David Veselý

A study of the effects of pigments and fillers on the properties of anticorrosive paints

Purpose – To investigate the properties of coatings containing various types of fillers from the point of view of their physical‐mechanical properties and anticorrosive properties.Design/methodology/approach – Research used fillers of different types varying in morphology and/or chemical composition; these were then compared with selected pigments and zinc phosphate, an anticorrosive pigment. The following parameters were observed for all of the fillers and pigments: oil absorption, CPVC value, density, extract pH, specific surface, particle size, and water‐soluble substances. The morphology of particles was observed by means of an electron‐scanning microscope. The coatings of these fillers and pigments were formulated on an epoxy resin binder basis cured with a polyamine hardener. The coatings prepared were subjected to the measurement of physical‐mechanical properties such as hardness and deepening resistance, flex resistance, adhesion to steel, and the gloss of the coatings. The coatings containing the...

Properties of anticorrosion pigments depending on their chemical composition and PVC value

Purpose – To identify the dependence of the anticorrosion efficiency of chemically varying pigments on their concentration in steel protecting paints.Design/methodology/approach – 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 ...

Anticorrosive spinel‐type pigments of the mixed metal oxides compared to metal polyphosphates

The spinel‐type pigments of a general formula corresponding to AB2O4 containing as A the Mg2+ or Zn2+ ions and as B the Fe3+ or Al3+ ions or combinations of both the A and B were prepared and investigated with respect to their anticorrosive action as pigments in organic coatings. For the same purposes, comparative pigments, known for their efficiency as the metal‐corrosion inhibiting ingredients in similar formulations, were used. Further evaluation was carried out on the properties of condensed phosphates as anticorrosion pigments. The results obtained showed the high anticorrosion action of the spinel‐type pigments.

Needle‐shaped anticorrosion pigments based on the ferrites of zinc, calcium and magnesium

Purpose – This paper seeks to synthesize needle‐shaped anticorrosion pigments based on the ferrites of Zn, Ca and Mg for metal protecting paints.Design/methodology/approach – Anticorrosion pigments were synthesized from oxides or carbonates at hot temperatures. The following pigments were synthesized: ZnFe2O4, MgFe2O4, CaFe2O4, Mg0.2Zn0.8Fe2O4, and Ca0.2Zn0.8Fe2O4. The prepared pigments were characterized by means of X‐ray diffraction analysis, by measuring the distribution of particle size and by means of scanning electron microscopy. The synthesized anticorrosion pigments were used to formulate epoxy coatings with PVC = 10 per cent for the synthesized pigment and with the PVC/CPVC ratio = 0.3. The coatings were tested for physical‐mechanical properties and in corrosion atmospheres. The corrosion test results were compared with aluminium zinc phosphomolybdate.Findings – The needle‐shaped particles were identified in the formulated pigments. It was found that all of the synthesized pigments had high antic...

Catalytic effects of transition metals in the form of the salts of organic acids in the cross linking of alkyds

Purpose – To study the drying effects of cobalt, manganous and mixed salts for their catalytic action in cross linking reactions occurring during the creation of an alkyd resin film.Design/methodology/approach – The driers of Co‐octoate, Mn‐octoate, Mn‐octoate with an active organic ligand, and mixed drier containing the salts of Mn, Ca, and Zn were employed in the cross linking reactions of alkyls. The study verified the possibility of using manganese as an active cation in catalytic curing reactions. The course of the cross‐linking of alkyds was monitored on a model system of the reactions of drier with ethyl linoleate, using FTIR spectroscopy. Reaction‐rate constants corresponding to the first phase of cross linking were obtained. The driers under scrutiny were used to identify the time of the drying of alkyd resin modified with flax oil. The final phase of the cross linking reactions was monitored by means of measurement the hardness of the created alkyd film depending on time.Findings – The driers un...

Pigments with Ti4 + −Zn2 + , Ca2 + , Sr2 + , Mg2 + ‐based on mixed metal oxides with spinel and perovskite structures for organic coatings

Purpose – The purpose of this paper is to synthesise X2TiO4 spinel‐type anticorrosion pigments and YTiO3, perovskite‐type anticorrosion pigments, where X = Zn, Mg, Ca, Sr; Y = Ca for metal protective paints.Design/methodology/approach – Anticorrosion pigments were synthesised from oxides or carbonates at high temperature. The following pigments were synthesised: TiO2 · ZnO, 2TiO2 · ZnO, TiO2 · 2ZnO, TiO2 · MgO, TiO2 · CaO, TiO2 · ZnO · MgO, and TiO2 · ZnO · SrO. The pigments obtained were characterised by means of X‐ray diffraction analysis, measurement of particle sizes and scanning electron microscopy. The anticorrosion pigments synthesised were used to produce epoxy coatings with PVC = 10 per cent for each synthesised pigment. The coatings were tested for physical‐mechanical properties and in corrosion atmospheres. The corrosion test results were compared with those of alumino zinc phosphomolybdate.Findings – A spinel or perovskite structure was found in the pigments synthesised. High anticorrosion eff...

Ferrocene‐based catalyst systems for alkyd paint drying

Purpose – To study the siccativation effects of metallocenes based on ferrocene and its derivatives as siccatives supporting their catalytic effects during meshing reactions proceeding during the creation of an alkyd resin film.Design/methodology/approach – Siccatives are used as catalysts of auto‐oxidation reactions between a binder dried by oxidation and atmospheric oxygen. Without these substances, the auto‐oxidation of the binder would be slow and paint film drying would take too long. The cobalt salts of organic acids are currently the most efficient and most widely used siccatives. Present‐day ecological efforts are aimed at reducing the content of volatile organic substances in paints. One way to achieve this goal is the application of the so‐called high solids of binders that create thicker paint films. However, fast meshing throughout the whole paint layer remains their downside.Findings – Ecological efforts are aimed at searching for the highly efficient catalysts of hardening reactions for pain...

The properties of ZnFe2O4 as an anticorrosion pigment dependent upon the structure of initial Fe2O3

Purpose – The purpose of this paper is to synthesize anticorrosion pigments ZnFe2O4 from diverse raw materials of various shapes and size of primary particles.Design/methodology/approach – Anticorrosion pigments were synthesized through a high‐temperature process during a solid phase. Zinc ferrites were prepared from hematite (α‐Fe2O3), goethite (α‐FeO.OH), magnetite (Fe3O4), and specularite (Fe2O3) entering into reaction with zinc oxide at temperatures ranging from 600 up to 1,100°C. The nature of the initial raw material, primarily the shape of its particles, affects the shape of the particles of the synthesized zinc ferrite. The formulated zinc ferrites had a rod‐shape, lamellar, and/or isometric shape. The shape of the particles of synthesized zinc ferrites was studied with regard to its effects on the mechanical and corrosion resistance of organic coatings. The obtained pigments were characterized by means of X‐ray diffraction analysis and scanning electron microscopy. The synthesized anticorrosion p...

Anticorrosion pigment based on calcium titanate with a perovskite structure

Purpose – To synthesise calcium titanate with a perovskite structure as an anticorrosion pigment for metal protecting paints.Design/methodology/approach – 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.Findings – Calcium titanate was prepared from materials that do not add any impurities to the an...

Synthesis and properties of pigments based on XxZnyFe2O4 ferrites with non‐isometric particles

Purpose – To synthesise anticorrosion pigments of a lamellar and core‐shell type based on Zn, Ca and Mg ferrites for metal protecting paints.Design/methodology/approach – The anticorrosion pigments were synthesised from oxides or carbonates at high temperature. The pigments synthesised had particles with a pronounced lamellar‐tubular shape consisting of MgFe2O4; Mg0.8Zn0.2Fe2O4; Mg0.6Zn0.4Fe2O4; Mg0.4Zn0.6Fe2O4; Mg0.2Zn0.8Fe2O4; ZnFe2O4; Ca0.2Zn0.8Fe2O4; and CaFe2O4. The other type of synthesised ferrite pigments were core‐shell anticorrosion pigments where a layer corresponding to the compositions including MgFe2O4/KAl3Si3O11; Mg0.8Zn0.2Fe2O4/KAl3Si3O11; Mg0.6Zn0.4Fe2O4/KAl3Si3O11; Mg0.4Zn0.6Fe2O4/KAl3Si3O11; Mg0.2Zn0.8Fe2O4/KAl3Si3O11; ZnFe2O4/KAl3Si3O11; Ca0.2Zn0.8Fe2O4/KAl3Si3O11; and CaFe2O4/KAl3Si3O11 was applied onto the core – white mica – by a chemical reaction. The pigments prepared were characterised by means of X‐ray diffraction analysis, particle size distribution measurement, and scanning el...