| 摘要 |
PURPOSE:To obtain a fluoroelastomer which provide a vulcanizate excellent in resistances against heat, solvents, and chemicals, etc., by selecting a fluoroelastomer contg. vinylidene fluoride units and hexafluoropropylene units in a specified wt. ratio and encowing specified physical properties. CONSTITUTION:A fluoroelastomer is selected which contains vinylidene fluoride units and hexafluoropropylene units in a wt. ratio of the former units to the latter of (40:60)-(80:20), if necessary further contains up to 35wt.% tetrafluoroethylene units, contains combined iodine, and has a multipeak mol.wt. distribution, a limiting viscosity number of 60-130ml/g, a ratio of the content (wt.%) of a low-mol.-wt. polymer having a mol.wt. of 50,000 or lower to limiting viscosity number of 0.15-0.60, and a ratio of wt. average mol.wt. to number average mol.wt. of 4-8. |
