Zytel HTN

A number of high melting poiat semiaromatic nylons, iatroduced ia the 1990s, have lower moisture absorption and iacreased stiffness and strength. Apart from nylon-6 /6,T (copolymer of 6 and 6,T), the exact stmcture of these is usually proprietary and they are identified by trade names. Examples iaclude Zytel HTN (Du Pont) Amodel, referred to as polyphthalamide or PPA (Amoco) and Aden (Mitsui Petrochemical). Properties for polyphthalamide are given ia Table 2. A polyphthalamide has been defined by ASTM as "a polyamide ia which the residues of terephthaUc acid or isophthahc acid or a combination of the two comprise at least 60 molar percent of the dicarboxyhc acid portion of the repeating stmctural units ia the polymer chain" (18). 

Amodel, Grilamid, Ixef, Laramid,Trogamid, Zytel HTN. 

Manufacturers and trade names Solvay Advanced Polymers Amodel , EMS-Grivory Grivory HT, DuPont Zytel HTN. 

Solutions in Zytel , DuPont , Zytel HTN high performance polyamide resins. DuPont 2003. 

John Gavenonis and Joshua E. Mcllvaine, Zytel HTN PPA and Zytel Nylon 6,6 and Nylon 6 resins in high temperature and automotive chemical exposure environments. DuPont White Paper 2009. 

The need to use lead-free solder in surface mount technology applications where soldering temperatures of between 220 °C and 240 °C are likely to be encountered has necessitated the use of such high temperamre polyamides as DuPont s Zytel HTN LX resins for board assembly. It is interesting to note that some Japanese companies have been using lead-free solders in their flow soldering processes since 1997. 

For example the DuPont ThermX polyester tolerates high temperatures and is based on poly(cyclohexylene-dimethylene terephthlate) chemistry. It has the chemical resistance, dimensional stability and processability of such polyesters as PET and PBT but with a melting point of 285 °C compared with PET (255 °C) and PBT (225 °C). DuPont claims that ThermX complements its other very high thermally capable Zenite TCP and Zytel HTN (high temperature Nylon) resins in applications which call for higher thermal capabilities than those of PBT, PET and PA66. ThermX,... 

Figure 15-23. Declining physical properties in a part from successive generation of regrind usage. (Courtesy of DuPont, Nylon Zytel HTN Molding Guide.)...

DuPont Engineering Polymers has announced an expansion of production capacity for its speciality products in Shenzhen, China, through a licence with a custom compounder in Shanghai. The products involved are speciality grades of DuPont Zytel HTN high performance polyamide, DuPont Thermx PCT thermoplastic polyester, DuPont Rynite PET thermoplastic polyester, DuPont Crastin PBT thermoplastic polyester, DuPont Hytrel thermoplastic polyester elastomers and DuPont Zenite LCP resin. Increased supply to the market is expected by the fourth quarter of 2004. 

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