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近年来,聚乙二醇(PEG)在照相工业中获得广泛应用。PEG是氧化乙烯的聚合物,通式为 HO(CH_2CH_2O)_nH,n<20时是液体,n≥20时是腊状固体,其熔点随n数的增大而升高。 1941年PEG曾被用作涂布润湿剂,后来发现它不仅有表面活性作用,而且还有照相作用。不过,对于照相作用的性质长时间内说法不一,有的资料介绍PEG能提高乳剂的感光度,而有的资料却认为PEG只能加快乳剂的化学成熟或显影速度,但不影响最大光密度。产生这种分歧的原因在于试验条件
In recent years, polyethylene glycol (PEG) has been widely used in the photographic industry. PEG is ethylene oxide polymer, the general formula HO (CH 2 CH 2 O) _nH, n <20 when the liquid, n ≥ 20 is a waxy solid, the melting point increases with increasing n number. PEG was used as a coating wetting agent in 1941 and was later found to have both surface-active and photographic properties. However, the nature of the camera for a long time to say different, and some information on the introduction of PEG can increase the sensitivity of the emulsion, while some data that PEG can only accelerate the chemical maturation of the emulsion or the development speed, but does not affect the maximum optical density . The reason for this disagreement lies in the experimental conditions