Process for Recycling Polythiourethanes, Thio Compounds, and Use Thereof
AssigneesBruno Bock GmbH, Friedrich-Schiller-Universität Jena
InventorsCatherine Mineur, Frank Ebmeyer, Matthias Rehfeld, Thomas Bätz, Stefan Zechel, Martin Hager
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Abstract
The invention relates to a process for recycling polythiourethanes. Disclosed herein is a process wherein polythiourethanes are depolymerized in the presence of di- or higher-functional thiols. Di- and/or higher-functional isocyanates, epoxides or ethylenically unsaturated compounds and optionally di- and/or higher functionalized thiols are subsequently added to the obtained monomer and oligomer mixture. The reaction mixture is then repolymerized. The process allows polythiourethanes to be recycled.
Claims24
A process for recycling polythiourethane comprising the following steps:
- a) providing a mixture of polythiourethane and di- or higher-functional thiol and a di- or higher-functional polar protic reactive solvent, wherein at least one mole of di- or higher-functional thiol is used per mole of thiourethane bond of the polythiourethane,
- b) depolymerizing the polythiourethane by treating the mixture from step a) at a first reaction temperature, thereby forming di- or higher-functional thiols from the polythiourethane and monomeric and oligomeric thiourethanes terminated with di- or higher-functional thiol,
- c) separating impurities from the mixture obtained in step b),
- d) adding di- or higher-functional isocyanate or epoxide or ethylenically unsaturated compound and di- or higher-functional thiol to the mixture from step b) or c),
- e) treating the mixture from step d) at a second reaction temperature which is lower than, equal to or higher than the first reaction temperature, whereby the temperature is sufficient to enable polymerization of the monomeric and oligomeric thiourethanes from step b), the compounds added in step d) and the reactive solvent present takes place, with the proviso that the depolymerization in step b) and the polymerization in step e) occur in substance or in the presence of a di- or higher-functional polar protic reactive solvent.
Compositions containing monomers of the formula (XIX) and oligomers of the formula (XXI) or containing monomers of the formula (XX) and oligomers containing structural units of the formula (XXII)
- wherein R1 and R2 independently of one another are divalent organic radicals,
- R5 is an (x+z2+1)-valent organic radical,
- R6 is a (z1+1)-valent or a (z2+1)-valent organic radical,
- R14 is a (t+1)-valued organic radical,
- t is an integer greater than or equal to 1,
- p is 2 to 10, preferably 2 or 3,
- s is an integer from 1 to 15,
- x is an integer from 0 to 9,
- z1 and z2 independently of one another are integers from 1 to 10,
- the sum x+z2 is an integer from 1 to 10
- that
- the oligomer of the formula (XXII) has further radicals of the formula (XVIII) which are linked to the oligomer via thioisocyanate groups
- wherein w is an integer greater than or equal to 1,
- R14 and t have the meanings defined above,
- w is less than t, and
- y is an integer with the value t+1−w, that
- the proportion of monomers of the formula (XIX) and of oligomers of the formula (XXI) in the composition may be from 0 to 100 mol %, based on the total amount of these compounds, the sum of these compounds always being 100 mol %, and that
- the proportion of the monomers of the formula (XX) and of the oligomers containing the structural units of the formula (XXII) in the composition may be from 0 to 100 mol %, based on the total amount of these compounds, the sum of these compounds always being 100 mol %.
The process of step 1 in the absence of step c).
Dependencies are inferred from the claim text.