| 摘要 |
Polyester elastomers are made by (1) partially curing a saturated polyester with an organic peroxide in an amount of 40-80% of the total peroxide to be used and (2) adding the remainder of the peroxide and completing the cure. The peroxide may be benzonyl peroxide, a , a 1 - diamyl peroxide, lauroxyl peroxide, 2:5-dimethyl-2:5-di-(t-butylperoxy)- hexane, 1 - menthone peroxide or methyl ethyl ketone peroxide and is preferably used in an amount of 6 - 12 parts per 100 parts of polyester. Preferably each curing step is effected at 200 DEG - 450 DEG F. for 1 - 120 minutes. The polyester may be derived by reacting (a) a glycol, e.g. ethylene - propylene-, trimethylene-, 1:3- or 1;4- butylene - neapentylene - or p-xylylene - glycol; or 1:4 - dimethylolcyclohexane or 2:2:4:4 - tetramethylcyclobutane - 1:3 - diol, with (b) a dicarboxylic acid e.g. succinic glutaric, adipic, pimelic, suberic, azelaic sebacic undecanedioic or dodecanedioic acid and possibly (c) 0.05-8 mol per cent of a polyhydroxy compound e.g. glycerine, 1:1:1-trimethyllolethane, 1:1:1 - trimethylolpropane or pentaerythritol. Fillers, pigments, reinforcing agents, tack reducing agents and plasticizers may be added at some stage in the process. Specified fillers are calcium carbonate (e.g. of particle size 0.033-0.040 microns), carbon black, iron oxide, clay, talc and silica. |
