Fluxes and remelting fluids for circuit board mfr. - comprising alkane phosphonic acids and/or their salts, half ester(s) di:ester(s) and half ester salts

摘要

Use of alkanephosphonic acids (I) and/or alkanephosphonic acid half esters (II) and/or alkanephosphonic acid salts (III) and/or alkanephosphonic acid half ester salts (IV) and/or alkanephosphonic acid diesters (V) as fluxes and remelting fluids in the prodn. of circuit boards: in which Mr+ = Li+, Na+, K+, NH4+, Mg2+, Ca2+, Al3+, Ti4+, Zr4+, H3N-C2H4OH+, H2N(C2H4OH)2+, HN(C2H4OH)3+, H3N-CH2-CH(OH)CH3+, H2N(CH2-CH)(OH)CH3)2+, HN(CH2-CH(OH)CH3)3+, morpholinium cation or piperidinium cation; R1 = 1-24C satd. alkyl gp., 3-6C unsatd. alkyl, 5-12C cycloalkyl, opt. substd. phenyl, opt. substd. naphthyl, or opt. substd. benzyl, R2 = (CH-CH2-O-)m-R6 in which R5 = H or Me or Et with m = 0 (in the case where R6 = 1-24C straight or branched, satd. or unsaturated alkyl or opt. substd. 5-12C cycloalkyl) or m = 1-25 in the case where R6 = H, phenyl or substd. phenyl; 1-24C straight or branched, satd. or unsaturated alkyl or 1-24C satd. or unsaturated acyl; or R2 may also be an amino oxalkylate of formula -(CHR5-CH2-O-)m-1-CHR5-CH2N-(R7)2 in which R7 = 1-22C alkyl or -(CHR5-CH2-O-)m-H in which m = 1-25 or the residue of a polyhydric alcohol such an penta erythritol, hexitol or glycerine; R3 = -(CHR5-CH2-O-)m-H with m = 1-25 and R4 = -(CHR5-CH2-O-)m-H with m = 1-25 and R3 and R4 may be the same or different. USE/ADVANTAGE - The cpds. (I)-(V) are useful as fluxes applied to circuit boards prior to hot tinning or as remelting fluids for remelting Sn-Pb alloys in the prodn. of circuit boards. The cpds. (I)-(V) have high thermal stability at temps. up to 200 deg.C, are water soluble or dispersible in water, have a pronounced wetting effect (surfactant character), do not form gels with water, do not evolve any toxic materials and have good biodegradability (can be eliminated biologically in clarifier units).