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hydroxyl moiety, a higher percent recovery of the instant hindered amine compound from the clearcoat over a plastic substrate is found indicating that much less of the instant hindered amine stabilizer migrates into the plastic substrate allowing for better stabilization of the clear topcoat over such plastic substrates. 

Waterborne coating comprise a significant and increasing proportion of the coating in use for a wide variety of applications including automotive basecoats, industrial coat› ings and trade sale coatings. These coatings may be pig› mented or transparent. The trends are also towards higher solids formulation which in general depend on light stabi› lizers to maintain properties on exterior exposure, and towards lower levels of cosolvents. This requires higher solubility of stabilizers in such cosolvents (primarily water) or actual solubility in water. 

The test stabilizers are incorporated into a waterborne dispersion by predissolution in a cosolvent blend. The waterborne dispersion is a commercially available acrylic/ urethane hydrid resin. The cosolvent blend is a 1:1 mixture of TEXANOLfi (2,2,4-trimethyl-1,3-pentanediol, Texaco) andARCOSOLVEfi TPM (tripropylene glycol methyl ether, AtlanticRichfield). 

0.45 gram of the test stabilizer is predissolved in 10 g of the cosolvent blend which is then incorporated into the following composition: 

<img src='content_image/948339.jpg'>

Each coating is brush applied onto 6"x6" sections of cedar and pine boards. The weight of the coating applied is regulated by weighing the coating and brush before and after application and ensuring that the same weight of coating is applied to each section. 

The coated board sections are allowed to dry at ambient temperature for two weeks, then evaluated for visual appearance, gloss and Hunter L *, a* and b* color. The sections are exposed on racks at a 45° angle in South Florida for six months before being returned and evaluated for visual appearance, gloss, color change and any other signs of degradation or delamination. 

The instant hindered amine compounds substituted on the N-atom with an -O-E-OH moiety provide better stabiliza› tion efficacy to the sections in respect to visual appearance, gloss retention, resistance to color change and to delamina› tion than do the corresponding -NOR compounds lacking such a hydroxyl moiety. 

Stabilization of Pigmented Automotive OEM Basecoat 

A basecoat pigmented with a mixture of Pigment Red 177 and mica is stabilized with 1 % by weight of a hindered 

Stabilization of Waterborne Wood Varnish 

## EXAMPLE 111 

## EXAMPLE 112 

amine stabilizer based on the total basecoat solids (pigment plus resin). The basecoat is spray applied at a dry film thickness of 1 mil (25 microns) to primed 4"x12" steel panels, then topcoated with a high solids commercially available automotive clearcoat. The coated panels are cured in an over at 250° F. (121 ° C.) for 30 minutes. The panels are then exposed in a Xenon-Arc Weather-Ometer under the following conditions: 

Cam 180 cycle: 40 minutes light only; 20 minutes light and front spray; 60 minutes light only; 60 minutes dark and rear spray condensate. 

Lamp filters are: quartz inner/borosilicate S outer. 

Irradiance: 0.55 watts per square meter. 

20° Gloss, Distinctness of Image, Hunter Color Space Values (L *, a*, b* and li.E) are measured before exposure and after 3000 hours of exposure. 

The instant hindered amine compounds substituted on the N-atom with an -O-E-OH moiety provide better stabiliza- tion efficacy to the panels in respect to distinctness of image, gloss retention and resistance to color change than do the corresponding -NOR compounds lacking such a hydroxyl moiety. 

Thermoplastic materials composed of mixtures of copoly› mers derived from the copolymerization of styrene mono- mer with acrylonitrile and the copolymerization of stryrene monomer with butadiene, generally referred to as ABS, are dry blended with the instant compounds and melt com› pounded into pellets. Typical formulations contain the instant compounds at levels from 0.05% to 2.0%, a metal stearate such as calcium stearate at 0.05% to 0.5%, pigments from 0% to 5%, UV absorbers at levels of 0.05% to 2.0%, phosphites at 0.0%-0.1 %, phenolic antioxidants at 0.0%-1.25%, N,N-dialkylhydroxylamine at 0.0%-0.1 %, and optionally other hindered amine stabilizers at levels of 0.0% to 2.0%. 

The pelletized fully formulated resin is then processed into a useful article such as extrusion into sheet, film, profile and pipe; molded into bottles; injection molded into a molded article; thermoformed into molded articles; or rota- tional molded into hollow articles. 

The materials containing the instant compounds exhibit stability against deleterious effects of UV light and thermal exposure. 

pKa Values 

In order to determine the pKa values of water insoluble material organic references with known pKa values in water are titrated non-aqueously. A plot of the half neutralization potential (HNP) versus the known aqueous pKa value of the reference material is establed. The HNP of the test material is determined and extrapolated to find the corresponding pKa value of the test material. Such organic reference materials include 2,2,6,6-tetramethylpiperidine; 4-hydroxy- 2,2,6,6-tetramethylpiperidine; 1-hydroxyethy 1-4-hydroxy-2, 2,6 ,6-tetramethy lpi peridine; triace tone amine and N-methylaniline. 

The reference materials, which are structurally at least peripherally related to the instant test materials and are soluble in both water and 1: 1 acetonitrile:chloroform, are used to make a calibration plot in the non-aqueous titration (1: 1 acetonitrile:chloroform solvent and 0.lN perchloric 

## EXAMPLE 113 

ABS Molding Applications 

## EXAMPLE 114 

