UV polymerisation appts. having light guide arrangement - has tube of plastics material contg. aq. soln. of di:potassium hydrogen phosphate, sodium di:hydrogen phosphate, or tri:potassium phosphate

摘要

In such appts for industrial purposes, comprising (A) radiation source (1) emitting short wave optical radiation (B) light guide arrangement contg tube (4) of plastics material (I) closed at its ends by transparent windows (3,3'), the tube is filled with transparent liq (5) whose refractive index is higher than that of (I) and contains aq soln contg K2HP04 and/or NaH2P04 and/or K3P04. Tube (4) is of FEP (copolymer of tetrafluoroethylene and hexafluoro-propylene ). Liq (5) contains K2HP04 in concn such that refractive index nD is at least 1.42. Liq is aq soln of K2HP04 with concn at least 8 mol/1, or of NaH2P04 with concn at least 7 mol/l, or of K3P04 with concn at least 2.5 mol/l. Liq contains fungicide and/or is sterilised by radiation. ADVANTAGE - The aq solns have excellent transmission for wavelengths down into UV B range and good long term stability under intensive UV B radiation.