| 摘要 |
Unsatd. polyester resins (I) contg. maleic acid (II), phthalic acid (III), propylene glycol (IV) and dipropylene glycol (V) units, with mol. ratio (II):(III) from 1:0.05 to 1:0.45 and mol. ratio (II):(V) from 1:0.05 to 1:0.6, are mfd. by (a) reaction of (III) with excess glycols, followed by (b) addn. of (II) or its anhydride or fumaric acid and any remaining glycol, and esterification. Pref. mol. ratio glycol:(III) in first stage is from 2:1 to 22:1; acid no. at end of (a) is pref. below 10; at end of (b) prod. pref. has acid no. 10-40, OH-no. 10-60, and melt viscosity 300-1500 mPa.s at 150 deg.C.
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