Not yet a member of Water Online? Register today. Sign up for the newsletter that brings you the industry's latest news, technologies, trends and products. Get the best of Water Online delivered straight to your Inbox! Sign in or Sign-up. Company Profile May 2, The Solvay Interox group of companies is the world's largest manufacturer of peroxygens with expertise in hydrogen peroxide going back over years.
Our manufacturing operations span the globe, with peroxygen facilities in more than fifteen countries on four continents, amounting to approximately 1.
This level of dedication and expertise demonstrates why Solvay Interox, Inc. Log In. I agree to the Terms. I agree to the Privacy Statement. First industrialized in the s by Solvay Food Experts, ethylvanillin provides a warm and powerful vanilla note. Discover Solvay best in class technology available for fire safety in textiles and garments: flame retardant protection for lifetime of the garment, strict quality procedures and extremely comfortable for wearers in Industrial and Personal environments.
Absolutely no carbon of petrochemical origin is used in its production. Solvay extensive ranges of technologies enable us to offer series of catalysts to meet different applications, continue developing innovations and provide advanced products as well as services in the increasing but changing market of polyurethane.
The product is an easy flowing powder and presents an optimized cost-in-use in food applications. Kosher, Halal certified and non-GMO. Catechol, also known as pyrocatechol or 1,2-dihydroxybenzene, is an organic compound essentially used as building block. It is available in two forms: Flakes solid form and Molten liquid form. Guar based fracturing fluids continue to be the most effective and reliable method for propagating fractures and placing proppant in a broad range of well conditions.
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Corporate Citizenship. Product Finder. Solutions by Market. Chemical Categories. Solvay One Planet. Despite the foregoing, the present inventors found that there remains a significant problem of stabilising hydrogen peroxide during the metal surface treatment of steel with aqueous sulphuric acid solutions of hydrogen peroxide. This is because the greater part of the literature was directed to the treatment of copper surfaces and the authors extrapolated to the treatment of other metals without adequate experimental support.
To some extent, this is demonstrated in U. Banush et al, which seeks to etch copper with acidic hydrogen peroxide solutions of long storage life that contain certain urea and aromatic acid compounds.
The specification suggests that the treatment can be applied to certain other metals but also that the solutions are less effective on certain other metals such as.
Since the patent disclosed results solely with copper, comments regarding other metals may be regarded simply as speculation. In the course of the present research to identify, if possible, a suitable stabiliser system for acidic hydrogen peroxide solutions which are severely contaminated with dissolved iron, resulting for example from the surface treatment of steels, a large number of comparative stability trials were conducted. Many of the substances tested fell within the classes of stabilisers identified in the above-mentioned patent specifications.
The trials indicated that many substances which had been described in the past as stabilisers for hydrogen peroxide in solutions containing only small amounts of catalytic ions, were unable to prevent rapid decomposition if substantial iron contamination was present, including chelating stabilisers like ethylenediaminetetraacetic acid, dipicolinic acid, nitrilotriacetic acid and ethylidenehydroxy-1,1-diphosphonic acid. Moreover, it was found that some substances that acted quite well as stabilisers when employed separately, acted no better or even less well when employed in cogitation under the conditions of the trial.
Other combinations of substances demonstrated strictly additive stabiliser properties. Accordingly, the trials demonstrated that a disclosure in a published patent specification that a substance had stabiliser properties towards hydrogen peroxide under much less extreme conditions or in the presence of copper as the main catalytic contaminant was no guarantee that it was capable of performing adequately in the presence of a substantial concentration of dissolved iron.
The trials also demonstrated that there was no guarantee that substances that had been suggested individually as stabilisers, possibly guarding against other sources of decomposition, would combine together even additively when employed in combination.
It is an object of the present invention to locate a combination of substances which could stabilise hydrogen peroxide effectively in aqueous sulphuric acid solutions that are employed in the surface treatment of steel and therefore become contaminated with significant concentrations of iron.
In the context of the present invention, the stabiliser combination comprises hydrofluoric acid, an aromatic acid and an aromatic amide. The hydroxybenzoic acid is particularly preferably p-hydroxybenzoic acid and the N- alkanoxyphenyl -acetamide, advantageously, contains a low molecular weight alkanoxy substituent and especially the compound is N- 4-ethoxy-phenyl -acetamide. Without being bound to any particular theory, the inventors believe that the components of the stabiliser system form a range of fluoride-containing complexes with iron and other ions that pass into solution during surface treatment of steels.
The properties of these complexes, and in particular their interaction with hydrogen peroxide are believed to dictate the stability and hence extent of decomposition losses of hydrogen peroxide during the surface treatments. Furthermore, the presence of hydrofluoric acid is believed to provide the potential for the iron complexes to be significantly different from corresponding complexes in the absence of hydrofluoric acid and that this may explain to at least some extent why it is so difficult to apply teachings given for other solutions in the prior art and teachings on individual components in respect of the combination of the present invention.
The solution preferably contains from 0. The concentrations of the aromatic acid and the aromatic amide in solution are each preferably at least 0. The weight ratio of the hydroxy benzoic acid to the acetamide is preferably in the range of to In one preferred method of employing the invention stabiliser combination, advantage is taken of the physical properties of the two aromatic components, namely the acid and amide.
In the preferred method, these two components are selected on the bases of their melting point and solubility. Such compounds will naturally be solids in the normal range of operating temperatures for hydrogen peroxide-based steel surface treatments and can dissolve to form a dilute, but saturated solution.
It is especially desirable to incorporate an excess amount of the aromatic acid and amide beyond that needed for a saturated solution so as to provide within the treatment bath a solid phase, a reservoir which can replenish the saturated solution as the compound is removed by the normal operation of the metal surface treatments, including in situ oxidation and by adhesion to the surface of the workpiece on separation from the bath.
It will be recognised that both the above-named aromatic acid and aromatic amide demonstrate both such preferred characteristics, thereby rendering them especially attractive for this preferred method. Whilst it is conceivable to incorporate such solids in the metal surface treatment solution in powder or granular form, there is a distinct tendency for that form of solids to be lost by carry out from a surface treatment bath.
Powders are not easy to observe, so that it can be difficult to know how much of the solids are still present and in the extreme case whether any is present at all. Accordingly, in a more preferred mode of operation, the two solid poorly soluble components of the stabiliser system are each employed in the form of a block containing either an individual component or a mixture of them.
The block is much easier to detect than is the corresponding amount of powder or flakes, either visually or by a non-manual system. Accordingly, regulation of the solid stabilisers in the treatment bath can be accomplished without recourse to elaborate and expensive monitoring equipment, whilst still minimising the possibility that the bath would be left without the organic components of the stabiliser system. The term "block" is used in its normal dictionary meaning, as in U.
It typically has a weight of at least 30 g and up to a few kg weight, e. For many practical purposes, it weighs initially from g to 5 kg, but will slowly be consumed during operation of the bath. The block is normally obtained by compression or binding of flakes, granules or powders into a tablet shape or in some other mould shape such as cube, cuboid polyhedron or cylinder, or by resolidification of a melt in such a mould or by extrusion of a rod or bar.
Such techniques are well known in the field of tablet or block formation and accordingly need not be described in further detail herein. The hydrogen peroxide solution is often described as a dilute solution. During normal operation, peroxide is consumed, so that without corrective means, its concentration would gradually diminish.
At the discretion of the user, he can seek to maintain a steady state by introducing peroxide gradually at a rate that matches its consumption, including decomposition, or he can permit the concentration to fluctuate by augmenting the peroxide concentration periodically. The residence period for the work-piece in the treatment bath is at the discretion of the user and naturally depends on the finish that it is desired to achieve.
Residence periods are often selected in the range of from 30 seconds to 30 minutes, and normally from 1 to 5 minutes. The stabilised acidic hydrogen peroxide solutions are primarily intended for the pickling or polishing of steels, including mild steel and is of especial value for treating stainless steels. Steels suitable for treatment by the invention process and compositions can contain minor proportions of such metals as chromium, nickle, and manganese; i.
It will be recognised that the process and compositions according to the present invention can be employed instead of nitric acid-containing metal treatment compositions, thereby avoiding the problems of NOx emissions that accompany the use of nitric acid.
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