Heat and light stabilizers

Heat and light stabilizers R2SnX2 R2Sn(SCH2COO-Oct)2 (R = Me, Bu, Oct, etc.)... 

Patents state that the addition products from 2,2,6,6-tetramethyl-piperidin-4-ol and tetrolic acid are heat and light stabilizers for polymers.276-277... 

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). 

Residual materials (e.g., surfactants, emulsifiers) from polymerization which remain on the surface of the resin particle can exhibit unique secondary manifestations of degradation, such as poor heat and light stability and susceptibility to fungal attack not associated with the polymer itself. This is particularly true of emulsion-prepared polymers (dispersion or paste resins) where the surfactant level may be as high as 3% to provide appropriate rheological properties to the resin. 

These materials, unfortunately, have certain severe limitations. Polymeric plasticizers are viscous, difficult to process, and inefficient. Their heat and light stability are poor, low temperature performance is very poor and they are readily attacked by fungi. Albeit, they are permanent and find significant use in vinyl compounding. 

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... 

Biocides. The attack of fungi on the several components of a vinyl formulation may manifest itself as an unsightly growth looking much like dirt or may result in the formation of discolored areas (yellow, pink, blue, clear) on the finished goods. Outdoor exposure, indoor exposure in humid atmosphere, soil burial or contact, and electrical insulation compounds are typical areas where biocide addition is indicated. Since most commercial biocides are heavy metal derivatives, care must be taken to assess their effect on heat and light stability and compatibility with the vinyl system in which they are used. 

Other Plastics Uses. The plasticizer range alcohols have a number of other uses in plastics liexanol and 2-ethylliexanol are used as part of the catalyst system in the polymerization of acrylates, ethylene, and propylene (55) the peroxydicarbonate of 2-ethylliexanol is utilized as a polymerization initiator for vinyl chloride various trialkyl phosphites find usage as heat and light stabilizers for plastics organotin derivatives are used as heat stabilizers for PVC octanol improves the compatibility of calcium carbonate filler in various plastics 2-ethylliexanol is used to make expanded polystyrene beads (56) and acrylate esters serve as pressure sensitive adhesives. 

Various polyesters derived from phosphorous or phosphoric acids were prepared. Efiicient polyphosphites were synthesised in the early 196(. Polyphosphite prepared from 152 and 4,4 -isopropylidenebis(cyclohexanol) was tested as a thermal stabilizer for PC [199] or as secondary AO for radiation sterilized EPM [200]. Built-in phosphites obtained by transesterification of triallcylphosphite with 4,4 -isopro-pylidenebisphenol or 4,4 -thiobisphenol possess antioxidant properties in polyolefins. Stabilizer containing phosphite moiety 153 was prepared from tris(2-hydroxy-ethyl)isocyanate, decyl alcohol and triphenylphosphite [201]. Various phosphites were derived firom polynuclear phenols or dihydric phenols. For example, a polycondensate prepared by reaction of phosphorus trichloride with 2,5-di-rert-butylhydroquinone was tested as heat and light stabilizer for PP [202], A linear polyester with a built-in phenolic moiety was synthesised from (2,6-di-tm-butyl-4-methylphenyl)bis(6-hydroxyhexyl)phosphite and dimethyl terephthalate [203]. 

Among the various types of cellulose derivatives, it is the cellulose esters that find the widest practical application and complete succesfully in a number of branches of the industry with synthetic polymers. The complete or partial esterification of the hydroxyl groups of cdlulose can yield cellulosic materials having such technically valuable properties as thermoplasticity, hydrophobicity, resistance to heat and light, stability to the action of putrefying microorganisms, bactericidal action, etc. 

Used primarily to keep plastics and rubber soft and pliable in flooring, upholstery, food packaging, hoses, tubing, blood bags and other products. The epoxy functionality provides heat and light stability. 

Use Waterproofing agent lubricant in metalworking, plastics, and rubber wax compounding preparation of greases heat and light stabilizer in plastics. 

Use Heat and light stabilizer for vinyl plastics and chlorinated paraffins. As an UV screening and antioxidizing stabilizer for vinyl and other chlorinated resins in paints and plastics. 

Paraplex [Hall]. TM for polymeric plasticizers for polymers and resinous coatings. Primarily polyesters, but some are epoxidized oils that impart heat and light stability as well as plasticization. Supplied as viscous liquids in a range of molecular weights all at 100% solids. Compatible with polyvinyl chloride, polyvinyl butyral, cellulosics, and other high polymers and elastomers. 

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