Delayed agents

The difluoromethyl ether AZD-7009 is in Phase II clinical trials as an atrial repolarization-delaying agent. 

Slurried Blasting Explosives with Cross-Linking Delay Agent... 

The ignition and burning processes arc similar to those of the B.M. Mixture, i>ut the reaction is leas violent and no delaying agents are noceaaary. The mixture is also more stable and more efficient per unit weight than the B.M. Mixture. 

Magnesium carbonate MgCOa Glitter delay agent... 

Antimony sulfide + any other delay agent(s). Physical delays ... 

The special reducing agent (a solution containing cupro-ammonia ions) is first prepared. Dissolve 63 g. of crystallised copper sulphate in 250 ml. of water in a 1-Utre heaker, add 100 ml. of concentrated ammonium hydroxide solution (sp. gr. 0-88), and cool the solution to 10°. Dissolve 17 8 g. of hydroxylammonium chloride or 21 g. of hydroxylammonium sulphate in 60 ml. of water, cool to 10°, and add 42 -5 ml. of QN sodium hydroxide solution if the resulting solution of tydroxylamine is not clear, filter it at the pump. Without delay add the hydroxylamine solution, with stirring, to the ammoniacal cupric sulphate solution. Reduction occurs at once, a gas is evolved, and the solution assumes a pale blue colour. Protect the reducing agent from the air if it is not used immediately. 

Telomerization. Polymerization of DAP is accelerated by telogens such as CBr, which are more effective chain-transfer agents than the monomer itself (65) gelation is delayed. The telomers are more readily cured in uv than DAP prepolymers. In telomerizations with CCl with peroxide initiator, at a DAP/CCl ratio of 20, the polymer recovered at low conversion has a DP of 12 (66). 

Rubber Chemicals. Sodium nitrite is an important raw material in the manufacture of mbber processing chemicals. Accelerators, retarders, antioxidants (qv), and antiozonants (qv) are the types of compounds made using sodium nitrite. Accelerators, eg, thiuram [137-26-8J, greatly increase the rate of vulcaniza tion and lead to marked improvement in mbber quaUty. Retarders, on the other hand (eg, /V-nitrosodiphenylamine [156-10-5]) delay the onset of vulcanization but do not inhibit the subsequent process rate. Antioxidants and antiozonants, sometimes referred to as antidegradants, serve to slow the rate of oxidation by acting as chain stoppers, transfer agents, and peroxide decomposers. A commonly used antioxidant is A/,AT-disubstituted Nphenylenediamine which can employ sodium nitrite in its manufacture (see Rubber chemicals). 

Cover the control of substances classified as very toxic, toxic, harmful, coiTosive, sensitizing or imtant under the Chemicals (Hazard Information and Packaging for Supply) Regulations 1994 (as amended) and to substances which have MELs or OESs. Also other substances that have chronic or delayed effects and biological agents. Special provisions are included for carcinogens. 

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