| 摘要 |
<p>The concentrate is based on a chemical blowing agent (I) and a satd. (co)polyester (II) with an intrinsic viscosity of 0.4-1.6 (pref. 0.7-1.0) dl/g as carrier, as in Parent patent. The improvement is that (II) has a crystalline m.pt. =140 degrees C, pref. 100 to 140 degrees C, esp. 110-130 degrees C. The concentrate is used in the prodn. of opt. filled, (glass fibre) reinforced and/or flame-retardant structural foam parts from polyalkylene terephthalates, pref. polytetramethylene terephthalate. The foamed prods. have good physical, mechanical and thermal properties.</p> |
