RC Newsletter 2012-01 - TEGO® RC Silicones

RC NewsletterRadiation Curable Silicones Issue 01 | August 2012Skin contact statement forTEGO® RC SiliconesDuring UV curing, RC Silicones changefrom a liquid oligomer to a solid polymer.In the polymeric stage the molecularweight can be assumed infinite. The reactivegroups are consumed during thecuring. The safety data for the liquid RCSilicones are thus not applicable for thecured RC Silicones. The standard DIN ENISO 10993 can help to estimate whether aInerting is keycured silicone coating based on our RCSilicones is innocuous for skin contact.We have had several RC release coatingswith various silicone formulations tested.The result of the tests were that none ofthe tested coatings are cytotoxic or a skinirritant. We can make available a copy ofthe tests if requested. Please use our faxform or contact your regular RC contact.EditorialDear Existing andFuture Customers,It’s time for another issue ofour RC Newsletter. In thisissue we would like to informyou about some personnelchanges in our globalRC organization and as usualwe have put together technicalinformation and newsfrom events around theglobe.Enjoy reading.Your Global RC TeamIn a joint effort with key suppliers in thePSA industry Evonik did a compatibilitystudy of HotMelt PSAs on easy releasecoatings based on the TEGO® RC 902/RC711 (70:30 blend). One of the key findingsof this study is the confirmation of theneed of nitrogen inerting during UVcuring. Basically this is not new at all.From the beginning of our RC activitiesover 25 years ago inerting always was akey. Residual oxygen of less than 50ppmis recommended along with state of theart UV units. Stable inerting and constantquality is proven to be possible for manyyears. However, our study once againproved that this is the main parameter tomaintain good quality release coatingswith good release properties.A higher than recommended level of residualoxygen causes higher levels of initialrelease with most adhesives and unwantedaging over time, particularly with tackifiedadhesives. However, non tackified adhesivesand tackifier resins based on C5 didshow no or little ageing. The route causeis a chemical side reaction of adhesivecomponents with peroxides formed onthe surface of the release coating. Itis known in literature, that any oxygenpresent does react to form peroxides.Consumption of the oxygen with radicalsfrom the photoinitiator (or growing chain)begins before the actual crosslinking reactionof the acrylic groups. Boundarylayer oxygen (from air) can migrate intothe surface and react this way. As a result,the silicone network becomes weaker(softer) and particularly the surface exhibitsmore than desired reactive pe r-oxide groups. Over time this increases thepotential for the peroxides to crosslinkinto the adhesive. Aromatic resins androsinester resins did show stronger potentialto react in a 6 months ageing period.As a consequence, a quality release coatingstill requires a good inerting of less than50 ppm oxygen in the UV chamber. ▸ ▸ ▸New literatureNew PracticalGuideWe have revised the existingbrochure and now it includescomprehensive hands oninformation about the radicalcuring and the cationiccuring technology. Ask foryour personal copy with thefax form or download itfrom our website.

2 Radiation Curable Silicones▸ ▸ ▸ A low UV dose for silicone curing,however, did not cause differences inproperties. Of course Evonik recommendsa dosage equal to one 120W/cmUV lamp (medium pressure mercuryarc lamp) for every 200 m/min. of linespeed. A higher UV dose is not neededfor good performing release liner productionbut may buffer UV lamp ageingand weakening of the reflector performance.The compatibility study hasbeen published at several conferencesand is available on our internet site orupon request. Recent work on waterbasedadhesives confirms that residualoxygen levels are just as important forthis class of adhesives, too.New Photoinitiatorto takethe leadA solution to an old phenomenonSubsequent UV radiation of a label laminatemay cause an increase in release thatis very much dependent on the combinationof materials. Waterbased adhesivesare less concerned than HotMelts andhere in particular hydrogenated adhesivecomponents are difficult. The effect isknown e.g. from UV curing of UV printinginks on UV translucent face stock. Areaswhere the UV light is reaching the silicone/adhesiveinterface may result inhigher release. The increase is predominantlycaused by UV light in the range of250-300 nm. Processes that involve UV-Band UV-A light do not have any impact onthe release at all. Blocking out the UV-Cportion by a selective filter when UVIt’s all togethercuring the printing ink may be a goodidea to maintain the original release performance.UV-C filters are available frome.g. Hereaus but are not common in UVunits for printing presses. This would benew and require modifications to theseunits. The use of such filters may need amodification on the printing ink as well.Nevertheless, photoinitiators that workin longer wavelength are available andthe retrofitting should be not a majortask. UV-C blocking may set ground fora solution of the unwanted effect of secondaryUV exposure. The idea should bekept in mind and where there is interestwe are happy to work with customers ona solution.With the registration complete in theUS and Canada last year, sales of TEGO®Photoinitiator A18 quickly began toramp up in the North American region.In Europe we observe an almost completeshift to Photoinitiator A18. Theproduction of Photoinitiator A17 will beterminated by end of 2012. This is alsodue to the limited availability of thespecial raw material used for A17. Wecan only guarantee this will last untilthe end of 2012.As many of you know, the two photoinitiatorsare chemically almost identicalmaterials and their performancesare virtually identical. Due to a minorchange in one of the raw materialsthere was a change in the CAS numbernecessary that made a new name necessary.Although the two can be interchangedwithout problems, there wasof course the need for certain reapprovalroutines, especially as thename or CAS number is not the same.This is the reason why we gave our customerbase enough time to shift fromA17 to A18. If you have not yet startedyour transition process, please considerthe limited availability of A17. In case ofany questions, please contact yourTechnical Service representative.We developed a new silicone for easy releaseapplications that can be used as is,without the need to add some other componentsor to agitate before use.The name of the new RC Silicone isTEGO® RC 702. Single component materialsare especially important if you do nothave the ability to mix several siliconecomponents and the photoinitiator. Mixingoften requires a separate room or atleast some seperate space to avoid crosscontamination with other coating materials.Now, with RC 702 you can just pumpthe silicone out of the drum and into thecoater head. There is no need for constantagitation as there is no separation withRC 702. This unique property is differentthan our single component silicone TEGO®RC 1002 that has to be agitated before itis taken out of the drum. However, withoffset gravure or printing heads thetrapped air in the silicone needs to be monitoredin order to avoid a large amountof foam formation. In such a case a siliconecirculation to a holding tank can be beneficial.RC 702 provides a low level of releasethat makes it suitable for many applicationsincluding labels. Nevertheless,please consider that the release level isslightly higher when compared to RC 902blends. This may be more or less pronounceddepending on the adhesive used.RC 702 has the advantage of a single componentmaterial but can not copy RC 902blends to the full extent. Test runs arerequired to qualify the new product. TypicallyRC 702 requires the same or evenless UV dosage for full cure as comparedto RC 902 blends. Nitrogen inerting is, asalways, required to be less than 50ppmresidual oxygen.RC 702 does have a good silicone anchorageto most substrates (with in-linecorona pre-treatment). There is no needto add RC 711 or other anchorage promoters.In fact organic acrylates that are typicallyused as anchorage promoterswould quickly separate thus eliminatingthe single component advantage. In addition,the release value would increaseconsiderably and has to be confirmed tobe suitable for the application.RC 702 not only is a single componentproduct, thus an easy to use silicone, italso comes at lower cost in many cases.Please contact us for more information.Newsletter RC | Issue 01 | 12

Radiation Curable Silicones 3Label Summit Africa 2012, March 19 – 20The first Label Summit Africa 2012 tookplace at the Cape Town International ConventionCentre from 19-20 March, focusingon the opportunities for the label andpackaging industry as the rapid growthof supermarkets continues by both localand international chains. The keynote wasgiven by Jay Gouliard, Avery Denison,highlighting sustainability as he looked ateco labels and the innovative packagingmarket. Other presentations, held byCorey Reardon of AWA Alexander WatsonAssociates and Gill Loubser of Packagingand Print Media gave an overviewof emerging trends and the latest developmentsin the African market. There werealso two panel discussions chaired byAndy Thomas, group managing editor ofLabels and Labeling. The first one wasfacing the problems of label convertersand looking at import and export opportunitiesas well as considering South Africaas an entry point for doing businessin the rest of Africa. The second one wasfocusing on private labels versus premiumbrands and personalization and short runpromotions.Day two explored trends in the SouthAfrican and global beverage industry, includingtrends in wine bottle decorationand new innovations in labeling includingapplications for pressure sensitive labels.The panel discussion was looking at newtechnologies and creating business opportunities.The conference program was accompaniedby a table-top exhibition with over30 leading global suppliers. In addition,delegates also enjoyed an exclusive dinnerand party on the beach at Grand Café &Beach in Granger Bay on the opening evening.There was also an excellent networkingopportunity including a tour, tastingand wine blending session at the Zevenwachtwine estate.Patrick Bennett, Dirk Schramm at the Evonik table topCIHPEC 2012 in Xiamen, April 18 – 20RC Team ChinaCIHPEC’2012— the 19th China InternationalTissue/Disposable Hygiene ProductsExhibition and Conference organized bythe China National Household Paper IndustryAssociation (CNHPIA) was held atXiamen International Convention Center,Fujian, China on Apr.18- 20th, 2012. It hasapproximately 60,000 sqm of exhibitionhall and ten special exhibition pavilions.For RC, it was our fifth time participatingin this exhibition and also the secondtime in Xiamen. Xiamen was the originalplace of fem. hygiene and Guangdong wasthe original place of diaper tape. Xiamenand Shenzhen both are coastal cities andhave very nice economic environments.During the exhibition, Xenia Ma gavea presentation on “Tego® RC Silicones –The Power of Hygiene Evolution” in theafternoon section of Apr. 19th. Therewere approximately 100 people in attendancefor Xenia’s presentation.Last but not least, the committee fromNational Tissue/Disposable Hygiene Productsexpressed great appreciation toEvonik China Interface & Performance forour contributions to the conference.Afera Tape College 2012, April 18 – 20Afera (European Association for the SelfAdhesive Tape Industry) held their 5thTape College from 18 - 20 April 2012 at theMarriott Hotel in Brussels. More than 90representatives from 16 countries attendedthe biennial 3-day educational seminar.The Tape College is dedicated toindustry newcomers, as well as those interestedin keeping abreast of the technicalessentials of self adhesive tapes,with an understanding of the fundamentalsof the tape business. This expanded,14-lecture event was intended to buildupon the immense success of Afera’s fourTape Colleges held in past years.The choice of the right release liner andrelease property is an essential aspect ofa profitable tape product. In his pre sentation”Selection of the right Releaseliner“, Jürgen Pomorin of Evonik gave anoverview of the variety of possible substratesand release coatings in variousfields of pressure sensitive materials.Newsletter RC | Issue 01 | 12

4 Radiation Curable SiliconesOrganizational changeswithin the RC TeamThe RC Team is part of Evonik’s Business Line Interface & Performance,which acquired Hamburg-based Hanse Chemie Group last year. Thisacquisition was followed by some organizational changes that also affectedthe RC Team.Meet withus here!You can meet us at the followingconferences, seminars and tradeshows.02. 08. 2012, AWA Asian ReleaseLiner Seminar,Bangkok, Thailand,table top and paper, Jin Wei,Xenia Ma, Gary Khoe10. 09. 2012, AWA Label ReleaseLiner Industry Seminar, Chicago / IL,USA, table top, RC Team AmericasJin WeiSabine RoosPatrick Bennett11. 09. – 13. 09. 2012, LabelexpoAmericas, Rosemont / IL, USA,stand no. 5300, RC Team AmericasThe new organization is structured regionally and is managed togetherwith our neighbouring segment for agricultural chemicals. Mikko Meyderis responsible for Europe, Africa and Middle East, Steve Rall is in chargefor the Americas and Jin Wei takes care for the Asia/Pacific region.In Europe, Sabine Roos took over the position as sales support fromYvonne Weidner, who took a materity leave. Another new face is PatrickBennett, who is our new Sales Manager for Sub-Saharan Africa.In America, Eduardo Gonzalez took over other responsibilities withinEvonik. His position was taken over by Liz Patterson, who will report toSteve Rall. Additionally, Scott Steudle is our new Technical Service Managerfor the Americas. He will report to Gary Freelin.03. 10. – 06. 10. 2012, AFERA Conference,Madrid / Spain,Annegret Lange, Jürgen Pomorin22.10. – 24.10.2012, MKVS MunichAdhesive and Finishing Symposium,Munich / Germany,RC Team EssenIn Asia, Allen Dang has taken over other responsibilities within Evonik.His position as Sales Manager in China was taken over by Sky Zhao.We believe that this new organization further enhances the proximity toour customers and that we will be even more successful in meeting localrequirements of our markets than in the past.New team USA: Scott Steudle, Steve Rall,Liz PattersonSky ZhaoEvonik Industries AGGoldschmidtstraße 10045127 EssenGermanyContact Sabine Roosphone +49 201 173-2711fax +49 201 173-712711sabine.roos@evonik.comwww.evonik.com/tego-rcNewsletter RC | Issue 01 | 12