Abstract:
A method for producing a foamed thermally crosslinked mass system, wherein the mass system is foamed at a first temperature in a first step, and crosslinker substances are added to the mass system in a subsequent step at a second temperature lower than the first temperature, wherein the crosslinker substances are crosslinker substances for thermal crosslinking of the mass system.
Abstract:
Methods provide a polymer foam having high bonding strength and improved compressive hardness characteristics wherein the polymer foam comprising cavities formed by microballoons, and also 2 to 20 vol. %, based on the total volume of the polymer foam, of cavities surrounded by the polymer foam matrix.
Abstract:
The present invention relates to an adhesive tape comprising at least one carrier that has a thickness of 20 to 250 μm, preferably 50 to 150 μm, and has at least one layer (i) based on preferably uncrosslinked thermoplastic polyurethane that has been produced by means of extrusion, wherein the polyurethane is based on aromatic polyisocyanate, such as aromatic diisocyanate in particular, or (ii) based on preferably uncrosslinked polyurethane that has been produced from a dispersion, wherein a pressure-sensitive adhesive layer is disposed on at least one side, preferably both sides, of the carrier. The invention also relates to processes for producing the adhesive tape and to the use thereof for bonding of components in electrical, electronic, optical or precision mechanical devices, such as, in particular, of windows or lenses in housings of precision mechanical, optical and/or electronic devices.
Abstract:
The present invention relates to an adhesive tape of thickness 40 to 300 μm that can be redetached without residue or destruction by stretching essentially in the plane of the bond, comprising at least one carrier of thickness 10 to 150 μm comprising at least one layer based on preferably uncrosslinked thermoplastic polyurethane that has typically been produced by means of extrusion and has a Shore A hardness of not more than 87, where the carrier has a ratio of force at 400% elongation F400% to breaking force Fbreak of not more than 45%, and on which a pressure-sensitive adhesive layer is disposed on at least one side, and wherein the adhesive tape has a ratio of stripping force Fstrip to breaking force Fbreak of less than 60%. The invention also relates to an adhesive tape of thickness 40 to 300 μm that can be redetached without residue or destruction by stretching essentially in the plane of the bond, comprising at least one carrier of thickness 10 to 150 μm comprising at least one layer based on preferably uncrosslinked polyurethane that has been produced from a dispersion and has a modulus at 100% elongation of not more than 1.8 MPa, where the carrier has a ratio of force at 400% elongation F400% to breaking force Fbreak of not more than 30%, and on which a pressure-sensitive adhesive layer is disposed on at least one side, and wherein the adhesive tape has a ratio of stripping force Fstrip to breaking force Fbreak of less than 60%. The invention also relates to a process for producing the adhesive tapes and to the use thereof for bonding of components in electronic devices.
Abstract:
Process for producing a syntactically foamed polymer composition, comprising a) introducing expandable microspheres into a matrix material and mixing in a mixing machine, b) expanding the microspheres, c) the temperature distribution in the mixing machine being inhomogeneous in a plane perpendicular to the transport direction of the machine, d) maintaining the temperature of a first surface bounding the mixing space of the mixing machine, in a plane perpendicular to the transport direction of the mixing machine, at a temperature sufficient for the polymer composition containing the microspheres coming into contact with such first bounding surface to reach a temperature sufficient for commencement and continuation of expansion, e) maintaining a second surface bonding the mixing space in the same plane at a temperature sufficiently low for the polymer composition containing the microspheres coming into contact with it, not to reach a temperature sufficient for commencement and continuation of expansion.
Abstract:
A polymer foam having high bonding strength and improved compressive hardness characteristics is accomplished by the polymer foam comprising cavities formed by microballoons, and also 2 to 20 vol. %, based on the total volume of the polymer foam, of cavities surrounded by the polymer foam matrix.