamine, pentaethylene hexamine, piperazine, aminoethylpiperazine, 1,4-bis(3 20 aminopropyl)piperazine, N,N'-bis(3 aminopropyl)ethylenediamine, 4,9-dioxa-l,12 dodecanediamine, 2,2'-(ethylenendioxy)bis(ethylamine), 4,7,10-trioxatridecane-l,13-diamine (TODA), 4,7 dioxadecane-l,10-diamine (DODA), polyetheramine T 403, 25 N,N-bis (3-aminopropyl)-ethylene diamine, 3-2(2 aminoethyl)aminopropyl amine, dipropyltriamine and 4,4'diamino-dicyclohexylamine; aminosilanes such as trimethoxysilyl(propyl)diethylenetriamine; epoxysilanes; glycidylethers such as trimethanolpropane triglycidylether 30 and polyethylene glycol diglycidylethers; aziridines such as trimethylolpropanetris(3-aziridinopropionate); and acids such as polyethylene glycoldicarboxylic acid or combinations thereof. Preferred adhesion promoters are amines such as TODA 35 and/or DODA. Preferred combinations of adhesion promoters include high and low molecular weight adhesion promoter WO2005/089480 PCT/US2005/009091 11 combinations such as high and low molecular weight polyethylene imines and high and low molecular weight polyether glycols, for example, 4,9-dioxa-1l, 12-dodecane diamine and polypropylene glycol. Other preferred 5 combinations include aminosilanes such as trimethoxysilyl(propyl)diethylenetriamine and epoxy compounds such as trimethanolpropane triglycidylether; 4, 7, 10-trioxatridecane-l, 13-diamine and epoxy silanes such as trimethylsilyl(propyl)glycidylether; and aziridines and 10 trimethylolpropanetris(3-aziridinopropionate), acids such as polyethylene glycol dicarboxilic acid or glycols such as glycol derivatives. The adhesion promoter(s) are generally present in an amount more than about 0.01%, preferably more than about 15 1%, more preferably up to about 50% and most preferably about 1% to about 50% based on the total weight of the combination of solvent(s), adhesion promoter(s) and any optional additives. One or more additives known in the art of coatings 20 may also be used in the method or activation treatment of the present invention. Suitable examples include rheology modifiers such as hydroxypropyl methyl cellulose (e.g. Dow, methocell 311), modified urea (e.g. Byk 411, 410) and polyhydroxycarboxylic acid amides (e.g. Byk 405); film 25 formers such as esters of dicarboxylic acid (e.g. Lusolvan FBH, BASF) and glycol ethers (e.g. Dowanol, Dow); wetting agents such as fluorochemical surfactants (e.g. 3M Fluorad) and polyether modified poly-dimethyl-siloxane (e.g. Byk 307/333); surfactants such as fatty acid 30 derivatives (e.g. Akzo, Bermadol SPS 2543) and quaternary ammonium salts; dispersants such as non-ionic surfactants based on primary alcohols (e.g. Merpol 4481, Dupont) and alkylphenol-formaldehyde-bisulfide condensates (e.g. Clariants 1494); substrate cling agents; anti foaming 35 agents; anti corrosion reagents such as phosphate esters (e.g. ADD APT, Anticor C6), alkylammonium salt of (2 benzothiazolythio) succinic acid (e.g. CIBA, Irgacor 153) WO2005/089480 PCT/US2005/009091 12 and triazine dithiols; stabilizers such as banzimidazole derivatives (e.g. Bayer, Preventol BCM, biocidal film protection); levelling agents such as fluorocarbon modified polymers (e.g. EFKA 3777); pigments such as 5 fluorescents (Royale Pigment and chemicals), and organic and inorganic dyes such as fluoroscein. The additives are usually present in an amount of less than about 10% based on the total weight of the combination of solvent(s), adhesion promoter(s) and 10 optional additive(s). The substrate for the above methods having an activated coating may be of any type including metals such as aluminum; composites such as epoxy-carbon fibre composites; or materials containing plastics, glass, wood 15 or fabric. There may also be various "sub" coating layers beneath the coating requiring reactivation including other decorative coating layers, primers, intermediate layers, conversion or anticorrosion coating layers and the like. When the solvent and adhesion promoter are combined 20 and applied in the form of an activation treatment this may take different physical forms such as solution, suspension, mixture, aerosol, emulsion, paste or combination thereof. Treatments which take the form of a solution or emulsion are preferred. 25 The activation treatment may be prepared by mixing the components together with any mixing equipment known to those skilled in the art such as but not limited to stirrers, shakers, high speed mixers, internal mixers, extruders, mills, ultra-sound and gas dispersers. When 30 the activation treatment is in the form of a solution, the solution may be prepared as a concentrate and diluted before use or prepared ready for use. The activation treatment or the application of the individual components thereof may be applied via any 35 method known to those skilled in the art such as but not limited to spray, brush, dip, knife, blade, hose, roller, WO2005/089480 PCT/US2005/009091 13 wipe, curtain, flood, flow, mist, pipette or combinations thereof. Application by spray is preferred. The method of activation may be conducted at ambient temperatures or alternatively at higher temperatures if 5 desirable. The activation treatment or individual components thereof may be applied to small or large areas, to sections of larger parts, components or full infrastructure such as infrastructure associated with the aerospace (e.g. aircraft), automotive (e.g. vehicles), 10 marine (e.g. ships), transportation (e.g. trains), military (e.g. helicopter, missile) or construction industries (e.g. buildings, factories, floors). The surface may have simple or complex geometry or may be at any inclination. Treatment may be conducted once or 15 multiple times prior to interaction with the separate entity. The exposure time of the activation treatment on the coating is more limited by the throughput and applications requirements. As such the exposure time may be short for example one minute or extended for example 20 3h. In certain circumstances it may be preferable to remove excess non interlocked adhesion promoter and/or solvent from the surface. This process may be conveniently carried out by techniques such as solvent or 25 water rinsing; dry, water or solvent wiping; air or gas knife; vacuum application; squeegee; and/or natural or forced connection evaporation. After the coating surface is activated, separate entities such as additional coating layers, adhesives, 30 sealants, pressure sensitive decals or logos and the like may be applied either immediately or at a later time, providing the surface remains predominantly uncontaminated during storage or that the contamination can be conveniently removed. The activation solution may need to 35 be reapplied in some cases. Any suitable method known to those skilled in the art may be used to assess whether the adhesive linkage between WO2005/089480 PCT/US2005/009091 14 the organic coating and further coatings and/or other entities is fit for purpose. Such tests include but are not limited to ASTM, ISO, and FAA standards, in-house test methods to simulate in-service performance, in-service 5 performance itself, and durability testing either actual or accelerated. For the case of aerospace coatings, test methods based on water impact, such as the Whirling Arm Rain Erosion or the Single Impact Jet Apparatus (MIJA Limited, Cambridge, UK), have been found to be 10 particularly useful for assessing inter-coat adhesion. In this case, the amount of overcoat removal is related to the level of inter-coat adhesion. BRIEF DESCRIPTION OF DRAWINGS 15 In the Examples, reference will be made to the accompanying drawings, in which: Fig 1 is a schematic diagram showing the general activation strategy; and Fig 2 is a diagram showing whirling arm rain erosion 20 performance assessment. EXAMPLES The invention will now be described with reference to the following non-limiting examples. The following 25 abbreviations are used in the examples: TODA - 4 ,7,10-trioxa-1,13-tridecanediamine PEI - polyethylene imine TETA - triethylene tetraamine PEG-DGE - polyethylene glycol diglycidyl ether 30 IPA - isopropyl acetate EEA - ethoxyethylacetate SOLO - spray on-leave on SOHO - spray on hose off MEK - methylethylketone 35 DABCO - diaminebicyclooctane WO2005/089480 PCT/US2005/009091 15 Although the examples concentrate on coatings derived from polyurethane chemistries it will be understood that the same activation methodology could be applied to coatings such as but not limited to those based 5 on epoxy, acrylic or polyester coatings through the appropriate choice of solvent(s), adhesion promoter(s) and optional additives under appropriate activation conditions. 1. Inter-coat adhesion of polyurethane paint as 10 function of cure conditions/age 2. Effect of different solvent used in the surface activation treatment on inter-coat adhesion 3. Effect of different adhesion promoter used in the surface activation treatment on inter-coat adhesion 15 4. Effect of different adhesion promoter concentration used in the surface activation treatment on inter-coat adhesion 5. Effect of surface activation treatment time on inter-coat adhesion 20 6. Effect of substrate inclination (angle) on application of the surface activation treatment and resultant inter-coat adhesion 7. Effect of additives used in the surface activation treatment on inter-coat adhesion 25 8. Effect of dwell time between activation and re coating on inter-coat adhesion 9. Impact of different application methods for applying the activation treatment on the resultant inter coat adhesion 30 10. Impact of different post treatment steps to remove excess treatment and /or solvent on the resultant inter-coat adhesion 11. Effect of different paint types and curatives on the activation treatment and resultant inter-coat adhesion 35 12. Durability of coatings applied to activated substrates WO2005/089480 PCT/US2005/009091 16 13. Inter-coat adhesion between aged and then activated organically pigmented coating towards an additional coating layer 14. Adhesion data from Whirling Arm Rain Erosion and 5 SIJA experiments of activated and re-coated specimens relative to specimens sanded prior to over-coating 15. SEM analysis of coating layers 16. Raman Spectroscopy illustrating activation solution penetration depth 10 17. Analysis of coating surface by XPS prior to and following activation 18. Scribe adhesion illustrating rapid build-up of intercoat adhesion in chemically reactivated samples 19. Intercoat adhesion of samples activated with two 15 adhesion promoters (SOLO) 20. Intercoat adhesion of chemically activated sample in solvent mixture (SOLO) 21. Scribe and SIJA intercoat adhesion of samples ctivated with two adhesion promoters (SOLO) 20 22. Intercoat adhesion of specimen activated over a vinyl mask prior to overcoating 23. Sealant immersion compatibility 24. Epoxy- graphite fibre composite immersion compatibility 25 25. Sealant immersion compatibility 26. Epoxy- graphite fibre composite immersion compatibility 27. Paint stripping 28. Impact of thermal cycling on surface activity and 30 intercoat adhesion All the components of the activation treatment influence the physical properties of the treatment and hence its ability to interact with the coating. Such impacts can be assessed theoretically by using solubility 35 parameters (Hanson, Hanson solubility Parameters - a users hand book, CRC, NY, Van Krevelen, D.W., Hoftyzer, P.J.,Properties of Polymers - their estimation and WO2005/089480 PCT/US2005/009091 17 correlation with chemical structure, Elsevier, NY) or UNIFAC (Hansen H.K., et al. Ind. Eng. Chem. Res 1991; 30 (10) p2352) to estimate the contribution of the individual components to the total interaction parameter of the 5 activation treatment. It is envisaged that suitable combinations of components of the activation treatment will differ depending on the type of coating to be activated. The appropriate choice of solvent(s), adhesion provider(s), 10 optional additives and activation conditions will differ depending on the type of coating to be activated. General Experimental Detail: 15 1. Aluminium Pre-Treatment Aluminium test coupons (Alcad 2024-T3) or Rain erosion Foils (Alclad 2024-T3) were cleaned and an Alodine type conversion coating was applied prior to painting. 20 2. Painting Conditions and Protocol An epoxy based primer was used for all samples. Desothane HS (Registered Trade Mark) polyurethane topcoats were employed for all trials using the standard flow control agent (CA 8000C) unless specified. The base CA8000 25 : activator CA8000B : flow CA8000C ratio employed was also calculated on a weight basis (121.06 : 51.32 : 39.81 for white 7067) unless stated in the example. Following component addition, both primer and topcoats were shaken for 15 min in a "Red Devil" paint shaker and allowed to 30 stand for a further 15 min prior to painting. Spray painting of flat panels was carried out employing a robotic painting arm incorporating a gravity fed automatic spray gun. Spray painting was conducted using an inlet pressure of 40 PSI, a scan rate of 100 mm/s 35 and a specimen to gun distance of 300 mm. A single pass was employed for the application of the primer whilst four individual passes were required for the top-coats allowing WO 2005/089480 PCT/US2005/009091 18 "tack-up" time between each individual pass. The coating thickness was controlled by the gun's fluid needle control position and scan rate with these adjusted in line with paint thickness measurements assessed using a Fischer 5 Isoscope (MPOD). An analogous strategy was employed for the application of the overcoat, Desothane HS polyurethane. For the majority of the research the painted films were over-coated following taping of the top and bottom of the coupons with vinyl tape to form a 10 leading paint edge on its removal. This edge was the impact target for SIJA analysis. Later investigations applied the tape through the middle of the coupon. Table 2 Painting & Cure Schedule 15 Polyurethane Conducted on the same day as the primer Top-coat Cure: 18 h, 49 0 C, 10-22% relative humidity, Thickness - 100 micron (measured each batch) Alternatively: Conducted on the same day as the primer Cure: -116hrs: a) 120F, 8-12%RH, 44 hrs b) 120F, 50%RH, 48 hrs c) 160F, 3-5%RH, 24 hrs Thickness -100 micron (measured each batch) Surface modification Generally conducted directly following completion of the and/or analysis cure cycle or on the following day Polyurethane over- Painting conducted on the same or next day following coat repainting treatment. Cure: 40h, 49 0 C, 10 - 22% relative humidity, Thickness -100 micron (measured each batch) Spray painting of curved surfaces (eg: rain erosion foils) was conducted using a Binks Ml-H HVLP gun configured with a 94 nozzle. In these cases the aluminium 20 was prepared in the same manner as the SIJA plates prior to the first top-coat being applied. Following cure of the first coating layer the front of the foils were masked WO 2005/089480 PCT/US2005/009091 19 prior to over-coating to form a leading edge once the over-coating was applied and tape removed. 3. Surface Modification 5 The solvents and reagents used for surface modification were purchased from the MERK and Sigma Aldrich Chemical Companies of an Analytical and Laboratory Reagent grade purity respectively. The specific adhesion promoter or solvent employed for activation is outlined in 10 the main body of the example. General treatment conditions are presented in Table 3. Activation of the (cured) 'aged' painted surfaces was conducted either on the same day or next day following completion of curing unless stated in the example. 15 Table 3 General Activation Protocol Treatment Coupons were placed: * Horizontally over a grid and then exposed to the treatment solution from 5 to 180 min, either periodically re-applying the solution or with just one application. * At angles of 0, 45, 90, 1350 and then exposed to a treatment solution spray at 10 min intervals for 30 min or with one application. Post-Treatment * Washed with isopropanol or water * Wiped with an isopropanol or water soaked cloth * Used directly for painting (where specified, SOLO) Re-coating Dry Reactivated coating were either painted on the: * Following Day (24 h) * Same day (5 min to 4 hours after treatment) Application was conducted either by pouring treatment 20 solution over the substrate with a pipette, application with a disposable pump action spray bottle or by using a Binks Ml-H HVLP gun employing a 92 or 94 nozzle and 40 psi inlet pressure.

WO 2005/089480 PCT/US2005/009091 20 4. Analysis Table 4 provides the equipment and conditions used for polyurethane surface analysis and adhesion testing. 5 Table 4 Analytical Equipment & Conditions FTIR FTIR analysis was carried out on a BRUKER FTIR/NIR spectrometer or Nicolet Instruments employing an ATR KRS 5 TiBr / Til mixed crystal associated with the microscope Raman Spectroscopy Raman spectroscopy was completed on a Renishaw, 1000 Raman microprobe spectrometer employing a 780 nm laser, focusing the laser spot down to 1 micron. Cross sections of the painted films on glass, or aluminium were prepared by cutting the paint film and exposing the cross section to the incident laser beam.

WO 2005/089480 PCT/US2005/009091 21 Table 4 Analytical Equipment & Conditions cont. XPS XPS analysis was completed on a Kartos AXISH5 spectrometer at an incident beam of 900 employing an Alumina source to generate survey and high resolution spectra. Curve fitting analysis of the data was completed using GRAMMS RESEARCH software package Contact Angle Contact angle analysis was completed using "FIRST TEN ANGSTROMS" semi-automated video equipped contact angle analyser. CH 2 1 2 and H 2 0 were employed as the reference solvents to calculate the dispersive (ysd) and polar (ysP) contributions to surface energy (Ys) through the Young Dupre relationship and Fowkes equation. SEM SEM analysis of the polyurethane cross-sections were collected on a Oxford Pentafet detector controlled by an Oxford ISIS system. Cross-sections of the samples prepared with a cut off saw appropriate for non-ferrous materials and were mounted in epoxy resin, ground and polished to a 1 micron finish and gold coated. Imaging and x-ray analysis was conducted using a 15 KV accelerating voltage and a 17 mm working distance. EDX analysis was specifically refined for carbon, nitrogen, oxygen, and chlorine. SIJA Adhesion testing was completed using a Single Impact Jet Apparatus (SIJA) manufactured by MIJA, Ltd in Cambridge, UK. The initial equipment was configured using a 0.8 mm nozzle and employed 0.22 calibre 5.5 min Crosman Accupell Pointed Pellets (#11246). Testing was completed following immersion in water for 16 to 18h employing a line laser to locate the impact position and using a 450 specimen to impact droplet geometry. A single water jet was employed at each site to test adhesion with the pressure employed for the "shot" indicated below its impact. The velocity of each individual shot was recorded for future reference, but generally the pressure to velocity conversion is specified below (±25 m/s). Pressure (PSI) Velocity (m/s ±25 m/s) L 350 100 725 200 895 300 1007 400 1079 In some cases the amount of overcoat removed, and hence the inter-coat adhesion was assessed employing image analysis techniques to quantify the area of paint removed. More overcoat removed corresponded with inferior inter-coat adhesion WO 2005/089480 PCT/US2005/009091 22 Table 4 Analytical Equipment & Conditions cont. Whirling Arm Rain Rain erosion testing was completed on a whirling arm rain Erosion Testing erosion apparatus employing a 52 inch zero lift helicopter like propeller run at 3600 rpm. Reference and activated polyurethane topcoat foils were over-coated (60 to 100 micron paint thickness) following masking to produce a leading edge. The foils were attached to the propeller at a distance along the propeller correlating to a velocity of 380 mile per hour at the mid point of the foil. The effective rain field density of 2 mm droplets used during the experiment was 1 inch per hour. After 30 min the impact of rain erosion on the inter-coat adhesion of the foils was evaluated according to a 0.5 to 5 rating correlating the amount of paint removed or tear lengths (see figure 2). The impact of water droplets on the leading edge of the over-coat formed on removal of the tape during the experiment erodes the over-coating layer relative to the strength of the inter-coat adhesion. Green Adhesion Green (scribe) adhesion was assessed according to BSS 7225, Class 5. Briefly heat aged Dethothane polyurethane coatings were reactivated and then over-coated (60-80 micron thickness) curing the over-coat for 16h at room temperature and humidity. The coatings were then scribed according to BSS 7225 and the adhesion test was performed with PG-777 grade tape Paint Stripping Procedure for the complete strip test is described in SAE MA4872, Annmlex A, pages 51 to 53 and is similar to BMS10 103 section 8.2.12d on page 13. In this Stage an abbreviated version was completed using CEEBEE-E2012A and Turco 1270-5 paint strippers with out thermal cycling to compare how the activated and over-coated specimens to untreated and_ reference specimens. Aged specimens (Al or composite substrate, ex-BOEING) were untreated, sanded, or activated were over-coated (60-75 micron) and cured for 40h at 120 0 F. The edges were taped with Aluminized tape (such as 3M Scotch Brand 425) prior to ,commencing the test.

WO 2005/089480 PCT/US2005/009091 23 Example 1 Inter-coat adhesion of white polyurethane painted specimens cured under various conditions prior to over 5 coating with blue polyurethane as assessed by SIJA: A. 4h at 49 0 C prior to over-coating B. 18h at 49 0 C prior to over-coating C. 156h at 49'C prior to over-coating D. 18h at 490C and then sanded prior to over 10 coating r -4 13 a o A. B. C. D. Results indicate: 15 Excellent inter-coat adhesion is obtained when samples are over-coated within a short cure window (A). Reduced inter-coat adhesion when the cure time or age of samples is increased (B) and (C). Sanding the specimens cured outside their re-application window prior to over 20 coating (D) re-established the adhesion performance with only limited over-coat paint removal. Example 2 Inter-coat adhesion as assessed by SIJA of white 25 polyurethane paint cured at 49 0 C for 18 h and then treated with the adhesion promoter specified in different solvents prior to over-coating with blue polyurethane.

WO 2005/089480 PCT/US2005/009091 24 1. Chlorinated Solvents (amine terminated polypropylene glycol adhesion promoter) Untreated Dichloromethane Dichloroethylene 5 2. Alcohol solvents (amine terminated polypropylene glycol adhesion promoter) Untreated Benzyl alcohol Ethylene glycol monomethyl ether 10 3. Ester Solvents (4,7,10-trioxa-1,13-tridecanediamine adhesion promoter) ; 500 500 200 P :0 200 loo Untreated ethyl acetate t-butyl acetate i-propyl acetate Untreated ethyl acetate t-butyl acetate 1-propyl acetate WO 2005/089480 PCT/US2005/009091 25 4. Ketone Solvents (4,7,10-trioxa-l,13-trLdecanediamine adhesion promoter) IMI 11" Untreated methyl amyl ketone 5 5. Ether Solvents (4,7, 10-trioxa-l,13-tridecanediamine adhesion promoter) Untreated ethylene glycol tetrahydrofuran dimethyl ether 10 6. Amide Solvents (4, 7, 10-trioxa-1, 13-tr:idecanediamine adhesion promoter) L Udyl Untreated N-methyl pyrrolicinone WO 2005/089480 PCT/US2005/009091 26 7. Solvent mixtures too Untreated N-methyl Pyrrolidinone Ethyl acetate (1:1) 4,7,10-trioxa 1,13-tridecanediamine 5 Untreated Dichloromethane Benzyl alcohol (1:1) amino terminated polypropylene glycol 10 Untreated Ethyl acetate Benzyl alcohol (1:1) 4,7,10-trioxa 1,13-tridecanediamine WO 2005/089480 PCT/US2005/009091 27 tooIt 00 Untreated Ethyl acetate : diglycol ether dimethyl ether (1: 1) 5 4,7,10-trioxa-1,13 tridecanediamine Results indicate: Chemical activation of polyurethane may be conducted 10 with suitable adhesion promoters in a variety of different solvents or solvent combinations to improve inter-coat adhesion relative to samples which are not activated prior to over-coating. 15 Example 3 The following example show the improvement in inter coat adhesion of aged polyurethane white coatings (18h, 49 0 C) treated with various adhesion promoters (50%) employing ethyl acetate or benzyl alcohol as the treatment 20 solvent prior to over-coating with blue polyurethane as assessed by SIJA analysis. (Treatment time 30 or 60 min) WO 2005/089480 PCT/US2005/009091 28 1. Amine terminated polypropylene glycol (Benzyl alcohol) Untreated Mn = 254 Mn=4000 2. Alcohol terminated polypropylene glycol (Benzyl 5 alcohol) Untreated Mn = 740 3. Epoxy terminated polypropylene glycol (benzyl alcohol) 10 Untreated Mn = 750 WO 2005/089480 PCT/US2005/009091 29 4. Polyethylene imine (PEI) (ethyl acetate) ... & Untreated Linear Branched Branched 5 (Mw 425) (Mw=800) (Mw=25000) 5. Amine functional ether compounds (ethyl acetate) Untreated 4,7,10-trioxa- 4, 9-dioxadodecane 4,7-dioxadecane 1, 13- -1, 12-diamine 1, 10-diamine 10 tridecanediamine 015 /00-200 /06~ 1000 Untreated 4,7, 10-trioxa- 4, 9-dioxadodecane 4,7-dioxadecane 1,13- -1, 12-diamine 1, 10-cliamine 10 tridecanediamine 15 WO 2005/089480 PCT/US2005/009091 30 6. Amine functional compounds (ethyl acetate) Untreated ethylene diamine triethylene pentaethylene tetraamine hexamine 5 7. Impact of employing a mono-functional adhesion promoter on inter-coat adhesion (benzyl alcohol) Untreated Propyl amine PEI linear (PEI - polyethylene imine linear MW=425) 8. Impact of employing adhesion promoter combinations on 10 adhesion (ethyl acetate) L L 010 Untreated PEI (branched MW 25K), 10% & PEI linear 0.43K 50% WO 2005/089480 PCT/US2005/009091 31 I~ Untreated 4,7,10-trioxa-l,13-tridecanediamine (40%), diethylene triamine (10%) in 5 benzyl alcohol Results indicate: A variety of different suitably functionalised adhesion promoters or adhesion promoter combinations may 10 be employed to improve inter-coat adhesion including those which are polymeric or discrete molecules. Example 3 (7) illustrates that inter-coat adhesion is slightly improved through the use of monofunctional adhesion promoters such as propyl amine, due to the similar amount of over-coat 15 paint removal compared with untreated samples.

WO 2005/089480 PCT/US2005/009091 32 -P 0 0 0 ~00\ 0 0 U) 4 -) -H 0 >1 CD 0 )00 00' r U) 0d U . 75 04 >10\ 4-' o 001 -H U 0 ~ C) V4 c i wa 4-) 1:1 0 Cd 0 01 44 ) m Cd\ 0 4) 4)0 C/) 0 Cd 0- 4 ) I l ) 0d (D C.) C) >i Cd rl (d (a 0 J1 a) 00. 01 a) 0D 0 Cd -i '-I 000 C4d 0~- goo WO 2005/089480 PCT/US2005/009091 33 .H co Hrz 001 4-) A 41 Pd fo 001 00SV U 0 0 V1 1 , 00 0% C) 0- (L) 00/ LO 0 ci) WO 2005/089480 PCT/US2005/009091 34 CCD 4~ Cf) 44- 0 Z3 0 0 (0

-H

ro 0 4-C 0H r- 4 0dc (i) -PU Q) -H 0c -Hcd ) d 4 -) 0 4-' ( 0-H -H I R o 4- 0C ........ 4-iA-i ( 0 U u 0)_ _ 0 4-) d -0 P-4 - I _ _ _ _ _ _ _ _ _ _ >1) Cd 0 m -H -- -1 $ -H 0 r= U) 4) Cd0 U) >1i c-I 4- A 0 Cd 4LI-HO 4 0 - 4 CI ) -4 0 - co 4 0I 0-H I 0 10 ri H WO 2005/089480 PCT/US2005/009091 35 co -0 * ~ - H l 0Q 4 (I) a)J H x 0 Cl) ci) U 001 -P 0 CD 0 00 p 0 @01 P4 I) 1 C) U) 0 0H ol H - 0 on rOo rl I 0P ac Ol -P )I 44J IV ) IDA -P- 4 0 1-0 -H rl WO 2005/089480 PCT/US2005/009091 36 0 .) >10 C0 0 -P r. H fd flj 0 co U- _ _ _ -n co -H ) 0d i a) -H 4J U) 4l U) (0 U) 4J -P 4 Vd- 0i rd C) Hl Cl) 0) L ) 4-) o d -P 4-) 6 Co 00 0 0 0 r-H r- S Q) 0 0 _ _ _ _ _ _ -H -4 O r 00 -H 4)42) 0 (5 0 (d 4-2 C.(d ci) 0 ()42 4-4 00 0 4242 C i) CCH l) -C CV'0 0 ) 4 J H 0 >1 >42 (a C (j) 0 0 r 0 Q4 U)-H 'rl 0) -0 Ci 4 H-H Cd- 0 4H F EW___________D Q0 (A 4~J I4 Cd I- - C C) x < ci) (D) CO ri 42 Cd 4-4 4 -H Cd 0 P-1 - WO 2005/089480 PCT/US2005/009091 37 V) a) -P -P U) o q C. >a) 0) CD -1 0d~ aY) 0d~)f a) 04 U 0 '0 4 4-) 0 w w 00 m P4 U) U-HO0 a) Q LC)0), (0 H d -H 0 0) 4 V) H1 -. i -4-) wl 0 rl p4 a) 4J 0 -0 4J 0\0 (1. C ) Cd 0 V) Qd U)0 ild -) ) a (ri J 4 - )~ WO 2005/089480 PCT/US2005/009091 38 co q, 00 0 co __ __ __ __ -H 4-) L) 4- -H 0 4 -) 0 H 4 71 4) 4-) U)~ 0 C0 rd- 3.0 -4 0) o\V)4 LP -H (0 > ) 0 1 ) r 0 w (a 0 O ld 4) \ -HH- 1 FI- H) 0 - 4 ))Q U 0- 1- cr1 0 44 0 j 0 -H-H] 0 .- 1 a) >1 CL (D ) 0 4-) 1 1 l c i (0 U)) m~d 0 U 0 H~ (bi >I) o Y4-) 0 4-) -H O 4 A OH 0 H) s 00H 0) -H (0 U) 4_ __(_) 1) O~-H (0a 0j M 4 ) 0- 4-J) 1- -H d (1 0 0x (0-r U),c: ) 4-.~-~4-c H ) F004-HI H 0P -H 0 U -1- (1)0 0): -H 0)', M ) H J -P 4J 4-)-Hr r-i --I 0 - ) H 0) d o 0 0 F. 0 m,- U) 4- 0 a) rd P4 4 -P 41_ _ __ _ _ __ _ _ >~U 0 w -H HCP rjP-H 0= 4 -P )4)1J 0 -Pml 9 -H -o >10 o 0d 0- w N ) 4J ) -040 WO 2005/089480 PCT/US2005/009091 39 0 V H 0 CD 0742c H 4J) 4-J~ C) o\0 0) r oD r o 42 0O4 (Ah i - 0 4-) H QA (1) 00 4.) 0\ 0 r, 4-) w +0 rO4-J o! 42-( ) 42 4-) U) 0 4 -H 4-) Q) OI ()-] 4 CO -H 42) a) 'd f. -H 0 0-H 4-1 >1 _ _ _ _ _ _ _ _ _ _ _5 10 4-it 4.) 0__ _ _ _ 0~ 0' M. -4 V, 'II~H0 4 U) 4-) 4i) 0 Q ,0 H 0 CDl 4 4-) 4 4 r,) 0 4) 0d C) -H H ___ __4__ H H L)0 V C fl -) 4 -H 0 01 4 o\ 0 1- - ) m 0 .. H: 0_ 4) Co 4-l ) V (a) C) 0 H- 0i 4-) 420 0 Cl ,~~0 Cl) (3 0i > 44 ~ ~ ~ ' 1- 42J i Qt -i-I 4-).) 4.)fl3 3 Q )V0I 4-I 1 (1) - 4 0 42 4 -H -H i ) -:D 4-) U)0 0 C) 0 4.)l - () () 0 U() 0 Cl) (0) C)

U-)

WO 2005/089480 PCT/US2005/009091 40 0 S E) P4 (D 4J >1) (dci 4 4~ d4 4-C) Q4 IQ 4-) 0 C-i ci) 0 CD) 0__ _ _ _ (1) LC)ci) 4-) 4-) H ) 41H 0~4 0 C) (El O\H - i 0 0 '0 (1) -H r 4 Ha H4 CY (1) H C

H

0 A -H 0O (El 4-) 0 _ (3* i b) (ED c) C~ Qa ) -0 0C) 4-4 d 0H QU) 4~ 4 -) El) 1 UU) 4-H (El- S U) WH 4- ) 1-OW (ai (El 0 H- 0 u 4-J 0j-H 0 '0 0 ) Cl) C) -1 4-) U)Q -1 0 -I f::>1 )o )H ]-l 0 o -H P4) C) o 0 i 0El0 (D HQElU UD 0 ) -HH I H OH r::W -H S H CC) >C) 0 Co 0) C) ( -( 0 Q4 4 ) rjP ) CD- 4-) U) ME I) 4-C ) (E l - 1 0) 4-4~ 0 4) *r 0 (E ) - CD) -H 01 (ElH ~ I- WO 2005/089480 PCT/US2005/009091 41 4-J Q u 0 a 0 -P~ -H 0 4-Jl il 0 0 HUH -1 0 0 1-l O U) *H 4J -H -) ' 4-3 4 (0( a) a) ( -P ) (D A 04-4-) -) 0') 0) (D 0>0 a) 4) A - A 4-i 0 _ _ __4_ _ -H H4~iA P-4 U) L~ H C)) -HL O (a Q) > C') -P0 0Cl 04 0 4-) O- -A) 4- c) _ _ _ _ 1 -1) -H (5 -H -1 - ) H 1 i u0 1 ) P4 - o C-Hr-0a) (D 44-) QA ) 0 4-i Wa) 0 Q4i 0 01 ci _ __ _ _ _ _ )iU C)0 I a) (D _ _ _ _ _ o> A- -H - H) (D a) WA - 4 tH a H 0 0 rd) I -H OH -i 4-iH4 a) H 0 H 0r cdt CD) 09 ~ C~) 0(nsa WO 2005/089480 PCT/US2005/009091 42 co 0 S .4-J -P (0 C 0> a) U 0 U 0 00 4- (0 > 0 \ H- P4 I -4] a) 00if 4J 4-) Q tOO 0 1- 4l) 0 >1 OH 'Q 0)Q 0 -) 0 0 Hf 0 1 4 -) 4- Q) H) o 0 0 Wr CPQ WW4Ot H- 00rl-H 14-4 U) O *H -H 4-4 - CO) O1 Cd 0d 0 . 4 U) 0 -H u 4 -A (0 -4 -P~ I 0u 0 P40 a) -H 0 0 0 0 aH rz - 0 >1 _ 4 0 44 -) 0.4 (0 C -H U) rd0 0- > m a 4 -HOi 0~ - U -P- -HO 0 C -4 CO 0 Cd U) Cd H0 0 -1 -P C ) a) -H0 co Cd 0U 0 04-4 4-4 0'0 M) 0 )~ 0 4 -4~1 -H 1l 0. -r- 'r' 0 0 4-4 4 HC, a)0 0 Cd - 0 Cd1 -P -i C) 0d - (di rz) HP 4-40 H d a~ 014) 44 ( >1 00 a) U) t 0l r. 0a H~-~ - 0 a) 4J-,-HO 4-) 4 > 4-) : -H U) 0 0q U) '0 a) -H 4-) Q, -H 0 0) rd >C(d0r 4 (a 0 -H X Cd Ur) Q) 4-i a) 4-) 4 -H t00t 0 4J 4-) E) 4-4 0' Q) YH I Cd I u- Cd -H -] 0C~ c ) goC) Ut Cd () -- H O ~-H a) 4~J Cd OH ~ 7 a-H Q) x a) I Ell 00 HF1 x Cd40 co~ rd a) -H to U) CD WO 2005/089480 PCT/US2005/009091 43 Example 11 The following example shows how the appropriate adhesion promoters such as 4,7,10-trioxa-l,13 5 tridecanediamine and solvents (eg ethyl acetate) may be used to improve inter-coat adhesion of aged (49 0 C, 18 h) : a. polyurethane coatings manufactured by different paint manufacturers and b. polyurethane coatings cured with hot thinners 10 (ie thinners incorporating higher level of cure catalyst) prior to over-coating with blue polyurethane. Water wash employed following treatment. Al. PPG Aerospace PRC Desoto oGoo r300 15 Untreated 50% 1% 4,7,10-trioxa-1,13-tridecanediamine A2. Eclipse Range (Akzo Nobel Aerospace Coatings) to-o Sooo L 1L IOU3 Untreated 50% 1% 20 4,7, 10-trioxa-1, 13-tridecanediamine WO2005/089480 PCT/US2005/009091 44 B. Desothane HS cured with hot thinners tooe IP UL L too Untreated 50% 1% 4,7,10-trioxa-1,13-tridecanediamine 5 Results indicate: The activation procedure is amenable for improving the adhesion between different types of polyurethane coatings and coating cured with different thinners (catalyst levels) and hence different cure rates and fresh 10 coating layers as assessed by SIJA analysis. Example 12 The following example illustrates that the activation procedure may be: 15 A. Carried out on aged coatings, that B. Under appropriate storage conditions the activated surface is durable, that C. Inter-coat adhesion is durable over time and that 20 D. Inter-coat adhesion is resistant to chemical exposure.

WO2005/089480 PCT/US2005/009091 45 A. Inter-coat adhesion of aged coatings prior to over-coating 5 (1) White coating aged for 156 h, 49 0 C prior to over-coating with Blue coating t 'i Untreated Treatment : Amino-terminated polypropyleneglycol 50% in dichloromethane (30 min) 10 (2) White topcoats cured for 16 h, 49 0 C and stored for 3 months under ambient conditions prior to over-coating with blue polyurethane coating (treatment: 50% adhesion promoter in ethyl acetate, 30 min) DIN, 15 Untreated 4,7,10-trioxa-l, Polyethylene- Triethylene 13-tridecanediamine imine (1) tetraamine WO 2005/089480 PCT/US2005/009091 46 B. Inter-coat adhesion of aged activated surface. (Aged white polyurethane coatings (49 0 C, 18 h), activated, and stored under ambient conditions for three months prior to over-coating with blue polyurethane). (Treatment 50% 4 ,7,10-trioxa-,13 tridecanediamine in ethyl acetate, 30 min) L 5 Original Adhesion Adhesion after 3 month ambient storage prior to over-coating (Treatment 50% Polyethylene imine (linear) in ethyl acetate, 30 min) LL Original Adhesion Adhesion after 3 month ambient 10 storage prior to over-coating WO2005/089480 PCT/US2005/009091 47 C. Inter-coat adhesion over time. (Activation of aged white polyurethane coatings (49 0 C, 18 h) prior to over coating with blue polyurethane). (Treatment 50% 4,7,10-trioxa-1,13 tridecanediamine in ethyl acetate, L30 min) 5 Adhesion 2 days Adhesion after 5 month ambient storage (Treatment 50% Polyethylenen imine (linear) in ethyl acetate, 30 min) Adhesion 2 Days Adhesion after 5 months ambient storage 10 WO 2005/089480 PCT/US2005/009091 48 D. Following exposure to Skydrol Hydraulic Fluid for 30 days No Exposure NCOo 30 day exposure LL 5 Untreated Polyethylene imine 4,7,10-trioxa-l,13 0 (linear) tridecanediamine (treatment 50% adhesion promoter in ethyl acetate) Results indicate: 15 Polyurethane coatings aged for extended periods under 30ambient or higher temperatures may be activated by application of the activation treatment to produce improved inter-coat adhesion as assessed by SIJA techniques. The activated surface itself is also robust 20 under appropriate storage conditions, as is the inter-coat adhesion between paint layers over time as well as lIto 12000 L Untreated Polyethylene imine 4,7, 10-trioxa-l, 13 10 (linear) tridecanediamine (treatment 50% adhesion promoter in eth-yl acetate) Results indicate: 15 Polyurethane coatings aged for extended periods under ambient or higher temperatures may be activated by application of the activation treatment to produce improved inter-coat adhesion as assessed by SIJA techniques. The activated surface itself is also robust 20 under appropriate storage conditions, as is the inter-coat adhesion between paint layers over time as well as WO2005/089480 PCT/US2005/009091 49 following exposure to chemicals such as those used in hydraulic fluid. Example 13 5 The following example illustrates the irater-coat adhesion between aged and then activated organically pigmented polyurethane coating (blue) towards an additional coating layer (white). a 10 Untreated 4,7,10-trioxa-1,13- 4,7-dioxadecane triethylene tridecanediamine -1, 10-diamine tetraamine Treatment 50% adhesion promoter in ethyl acetate, 30 min. 15 Results indicate: The adhesion promoting treatment provides improved inter-coat adhesion between aged organically pigmented 20 coating (eg blue) and additional coating layers.

WO 2005/089480 PCT/US2005/009091 50 H1 , CD Cl u 0 i C 00 mu 0 4 ( -H -H( 0 rcu 024 -' 4 -) Cu0 04 0 >1H '0-- 0 w_ _ __ _ _ 0u 4 0H U (D m 0 0- 0 w CuI C b2 00 41 u -H -P '0 Q C 0 Cu ___ ___ __ Cu 0 M 0 Y~ I~ u~~C ( Q . Cu " rl o -H -3 42H~ r, U) -HI -) 8 ,Cu V 0u 4-4 4J -H-g~ H 0 Cu'0H Cu H 0 0-) a) C-4-) 0 0 co C 4 002 C' C4 u 0 0 C u4 C 0 Cu - Cu Cu H1 0 Cu) Cu C) Cu Cu 0 O m 4 42H Cu 0 42 ~H 0 42 C ~4-H Cu xC (0 -H '0 > Cu 01 t 0 Q 4 .Cu 0002 Cu-)1 0-H- 0 04 a)_ _ _ __ _ _ _ _ 0u C C 0 CuMCu 0 ~ Cu ') 0 - C *H C (1C5 02 U) 4-J Cu4 42 44 4-) Cu 020 rc- .0 u ~W Cu Cu- 4 2 - ( WO 2005/089480 PCT/US2005/009091 51 B. Whirling arm rain erosion results of inter-coat adhesion of aged polyurethane coatings (490C, 18h) which were then over-coated with blue polyurethane top-coat 5 (activation solution 50% adhesion promoter in ethyl acetate) Polyethylenenimnine (lineaO) Untreated R = 4., Area = 0.6% Ref (No Sa.nd): R= 0.5; Area= 8 % 4,7,10-trioxa-1,13-tridecanediamine Sanded Sanded: R = 4.5:; Ara = 0.4% R = 5.0; Area = 0.0% Results indicate: Analysis by SIJA and whirling arm rain erosion 10 experiments indicate that inter-coat adhesion of specimens activated with suitable adhesion promoter and solvent is comparable to the performance obtained by sanding aged polyurethane coating prior to over-coating. In terms of rain erosion analysis: 88% of the over coat is removed 15 from untreated samples, 0.4% from sanded, 0.6% from sample chemically activated with PEI and 0% with those activated with 4,7,10-trioxa-l,13-tridecanediamine prior to over coating. In terms of SIJA experiments assessment of the paint area removed indicated that 177 mm 2 of the over coat 20 is removed from untreated samples, 13 mm 2 from sanded, 28 mm 2 from sample chemically activated with PEI and 13 mm 2 WO 2005/089480 PCT/US2005/009091 52 with those activated with 4,7,10-trioxa-1,13 tridecanediamine prior to over-coating. Example 15 5 SEM analysis of inter-coat adhesion of specimens painted with white polyurethane cured / aged for 18h at 49 0 C and activated prior to over-coating with blue polyurethane: A. 18h at 49 0 C prior to over-coating 10 B. 18h at 49 0 C and then sanded prior to over coating C. 18h at 490C and then treated with amine terminated polypropylene glycol (Mn 230, 50%, 60 min) in benzyl alcohol prior to over-coating 15 A.

WO2005/089480 PCT/US2005/009091 53 B. C. 5 Results indicate: Poor inter-coat bonding in A. with voids, cracks and de-lamination between the coatings. Additional coat does not appear to wet the aged white existing coating layer. Good inter-coat adhesion in B. when the sample has 10 been sanded prior to re-painting. Good inter-coat adhesion in C. when sample has been chemically activated prior to over-coating.

WO 2005/089480 PCT/US2005/009091 54 In both Examples 15 B & 15 C the fresh coating appears to wet the aged coating well.

WO 2005/089480 PCT/US2005/009091 55 Cd ~ E (H d 0 0 P4 CD LO 4 C) (0 0 Q)C) c 4-3 0 4-)H rjC 0 - 0I U) 0 4-J >1 (0 N 4 0) (6) C'. N CD 4J Q 0 Ratio: BeOH IP 4-) 0N 4-P H) 0 v *H1 0 ( C) 0 U~ ~ \ -,7, H 0 C0 00~ H 4- >1 (1) U) F. $Z! 4 (D 0 C) ) 04 WO 2005/089480 PCT/US2005/009091 56 1.6 1.4 -0- [Trioxa 50% ] - 30 min --v- [ Trioxa 50% ] - 5 min. 1.2 1.0 0.8 0.6 0.4 S 0.2 0.0 . .. 0 1 2 3 4 5 6 7 8 Cross-section of the Topcoat (im) B. 4 ,7,10-trioxa-1,13-tridecanediamine in benzyl alcohol (50%) 2.75 2.50 [ PEI 50% ] - 5 min. 2.25 --- [PEI 50% ]- 30 min. 2.00 1.75 1.50 1.25 1.00 0.75 0.50 1 0.25 0.00 0 1 2 3 4 5 6 7 8 9 10 Cross-section of the Topcoat (pm) 5 C. Polyethylene imine (linear, Mw=425) in benzyl alcohol (50%) WO 2005/089480 PCT/US2005/009091 57 Results indicate: Unlike benzyl alcohol when used on the painted surface alone, solutions of 4,7,10-trioxa-1,13 tridecanediamine or polyethylene imine in benzyl alcohol 5 even after 30 min exposure time penetrate the paint film less than 7 micron (re: 55 micron for benzyl alcohol alone). This indicates that the activation treatment is limited to the coating surface through the appropriate choice of solvent/s adhesion promoter/s and adhesion 10 promoter/s concentration. Example 17 XPS analysis of a polyurethane coating before and following surface treatment in Dichlormethane. 15 Untreated (average of 3 batches) 78.2 119.82. 60 min Treatment Amine-terminated polypropylene 70.5 26.1 3.4 glycol Mn=230, 10% Amine-terminated polypropylene 66.3 26.7 3.7 glycol Mn=230, 50% 180 min Treatment Amine-terminated polypropylene 69.2 28.1 2.7 glycol Mn=230, 10% Amine-terminated polypropylene 68.5 28.2 3.3 glycol Mn=230, 50% WO2005/089480 PCT/US2005/009091 58 XPS analysis of a polyurethane coating before and following surface treatment in benzyl alcohol. 5 Untreated 27.9 5.5 60 min treatment Polyethylene imine (Linear) Mw 25.7 8.9 425 Polyethylene imine (branched) Mw 25.5 8.5 800 Results indicate: Changes in elemental composition occur on treatment 10 of an aged polyurethane surface (49 0 C, 18h) following treatment with appropriate activation solution. The changes in elemental composition are consistent with adhesion promoter being embedded or bonded to the coating.

WO 2005/089480 PCT/US2005/009091 59 0 0 H~ -P i)C U0 o\ m 4 4ci 0 4-) NH U DQ 0 0r) U-) *A 4- 000 0 0 4 4-)) Ln > S 0 04 U Ci) r0 C)i 0 Q0 0 4i)I 0 m k- 4J CD(D4- 4 CD -H! 4- 0(i) 0\ 00 U) ,D0l c 4-c- H O 4 -H -0 Cl ) 4J OcD C) 0 cI) 0l H2 410 -' C In cd- (d 4- ) M (D 1 0\ 0 0 f:) 0 u~< 0 (2) U)- H 0 ', H o 0- - +1H4J ( 0-~l ' (0 00 41' a) r rd0-~ id a) ~-H 0) 0 U) 00 HH 3 Q WO 2005/089480 PCT/US2005/009091 60 u4 U) i l 0 00 .H X -) 44 -) Lo -H I-I 4-) +1 4-3 0 a) C, 00 0 0 CD kn 04-) I-- CD). ~H -1 0) + -, 0 0) U)~ 0)4-4-) 41~~( rc-( l-S * U)) 0-d o0 rd H 04-4 S~M4 4-)) 4 -L 0 -H 0 ) U ) C Co -) 4-) <~-~a - a)h 0)Q )U 0Pc~ 00 4-~.C ) y -H H Q 4-) CO4- WO 2005/089480 PCT/US2005/009091 61 Q)) 4-) -H -H CO ,9' 4 f.'U)H I 0 U) uN -P ) t 4 Q) +1 (0 0 4-) C) -H -) C) mC0 C) 00 C) Cd0 0d j 0 C o 4-) C)C 0 W Q Cd C-) Q ) 05L( 0 ~>1 -H -4 Cd o LC) f4 (0 (Di Cd Cd -Hp 42 (d C 0 P0( (07 4) U) U (D -P CD0 Cd U) C\N C) r -A C) W 1- -- 1 +1 V 4-) 0) 4dH' H U IA >1 w d' CD t) 04 G) 4-)) (Nj 0 mI >1 C) 0 0- w~ co -I (0 C - WP 4 ) W 0 Q H> r- H-H E a ) > H r-H C) (dbF - c -1 UD QA~ x H : -H TOA wC 0 aC wC(I ) () U) U) -4~ (d rQ (0 C) -1 WO 2005/089480 PCT/US2005/009091 62 4- d C) uH -H > -1 r Cl) CD14 (C ) 4J -I-) 0 0= (7- 0 t4CD) E E Q OrA 0 0 o V) oN r (d M6 (a 0 o 0 ~l U, CDC* CIC' '-l Hd 1- C y LO Cd Cl WO 2005/089480 PCT/US2005/009091 63 (d 0 4 J 0 Cl 0 04 0 U) r a) (0 > 01 0 0 p4 0 H04 a) Q4 0)U WO 2005/089480 PCT/US2005/009091 64 a) f.- a)a) I I - 4 42 a) Ln 4-C +1 Co 4> ,C 4-H -H U) 0 CU) H - ) ~ 4-)H ~t iC r0 0f4 424)IIF a )0 0 ( H ( )4 '- r.) n $:I)a C C) a)Z - V a) nH a) - - C 4- -H C) U) 0~ 0 a) r-H 2U 4-) 0 4 4 Re-Z-H p C- C C= M 4-) 4- (044-) r H 0)~ '0 -- t PH t 2 0 ia Q)~ Ui 0)C -H \o -H 4 U) Lf ( 1) 4-4 I -I -4 -P 0a 42 Cd 4- U) C iH ni0 Ca)If cii U)N W-3U (o 0 4- ( 1) r, a) ci CD 1 H 0~ a) W~~~ CU) U U)4) t n C) H 2

HOU)U

WO 2005/089480 PCT/US2005/009091 65 (d 0 0 -) 00 a) 0 4-)p rCi Cfd rAD 0- -C 0d 0 44 S Cl) o 0 0 U -) 4-) 0 o4-H 00 C) 0 oo ( -H CO-H M4 0y 0 U4 j J ) 4- (L _ H 42U ro 0 Ln CD .) -i r WO 2005/089480 PCT/US2005/009091 66 a) 42 4- a 424 Cdd 4 4 42 4a ) Cfd 4 42 41 0 ~-4 d E CCd LOQ 04 -Ji iaa)U 0o 0 0 r ) UE .1i > 4 4- -H > 4-) 01 42 0 P4ciV- i9 ) ( x d4 0_ ()LIC %(U Ln CD Ln CD) -Hr- H N1 ~~4 WO 2005/089480 PCT/US2005/009091 67 0 U) -A 0 Q~4-)

U.

1 .H a) 4 *H ) 4J4 4-) 0 0 ~-H 0 * -H A1 ( ) 42 Uz 0 '04 -H a4 ) 42 a) *H- P a) U/) 0 0 42 H0 0 42- U U) a) (D ( a) 0 H 0 4!4 0 a) a qf)4 0 C) U ) a) E)-. 1 H A4 00 (HH 4-) H-1A -H) 0 P) Ln a) 0 a) 4-) 0420 4-) ) >1 0dP(4 00) a) Hq 42 Ida (- 42- CO H 4 WO 2005/089480 PCT/US2005/009091 68 Q4 Q4 owA -& A >i4J ci) H Hm u A 0 mi ci) 0 4-) ~ 042 40 -1 c) a) 0 42 U)d w OH ci) 0o40 a- C) Cl) ci) 0 04 -H Cl) 0 4 0 W H4 0 FH PQ IH 0 4 p) V) Clul IA4GL r4 ci) C)4 -d od 0:Aod 42 H- - a) ou p 0jf O Wt -H I-c' je~ Cd) Cl) m* 0E IOZ -Hae 00 -4O -H

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> ci)14) ~ 4-) 0 -H 442 H 4 Q >1 M 04%4) 4) 0 0 4 0 0 4 (d 4)0 -H4) r Wd H 4 tJ 4 ci)o - -H 4-J (d LO C LC) C) -1 C~H WO 2005/089480 PCT/US2005/009091 69 rC d ~~rd , 4 ap ) 4j -P -J 00 Cl r-H 0) 4J 0 4 0 CD Cl)lH CD~ o U/) -P 44 4J U)H f -Q-4 P4 0 0~ (d -H +r a) 4 4 C l) on 0 4-) 4- rc 0) LO Cd WO 2005/089480 PCT/US2005/009091 70 4J U) 4C 0 bi) 4-)~ o~ 4- c ) 0 -) HdU r~>1 -) 0) C E-i V) c4-) o CD U 0 4Jc) dC )H Cl4 4 >C 4d - r)1 4 H ID 0 ) 0dC 4 0 4- 00 i (, u Q) 0~ U) m) co c) -T (d r ci -P bCdq 4- H uZ H 0 0 4 U) H 0iC/ v ~co 0 d (Dci ~0 4 4 H4H H ~ C> ci) 4 J - ACl X< 0 MH (1)ci

H

WO2005/089480 PCT/US2005/009091 71 In summary, the present writing relates to a method of activating an organic coating, a coated substrate having an activated coating and an activation treatment fo an organic coating. In particular, the activation method improves the adhesion of the organic coating to further coating layers and/or to other entities. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments 5 without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (43)

1. A method of activating an organic coating to enhance adhesion of the coating to a further coating and/or to other entities comprising applying a solvent and 5 an adhesion promoter to a surface of the organic coating, wherein contact of the organic coating with the solvent or the solvent and adhesion promoter combination results in swelling of the organic coating.

2. A method according to claim 1, in which the 10 adhesion promoter is a compound having at least one functional group.

3. A method according to claim 2, in which the adhesion promoter is a compound having two or more functional groups which are of the same or different 15 functionality.

4. A method according to claim 2 or claim 3, in which the functional group is nucleophilic.

5. A method according to claim 4, in which the functional group is selected from amine, alcohol, 20 carboxylic acid, amine, ester, thiol, ether, epoxy, isocyanate, isothiocyanate and anhydride groups.

6. A method according to claim 5, in which the functional group is an amine and/or alcohol group.

7. A method according to claim 1 or claim 2, in 25 which the adhesion promoter is selected from linear and branched polyethylene imines (PEI); amine, epoxy, isocyanate and/or hydroxyl terminated polyether glycols; dendrimers; low molecular weight amines; aminosilanes; epoxysilcones; glycidcylethers; aziridines and acids or 30 combinations thereof.

8. A method according to claim 7, in which the amine, epoxy, isocyariate and/or hydroxyl terminated polyether glycols are selected from polyethylene glycol, polypropylene glycol and polyethylene oxide. 35

9. A method according to claim 7, in which the dendrimers are selected from polypropylene imine octamine dendrimer and polypropylene imine tetraamine dendrimer. WO2005/089480 PCT/US2005/009091 73

10. A method according to claim 7, in which the Low molecular weight amines are selected from ethylene diamine, diethylene tetraamine, triethylene tetraamine 5 (TETA), tetraethylene pentamine, pentaethylene hexamine, piperazine, aminoethylpiperazine, 1,4-bis(3 aminopropyl)piperazine, N,N'-bis(3 aminopropyl)ethylenediamine, 4,9-dioxa-l,12 dodecanediamine, 2,2'-(ethyleneioxy)bis(ethylamine), 10 4,7,10-trioxatridecane-l,13-diamine (TODA), 4,7 dioxadecane-l,10-diamine (DODA), polyetheramine T 403, N,N-bis (3-aminopropyl)-ethylene diamine, 3-2(2 aminoethyl)aminopropyl amine, dipropyltriamine and 4,4'diamino-dicyclohexylamine. 15

11. A method according to claim 10, in which the low molecular weight amines are selected from TODA and DODA.

12. A method according to claim 7, in which the aminosilanes are selected from trimethoxysilyl (propyl)diethylenetriamine. 20

13. A method according to claim 7, in which the glycidylethers are selected from trimethanolpropane triglycidylether and polyethylene glycol digycidyl ethers.

14. A method according to claim 7, in which the aziridine is trimethylolpropanetris (3-aziridino 25 propionate).

15. A method according to claim 7, in which the acid is polyethylene glycoldicarboxylic acid.

16. A method according to claim 1, in which the adhesion promoter has a molecular weight less than about 30 100,000.

17. A method according to claim 16, in which the adhesion promoter has a molecular weight less than about 10,000.

18. A method according to claim 1, in which two or 35 more adhesion promoters are present. WO2005/089480 PCT/US2005/009091 74

19. A method according to claim 18, in which high and low molecular weight adhesion promoters are present.

20. A method according to claim 19, in which the 5 high and low molecular weight adhesion promoters are high and low molecular weight polyether glycols.

21. A method according to claim 20, in which the high and low molecular weight polyether glycols are 4,9 dioxa-l, 12-dodecane dianine and polypropylene glycol, 10 respectively.

22. A method according to claim 18, in which the adhesive promoter is a combination of aminosilane and epoxy compounds; 4, 7, 10-trioxatridecone-l, 13-diamine and epoxy silanes; aziridines and trimethylolpropanetris 15 (3-aziridino propionate); aziridine and acids; or aziridine and glycols.

23. A method according to claim 1, in which the adhesion promoter is present in an amount more than about 0.01% based on the total weight of the combination of 20 solvent and adhesion promoter.

24. A method according to claim 1, in which the adhesion promoter is present in an amount of about 1% to about 50% based on the total weight of the combination of solvent and adhesion promoter.

25 25. A method according to claim 1, in which the solvent is an organic solvent.

26. A method according to claim 25, in which the organic solvent is selected from ester based solvents, ketones, alcohols, ethers, amides, aromatics and 30 halogenated solvents.

27. A method according to claim 26, in which the solvent is selected from ethyl acetate, isopropyl acetate, tertiary butyl acetate, glycolether acetates based on ethyleneglycol and propyLene glycol repeat units, methyl 35 amyl ketone, methyl isoarnyl ketone, benzyl alcohol, isopropylalcohol, glycoldiethers, N-methyl pyrrolidinone, dichloromethane and dichloroethylene. WO2005/089480 PCT/US2005/009091 75

28. A method according to claim 26 in which the solvent is a combination of N-methyl pyrrolidinone and ethyl acetate; dichloromethane and benzyl alcohol; ethyl 5 acetate and benzyl alcohol; ethyl acetate and diglycol ether dimethyl ether; or isopropylalcohol and ethoxyetheylacetate.

29. A method according to claim 1, in which the solvent is present in an amount less than about 99.9% 10 based on the total weight of the combination of solvent and adhesion promoter.

30. A method according to claim 29, in which the solvent is present in an amount of about 50 to about 99.9% based on the total weight of the combination of solvent 15 and adhesion promoter.

31. A method according to claim 1, in which an additive is also applied to the organic coating.

32. A method according to claim 31, in which the additive is selected from rheology modifiers, film 20 formers, wetting agents, surfactants, dispersants, substrate cling agents, anti-foaming agents, anti corrosion reagents, stabilizers, leveling agents, pigments and dyes.

33. A method according to claim 31, in which the 25 additive is present in an amount of less than about 10% based on the total weight of the combination of solvent, adhesion promoter and additive.

34. A method according to claim 1 or claim 31, in which the solvent, adhesion promoter and additive are 30 applied either simultaneously, sequentially or separately.

35. A method according to claim 1 or claim 31, in which the solvent, adhesion promoter and additive are applied simultaneously in the form of an activation treatment. 35

36. A method according to claim 1 or claim 31, in which the solvent, adhesion promoter and additive are applied via a spray, brush, dip, knife, blade, hose, WO 2005/089480 PCT/US2005/009091 76 roller, wipe,curtain, flood, flow, mist, pipette or combinations thereof.

37. A method according to claim 1, in which the organic coating is a polyurethane, epoxy, polyester, 5 polycarbonate and/or acrylic coating.

38. A method according to claim 1, in which the other entities are selected from adhesives, sealants, pressure sensitive decals and logos.

39. A method according to claim 1, in which excess 10 solvent and/or adhesion promoter is removed by solvent or water rinsing; dry, water or solvent wiping; air or gas knife; vacuum application; squeegee; and/or natural or forced convection evaporation.

40. A coated substrate having an activated organic 15 coating, wherein the adhesion of the activated coating to a further coating and/or other entities has been enhanced by application of a solvent and an adhesion promoter to the surface of the activated coating such that contact of the organic coating with the solvent or the solvent and 20 adhesion promoter combination results in swelling of the organic coating.

41. A coated substrate according to claim 40, in which the substrate is a metal, composite or a material containing plastics, glass, wood or fabric. 25

42. An activation treatment for an organic coating to enhance adhesion of the coating to a further coating and/or other entities comprising an adhesion promoter and a solvent, wherein contact of the organic coating with the solvent or the solvent and adhesion promoter combination 30 results in swelling of the organic coating.

43. A method for the preparation of the activation treatment according to claim 42, comprising the step of mixing the solvent with the adhesion promoter.