Unpigmented coatings

Preparation of unpigmented coatings. Coatings of the resins described in Table II were prepared by dissolving polyester resin and HMMM resin (Resimene 746) in a 3/1 weight ratio in xylene, adding 0.3... 

Floor sealers are clear, unpigmented coatings rqiplied to porous substrates like conoete and tiles to seal the surface and protect against soiling. Reladvely hard (Tg 50-90°Q, solvent and water resistant, thermoplastic compositions, similar to those for OEM coatings, are used. 

If the pigment is omitted, the material is usually called a varnish. The term clearcoat is used for unpigmented coatings applied over metallic paints. The pigmented varnish - the paint - is sometimes called an enamel, lacquer, finish or topcoat, meaning that it is the last coat to be applied and the one seen when the coated object is examined. Lacquers are normally thermoplastic solution paints or varnishes, but the term is sometimes (confusingly) used to describe all clear woodfinishes. Enamels are normally thermosetting paints, hard, with a superficial resemblance to vitreous enamels. 

Evaluation of the surface coating properties of resins derived by diepoxide route. Unpigmented coatings containing cobalt naphthenate drier (0.05% cobalt as naphthenate on the drying oil content of the resin) were applied by brush or doctor blade to various substances including aluminium, glass and polyethylene... 

The energy required to initiate an explosion and the maximum explosive pressure developed by a number of polyester—epoxy powder coatings has been studied in some detail (89). The variables studied included composition, level and type of pigmentation, particle size, and concentration in air. The lowest MEG for unfilled and unpigmented powders was 33—35 g/m. ... 

ThermoWood is not resistant to exterior weathering and the colour will gradually change to the grey that is characteristic of outdoor exposed wood. In addition, exposure in exterior conditions results in the formation of small cracks on the surface of uncoated wood. Unpigmented or low-build stain coatings do not protect the surface of the wood, but solvent-borne alkyds and water-borne acrylic paints have been found to exhibit better performance than on unmodified wood. VOC emissions from the heat-treated wood are lower compared to unmodified wood and the compositions of the emissions differ. The level of emissions is lower when the wood is treated at a higher temperature. Emissions of terpenes are reduced to very low levels, and the VOC content is dominated by furfural, hexanal and acetic acid (treated at 180 °C), and by acetic acid (treated at 230 °C). ThermoWood passes ecotoxicity tests. 

Figure 5. Potential vs time for coated specimens in 3% NaCl. Key , bitumen A, Zn rich + bitumen 0> polyurethane, one coat (unpigmented) V, polyurethane, two coats (unpigmented) 0, polyurethane, one coat (pigmented) and X, polyurethane, two coats (pigmented).

From the data obtained for the different specimens it can be seen that there is significantly different behaviour between the poor, porous coatings (bitumen) and the polyurethane paint samples. Of the polyurethane samples only one showed any evidence of corrosion beneath the coating during the duration of the test and this was an unpigmented single coat specimen. 

Figure 9. Analogue potential and current noise traces for polyurethane 2 coats unpigmented. Day 2.

The d.c. potentials, however, only Indicated whether the material being studied was in a corrosion regime, both the bitumen and unpigmented single coat polyurethane assumed very similar potentials over the period of the test, even though the corrosion rates were grossly different. 

Figure 12. Nyquist plots for polyurethane (1 coat) unpig ...

Figure 12 illustrates the difference in inpedance behaviour between the two samples of unpigmented polyurethane (applied at 40(jm) after 50 days e q)OSure. Panel A gave a response indicative of a good, intact coating (almost purely... 

D. Thermoplastic Resin, used for coating the cords shall comply with Spec L-P-390. The plastic outer covering shall be of smooth texture and, unless otherwise specified,unpigmented and colorless Other Requirements and Tests ... 

There are solvent-free systems with 100% solids principally used as protective coatings for concrete or metal storage tanks. Such coatings are unpigmented, clear compositions. They are thixotropic and can be applied both on horizontal and on vertical surfaces. 

Okhamafe, A.O. York, P. The adhesion characteristics of some pigmented and unpigmented aqueous-based film coatings applied to aspirin tablets. J. Pharm. Pharmacol. 1985, 37, 849-853. 

Nishikawa et al, 1991). These studies showed a critical dependency of melanocyte development on c-kit at El3.5-14.5, and effects on coat colour were seen following intradermal injection of pregnant mice as early as E10.5. Even in the adult, intradermal injection of the anti-c-k/f antibody when the hair cycle was activated resulted in unpig-mented areas. In addition, studies in and... 

Impact resistance of epoxy coatings, as determined by a reverse Gardner impact test, is enhanced by liquid polymer addition independent of functional type. Again, these results are consistent with both unpigmented and pigmented model coatings. Although... 

Novolacs are solid at normal temperature and generally have a well-defined melting point. The largely inert behaviour of novolacs means that they can only be used for physically drying paints and coatings. They are extremely good soluble in polar solvents such as alcohols, ketones, and esters, but are insoluble in aromatic and aliphatic hydrocarbons (e.g., xylene, benzene). Spirit varnishes are novolacs dissolved in alcohol that are primarily used as unpigmented varnishes they have an... 

The assessment of Shell s olefmic color coats was done in February 1996. A preliminary routine evaluation of Shell s unpigmented olefmic color coats combined with the production clear coats and applied over the production TPO substrate showed extraordinary adhesion properties. Long term testing and evaluation of... 

Uses Defoamer for emulsion paints, esp. in low vise, and unpigmented systems defoamer for coating colors in paper prod., wastewater treatment... 

Chem. Descrip. Blend of hydrocarbons, waxes, and nonionic emulsifiers Uses Defoamer for emulsion polymers, water-dilutable systems, pigmented and unpigmented systems, coating colors for paper prod. in resinous/polymeric food-contact coatings food-contact paper/paperboard Features Silicone-free... 

Chem. Descrip. 2H-1-Benzopyran-2-one, 7-(diethylamlno)-4-methyl CAS 91-44-1 EINECS/ELINCS 202-068-9 Uses Optical brightener for polymeric substrates (unpigmented, pigmented) as cellulose acetate, polystyrene, vinyls, and other resins, particularly those used for surf, coatings Properties Brn. yel. powd. sol. (g/100 ml) > 50 g in acetone, methylene chloride, toluene, 34 g in ethyl acetate, 26 g in methanol pract. insol. in water m.w. 231.3 bulk dens. 0.40-0.50 g/cm m.p. 70-72 C Use Level 0.01-0.10%... 

---