摘要:
A method for the reversible crosslinking of, for example, adhesives or coating materials, and a composition stable on storage at room temperature for implementing the crosslinking reaction. The reversible crosslinking method allows very rapid crosslinking even at a low first temperature, and undoing of the crosslinks at higher temperatures, thereby recovering thermoplastic processability and, for example, allowing the originally bonded substrates to be parted from one another again easily. A particular aspect is that a plurality of cycles of crosslinking and undoing of the crosslinks are possible with the present system. A feature of the system used for the reversible crosslinking is that it contains two components, A and B, where component A is a compound having at least two protected dithioester functionalities, preferably cyanodithioester functionalities, and component B is a compound having at least two diene functionalities.
摘要:
The present invention relates to an innovative method for the reversible crosslinking of, for example, adhesives or coating materials. The reversible crosslinking method allows very rapid crosslinking even at room temperature and undoing of the crosslinks at higher temperatures, thereby regaining the capacity for thermoplastic processing and allowing the originally bonded substrates to be separated from one another again with ease. A particular aspect in this context is that a plurality of cycles of crosslinking and undoing of the crosslinks are possible with the present system.
摘要:
The present invention relates to a novel method for photoinduced crosslinking of, for example, adhesives or coating compositions.More particularly, the present invention relates to a novel, irreversible crosslinking mechanism in which it is possible to obtain, through irradiation with visible light, specific photoactive systems via photoenol reactions controlled high-reactivity diene intermediates which crosslink polymers containing double bonds by means of a Diels-Alder reaction.
摘要:
The present invention relates to an innovative method for the reversible crosslinking of, for example, adhesives or coating materials. The reversible crosslinking method allows very rapid crosslinking even at room temperature and undoing of the crosslinks at higher temperatures, thereby regaining the capacity for thermoplastic processing and allowing the originally bonded substrates to be separated from one another again with ease. A particular aspect in this context is that a plurality of cycles of crosslinking and undoing of the crosslinks are possible with the present system.
摘要:
In the present process, reversibly crosslinking composites or storage-stable prepregs are produced by means of a hetero Diels-Alder reactions (HDA,) for example of PMMA polymers. At slightly elevated temperature, these prepregs can be reversibly decrosslinked again by a retro hetero Diels-Alder reaction so that they become moldable. The back-reaction to products which are again crosslinked or high molecular weight then takes place at room temperature.
摘要:
In the present process, reversibly crosslinking composites or storage-stable prepregs are produced by means of a hetero Diels-Alder reactions (HDA,) for example of PMMA polymers. At slightly elevated temperature, these prepregs can be reversibly decrosslinked again by a retro hetero Diels-Alder reaction so that they become moldable. The back-reaction to products which are again crosslinked or high molecular weight then takes place at room temperature.
摘要:
The present invention relates to an innovative polymerization technique for (meth)acrylates and styrenes, in which the polymerization is initiated by isocyanates and special bases with imine structure and is activated/accelerated by addition of ionic liquids. With this new technique, which can be employed selectively, it is also possible to produce high molecular weight poly(meth)acrylates with in some cases narrow molecular weight distribution.The (meth)acrylate notation here denotes not only methacrylate, such as methyl methacrylate, ethyl methacrylate, etc., but also acrylate, such as methyl acrylate, ethyl acrylate, etc., for example, and also mixtures of both.
摘要:
A hyperbranched polyurethane which is obtainable by reacting a diisocyante or polyisocyanate with a triol of the formula (1) where R and R″ each independently of one another are hydrogen or an alkyl group having 1 to 4 carbon atoms and where n is an integer greater than 2 and which has a numerical average of at least 4 repeating units of the formula (2) per molecule.
摘要:
A claim is laid to a permeable composite, a process of production of the composite as well as the use of this composite. The composite essentially contains a perforated and permeable carrier, on and in or on or in which another component that essentially contains metallic compounds with elements from group III to VI of the periodic system is stabilized. Stabilization of the component on or in the carrier is carried out by heating a suspension consisting of the component suspended in a metallic oxide sol that has been applied onto or into or onto and into the carrier.In this way, it is possible to produce a permeable composite that is ideally suited for use in filtration and membrane technologies under very mild conditions either by heating for a short time or warming for a longer time.