It has just come to my attention that Paraloid B72 adhesive in the tube is being prepared with 8-12% nitrocellulose. I have recently purchased some from Conservation Resources UK and noticed this anomaly on the data sheet supplied. Paraloid B72 resin is made by Dow and this adhesive solution made by HMG Paints. I contacted HMG to confirm the composition and this is what they said;
The HMG B72 adhesive does indeed contain a small amount of cellulose nitrate; however the predominant resin within the product is Paraloid B72, and looking on the Symbiosis formulation system this has been the case since the product was developed. I was not involved with the development of the product (long before my time) but I would take an educated guess that the cellulose nitrate was used in the formulation to speed up drying time, the actual amount of cellulose resin is under 8%. Nitro cellulose adhesives will contain mainly cellulose nitrate as the main resin, possibly with a small amount of alkyd resin for plasticity, but it is fair to say given the quantities involved that the B72 adhesive can be described as acrylic as this is by far and away the main resin contained within the product. The data sheet supplied by Conservation Resources, which was last revised in 2008, indicates there is 12% nitrocellulose content but gives no indication of any acrylic content. Previous data sheets I have had for B72 in the tube, up to 2005, have not indicated the presence of nitrocellulose. I rarely use the adhesive from the tube as I normally make up solutions according to the job in hand, but occasionally the ready made solution is handy. I wont be using the new batch. Tracey Seddon ACR Senior Organics Conservator National Museums Liverpool Midland Railway Building 1 Peter Street Liverpool L1 6BL T: 0151 478 4843 E: [email protected] Tracey Seddon Head of Organics Conservation Objects Conservation National Museums Liverpool Midland Railway Building, 1 Peter Street L1 6BL Tel: 0151 478 4843 www.liverpoolmuseums.org.uk<http://www.liverpoolmuseums.org.uk> Gift ideas and treats for yourself in our online shop.<http://www.liverpoolmuseums.org.uk/onlineshop> [http://www.liverpoolmuseums.org.uk/images/email-footer/tw-email-footer-04.jpg]<http://www.liverpoolmuseums.org.uk/wml/exhibitions/terracotta-warriors/index.aspx?utm_source=Facebook&utm_campaign=Terracotta%20Warriors%20email%20footer> National Museums Liverpool is regulated by the Department of Digital, Culture, Media and Sport (DCMS). Museums and galleries regulated by DCMS are exempt charities under Schedule 3 of the Charities Act 2011. National Museums Liverpool Disclaimer: This email and any attachments transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed, and may contain information that is confidential, subject to copyright. If you have received this email and you are not the intended recipient please notify [email protected]<mailto:[email protected]> and delete this email and you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this email are strictly prohibited. Please note that any information sent, received or held by National Museums Liverpool may be disclosed under the Freedom of Information Act 2000. This email does not conclude a binding agreement. Any views or opinions presented in this email are solely those of the author and do not necessarily represent those of National Museums Liverpool. Although National Museums Liverpool routinely screens for viruses, recipients should scan this email and any attachments for viruses. National Museums Liverpool makes no representation or warranty that this email or any of its attachments are free of viruses or defects and does not accept any responsibility for any damage caused by any virus or defect transmitted by this email. As part of conducting its business, National Museums Liverpool may monitor and record emails and their contents passing through their network under the Telecommunications (Lawful Business Practices) and (Interception of Communications) Regulations 2000. [http://www.liverpoolmuseums.org.uk/images/sitewide/nml-logo.gif] ****** Unsubscribe by sending a message to [email protected] Searchable archives: http://cool.conservation-us.org/byform/mailing-lists/cdl/
