Reference

Stabilized photochromic materials

Stabilized photochromic materials. Uhlmann, Donald R.; Snitzer, Elias; Hovey, Richard J.; Chu, Nori Y. C.; Fournier, Joseph T., Jr. (American Optical Corp., USA). U.S. US 4046586 6 Sep 1977, 7 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C08L001-10. NCL: 106194000. APPLICATION: US 74-498506 19 Aug 1974. DOCUMENT TYPE: Patent CA Section: 37 (Plastics Fabrication and Uses) Ag halide photochromic crystals (30-10,000 .ANG.) are sealed with an inorg. coating material and incorporated into plastic eyeglass lenses esp. useful as sunglasses. Thus, a AgBr [7785-23-1] sol was stabilized by treating with poly(vinylpyrrolidinone) [9003-39-8] in EtOH and the particles were treated with titanyl sulfate [13825-74-6], dried, and incorporated (0.7 g) into allyl diglycol carbonate prepolymer [25656-90-0] contg. 5 g iso-Pr2O2. The mixt. was formed into plastic lenses in the usual way. The lenses were colorless and turned a gray shade in bright sunlight; they returned to their normal colorless condition in 20-30 min when brought indoors.

Titanium dioxide pigment

Titanium dioxide pigment. Sheinkman, A. I.; Sheinkman, F. P.; Dobrovol'skii, I. P.; Gruzdev, Yu. A.; Krakhaleva, L. N. (USSR ). U.S.S.R. SU 598918 25 Mar 1978 From: Otkrytiya, Izobret., Prom. Obraztsy, Tovarnye Znaki 1978, 55(11), 81. (Russian). (Union of Soviet Socialist Republics). CODEN: URXXAF. CLASS: IC: C09C001-36. APPLICATION: SU 76-2378939 5 Jul 1976. DOCUMENT TYPE: Patent CA Section: 42 (Coatings, Inks, and Related Products) Section cross-reference(s): 49 In the prepn. of TiO2 pigment by thermal hydrolysis nucleation of a mixt. of titanyl sulfate (I) [13825-74-6] and inorg. surfactant at the b.p., followed by washing and calcining of the ppt., the whitening ability of the product is improved when 0.05-2 g org. surfactant/L I soln. is preaged for 0.5-5 h with 1-10% I soln.