2 JUNE 2009

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discuss the curing capabilities ofhigh powered UV LED sourcesand their potential to contest UVmercury lamps.

There will be no betteropportunity for formulators tofamiliarise themselves with thevarious radiation curing techniques,while global economies arecompromised and the emphasis ison energy conservation!

Matte finishes are an importantand sizeable market requirementand powder coatings formulatorsuse a wide range of differentmethods for achieving the desireddegree of gloss. While mattepowder coatings applied forindoors applications present littleproblem in meeting the customerspecification, there have beenlimitations to the reliability ofpowder coatings formulated foroutdoor applications. A newtechnology has been introducedby Cytec, which is claimed tomake it possible to formulateoutdoor powder coatings basedon polyester/Primid systems withgloss levels between 8 and 40units measured at 60°. There aremany reasons for specifyingmatte finishes. Their ability toreduce the reflected light can helpto hide substrate defects and filmsurface irregularities, but the mainreason for choosing a matte finishis the aesthetic appeal it gives toitems such as black wheel trimsand garden furniture. While it isnot yet possible for Cytec tointroduce a new resin where “oneproduct fits all”, it has developeda range of one-shot carboxylatedpolyesters. The formulator is ableto produce the desired mattelevel by selecting the rightamounts of a pair of these resins,and by a single extrusion processgive a reproducible product. Theresins are available in standard orsuper durable qualities and aredesigned for use in Primid curedpowder systems.

In this period of globalrecession, the major powderproducers have taken their usualaction by drastically reducing theirlabour force, a course of action,which I am sure, will seriously

affect their commercialrecuperation when the economyrecovers. I was, however, pleasedto note that some perceptivecompanies have taken thisopportunity to discard, or betterstill, sell off the older powdercoating products that gave little orno profitability, whilst retaining thepromising powder technologieswith future potential.

If Dow Chemical decided tosell the Rohm & Haas powdercoating division to a progressivepowder producer then this actionwould free the company from theoppressive atmosphere of anacquisition that can only stifle thepotential of this major powderproducer. Retaining theindividuality of R & H PowderDivision would be good for thewhole industry by continuing topromote healthy competition, theexploitation of new marketpotentials, and the introduction ofnew technologies.

Sid Harris

TECHNICALNew resins for matte powdercoatings

There are several techniquesused to control the matting effectin powder coatings and the mostwidely used method is the dryblending technique of mixing twoready-made powder coatings withdifferent reactivities prior to finegrinding, or in some instances, bydry blending the completedpowder coatings. This methoddoes, however, have someinconsistencies. Differences inparticle size distribution betweenthe two powders can cause asparkle effect due to non-homogeneity of the cured film,and during recycling of theoverspray the particle sizedistribution may alter arising fromthe different charging behaviour ofeach powder and differences inparticle size distribution.Mechanical properties of these

blended powders are diminishedby the weak bonding between thetwo phases of the powders, andadditional costs of manufactureresult from the need to extrudetwo separate products to producea single matte powder.

While the dry blended mattepowders are generally suitable forindoor applications, there is aprime requirement in architecturaland other outdoor applications.The range of matte effects isclaimed to be between <10 andup to 45 measured at 60°reflective angle. High valueoutlets exist for dull-matte (<10)powders to provide an aestheticfinish on glass bottles; officefurniture is typically coated withsemi-matte powders (25-45);window frames coated with woodeffects that perform best at lowgloss levels; automotive trim partsare coated with matte (10-25) orsemi-matte UV resistant powdersto prevent distracting lightreflection; and dull-matte powdersare used on bicycle frames andon a number of militaryapplications. The potential marketfor exterior durable low glosspowder coatings is about 20% ofthe total outdoor decorativepowder market, equivalent toapproximately 100,000 metrictonnes globally. Cytec SurfaceSpecialities claims that it has nowdeveloped a new technology thataddresses the need for highlydurable outdoor matte powderfinishes. In a paper presented atthe recent European CoatingsCongress, Dietmar Fink of Cytecdescribes the development of arange of carboxylated polyesterresins designed for use inconjunction withhydroxyalkylamide (Primid)crosslinkers. From the range ofnew resins the formulator is ableto select a pair to achieve thecorrect degree of reproduciblematting with only one extrusion.The product types are defined inthree categories: industrialoutdoor; standard durable; andsuper-durable, and each categoryuses a different blend of resin toproduce finished products with

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gloss readings at 60° of 20-35 or6-20. Nine experimental resinsare described in these categories.

The paper gives a formulationfor RAL 8014 brown with themajor components shown asbinder 80% and blanc fixe 15%.The product is applied at 60-70μm and cured at 200°C for 10minutes. A number of hydroxy-alkylamides are availablecommercially including Primid XL552 from EMS-Primid AG andVestagon EP-HA 320 from EvonikAG. A lower functionality productPrimid SF 45-10 yields glosslevels about 10 units higher thanthe basic grades. Formulators areadvised to use only ratios of thepolyester pairs that do not exceed55/45 or 45/55 since higher ratiosresult in higher gloss levels andare not always reproducible. Themain differences in commercialhydroxyalkylamides appear to beshown by slight variations in glosslevels although their effect onchemical and mechanicalproperties is identical.

Two of the new resinsCrylcoat E 04187 and Crylcoat E04211 can be paired to give verygood mechanical properties thatare superior to any powdersmade by dry blendingtechniques. They also exhibitgood storage stability and thepowders do not alter in reactivity,flow and flexibility properties aftertesting for one month at 40°C.This resin blend was also shownto give very constant gloss levelsat different stoving schedulesranging from 15’@200°C to25’@170°C. The combinationalso exhibits gloss retention after12 months in Florida (5° South)well above 50% and givesweathering properties to meetboth GSB and Qualicoatapprovals.

As an alternative to Crylcoat E 04211 it is possible to useCrylcoat E 36988 to giveimproved weathering propertiesand smoother films in the 10-20units gloss range.

Test results also show theexcellent performance of thesuper-durable resins.

Further developments at Cytecare targeting matte finishes forspecific market needs for specialapplications. These includeimproved burnish resistance;efforts to broaden the scope ofpigments in these products; andflow modifiers or resinmodifications to reduce the impactof binder content on film flow.

In conclusion it is claimed thatthese new resins offer a costeffective technique for replacingthe current out-dated technologiesfor outdoor resistant matte powdercoatings. It is calculated that 15to 25% savings are possible inprocessing time and yieldimprovement.

Paper entitled “New Powder Coating Resinsfor Superior Matte Finishes” by Dietmar Finkand associates at Cytec Surface Specialities,Germany, presented at European CoatingsCongress in Nuremberg on 30 Mar 2009 to1 Apr 2009. Copies of the Congress papersare available from the organizers, VincentzNetwork

INDUSTRYNEWS

ChemPoint.com chosen

Chemical e-distributorChemPoint.com was tapped byAkzoNobel Coatings to become itspreferred supplier of Interpon rapidsupply and express colour powdercoatings products and services inNorth America. The deal requiresChemPoint to supply Interponclients marketing, technical salesand tailored customer servicethroughout the USA.

PPCJ, Polymers, Paint, Colour Journal, Apr2009, 199 (4535), 7

Jotun Thailand will push ahead

Jotun Thailand, despite the Thaipaint industry seemingly up for adownturn in several segments,has affirmed its commitment tosurge ahead without makingreductions, particularly in itsworkforce. The company,confident that it will weather thecontraction in demand, maintained

its paint and coating sales targetof 45 M litres for 2009. Jotun alsoplans to hire more people in salesand marketing.

APCJ, Asia Pacific Coatings Journal, Apr2009, 22 (2), 10

Dow to continue divestments topay loan

Dow Chemicals will continue todivest its businesses to settle its$9.2 bn bridge loan by end-2009.Over $4 bn is expected to beraised by the firm in the next fewmonths through assets sale,including the divestment of MortonSalt to Germany’s K+S. Dow alsoplans to divest its 45% interest inTotal Raffinaderj Nederland, itsrefining partnership with Total, aswell as its shares in certainolefins and derivatives operationsin Southeast Asia. Also for sale isDow’s styrene-butadiene (SB) andSB latex operation, which couldgenerate proceeds of $1-2 bn,and Rohm & Haas’ (R&H) powdercoatings operation. Dow couldalso divest, spin off, or pursue ajv for Dow Agrosciences. Dow isalso looking for a partner orregional collaboration for its K-Dow petrochemical assets.

Chemical Week, 4 May 2009, (Website:http://www.chemweek.com)

Ferro reports 1Q 2009 results

Ferro Corp announced that netsales for 1Q ended Mar 2009were $358 M, a decline of 39%from 1Q ended Mar 2008. Thecompany recorded a loss fromcontinuing operations for 1Q 2009of $19.7 M or $0.46/diluted share(income of $7.9 M or $0.17/sharein 1Q 2008). Sales during 1Q2009 from Performance Coatingswere $108.588 M ($160.792 M in1Q 2008), Electronic Materialswere $82.489 M ($140.993 M in1Q 2008), Polymer Additives were$59.447 M ($92.311 M in 1Q2008), Speciality Plastics were$34.859 M ($61.793 M in 1Q2008) and Pharmaceuticals were$357.809 M ($590.838 M in 1Q2008). Ferro Corp is a leading