| 摘要 |
Dispersant compsn. comprises: (a) a first succinic deriv. dispersant obtd. by reacting (i) a substd. succinic acylating agent substd. by aliphatic gp. derived from polyalkene with GPC (gel permeation chromatography) number average mol. wt. 700-2500 with (ii) alkylene polyamine contg. 3-6 N per mol., the mole ratio of (i):(ii) in first dispersant being less than 1.85 and (b) a second succinic deriv. dispersant obtd. by reacting (iii) substd. succinic acylating agent substd. by aliphatic gp. derived from polyalkene with GPC number average mol. wt. 1100-2800 with (iv) hydroxypropylated alkylene diamine contg. 2-12C per mol. and an average 2.5-3.5 hydroxypropyl gps. per mol., the mole ratio of (iii):(iv) in the second dispersant is 1-1.5. The pts. wt. ratio of (a):(b) on active basis is 0.25-10:1. A lubricant compsn. comprises a major amt. of an oil of lubricating viscosity and at least one of (a) and (b) as above, the wt. ratio of (a):(b) being 0.25-10:1 and: (c) at least one Ca phenate or Ca sulphurised phenate compsn. of TBN 160-260 and (d) at least one Ca sulphonate with TBN up to 420; the amts. of (c) and (d) being such that if (d) has TBN up to 50 mg KOH/g, the total sulphated ash content of the compsn. is 1.8 wt.% max., whereas (d) has TBN more than 50 mg KOH/g, the total sulphated ash content is up to 2.5 wt.%. An additive concentrate comprises a minor amt. of inert diluent oil and major amt. of additive components (a), (b), (c) and (d) as above. |
