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Sheen Instruments last week held a very successful two‐day agents sales conference in Portsmouth, which was attended by their distributors from all over the world. The conference also marked the official launch of the new Sheen Automatic Panel Sprayer to agents and specially invited U.K. customers.

Organophilic Sylodex Bentonites are organically treated forms of the clay mineral montmorillonite. The latter is present in the form of microscopically small platelets. The platelets are characteristic of the crystalline structure of the montmorillonite. The chemical composition is that of an aluminium hydrosilicate in which the silicon, aluminium and oxygen atoms are arranged in 3 layers (see Fig. 1). The outer layers consist of SiO2‐tetrahedra and the inner layers of (AlO4(OH)2) octahedra. An idealized initial structure of the precursor of montmorillonite exhibits the following neutral formula:

The worldwide production and the consumption of CFCs are now controlled through the Montreal Protocol. A meeting in London in June 1990 of the signatories of the Protocol will almost certainly tighten the controls on CFCs and introduce regulations to control other common chlorinated solvents. This paper gives the reasons why worldwide control of emissions of chlorinated substances is necessary, the events that led up to the present controls and the prognosis for future regulations. The properties and uses of the six key chlorinated solvents are discussed. Each industrial solvent‐using sector has a range of options available to implement cutbacks and eventual elimination of chlorinated solvents.

Permastrip P900 Paint Stripper has multiple action. Permalite Ltd is now adding a range of paint and powder coating strippers to its extensive list of products and processes for the metal finishing industry. Already being marketed, the first stripper in the range is Permastrip P900, which is a cold, organic solvent paint stripper for the really tough finishes, including epoxy resins and all types of acrylics, which it completely removes due to its multiple stripping action.

A new corrosion protection system developed at B.A.C. Weybridge was first introduced on Vanguard aircraft and has remained in use almost unchanged up to the VC10 and B.A.C.1 11 aircraft which are being produced at this time. The system represented a complete change from previous ones, both in materials and methods of application and was the result of a very considerable amount of research into the limitations of the protective methods used up to that time. Through these investigations it became evident that insufficient emphasis had been placed on the importance of organic materials in corrosion protection and that the paints then in use failed to give satisfactory service due to lack of adequate‐fluid resistance and an inability to withstand repeated flexing and straining of the metal substrate without cracking of flaking. Hence the paint had to be resistant to all anticipated contaminants, including freight spillage, over the entire temperature envelope of the aircraft and had to be sufficiently adherent and flexible to withstand deformation of the substrate up to the point of metal failure. Long term protection from corrosion and compatibility with other forms of protection e.g. sealants, jointing compounds, etc. was also required, as well as an ability to withstand casual damage during service and maintenance. This lead to the decision (hat the Vanguard was to be an all‐painted aircraft and that the many and often conflicting requirements of the paint could only be met by a polyamide‐cured epoxy material. Having thus established the basic concept, consideration can now be given to the detailed requirements.

Introduction A standard formulation of paint stripper based on dichloromethane will contain an activator to promote the rate of solvent action, either an acid—especially formic acid—or an amine such as ethanolamine. A frequent method of application is to arrange the components on jigs or in baskets, followed by immersion in stripping solution subsequently flushing off the loose paint by water jets. To minimize loss of volatile dichloromethane the immersion tank carries a water seal floating on the surface of the organic phase.