| 摘要 |
Water-swellable sealing materials with rubber-like properties (I) contain knwon substances (II) which become very swollen in water, incorporated into a matrix which is obtd. by reaction of known hydrophilic isocyanate prepolymers (III) with chain extenders such as water, alcohols or amines (IV) in the ratio (III):(IV) of(1:9)-(9:1). Pref. (I) can be produced with a homogeneous solid, microporous or cellular foam structure. The following can also be added to modify the properties of (I) or to reduce shrinkage on drying: (a) known aq. dispersions or solns. of high polymers, (b) aq. emulsions of bitumen, asphalt, or tar, or combinations thereof with (a), with ratio (III): (a or b) = (1:9)-(9:1) or ()c) solid (in)organic fillers with definite particle size, or fibres and colour pigments, in amts. of 1-150% w.r.t. binder. The properties can also be modified by combining (I) with a carrier material consisting of (non)woven (in)organic fabric, rubber or rubber elastomers or other known solid of foamed prods. USE/ADVANTAGE - Used e.g. for the prodn. of highly elastic joint sealing tapes, etc. which undergo reversible swelling on contact with water. (I) provide a better permanent seal under wet conditions than prior-art systems (e.g. elastomer sections, metal plates embedded in concrete) and are suitable for use in constructional joints, sewage pipes, etc. esp. where elasticity is also required
|
