| 摘要 |
1,245,928. Dental cements. AMALGAMATED DENTAL CO. Ltd. 27 Sept., 1968 [10 Oct., 1967], No. 46301/67. Heading C3N. A dental silicate cement of the kind comprising a powder component part comprising a metal silicate and a liquid component part incorporating an acid reactive with the powder component part to cause liberation of silicic acid is characterized by containing as an alcoholic compound an organic mono- or polyhydric alcohol, a mono-ether of a polyhydric alcohol, or a mono-phosphoric ester of a polyhydric alcohol, said mono- or poly-hydric alcohol being derived from aliphatic, aromatic or cyclic hydrocarbons or heterocyclic compounds, which alcoholic compound imparts improved resistance to crazing without the use of water-repellent substances. The maximum amount of alcoholic compound in either one of the component parts of the cement will be generally 20% by weight. Preferably the alcoholic compound is incorporated in said powder component part to a concentration of from 0À07-7À0% by weight of said component part, and in said liquid component part to a concentration of from 0À14-14À0% by weight of said liquid component part. Specified alcoholic compounds are methyl alcohol, ethyl alcohol, propyl alcohol, iso-octyl alcohol; ethylene glycol, propane 1,2-diol, butane 1,3-diol, butane 1,4-diol, 1,4-dihydroxy but-2-ene, 1-4- dihydroxy but-2-yne, pentane 1,5-diol, hexane 1,6-diol; triethylene glycol, dipropylene glycol, "polyethylene glycol 200", "polyethylene glycol 600"; ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, 1,2-propylene glycol-monobutyl ether, triethylene glycol monoethyl ether; diglycerol, glycerol, pentaerythritol, sorbitol, 1,2,4-butanetriol, 1,2,6-hexanetriol; benzyl alcohol, cinnamyl alcohol, 2- phenyl ethanol, 3-phenyl propanol, cyclohexane-1,4 diol, 2,2,4,4-tetramethyl 1,3-cyclobutanediol; and furfuryl alcohol, tetrahydro furfuryl alcohol. In one embodiment the liquid component part comprises a preformed reaction product of phosphoric acid and as alcoholic compound a polyhydric alcohol. Preferably the concentration of the alcoholic compound is from 0À05-5À0% by weight of said dental silicate cement. |
