Light stabilizers compositions

Bopp RC. U.V. light stabilizer compositions comprising cyclic aliphatic epoxy, UV screener, and polyalkyldipiperidine (HALS) compounds. U.S. Patent 4843116. June 27,... 

The 2-imino-4-thiazolines may be used as ultraviolet-light stabilizers of polyolefin compositions (1026). 2-Aminothiazole improves adhesive properties of wood to wood glue (271). Cbmpound 428 exhibits antioxidant properties (Scheme 242) (1027). Ammonium N-(2-thiazolyl)dithio-carbamate (429) is a bactericide and fungicide used in industrial products such as lumber, paint, plastics, and textiles (1037). Compound 430 is reported (1038) to form an excellent volume of foam coating in aluminum pans when ignited with propane. 

Sesamex [51-14-9] (Sesoxane) (30) is a synergist oflow toxicity, acute oral LD q (rat) = 2000 2270 mg/kg, for pyrethrins and allethrin. 6,7-Dihydroxy 4-methylcoumarin has been offered as an antioxidant for phenoHcs and polymers, and as an anthelmintic. 2,4,5-Trihydroxybutyrophenone has been available as an antioxidant and light stabilizer for polyolefins, waxes, and foods. Isoflavones, eg (31), have been patented as components of antioxidant compositions for foods and cosmetics (qv) (97). 

The stabilizers chosen for evaluation include different types of heat and light stabilizers selected to represent different mechanisms of action as well as chemical compositions (ArJi). Types of stabilizers evaluated include benzotriazole and benzophenone light stabilizers [ultraviolet (UV) light absorbers], hindered amine light stabilizers (HALS, catalytic radical scavengers), hindered phenol heat stabilizers (antioxidant radical scavengers), and thioester heat stabilizers (antioxidant hydroperoxide decomposers). 

Fillers. Inert inorganic substances such as calcium carbonate, clay, silicates, and asbestos are often utilized in vinyl compositions where clarity is not a requirement. While the carbonates and clay are used ostensibly to reduce cost, beneficial results are forthcoming. The carbonates produce a dry, matte surface and are claimed, because of their alkaline nature, to benefit heat and light stability. Clay improves electrical insulation. Silicates enhance surface dryness. Asbestos fibers provide the reinforcement necessary for dimensional stability in floor tile. Antimony oxide, per se or as a surface coating on an inert carrier, provides flame retard-ance. Their only major adverse effects are to reduce tensile strength and elongation and require an increase in plasticizer level to compensate... 

Acrylics. Manufacturers of acrylic fibers have not generally published or confirmed the chemical composition of their fibers (116). Acrylic fiber will generally contain 85-94% acrylonitrile the balance is made up of comonomers having a specific function, such as to provide dye affinity for specific dye classes or to regulate diffusion of dye into the fiber. A list of typical comonomers has been published (116). Acrylic fibers may also contain heat (117) and light stabilizers (116). They may also contain a delustrant such as titanium dioxide. Some products contain optical brightening agents. These materials probably never exceed 4r-5% of the total composition. The cross-sectional shapes of the fibers vary (116). 

Triphenylphosphate, igranox, diglycol phosphate, trimethyl borate [265], benzotriazole [266] are used as light stabilizers. Fibres modified by such substances exceed goods from compositions produced by traditional method to a far greater extent as to their resistance to ultra-violet irradiation. 

This volume is including information about thermal and thermooxidative degradation of polyolefine nanocomposites, modeling of catalytic complexes in the oxidation reactions, modeling the kinetics of moisture adsorption by natural and synthetic polymers, new trends, achievements and developments on the effects of beam radiation, structural behaviour of composite materials, comparative evaluation of antioxidants properties, synthesis, properties and application of polymeric composites and nanocomposites, photodegradation and light stabilization of polymers, wear resistant composite polymeric materials, some macrokinetic phenomena, transport phenomena in polymer matrix, liquid crystals, flammability of polymeric materials and new flame retardants. 

TABLE 16.7 Effect of a light stabilizer Cyasorb UV-3853 (Cytec) on fading of a wood-HDPE composite material... 

When the aldehyde in the acetalization reaction is butyraldehyde, i.e., R=CH3CH2CH2-, the product is poly(vinyl butyral). Sulfuric acid is the catalyst in this reaction. Poly(vinyl butyral) is characterized by high adhesion to glass, toughness, light stability, clarity, and moisture insensitivity. It is therefore extensively used as an adhesive interlayer between glass plates in the manufacture of laminate safety glass and bullet-proof composition. 

Cadmium stearate n. (Ci7H35COO)2Cd. A heat- and light-stabilizer, used when good clarity in transparent compositions is desired. 

Recommended for polymers PMMA, ABS, SAN, HIPS, high efficient light stabilizer for Wood Plastic Composites (PE/PP based WPC) ... 

---