Reference

Friedel-Crafts polymerizations with

Friedel-Crafts polymerizations with .alpha.,.alpha.'-dimethoxy-p-xylene. II. Self-polymerization of .alpha.,.alpha.'-dimethoxy-p-xylene. 61537-67-5 and 7646-78-8 are cas registry numbers. These chemicals are also mentioned in this article. Grassie, N.; Schoff, C.; Cunningham, J. G. (Dep. Chem., Univ. Glasgow, Glasgow, Scot.). Eur. Polym. J., 12(9), 647-50 (English) 1976. CODEN: EUPJAG. DOCUMENT TYPE: Journal CA Section: 35 (Synthetic High Polymers) Section cross-reference(s): 25 SnCl4 [7646-78-8] catalyzed the homopolymn. of .alpha.,.alpha.1-dimethoxy-p-xylene [6770-38-3] giving a mixt. of products, 6 of which were sepd. by gel permeation chromatog. and identified by ir and mass spectroscopy. A mechanism was given involving formation of 2 complexes between SnCl4 and dimethoxyxylene, one through the ether O and the other through the arom. ring. .

Hardenable resin compositions

Hardenable resin compositions. (Hitachi, Ltd.; Hitachi Chemical Co., Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 58149917 A2 6 Sep 1983 Showa, 6 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: C08G073-10; C08L079-08; C09D005-25. APPLICATION: JP 82-30613 1 Mar 1982. DOCUMENT TYPE: Patent CA Section: 37 (Plastics Manufacture and Processing) Section cross-reference(s): 42 Thermosetting resin compns., useful for coating or potting semiconductors, contain polyimides (or their precursors) having 32 phenol groups and 31 active H ortho or para to the OH group and crosslinking agents which react with the active H, i.e., compds. with the structure Z(CH2R)n (Z = an arom. residue; R = halogen, OH, OAc, or alkoxy; n 32) or conventional crosslinking agents for novolak resins. Thus, a polyimide [88209-84-1] from (4-H2NC6H4)2O 13.16, 3,5-diaminophenol 0.62, [H2N(CH2)3SiMe2]2O 7.46, and pyromellitic anhydride 21.81 g in 243.9 g N-methylpyrrolidinone was crosslinked with (MeOCH2)2C6H4-p [6770-38-3] to give a cured coating with good solvent and moisture resistance.