Solvent-based Paints Research Articles

Solvent-based paint and varnish removers: a focused toxicologic review of existing and alternative constituents.

Paint and varnish removers constitute a major potential source of organic solvent exposure to contractors and home improvement enthusiasts. Unfortunately, the leading paint remover formulations have traditionally contained, as major ingredients, chemicals classified as probable human carcinogens (eg, methylene chloride) or reproductive toxicants (eg, N-methylpyrrolidone). In addition, because of its unique toxicology (ie, hepatic conversion to carbon monoxide compounding generic solvent narcosis and arrythmogenesis), high volatility, and rigorous requirements for personal protective equipment, methylene chloride exposures from paint removers have been linked to numerous deaths involving both occupational and consumer usage. The aim of this review is to summarize the known toxicology of solvent-based paint remover constituents (including those found in substitute formulations) in order to provide health risk information to regulators, chemical formulators, and end-users of this class of products, and to highlight any data gaps that may exist.

Anticorrosion coatings based on novel acrylate binders containing MeO nanoparticles

Abstract Water based paints are increasingly attracting interest mainly with a view to reducing air pollution with volatile organic compounds (VOC). However, the protective properties of water-based paints are inferior to those of solvent-based paints and so new ways to increase the resistance of water-based systems are sought. The present contribution describes the preparation and testing of environmentally friendly anti-corrosion paints based on novel water-based self-crosslinking acrylate latexes containing appropriate pigments and ZnO or MgO nanoparticles at a concentration of 1.5 % (with respect to the monomers) compared to the same systems free from the nanoparticles. Both the effect of the MeO nanoparticles and the effects of the pigment species and particle shapes on the paint film properties were examined. The MeO nanoparticles were found to improve all the properties tested. The latexes with MgO exhibited the highest resistance to flash corrosion while the latexes with ZnO exhibited the highest anticorrosion resistance. Furthermore, the systems with the calcium-aluminium polyphosphosilicate based pigment were superior to all the remaining systems in this respect. It is concluded that binders with nanoparticles can be used as a basis for anticorrosion coatings provided that a suitable pigment is selected.

Nanocellulose-Reinforced Polyurethane for Waterborne Wood Coating.

With the enhancement of people’s environmental awareness, waterborne polyurethane (PU) paint—with its advantages of low release of volatile organic compounds (VOCs), low temperature flexibility, acid and alkali resistance, excellent solvent resistance and superior weather resistance—has made its application for wood furniture favored by the industry. However, due to its lower solid content and weak intermolecular force, the mechanical properties of waterborne PU paint are normally less than those of the traditional solvent-based polyurethane paint, which has become the key bottleneck restricting its wide applications. To this end, this study explores nanocellulose derived from biomass resources by the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation method to reinforce and thus improve the mechanical properties of waterborne PU paint. Two methods of adding nanocellulose to waterborne PU—chemical addition and physical blending—are explored. Results show that, compared to the physical blending method, the chemical grafting method at 0.1 wt% nanocellulose addition results in the maximum improvement of the comprehensive properties of the PU coating. With this method, the tensile strength, elongation at break, hardness and abrasion resistance of the waterborne PU paint increase by up to 58.7%, ~55%, 6.9% and 3.45%, respectively, compared to the control PU; while the glossiness and surface drying time were hardly affected. Such exploration provides an effective way for wide applications of water PU in the wood industry and nanocellulose in waterborne wood coating.

The assessment of anticorrosive behavior of calcium carbonate from different sources in alkyd-based paints

Great progress has been devoted recently in corrosion protection of metals via using cheap and efficient protective organic coatings. Calcium carbonate is common filler used in coatings industry due to its distinctive properties and the variation of its sources. The scope of this work is to study the effect of calcium carbonate developed from different sources (e.g. natural calcite, marble and egg shell wastes) on the corrosion protection performance of anticorrosive coatings.The different calcium carbonate sources were characterized using different analytical techniques, such as X-ray diffraction (XRD), X-ray fluorescence, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The three calcium carbonates were then incorporated in solvent-based paint formulations using medium oil-modified soya-bean dehydrated castor oil alkyd resin. The physico-mechanical properties of dry films were tested. Immersion test, electrochemical impedance spectroscopy and SEM/EDAX were used to inspect the corrosion protection performance of coatings containing the three sources of calcium carbonate. The results showed that the corrosion efficiency of egg shell was the best among the three sources due to its unique particle shape structure.

A facile preparation of UV-cured films from waterborne unsaturated polyester via click reaction

Due to the deterioration of the environment, the environmental protection has received more and more attention from the world. Various countries have established regulations to strictly limit the emission of organic volatiles (VOC) in paints. Solvent-based paints contain a large amount of VOC components, which not only pollutes the environment and wastes resources but also endangers people's health. Waterborne polyester coatings as representative waterborne coatings have become the development direction of coatings. In this study, a novel waterborne unsaturated polyester was synthesized by melt polycondensation and its water solubility was regulated by changing the amount of sodium sulfonate group. Then, a series of UV curable polyester networks were obtained utilizing the waterborne unsaturated polyester and multifunctional thiols via thiol–ene click reaction. The water resistance, gel content and mechanical properties of the films were characterized. It was found that the UV-cured films exhibited excellent physical properties including adhesion (1), pencil hardness (5 H), water resistance and contact angle (105.36). This shows that it is feasible to prepare high-performance UV-cured films based on thiol-ene click chemistry.

Performance of coatings containing treated silica fume in the corrosion protection of reinforced concrete

PurposeThis study aims to apply novel anticorrosive pigments containing silica fume-phosphates (Si-Ph), which were prepared using core-shell technique by covering 80-90 per cent silica fume (core) with 10-20 per cent phosphates (shell) previously, to play dual functions simultaneously as anticorrosive pigments in coating formulations and as an anticorrosive admixture in concrete even if it is not present in the concrete itself. Two comparisons were held out to show the results of coatings on rebars containing core-shell pigments in concrete, and concrete admixtured with silica fume can perform a dual function as anticorrosive pigment and concrete admixture. The evaluation of corrosion protection efficiency of coatings containing core-shell pigments and those containing phosphates was performed.Design/methodology/approachSimple chemical techniques were used to prepare core-shell pigments, and their characterization was carried out in a previous work. These pigments were incorporated in solvent-based paint formulations based on epoxy resin. Different electrochemical techniques such as open-circuit potential and electrochemical impedance spectroscopy were used to evaluate the anticorrosive efficiency of the new pigments.FindingsThe electrochemical measurements showed that concrete containing coated rebars with core-shell pigments exhibited almost similar results to that of concrete admixtured with silica fume. Also, the anticorrosive performance of coatings containing Si-Ph pigments offered protection efficiency almost similar to that of phosphates, proving that these new pigments can perform both roles as anticorrosive pigment and concrete admixture.Originality/valueAlthough the new Si-Ph pigments contain more than 80 per cent waste material, its performance can be compared to original phosphate pigments in the reinforced concrete.

Water-Based Automobile Paints Potentially Reduce the Exposure of Refinish Painters to Toxic Metals

Exposure to lead-containing dusts is a global public health concern. This work addresses an important issue of whether eco-friendly water-based paints reduce the exposure potential of auto-repainting workers to metals. With this aim, metal levels in automobile paints and worker metal exposure were measured using both solvent- and water-based paints. The levels of metals, and particularly Pb, Cr (total), Fe, and Cu, in solvent-based paints varied greatly among colors and brands. Lead concentrations ranged from below the detection limit (~0.25 μg/g) to 107,928 μg/g (dry film) across all samples. In water-based paints, the concentrations of Pb and Cr (total) were generally two to three orders of magnitude lower, but the concentrations of Al and Cu exceeded those in some solvent-based paints. The personal short-term exposure of workers who applied water-based paints of popular colors, such as black and white, were generally low, with Pb levels of less than <4 µg/m3 and Cr (total) levels of less than 1 µg/m3. Conversely, mean short-term exposure to Pb during the painting of a yellow cab using solvent-based paints were 2028 µg/m3, which was ~14 times the Taiwan short-term permissible exposure limit, while the mean level of exposure to Cr (total) was 290 µg/m3, which was well below the exposure limit. This study demonstrates that water-based paints reduce the exposure potential to lead, and highlights the importance of source control in limiting the toxic metals in paints.

Fizz fixes water-based-paint performance

Replacing solvent-based paints with greener, water-based counterparts sounds nice, but the performance of those alternatives just doesn’t cut it for demanding applications in the furniture or automotive industry. Now, researchers have come up with a waterborne coating that behaves more like a solvent-based paint. In a refreshing twist, the solvent is carbonated water. Unlike environmentally harmful oil- or solvent-based paints, in which the film-forming polymer that coats a surface starts fully dissolved, water-based latex paints are a suspension of microparticles. “In theory those particles are supposed to merge together to make a continuous film, but they don’t do it very well,” says Philip G. Jessop, who led the work. It’s hard to get a glossy finish with latex paints, and the coatings are damage prone. To make their new paint, Jessop, graduate student Jaddie Ho, and their colleagues at Queen’s University started with a carbon dioxide-responsive polymer (Green Chem. 2018,

Determination of optimal quantities of different types of driers for addition in the batches of paint formulation

Paint is generally considered as a mixture of pigment, binder (vehicle), solvent, driers and other additives. Though the basic function of driers is to decrease the drying time after application, it significantly affects the gloss and clarity of paint coatings too. In a batch of manufactured paint usually three kinds of driers (surface drier, through drier and auxiliary drier) are used. An Indian paint manufacturing company identifies that determination of optimal quantities for different types of driers for addition in a batch of solvent-based paint production is a major quality problem for the organization. This paper describes how the management of the company resolved the quality problem by carrying out properly planned statistical studies. Using rotatable central composite design (RCCD), response surface methodology (RSM) and goal programming (GP) technique optimal quantities of the three types of driers for a batch are determined and implemented. The results show that the paint quality improved substantially.Keywords: Rotatable central composite design, Response surface methodology, Multiple response optimization, Goal programming

A Study on the Fire Risk Assesment of Solvent-based Paints

A Study on the Fire Risk Assesment of Solvent-based Paints

Experimental study of the performance of intumescent coatings exposed to standard and non-standard fire conditions

Three different experimental setups corresponding to three different fire scenarios were used to investigate how different heating conditions and heating rates affect the behaviour of two different thin intumescent coatings (a solvent-based and a water-based paint). Coated steel samples were exposed to different standard and non-standard fire conditions in an electric oven, in a gas furnace and in a cone heater. A common trend was observed in the thermal resistance development of the tested coatings and three phases (inert phase, transient phase and steady phase) were identified according to four critical points: activation, end of reaction, binder exhaustion and steel austenitization point. The results also showed that the water-based paint performed better at low heating rates, while the tested solvent-based paint performed better at high heating rates and did not activate or provide proper insulation at very low heating rates. In summary, the study confirms that the current procedure for the design of intumescent coatings has shortcomings, as different paints have different performances according to the heating conditions and, in particular, according to the fire heating rate.

Direct and potential risk assessment of exposure to volatile organic compounds for primary receptor associated with solvent consumption.

Rapid development of industrial production has stimulated the growth of consumption of raw and auxiliary materials including organic paints, among which volatile organic compounds (VOCs) are proved harmful to the population who inhale the polluted air based on epidemiologic studies. Therefore, new types of environment-friendly paints were developed to replace solvent-based paints (SBPs). Nevertheless, new types of paints containing VOCs failed to replace SBPs entirely due to certain disadvantages. Hence, five kinds of paints were employed in simulation experiments to assess the health risk of primary receptor including three kinds of water-based paints (WBPs) and two kinds of SBPs. Conclusions showed that mean TVOC concentration in breathing zone of primary receptor ranged from 9.5 to 13.6mg/m3 and 3.4×103 to 1.4×104mg/m3 for WBPs and SBPs, respectively. Assessments of non-cancer risk concluded that nearly one third quantified compounds exceeded corresponding thresholds for WBPs, and the maximum risk value was 101.33; for SBPs, the maximum risk value reached 50760.20, and twenty-two compounds exceeded the reference limits. The calculation of cancer risk values showed that seventeen compounds were higher than acceptable limit amongst which 1,2-dibromoethane had maximum values of 1.27×10-2 to 3.24×10-2 for WBPs; for SBPs, all quantified compounds exceeded the acceptable limit, and 82.61% VOCs were distributed in a scope larger than 1×10-3. Additionally, a removal efficiency of 60% was considered for primary receptor with personal protective equipment, and subsequent results confirmed its inability of lowering the risk resulted from hazardous VOCs. The calculated potential health risk could be applied to estimate the total health risk for both primary and secondary receptor based on consumed materials. The finding suggested that WBPs could improve VOCs exposure condition and reduce the direct and potential health risk significantly for primary receptor, although they might dissatisfy acceptable limit.

Exposure profile of volatile organic compounds receptor associated with paints consumption

Epidemiologic studies regarding solvent-based paints (SBPs) containing VOCs have demonstrated a strong correlation between chronic and acute adverse health effects and the SBPs. Therefore, new environmentally friendly paints as substitutes containing less or none VOCs have been rapidly developed in research for future sustainable use. However, a few studies focusing on penetration and exposure condition of the substitute have been reported duo to the complexity and inaccessibility of painting industry. Surveys specifically looking at the present status of exposure condition were conducted to ascertain the popularization of water-based paints (WBPs) which concluded that markers of SBPs were detected in all 134 samples indicating bad industrial penetration. VOCs exposure concentrations of painters ranged from 3.8 to 18.2mg/m3 for WBPs, 3.5×103 to 14.8×103mg/m3 for SBPs, respectively. The negative correlation between ambient concentration and breathing zone concentration suggested the former was incapable of representing the actual exposure concentration. The real-time concentration was proved to be closely associated with the activity patterns while the mean concentration level was found mostly dependent on the paint types. Authentic inhalation dose ranged from 7.68 to 15.84mg (WBPs) and 3.84 to 15.59g (SBPs), respectively, for occupational painters (work 8h per day) and the total inhalation dose was estimated through a new conception. The findings suggested that WBPs could significantly reduce VOCs emission and occupational exposure.

Patterns in hammertone paints

Purpose The purpose of this study is to determine required paint and silicone proportions, their mixing rate and duration to eliminate the pattern problems caused by the misuse of silicone polymers in hammertone paints. Results of the findings aim at preventing raw material, manufacturing time and labour losses in hammertone paint production. Design/methodology/approach A paint formulation produced commercially was used. The effects of silicone proportion and mixing rate and paint and pigment density on the pattern formation within the paints, to which the spray painting method was applied, were investigated. Brightness controls of the produced paints were done, and the effect of the additive polymer on brightness was investigated. Photographs of paints for each practice were taken. Findings The most suitable silicone proportion and mixing conditions for the silver grey paints, in which Al non-leafing pigments were used, were calculated as 0.034-0.036 g/kg-paint and 15 s at 200 rpm, respectively. It was observed that the increase in pigment density increased required silicone proportion for the desired pattern. It was determined that mixing rate and duration were very significant in pattern formation, and that silicone decomposed and the pattern was disrupted in long-continued mixings. In addition, excess silicone use disrupted the pattern and decreased the paint brightness. Research limitations/implications This research was conducted for hammertone paints, which are industrial and self-patterned aluminium silvered decorative paints. The results can be used for hammertone paint production. Practical implications The results will enable manufacturers to produce hammertone paints more economically. Results can be used in the paint industry to produce such paint. Originality/value It is crucial to produce high-quality products using less raw materials in today’s industry, where the amount of raw materials is decreasing, and economical and reliable production is becoming increasingly important. When environmental impacts in the solvent-based paint industry are taken into consideration, paint production in shorter times is important for both workers’ and environmental health. As a result of this study, hammertone paints will be produced more economically by appropriate production conditions yet without any energy, raw material and time loss.

Comparative Life Cycle Assessment of Water-based and Solvent-based Primer Paints for Steel Plate Priming

Nowadays, hazardous substances such as volatile organic compounds (VOCs) are still being used and released in steel plate priming processes. These releases might have severe negative impacts on the environment. One of the well-established methods for the evaluation of these impacts is the life cycle assessment method. In this study, life cycle assessment (LCA) was used to justify product substitution in a Lithuanian company due to regulatory concerns. In this study, life cycle impacts of this substitution were assessed by using LCA methodology. The results, within the mentioned uncertainties, indicated that the substitution to the water based primer paint was beneficial in all environmental impact categories. The study results also showed the importance of conducting an LCA study, and the shortcomings of local assessments. DOI: http://dx.doi.org/10.5755/j01.erem.72.2.16236

Introducing rice husk after utilizing new technology as anticorrosive pigments in organic coatings

Abstract The aim of this study is to introduce rice husk after simple chemical modification as new eco-friendly anticorrosive pigments. Uncontrolled burning of rice husk is often considered the most disposal method in Egypt; this seasonal and highly localized massive burning generates excessive air pollution. The usage of this waste as anticorrosive pigments will decrease the danger of environment pollutions. The new anticorrosive pigments based on rice husk as core comprising 80–85% of new pigment covered with thin shell of ferrites that comprises about 15–20% were prepared using new technique called “core-shell”. The different ferrites/rice husk pigments were characterized using different analytical and spectro-photometric techniques, such as X-ray fluorescence (XRF), Energy dispersive X-ray (EDAX) and transmission electron microscopy (TEM). These core-shell pigments were then incorporated in solvent-based paint formulations based on epoxy resin. The physico-mechanical properties of dry films were tested. The corrosion properties using immersion test in 3.5% NaCl and electrochemical impedance spectroscopy (EIS) for 28 days were determined.

Characterization of drying paint coatings by dynamic speckle and holographic interferometry measurements.

In this work we implemented dynamic speckle and holographic interferometry techniques to characterize the drying process of solvent-based paint coatings. We propose a simple way to estimate drying time by measuring speckle activity and incrementally fitting experimental data through standard regression algorithms. This allowed us to predict drying time after about 20-30 min of paint application, which is fast compared to usual times required to reach the so-called tack-free state (≈2 h). In turn, we used holographic interferometry to map small thickness variations in the coating surface during drying. We also demonstrate that results obtained from both techniques correlate with each other, which allows us to improve the accuracy of the drying time estimation.

New eco-friendly anticorrosive core-shell pigments

Purpose– The purpose of this paper is to present the preparation of core-shell ferrites/kaolin pigments and comparing their efficiency in protecting metal substrates to original ferrites which were also prepared. Core-shell structured particles are recently gaining lots of importance due to their exciting applications in different fields; these particles are constructed from cores and shells of different chemical compositions which show ultimately distinctive properties of varied materials different from their counterparts. The new core-shell pigment is based on shell of different ferrites that comprises only 10-20 per cent of the whole pigment on kaolin (cores) which is a cheap and abundant ore that comprises 80-90 per cent of the prepared pigment. The new pigments do not only comprise two different components, but they also contain pigment and extender in the same compound; their loadings in the paint formulations ranges from 50 and 75 per cent of the whole pigment. The work showed that these eco-friendly and cheap core-shell pigments are comparable in their efficiency to that of ferrites in protecting steel substrates.Design/methodology/approach– The different ferrites and ferrites/kaolin pigments were characterized using different analytical and spectrophotometric techniques, such as X-ray fluorescence, X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray (SEM/EDAX) and transmission electron microscopy (TEM). Evaluation of these pigments was done using international standard testing methods (ASTM). After evaluation, the pigments were incorporated in solvent-based paint formulations based on medium oil-modified soya-bean dehydrated castor oil alkyd resin. The physico-mechanical properties of dry films and their corrosion properties using accelerated laboratory test in 3.5 per cent NaCl for 28 days were determined.Findings– The results of this work revealed that ferrite/kaolin core-shell pigments were close in their performance to that of the ferrite pigments in protection of steel, and at the same time, they verified good physico-mechanical properties.Practical implications– Treated kaolin can be applied in many industries beside pigment manufacture and paint formulations; it can be applied as reinforcing filler in rubber, plastics and ceramic composites. Also, it is applied in paper filling, paper coatings and electrical insulation.Originality/value– Ferrite and ferrite/kaolin are environmentally friendly and can replace other hazardous pigments (e.g. chromates) with almost the same quality in their performance; also, they can be used in industries other than paints, for example paper, rubber and plastics composites.

Modified poly(butyl methacrylate- b -glycidyl methacrylate) dispersant for solvent-based paint by Reverse Atom Transfer Radical Polymerization

Block copolymers of butyl methacrylate (BMA) and glycidyl methacrylate (GMA) were synthesized using reverse atom transfer radical polymerization. Azobisisobutyronitrile/copper (II) bromide/pentamethyldiethylenetriamine was used as a precursor. These copolymers had a constant block length but variable molecular weights of 7500, 10,000, and 15,000, respectively. The copolymers were further reacted with methyl ethanol amine to form dispersible modified poly(BMA-b-GMA) (MPBGA). The synthesized block copolymers were structurally evaluated by gel permeation chromatography, Fourier transform infrared spectroscopy, differential scanning calorimetry, and nuclear magnetic resonance. The ability of additives to function as wetting and dispersing agents was evaluated by analyzing their mechanical, optical, chemical, and rheological properties in solvent-based paints at different pigment volume concentrations. The effects of the chain length of copolymers on dispersibilty and optical properties were studied. The optical properties of paints suggested that the dispersibilty of MPBGA increased with an increase in the molecular weight of the copolymer.

APPLICATION AND CHARACTERISTICS OF WATERBORNE ROAD MARKING PAINT

Horizontal road markings are one of the essential safety features of modern roadways. All of the utilised systems consist of a pigmented coating containing partially embedded retroreflective elements such as glass beads. In addition to durability and functionality of the road marking, ease of application and effect on human health and environment are primary considerations for their selection. Road marking systems can be divided into plural component materials that cure due to chemical reaction occurring at the site of application, thermoplastics that require heat for application, and paints, drying upon evaporation of the dissolving medium. The focus of this paper is on road marking paints with a special emphasis on contemporary waterborne materials. Over 100 years old solventborne technology furnishes paints that afford consistent application properties under a variety of conditions such as lower temperatures and high humidity. Their environmental and human health impact is significant and durability quite poor. Modern waterborne paints are based on acrylic resins and incorporate developed in the 1990s quick-set chemical mechanism for drying. Under favourable weather conditions, they dry faster as compared to solventborne. However, their known weakness is risk of washout in case of rain and sluggish development of washout resistance at marginal application conditions like high humidity and low temperature. Impact of waterborne paints on human health and environment is very significantly minimised as compared to other materials. Their durability is significantly higher as compared to solvent-based paints. Analysis of characteristics of waterborne road marking paints and preliminary results from their trial application in Croatia are presented herein. Based on the presented comparison with solventborne materials, after results from test application become available, intelligent decisions regarding future use of waterborne road marking paints in Croatia and other countries that have not embraced this technology shall be possible.