Migration resistance, plasticizer

Raw Materials. PVC is inherently a hard and brittle material and very sensitive to heat it thus must be modified with a variety of plasticizers, stabilizers, and other processing aids to form heat-stable flexible or semiflexible products or with lesser amounts of these processing aids for the manufacture of rigid products (see Vinyl polymers, vinyl chloride polymers). Plasticizer levels used to produce the desired softness and flexibihty in a finished product vary between 25 parts per hundred (pph) parts of PVC for flooring products to about 80—100 pph for apparel products (245). Numerous plasticizers (qv) are commercially available for PVC, although dioctyl phthalate (DOP) is by far the most widely used in industrial appHcations due to its excellent properties and low cost. For example, phosphates provide improved flame resistance, adipate esters enhance low temperature flexibihty, polymeric plasticizers such as glycol adipates and azelates improve the migration resistance, and phthalate esters provide compatibiUty and flexibihty (245). 

Tris(2-ethylhexyl) phosphate shows good compatibiUty with PVC and also imparts good low temperature performance in addition to good fire retardancy. 2-Ethyhexyl diphenyl phosphate has widespread use in dexible PVC appHcations due to its combination of properties of plasticizing efficiency, low temperature performance, migration resistance, and fire retardancy. 

Plasticizers. Plasticizers are materials that soften and flexibilize inherently rigid, and even britde polymers. Organic esters are widely used as plasticizers in polymers (97,98). These esters include the benzoats, phthalates, terephthalates, and trimeUitates, and aUphatic dibasic acid esters. Eor example, triethylene glycol bis(2-ethylbutyrate) [95-08-9] is a plasticizer for poly(vinyl butyral) [63148-65-2] which is used in laminated safety glass (see Vinyl POLYMERS, poly(vinyl acetals)). Di(2-ethyUiexyl)phthalate [117-81-7] (DOP) is a preeminent plasticizer. Variation of acid and/or alcohol component(s) modifies the efficacy of the resultant ester as a plasticizer. In phthalate plasticizers, molecular sizes of the alcohol moiety can be varied from methyl to tridecyl to control permanence, compatibiUty, and efficiency branched (eg, 2-ethylhexyl, isodecyl) for rapid absorption and fusion linear (C6—Cll) for low temperature flexibiUty and low volatility and aromatic (benzyl) for solvating. Terephthalates are recognized for their migration resistance, and trimeUitates for their low volatility in plasticizer appHcations. 

Introducing acidic substituents into the basic structure of a typical monoazo yellow pigment makes it possible to convert the material into a lake by salt formation. This improves the application properties of a pigment compared to its non-laked counterpart. Such pigments exhibit particularly good migration resistance and heat stability, making them useful colorants for plastics. 

P.R.95 is suitable for a variety of printing techniques. Poor migration resistance and insufficient fastness to plasticizers render the pigment unsuitable as a colorant in special gravure inks for plasticized PVC. 

Due to the disadvantage of comparatively poor migration resistance, P.R.5 is not used in plasticized PVC, but it can be applied in rigid PVC. Its lightfastness is excellent in this medium, transparent and opaque colorations (up to 0.01% pigment + 0.5% TiOz) equal step 7 and, respectively, step 6-7 on the Blue Scale. Dispersed pigment preparations are available for the mass coloration of viscose films as well as for spin dyeing of viscose rayon and viscose cellulose. 

P.R.171 is used in plastics and in paints. Its lightfastness in PVC equals step 7 to step 8 on the Blue Scale, depending on the exact composition of the tested system, the pigment concentration, and the Ti02 content. Incorporated in plasticized PVC, P.O.171 is migration resistant and heat stable up to 180°C. It is used in conjunction with organic yellow pigments, frequently also with iron oxides, to produce shades of brown. Shades of bordeaux are accessible in deep transparent colorations. 

P.O.64 shows good migration resistance in plasticized PVC and exhibits medium tinctorial strength. The pigment is also used in polystyrene and similar polymers and is also recommended as a colorant for rubber. 

Meanwhile, Rohm and Haas introduced the first of the polymeries - polyesters based on the reaction of a dibasic acid with a glycol and with a monohydric alcohol or monobasic acid as chain terminator(j>). These plasticizers were developed as highly permanent, extraction and migration resistant types for specialty applications. 2-Ethylhexanol and isodecyl alcohol are examples of monohydric alcohols used as chain terminators in today s polymeries. 

Tuning of Blend Properties and Migration Resistance Through the Architecture of Plasticizer... 

Polymeric plasticizers offer a three-fold profile of permanence low volatility, low oil extraction, and good migration resistance. Trimellitates are even lower in volatility and show low extraction by water but are not oil resistant. 

Uses Plasticizer for PVC and rubber formulations such as wire and cable coatings offering good elec, props., film, tape, and coated fabrics Features Good humidity stability, migration resist, to rubber, oil and hexane resist., low volatility Properties Low odor med. m.w. 

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