| 摘要 |
A paste composition which is used in the preparation of dental impression compositions containing: (a) at least 100 ppm by weight, based on the weight of the paste composition of platinum calculated as the element; (b) 35 to 75 percent by weight, based on the weight of the paste composition, of a diorganopolysiloxane which contains at least 2 SiC-bonded vinyl groups per molecule and has a viscosity of at least 100 mPa.s at 25 DEG C.; (c) 10 to 25 percent by weight, based on the weight of the paste composition, of a hydrocarbon which is liquid or spreadable at room temperature and is free of aliphatic carbon-carbon multiple bonds; and (d) 3 to 15 percent by weight, based on the weight of the paste composition, of hydrophobic silicon dioxide having a surface area of at least 50 m2/g; in which the sum of the percentages of (a) to (d) including other additives which may be present in the paste composition is equal to 100 percent. The paste composition is mixed with the other ingredients of the dental impression compositions such as diorganopolysiloxanes having SiC-bonded vinyl groups, organopolysiloxanes having at least 3 Si-bond hydrogen atoms per molecule and filler to form dental impression compositions.
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