D 1370 R RADIATION-CURABLE SECONDARY COATING FOR OPTICAL FIBRE Russian patent published in 2011 - IPC C09D175/04 C09D175/16 C03C25/10 C03C25/26 

FIELD: chemistry.

SUBSTANCE: radiation-curable secondary coating composition contains A) a mixture of secondary coating oligomers which is mixed with B) a first diluent; C) a second diluent; D) an antioxidant; E) a first photoinitiator; F) a second photoinitiator; G) an optional slide-enhancing additive or a mixture of slide-enhancing additives; where said mixture of secondary coating oligomers contains α) Alpha-oligomer; β) Beta-oligomer; γ) Gamma-oligomer; where said Alpha-oligomer is synthesised via reaction of αl) anhydride with α2) acrylate containing a hydroxyl group; and the reaction product of α1) and α2) then reacts with α3) epoxide; in the presence of α4) a first catalyst; α5) a second catalyst; and α6) a polymerisation inhibitor; to obtain an Alpha-oligomer; where said Beta-oligomer is synthesised via reaction of β1) acrylate containing a hydroxyl group; β2) diisocyanate; and β3) polyether polyol; in the presence of β4) a catalyst; where said catalyst is selected from a group containing copper naphthenate, cobalt naphthenate, zinc naphthenate, triethylamine, triethylene diamine, 2-methyltriethylene diamine, dibutyl tin dilaurate, metal carboxylates, sulphonic acids, catalysts based on amines or organic bases, zirconium and titanium alkoxides, and ionic liquid salts of phosphonium, imidazolium and pyridinium, and said Gamma-oligomer is epoxy diacrylate. The method of applying the coating onto an optical fibre involves a) using a glass drawing column to obtain optical glass fibre; and b) applying a radiation-curable primary coating composition onto said optical glass fibre; c) optional exposure of said radiation-curable primary coating composition to radiation in order to cure said coating; d) applying a radiation-curable secondary coating composition onto said optical glass fibre; e) and exposing said radiation-curable secondary coating composition to radiation in order to said coating.

EFFECT: improved technological or operational characteristics of secondary coating, particularly improved curing and high rate of curing.

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