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Styrene‐acrylic resin paints having a pigment volume concentration of 31 per cent and consisting of a constant level of ethylene glycol, titanium oxide, water, rheological agent, inhibitor and defoamer and variable levels of dispersant (x), anticorrosion pigment (y) and wollastonite (z) were prepared. Such emulsion paints were applied to the flat carbon steel test panels. The dried paint films were subjected to various standard anticorrosion tests. The results obtained showed different types of relationship between the anticorrosive behaviour of the paints and variables x, y and z. The antifouling properties of the paint films were obtained through corrosion tests in a marine‐industrial environment at ambient temperatures.

Substitution of zinc chromate or zinc yellow, traditionally used as anticorrosive pigment, for other phosphate‐based pigments that are not hazardous to health and have the same anticorrosive behaviour or even better, is studied in this paper. Four alkyd paints were specially prepared; two of them contained calcium acid phosphate or micronised zinc phosphate as anticorrosive pigments respectively. A paint containing zinc chromate was used as reference and a paint without anticorrosive pigments was used as a blank, in which the other ingredients were increased proportionally to attain the desired PVC relationship. The corrosion behaviour of low carbon steel panels coated with these paints in a 3 per cent NaCl solution was assessed by electrochemical impedance spectroscopy (EIS). In addition, other painted panels were evaluated by salt spray and humidity chamber tests. Results of all tests showed that the paint with calcium acid phosphate and especially that with micronised zinc phosphate exhibited better behaviour than paint with zinc chromate. Analysis of impedance parameters (ionic resistance and capacitance of the paint film) against immersion time allowed the paints to be ranked in the same order as that obtained with salt spray and humidity chamber tests.

This paper aims to synthesize anticorrosion pigments containing tungsten for paints intended for corrosion protection of metals.

The anticorrosion pigments were prepared by high-temperature, solid-state synthesis from the respective oxides, carbonates and calcium metasilicate. Stoichiometric tungstates and core-shell tungstates with a nonisometric particle shape containing Ca, Sr, Zn, Mg and Fe were synthesized. The pigments were examined by X-ray diffraction analysis and by scanning electron microscopy. Paints based on an epoxy resin and containing the substances at a pigment volume concentration (PVC) = 10 volume per cent were prepared. The paints were subjected to physico-mechanical tests and to tests in corrosion atmospheres. The corrosion test results were compared to those of the paint with a commercial pigment, which is used in many industrial applications.

The tungstate structure of each pigment was elucidated. The core-shell tungstates exhibit a nonisometric particle shape. The pigments prepared were found to impart a very good anticorrosion efficiency to the paints. A high efficiency was demonstrated for the stoichiometric tungstates containing Fe and Zn and for core-shell tungstates containing Mg and Zn.

The pigments can be used with advantage for the formulation of paints intended for corrosion protection of metals. The pigments also improve the paints’ physical properties.

The use of the pigments in anticorrosion paints for the protection of metals is new. The benefits include the use and the procedure of synthesis of anticorrosion pigments which are free from heavy metals and are acceptable from the environmental protection point of view. Moreover, the core-shell tungstates, whose high efficiency is comparable to that of the stoichiometric tungstates, have lower tungsten content.

The purpose of this paper is to synthesize anticorrosion pigments of the perovskite type, YXO₃, where X = Ti, Zr, Mn or Al and Y = Ca, Sr, La or Fe, for coating materials intended for corrosion protection of metals. Also, to synthesize pigments containing hexavalent Mo and W (double perovskites).

The anticorrosion pigments were synthesized from oxides or carbonates by a high-temperature process. The following pigments were synthesized: CaTiO₃, SrTiO₃, CaZrO₃, SrZrO₃, LaTiO₃, LaMnO₃, CaMnO₃, SrMnO₃, LaFe₂O₃, SrFe₂O₃, LaAlO₃, Ca₂ZnWO₆ and Ca₂ZnMoO₆. The pigments were characterized by the physico-chemical properties of the powders, by X-ray diffraction analysis and by scanning electron microscopy. Epoxy-ester coating materials containing the pigments at a volume concentration PVC = 10 per cent were prepared and subjected to tests examining their physico-mechanical properties and tests in simulated corrosion atmospheres.

The perovskite structure was identified in the majority of the pigments. The pigments were found to impart good corrosion inhibiting properties to coating materials. The highest calculated anticorrosion efficiency was found for paints containing CaMnO₃ or SrMnO₃ as the pigments.

The pigments synthesized can be used with advantage in paints intended for corrosion protection of the substrate metals.

The use of the above pigments in anticorrosion coating materials to protect metals is new. Especially beneficial are the uses and procedures for the synthesis of anticorrosion pigments which do not contain heavy metals and are acceptable from the environmental protection aspect.

To synthesise calcium titanate with a perovskite structure as an anticorrosion pigment for metal protecting paints.

Calcium titanate was synthesised from titanium dioxide and calcium carbonate at high temperature. The pigment obtained was characterised by means of X‐ray diffraction, particle size distribution measurement and scanning electron microscopy. The pigment obtained was further characterised with regard to the parameters required for paint formulation; its specific mass was determined by oil consumption and critical pigment volume concentration. The synthesised calcium titanate was used to prepare epoxy coatings with varying contents of the anticorrosion pigment. The coating was tested for physical‐mechanical properties and in corrosive atmospheres. The results were compared with titanium dioxide that served as a starting material for calcium titanate preparation.

Calcium titanate was prepared from materials that do not add any impurities to the anticorrosion properties of the pigment. It was identified that calcium titanate of perovskite structure is a highly efficient anticorrosion pigment for paints.

Calcium titanate can be utilised for the preparation of anticorrosion paints to protect metal bases from corrosion.

The method of synthesising calcium titanate as an anticorrosion pigment is new. The literature has not yet described the use of calcium titanate as a pigment with inhibitive properties in paints. From an ecologic standpoint, the application of a new anticorrosion pigment for paints presents a highly positive trend.

The requirement to test paint arises at every stage in the development and manufacture of coatings though the exact nature of the test procedure varies widely. For example, in the development of a formulation it will be necessary to evaluate changes in the decorative and protective properties of the coating on its substrate, whilst once the product is in production quality control testing will be required. This typically involves rapid evaluation of liquid and dried paint samples to check for conformation to preset limits. A very wide range of techniques are used in these forms of testing though, in general, the equipment and procedures involved are familiar to all paint technologists and include apparatus such as viscometers, glossmeters, colorimeters, hardness testers and artificial weathering machines.

This paper aims to synthesise anticorrosion pigments containing molybdenum for paints intended for corrosion protection of metals.

The anticorrosion pigments were prepared by high-temperature solid-state synthesis from the appropriate oxides, carbonates and calcium metasilicate. Stoichiometric molybdates and core-shell molybdates with a non-isometric particle shape containing Ca, Sr, Zn, Mg and Fe were synthesised. The pigments were examined by X-ray diffraction analysis and scanning electron microscopy. Paints based on an epoxy resin and containing the substances at a pigment volume concentration of 10 volume per cent were prepared. The paints were subjected to physico-mechanical tests and to tests in corrosion atmospheres. The corrosion test results were compared to those of the paint with a commercial pigment, which is used in many industrial applications.

The molybdate structure of each pigment prepared was elucidated. The core-shell molybdates exhibit a non-isometric particle shape. The pigments prepared were found to impart a very good anticorrosion efficiency to the paints. A high anticorrosion efficiency was found with the pigments Fe₂(MoO₄)₃ and Fe₂(MoO₄)₃/CaSiO₃ and with Mg and Zn molybdates.

The pigments can be used for the formulation of paints intended for the corrosion protection of metals. The pigments also improve the paints’ physical properties.

The use of the pigments in anticorrosion paints for the protection of metals is new. The benefits include the use and the procedure of synthesis of the anticorrosion pigments which are free from heavy metals and are acceptable from the aspect of environmental protection. Moreover, the core-shell molybdates, whose high efficiency is comparable to that of the stoichiometric molybdates, have lower molybdenum contents.

Previous articles in this series have considered techniques of paint analysis, as well as methods of studying surfaces and interfaces and ways of following the various physico‐chemical reactions which occur within coatings, particularly those concerned with film curing. Many of the techniques described in these articles required sophisticated analytical equipment and certainly in larger organisations the care and operation of this would be in the hands of specially trained personnel. There are however, a wide range of tests which paint chemists more or less routinely use in their day to day work on formulation control and development. These are the types of test which charactertise liquid or paint film properties such as viscosity (which has been considered in a previous article), colour and gloss, drying time, hardness, durability etc. The equipment used in these tests tends to be less complicated than required for many of the techniques described in the previous articles though as much care and attention to detail is required in operation and interpreting the data obtained. The last two parts in this series will be concerned with a review of some of the recent literature concerned with certain aspects of paint film testing. This article will consider test panel preparation and some of the literature concerned with measuring gloss level and film mechanical properties. Recent advances in the field of durability and corrosion testing will form the basis of a subsequent article.

The anticorrosive action of the two compounds: 4‐(p‐chlorobenzylidene‐amino)‐3‐hydrazino‐5‐thio‐1,2, 4‐triazole (I) and 4‐(p‐chloro‐benzylideneamino)‐3‐(p‐chlorobenzy‐lidenehydrazino)‐5‐thio‐1,2,4‐triazole (II) against marine corrosion have been tested using four different marine paint compositions containing the compounds. The paints were applied on steel panels and tested in a sea‐water medium. The same paint formulations were tested for antifouling activity by applying the paints containing the compounds on PVC panels and immersing them in the water of Alexandria western harbour. The formulations based on compounds (I) showed better steel protection than their analogue containing compound (II), and protect their surfaces from marine corrosion for about seven months.

To identify the dependence of the anticorrosion efficiency of chemically varying pigments on their concentration in steel protecting paints.

Anticorrosion pigments from a group of nontoxic substances were chosen and compared with a chromate pigment. With all pigments, the following parameters were observed namely, oil absorption, critical pigment volume concentration value, density, extract pH, specific surface, particle size, water‐borne substances content, and the specific electrical conductivity of pigment extracts. The aqueous extracts of pigments were used to determine the corrosion loss of steel. The morphology of pigment particles was observed by means of an electron‐scanning microscope. Paints containing these pigments were formulated on the binder basis of an epoxy resin. The paints prepared were subjected to measurement of physical‐mechanical properties such as hardness and resistance in deep drawing. Paints containing anticorrosion pigments were subjected to corrosion tests in a SO₂ condenser chamber, salt spray cabinet and to a test according to Machu and Schiffman.

The experimental investigations revealed the absolute values of the anticorrosion effects of individual pigments as well as dependence of efficiency on the concentration of the pigments in the paints. It was found that environment‐friendly pigments achieved comparable or even better anticorrosion efficiency than toxic strontium chromate.

The anticorrosion properties of the paints concerned can be tested in paints by means of atmospheric exposure such as the Florida test.

The results find their application in the formulation of anticorrosion paints for industrial applications with environment‐friendly effects.

This research paper presents the results of the anticorrosion effects of a great number of industrially used pigments. Based on this paper, the formulation of highly effective steel‐protecting paints can be optimised.