Weathering polyester resin

Uses. Neopentyl glycol is used extensively as a chemical intermediate in the manufacture of polyester resins (see Alkyd resins), polyurethane polyols (see Urethane polymers), synthetic lubricants, polymeric plasticizers (qv), and other polymers. It imparts a combination of desirable properties to properly formulated esterification products, including low color, good weathering and chemical resistance, and improved thermal and hydrolytic stabiUty. 

Polyester polyols, 25 464 468 Polyester resin(s), 11 302 coating resins, 7 104-106 cyclopentadiene and dicyclopentadiene applications, 8 230 flammability of, 20 115-116 properties in powder coating, 7 43t standard test methods for, 20 11 It unreinforced, 10 187t weathering of, 20 116 Polyester resin-based powder coatings, organic titanium compounds in, 25 125 Polyester resin composites, 26 762-763 Polyester resin formulations ingredients of, 20 96t unsaturated, 15 511-512 Polyesters, 10 185-189, 497 12 655-656. See also Thermoplastic polyesters Unsaturated polyesters acid resistance of, 20 7-8 antioxidant applications, 3 121 aromatic ionic, 23 722 based on 1,4-cyclohexanedimethanol, 12 674-675... 

Hydroxypivalyl hydroxypivalate or 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropionate (9) is a white crystalline solid at room temperature. It is used to manufacture polyester resins for use in surface coatings where good resistance to weathering and acid rain are of particular importance (6). 

In general crosslinked polyesters have better light and weathering resistance than uncured polyester resins. Apparently the concentration of unsaturated double bonds is a determining factor. In our previous studies (14) we have shown that under UV irradiation of unsaturated polyesters the primary photoreactions involve excitation of conjugated structures carbonyl groups ( in ester... 

Although linear polyester resins do not readily undergo heat curing, they form extremely flexible paint films with excellent adhesion to metal substrates. Poiyisocyanate resins are more resistant to hydrolysis than amino resins. Polyester-polyurethane paints therefore exhibit improved resistance to moisture and weathering but are more expensive. 

On account of their insensitivity to solar radiation, some polyester resins are particularly suitable for weather-resistant topcoats (e.g.. facade claddings, blades of shutters and Venetian blinds, vehicle claddings, metal signs). Melamine-formulated paints are economical and have a well-balanced property profile. Polyurethane-formulated paints have an even better processability and weather resistance (colorfastness, chalking resistance) [2.92],... 

Industrial Paints. Stoving enamels used to spray or dip-coat machinery, domestic appliances, vehicles, and office furniture are termed industrial paints. On account of their good adhesion and resistance to hydrolysis, polyester-melamine stoving enamels provide very good protection of metal surfaces against undercoat corrosion creep. Polyester resin grades are available for special mechanical requirements (high impact resistance, hardness, abrasion resistance) or for exterior use (weather resistance). 

Polyester resins combined with aliphatic polyisocyanate resins have outstanding weather resistance, good substrate adhesion, and high flexibility even under very large temperature changes (aircraft finishes). 

Specialized polyester resins are commonly used in processes such as hand lay-up and spray-up, to provide an attractive and weather-resistant surface finish to molded parts. These gel coats are sprayed onto the mold before the reinforcement is introduced. In addition to their cosmetic function, gel coats can also provide the RP surface with resistance to impact and abrasion. There is also anti-bacterial additive technology to gel coats, especially for applications such as baths and... 

The constitution of the unsaturated polyester resin used to make a gelcoat is obviously a prime factor in determining its weathering performance. Base polyesters (which are subsequently dissolved in the monomer) are made by reacting together saturated and unsaturated diacids and diols, and variation of these ingredients enables properties such as flexibility, heat distortion... 

Chem. Descrip. Polyester resin (78%) in butyl acetate Uses Polyester tor ultra high solids, two-pack, clear and pigmented top coats tor automotive repair and industrial lacquers Features Hydroxy-tunctional crosslinkable with polyisocyanates cured films provide high hardness, exc. solv.- and chem. resist., superior weathering stability can produce dear coats with VOC 350 g/l, and pigmented top coats with VOC 420 g/l... 

Chem. Descrip. Sat. polyester resin in naphtha/butylglycol Uses Polyester for weather resist, coil coalings Properties Dens. 1.08 g cm vise. 3.5 Pa-sj add no. < 3 hyd. no. 35 60% solids... 

CAS 3896-11-5 EINECS/ELINCS 223-445-4 Uses UVabsorber tabilizerforABS, PE, PP, PS, PU, PVC, unsat. polyester resins and coatings, other polymers, elastomers, food pkg. heat stabilizing effect in PVC Features Improves weathering resist. 

Synonyms Polyester resin, saturated Saturated polyester resin Uses Raw material for high-solids industrial coatings with high weather and chem. resist. can coatings interior lining for food and alcohol contact film-former for cosmetics... 

If one works at higher temperatures, then the butadiene preferentially polymerizes at the 1,2 position. The vinyl groups thus produced can subsequently be cross-linked. Thus, the product has about the same field of application as unsaturated polyester resins, but it is less sensitive to weathering, because of the absence of heteroatoms. 

The resin is an isophthalic polyester resin. Its principal advantage, besides low cost, lies in its rapid and controllable cure chemistry and therefore in its ease of use within hand lay up fabrication processes. There are several types of polyester but isophthalic resins offer the most attractive combination of mechanical properties and environmental resistance (i.e. reduced corrosion and maintenance costs, and good resistance to attack by chemicals). Moreover, previous studies on effects of immersion and weathering (exposure to wind, rain, sun) show that the performance of glass FRP laminates are generally good, especially with isophthalic polyester resin. 

---