Light stable polyurethane

A trend ia the utihty of isophorone is as an important iadustrial building block. Foremost among these developments has been the use of isophorone as a raw material, and isophorone diisocyanate [2855-13-2] (IPDl), for the production of the light-stable polyurethane. The U.S. market for IPDl-based products was 31 million ia 1989, and is estimated to grow to 53 million ia 1994 (230). 

Most of the hexamethylenediamine produced is used for the manufacture of Type 66 nylon by polymerization with adipic acid. A minor use is for the preparation of hexamethylene diisocyanate used in light-stable polyurethane coatings. 

The industrial production of hexamethylenediamine became important with the discovery of the use of polyamides as synthetic fibres, the most important being Nylon-6,6. This polymer, prepared from adipic acid and hexamethylenediamine, was commercialized by DuPont in 1938 and it was virtually the only consumer of the entire production of this diamine until the development of light-stable polyurethanes. Those polymers, e.g. Desmodur N (Bayer) used in paints, are based on aliphatic diisocyanates prepared from the corresponding aliphatic diamine. 

BRN 2726467 CCRIS 6252 Cyclohexane, 5-isocyanato-1-(isocyanatomethyl)-l,3,3-trimethyl- EINECS 223-861-6 HSDB 6337 IPDi Isophorone diamine diisocyanate Isophorone diisocyanate UN2290 Vestanat IPDI, Raw matenal for mfg. of light stable polyurethanes. Degussa-Huls Corp. 

A number of specialty aliphatic polyisocyanates have been introduced recently in attempts to produce a light-stable polyurethane coating. Triisocyanate made by reacting hexamethylene diisocyanate with water (Figure 4.28c) is reported to impart good light stability and weather resistance in polyurethane coatings and is probably the most widely used aliphatic polyisocyanate. 

Isophorone diisocyanate (IPDI) is another low-viscosity aliphatic diisocyanate that is useful in formulating light-stable polyurethane adhesives, and is somewhat lower in cost than hexamethylene diisocyanate. IPDI has a low vapor pressure at room temperature but, like most low-weight isocyanates, still can present... 

Aliphatic isocyanates have a small but growing market application in thermoplastic polyurethanes (TPU). Medical appflcafions include wound dressings, catheters, implant devices, and blood bags. A security glass system using light-stable TPU as an inner layer is under evaluation for shatterproof automotive windshield appflcafions. 

Methylenedi(cyclohexyhsocyanate) (45) [5124-30-1] (MDCHl, Desmodur W) is the dominant derivative of MDCHA and is used in light-stable urethanes. Polyurethane physical properties are dependent on the diamine geometric isomer composition used for the derivative diisocyanate which reacts with diol (87). 

The diisocyanates are reacted with diols to produce polyurethanes that end up in consumer products, such as seat cushions, mattresses, insulation, car bumpers, swim suits, floor coatings, paints, and adhesives.12 The aromatic diisocyanates are cheaper, but yield less light-stable polymers than the aliphatic ones. 

Aromatic urethanes have been stabilized by complexation of peroxides in the polymer and the effect of prior y-irradiation has been investigated, on polyurethanes.The ageing of polyurethane coatings has been investigated, and light-stable integral skin foams have been developed for polyurethanes. Creep behaviour of polyurethanes on ultraviolet exposure has also been investigated. ... 

Chem. Descrip. Isophorone diisocyanate CAS 4098-71-9 EINECS/ELINCS 223-861-6 Uses Used to produce light-stable, weather-resist, polyurethane coatings, elastomers, and foams for paints (metal finishing for automotive, aircraft, machines), coatings (wood, plastics, textiles, leathers, flooring),... 

Various forms of polyurethane coatings are available. For maximum toughness and light stabihty, an acrylic polyol and a light-stable polyisocyanate, e.g. the HDI derivatives, may be applied (Thapliyal and Chandra, 1990). Polyisocyanates and derivatives are freqnently added to alkyd resins to improve their properties of toughness and adhesion. They suffer from many of the instabilities of the parent aUcyds. 

Complex compounds of chlorine, phosphorus and bromine have been developed for flameproofing polyester resins, polyolefins and polyurethanes. Unfortunately such compounds are usually toxic and expensive, and many of them, especially those containing hi proportions of bromine, suffer from poor heat and light stability. Considerable research effort is being expended to develop a broad spectrum, highly efficient heat and light stable flame retardant additive for plastics materials which could be sold at an economic price, but none of the products currently on the market fully satisfy all the requirements of an ideal flame retardant. 

Hexamethylene diisocyanate is a liquid with a volatility of the same order as that of tolylene diisocyanate. It is respiratory irritant and also has powerful effects on the skin and eyes. Hexamethylene diisocyanate was one of the first diisocyanates utilized for making polyurethanes, being used to prepare fibres and moulding compounds. These applications are no longer of importance but hexamethylene diisocyanate now finds use mainly in coatings which are more light stable than those based on aromatic isocyanates. 

Foams have a large variety of applications. Solid foams are widely used as insulating materials. Due to the presence of air bubbles they have a low thermal conductivity. Polyurethane foams and Styrofoam are examples. Styrofoam is also used as a packing material. The light weight of polymer foams makes them attractive as filling materials to stabilize otherwise hollow structures. A natural solid foam is pumice stone. Metal foams are used in the automotive and aerospace industry as light and stable materials [567], Ceramic foams are developed for electronic applications as piezoelectric transducers and low dielectric constant substrates [568],... 

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