Reusable elastic adhesive sheet redetachable without residue or damage
First Claim
1. Single-sidedly or double-sidedly pressure-sensitively adhesive, elastic adhesive sheet comprising at least one layer of a pressure-sensitive adhesive, and having a maximum stretchability of more than 200% and a recovery of more than 60% after stretching to ⅔
- of its maximum elongation, said pressure-sensitive adhesive (PSA) being based on a chemically crosslinked polyurethane, wherein the starting materials for the chemically crosslinked polyurethane include at least one isocyanate-reactive substance having a functionality of more than 2.0, in an amount of at least 5% by weight, based on the weight of the polyurethane composition, the molecular weight of at least one of the starting materials used to form the polyurethane being greater than or equal to 1000, at least difunctional polyisocyanates being used to form the polyurethane, and the ratio of maximum tensile stress to stripping stress of said elastic adhesive sheet being more than 1.2, and the tensile stress at an elongation of 200% is being not more than 2.0 N/mm2.
2 Assignments
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Accused Products
Abstract
Single-sidedly or double-sidedly pressure-sensitively adhesive, elastic adhesive sheet which can be reused more than once and is preferably in the form of diecuts or cut shapes, intended for the redetachment of adhesive bonds without residue or damage, particularly on low-strength substrates such as paper, for example, by peeling and/or extensive stretching of the adhesive sheet,
characterized in that
the adhesive sheet is composed of at least one layer of a pressure-sensitive adhesive, the adhesive sheet further has a maximum stretchability of more than 200% and a recovery of more than 60% after stretching to ⅔ of its maximum elongation, and the pressure-sensitive adhesive (PSA) of the adhesive sheet is based on a chemically crosslinked polyurethane, the starting materials for the chemically crosslinked polyurethane including at least one isocyanate-reactive substance having a functionality of more than 2.0, in a fraction of at least 5% by weight, based on the polyurethane composition, where
the molecular weight of at least one of the starting materials used to form the polyurethane is greater than or equal to 1000,
at least difunctional polyisocyanates are used to form the polyurethane, and the ratio of maximum tensile stress to stripping stress is more than 1.2, preferably more than 1.5, more preferably more than 2.0, and
the tensile stress at an elongation of 200% is not more than 2.0 N/mm2, preferably not more than 1.0 N/mm2, more preferably not more than 0.5 N/mm2.
38 Citations
17 Claims
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1. Single-sidedly or double-sidedly pressure-sensitively adhesive, elastic adhesive sheet comprising at least one layer of a pressure-sensitive adhesive, and having
a maximum stretchability of more than 200% and a recovery of more than 60% after stretching to ⅔ - of its maximum elongation, said pressure-sensitive adhesive (PSA) being based on a chemically crosslinked polyurethane, wherein the starting materials for the chemically crosslinked polyurethane include at least one isocyanate-reactive substance having a functionality of more than 2.0, in an amount of at least 5% by weight, based on the weight of the polyurethane composition, the molecular weight of at least one of the starting materials used to form the polyurethane being greater than or equal to 1000,
at least difunctional polyisocyanates being used to form the polyurethane, and the ratio of maximum tensile stress to stripping stress of said elastic adhesive sheet being more than 1.2, and the tensile stress at an elongation of 200% is being not more than 2.0 N/mm2. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
- of its maximum elongation, said pressure-sensitive adhesive (PSA) being based on a chemically crosslinked polyurethane, wherein the starting materials for the chemically crosslinked polyurethane include at least one isocyanate-reactive substance having a functionality of more than 2.0, in an amount of at least 5% by weight, based on the weight of the polyurethane composition, the molecular weight of at least one of the starting materials used to form the polyurethane being greater than or equal to 1000,
Specification