摘要:
Cement dispersants made of graft copolymers of a specified type and/or their salts are produced by using as an intermediate product allyletherester monomers prepared by an esterification reaction of α-allyl-ω-hydroxy-polyoxyalkylene refined so as to have peroxide value less than 5.0 meq/kg and aliphatic monocaboxylic acid under a specified condition in the absence of solvent and in the presence of an antioxidant.
摘要:
A multi-functional admixture for simultaneously providing specified characteristics to hydraulic cement compositions such as concrete contains one or more of specified reaction mixtures obtained by specified two processes as well as partially or completely neutralized substances obtained from such a reaction mixture through a specified third process. The specified two processes include initiating a radical copolymerization process of a radical polymerizable monomer mixture containing maleic anhydride and a monomer of a specified kind in a non-aqueous system in the presence of a non-aqueous radical initiator and stopping the radical copolymerization reaction in its midst while the inversion rate of polymerization is at a specified level by adding water to the reaction system to thereby obtain a reaction mixture. The specified third process is for partially or completely neutralizing the reaction mixture.
摘要:
A gypsum slurry composition contains gypsum, a dispersant and water. A graft copolymer substance of a specified kind, which is one or more of graft copolymers and their salts obtained by specified processes, is contained as the dispersant in an amount of 0.01-1.0 weight %.
摘要:
A multi-functional cement dispersant contains a graft copolymer obtained by a graft reaction of one or more selected from polyoxyalkylene monoalkylester, polyoxyalkylene monoalkylether and polypropyleneglycol of specified kinds to a copolymer obtained by radical polymerization of a mixture of radical polymerizable monomers containing maleic anhydride and monomers of a specified kind at a specified ratio. Hydraulic cement compositions produced with such a multi-functional cement dispersant have a superior fluidity with reduced loss over time and hardened objects produced from such a composition exhibit a superior early strength and have a low dry shrinkage and a high resistance against freezing and thawing.
摘要:
An image forming apparatus including a plurality of filters for obtaining reusable toner from used toner scraped off of an image carrier. Also included is a reusable toner container for storing the reusable toner, and a toner transfer device for transferring the reusable toner stored in the reusable toner container to a developing device so that the reusable toner is reused by the developing device. The plurality of filters have a different mesh-size and are positioned in a used toner stream in an order based on the different mesh-size.