| 摘要 |
The invention provides multi-layer transparent units (such as double-glazing units) of single-layer seal type which are excellent in shape retention and the resistance to moisture transmission. A multi-layer transparent unit (suc h as a double-glazing unit) of single-layer type, set by the use of an elastom er spacer alone, wherein the elastomer spacer contains as the matrix component at least one butyl elastomer selected from the group consisting of polyisobutylene, butyl rubbers, and modified butyl rubbers and the molecular weight index (MWI) as defined by the formula (1) is 400000 or above: [wherei n i is an integer of 1 or above which represents the number of kinds of butyl elastomers contained in the spacer as the matrix component; and Mw(i) is a viscosity-average molecular weight of the ith butyl elastomer], and wherein the elastomer spacer is free from crystalline polyolefins or if it contains crystalline polyolefins, the content thereof is as low as less than 2% by ma ss.
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