Issue 3 – 19 May 2016
Please note that this page will be updated regularly, so please ensure that you are using the latest issue.
Issue 3 – 19 May 2016
Please note that this page will be updated regularly, so please ensure that you are using the latest issue.
As manufacturers of high performance coatings to the aerospace, defence and allied industries, Indestructible have a long history of supplying anti-corrosive coatings that traditionally contained hexavalent chromium.
In the late 1990’s we commenced investigation into chrome free alternative anti-corrosive primers, for both baking and room temperature cure systems. Working closely with Pratt & Whitney in Canada, followed by Pratt & Whitney America; the Safran group in France, and the Meggitt group in the UK, we developed high performance chrome free primers to meet the exacting standards of these groups. The approved products have been in successful use for over 10 years. Typical uses are aerospace engineering components including aluminium and magnesium engine parts, helicopter gearboxes and componentry for wheels and braking systems.
These chrome free products have been supplied alongside our traditional chrome containing products, to include wash primers, room temperature cure primers and baking primers.
We endeavour to update the position, and availability of chrome containing products, in the light of REACH restriction and authorisation, environmental issues and client specific requirements.
Using a colour key, we have attempted to identify products where we believe hexavalent chrome will be authorised for continued use, or where the chrome will not be authorised for use beyond a sunset date.
Yellow Block: Current products containing hexavalent chrome
Red Block: Indicates products that use chemicals that will not be authorised beyond the sunset date
Blue Block: Indicates products that use chemicals where authorisation is being sought and will we believe have continued availability beyond the sunset date
Green Block: Recently formulated chrome free alternative or replacement product
To remind ourselves, the REACH regulations came into law throughout Europe about 10 years ago. The remit behind the law was to register and control the use of chemicals within Europe. This process / law looks at chemicals deemed by member states to be ‘dangerous’ to either people or the environment, and to list these chemicals as ‘substances of very high concern’ (SVHC’s). Once a chemical is listed as a SVHC, it can be moved into Annex XIV of the regulations, which will define a sunset date, beyond which the chemical will not be allowed to be used without an authorisation issued by the Commission, after investigation by the European Chemicals Agency (ECHA).
Chromium Trioixde and various chrome salts are listed in Annex XIV, and therefore have sunset dates. For record, the chemicals concerned, that affect Indestructible Paint Ltd, are as follows:
Chromium Trioixde (Chromic Acid): CAS No: 1333-82-0 Sunset Date: 21 September 2017
Strontium Chromate: CAS No: 7789-06-2 Sunset Date: 22 January 2019
Zinc Tetraoxy Chromate: CAS No: 49663-84-5 Sunset Date: 22 January 2019
Indestructible are members of two Europe wide consortiums, formed to work towards the authorisation of SVHC chemicals to allow continued use for specific applications after the relevant sunset date.
CTAC covers the use of chromium trioxide in specific uses in pre-treatments and sacrificial coatings. A dossier to cover authorisation for continued use has been submitted to ECHA. Although there is no guarantee, it is hoped that an authorisation for continued use will be granted.
CCST covers the use of hexavalent chromium used in anti-corrosive systems. The two main chemicals of interest within this grouping salts are Strontium Chromate and Zinc Tetraoxy Chromate. Strontium Chromate and Zinc Tetraoxy Chromate are being supported in CCST and a dossier submission to ECHA is being prepared.
Traditionally we have worked with commercially available hexavalent chrome products, and the aerospace industry have almost universally worked with chrome based systems, to include Alocrom 1200 and similar conversion coatings or Chromic Acid Anodising.
At first it was thoughts that Alocrom 1200 would not be supported, but we understand that Henkel have agreed to support the use of chromium trioxide in chrome based conversion coatings (Alocrom 1200).
DOW 19; chemical conversion coating for magnesium.
As part of our continuous development of new systems, Indestructible have been working on chrome free alternative pre-treatments. Our developments are hexavalent and trivalent chrome free.
IPTREAT 1: silane based adhesion promoter formulated for use with high heat capable coatings, needed force curing, and gave no corrosion protection in its own right. This product is now withdrawn.
IPTREAT 12: chrome free conversion coating, with limited corrosion protection, but excellent adhesive characteristics. Restricts filiform corrosion under chrome free primers. Typically used with aluminium alloys, but has given good results on magnesium. Please contact our Sales Department on +44 (0) 121 702 2485 or on email@example.com to discuss this further.
MagSol: Anti-corrosive Sol-Gel. Initially for magnesium. Currently under test within commercial processes.
Ipcote Range of inorganic basecoats and seal coats manufactured using hexavalent chrome.
The use of chromium trioxide within these coatings is supported in CTAC and covered in the authorisation request dossier. Products involved:
IP9183-R1 Ipcote sacrificial aluminium basecoat
IP9356 Ipthin thin film aluminium basecoat
IP9442 Smoothcote basecoat
IP9184 Seal coats; typically either Khaki or Green, but other colours to include black and blue
IP9444 Smoothseal seal coat
IP1041 Ipal diffusion coating: for turbine components high temperature and sour gas resistant capability
LR3210 Chrome free touch up basecoats, replacement for PL177 and IP9138-R1 (when burnished)
Organic chrome free alternatives for both basecoats and seal-coats are currently available;
LR1715 Organic sacrificial basecoat for high temperature alloys only. Requires processing at 490°C and peening
IP9029-R3 High temperature aluminium coating; acts as a barrier coat and can be used in place of sacrificial basecoats which have not been peened.
J900 Clear organic sealcoat
IP1949 Blue organic sealcoat
Additionally, chrome free alternative basecoats based on inorganic, silicate chemistry are available. These have the draw-back of much reduced corrosion resistance, even when used as a sacrificial coating.
As part of our strategy for continous development, we are involved in two Innovate UK funded projects to formulate acidic based, chrome free systems.
AMSCA covers the formulation of a chrome free sacrificial basecoat. The project runs until 2017. Results to date are very encouraging with in excess of 1000 hours neutral salt spray. Linked to the project is additional development of chrome free inorganic sealcoats.
CASCOAT covers the formulation of a chrome free diffusion coating to replace IP1041.
Thin film primers used as direct to metal or where no other pre-treatment system is possible. Covered by defence standard Def-Stan 80-15 or aerospace British Standard BSX32. These products are typically formulated on Zinc Tetraoxy Chromate, which is being supported for authorisation in CCST. Please see the CCST Press Release, for further information.
Two Indestructible Products are concerned:
IP80-15 2 pack etch primers to Def-Stan 80-15
IP9064-4853/4854 2 pack wash primer to BSX32
A chrome free alternative, IP3-4853/4854 is available but whilst this gives excellent adhesion, has lower corrosion performance than chrome containing coatings.
Two development products are being evaluated against both the Defence Standard 80-15 and British Standard BSX32:
LR3113 Wash primer formulated on alternative chromate (product available subject to authorisation).
LR3018 Wash primer formulated on latest generation chrome free anti-corrosive pigments.
There are a limited number of ‘basic’ air drying primers still used in high performance applications.
US specification TTP1757 calls for a zinc chromate based primer. This originally also included a lead chromate colour pigment.
IP1757-R1 is now available, still containing chromate, but lead chromate free colour pigments. Development of a non chromate version is ongoing. Please contact our Sales Department on +44 (0) 121 702 2485 or on firstname.lastname@example.org to discuss this further.
IP2066 Chrome free alternative to FE6; single pack AD primer, with excellent steel protection properties.
IP2878 Alternative to Suncorite ‘conversion’ primer. Chrome free holding coat.
These products are widely used in multiple aerospace applications, and have traditionally been formulated on strontium chromate. The products are covered by multiple international and company specific specifications, including BSX33; BS2X33; DTD 5567 (DTD 5555; DTD 5580); MIL-PRF-23377; MSRR 9064.
As authorisation is being sought for this chemical it is likely that these primers will continue to be available in the short to medium term.
Indestructible can offer two variants:
IP9064-6362 Standard VOC 2 component epoxy primer
IP3-6362 Low VOC 2 component epoxy primer
These product types have seen much development of chrome free alternatives, in the main driven by the requirement of the aerospace primes to utilise chrome free anti-corrosive technology.
Indestructible have been working for over ten years on this technology, and can offer a range of products to varying client and international standards:
IP714: Low VOC Chrome Free Epoxy Primer Grey: CPW 714; PWA36568; SPOP148/155. Meets the performance requirements of BS2X33; MIL-PRF-23377 type N
IP3-6500: Low VOC Chrome Free Epoxy Primer: LB568. Meets the performance requirements of BS2X33; MIL-PRF-23377 type N
IP3-6600: Low VOC Fluid Resistant Chrome Free Epoxy Primer Yellow-Green: Meggitt PRO599 (ML-TR-100031).Meets the performance requirements of BS2X33;MIL-PRF-23377 type N
IP9064-6500: Standard VOC Chrome Free Epoxy Primer. Meets the performance requirements of BSX33; MIL-PRF-23377 type N
The introduction of new generation chrome free anti-corrosive pigments has resulted in new developments of standard and low VOC primers with increased corrosion performance.
LR2962 (IP5-2000) Standard VOC: alternative to IP9064-6500 on small components, small volume usage where VOC emissions are not a concern
LRxxxx (IP5-3000) Low VOC, Fluid Resistant: alternative to IP3-6500 and IP3-6700.
Please contact our Sales Department on +44 (0) 121 702 2485 or on email@example.com for the latest product updates.
Building on the need for low VOC primers, but which can be applied as thin films a new range of water based epoxy systems are in development. These utilise latest generation chrome free anti-corrosive pigments. An advantage of the water based resin is a much increased fluid resistance.
We currently offer a range of baking anti-corrosive primers for typically original equipment use. These are widely used on aerospace components, including fan case assemblies, helicopter components, wheels and braking systems amongst others. The main range is based on our ‘Rockhard 985’ epoxy chemistry, which gives high heat performance up to 220°C, allied to excellent chemical resistance.
Three primers are available that contain hexavalent chrome anti-corrosive systems:
700-155-003 subject to current authorisation activity.
Chrome free alternatives are being formulated. LR2992 contains Chromate (not ‘yet’ listed in Annex XIV). Further formulations are being examined, to replace the chromate anti-corrosive pigments with strontium chromate or chrome free technologies. Please contact our Sales Department on +44 (0) 121 702 2485 or on firstname.lastname@example.org for further details.
588-0060/2 Expected to be covered by authorisation of the chromate in CCST.
588-0060/3 Expected to be covered by authorisation of the pigment in CCST.
Alongside the work conducted in the early 2000’s on the two component primers, a chrome free baking primer was developed utilising the same anti-corrosive pigment. The product, IP985-6500, has several aerospace approvals to include ECS2178; LB569; Safran Landing Systems (M-B-D).
Following on from the recent developments of two component primers, a revised primer, LR2965, utilises the latest generation chrome free anti-corrosive pigments. Please contact our Sales Department on +44 (0) 121 702 2485 or on email@example.com for further details.
A higher temperature capable primer which can operate up to 300°C is also available. IP9310 is formulated on a strontium chromate, and therefore it is hoped will continue to be available. Development of a chrome free alternative, IPCF9310 is ongoing. Please contact our Sales Department on +44 (0) 121 702 2485 or on firstname.lastname@example.org for further details.
Little used in the engineering areas of the aerospace industry, we do however offer a low VOC polyurethane primer that is chrome free. Product Coding: IP6-6500.
Indestructible Paint have been concentrating on aerospace coating systems, however, loss of chromate issues will arise on land based systems. For example, one of the main primers specified for Defence land vehicles, Def-Stan 80-207, specifies zinc chromate anti-corrosive pigment. This chemical has not been registered under REACH, and therefore, in theory cannot be used within Europe. If Zinc Tetraoxy Chromate has been substituted, this will become available only if authorised. This is not covered under CCST which specifies aerospace use only.
Indestructible Paint is not aware of an authorisation request to cover land based systems. Indestructible Paint has chrome free alternative products suitable for Defence, End of Vehicle Life and RoHS compliant applications. For further details regarding this please contact our Sales Department on +44 (0) 121 702 2485 or on email@example.com