摘要:
This invention relates to a process for increasing the molecular weight of polyesters, copolyesters or polyester blends by adding an organic phosphate to the processing apparatus and fusing the mixture to above the melting point, in which process the processing apparatus is a single-screw extruder, twin-screw extruder, planetary-gear extruder, ring extruder or co-kneader having at least one vent zone to which underpressure is applied.
摘要:
This invention relates to a process for stabilising and at the same time phase compatibilising plastics or plastic compositions by incorporating polymeric compounds obtainable by reacting a compound selected from the group consisting of the sterically hindered phenols, sterically hindered amines, lactones, sulfides, phosphites, benzotriazoles, benzophenones and 2-(2-hydroxyphenyl)-1,3,5-triazines, which compounds contain at least one reactive group, with a compatibilisator.
摘要:
By heating at above the melting point and/or glass transition point of the polycondensate and adding an aromatic dicyanate; or adding a mixture comprising an aromatic dicyanate and a polyfunctional compound selected from the class of sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites and secondary aromatic amines; or adding a mixture comprising (i) an aromatic dicyanate, (ii) at least one polyfunctional compound selected from the class of sterically hindered hydroxyphenyl-alkyl-phosphonic esters and monoesters, diphosphonites and secondary amines, and (iii) a difunctional epoxide, it is possible to bring about an increase in the molecular weight and/or viscosity of virgin polycondensate and polycondensate recyclates.
摘要:
Recycled mixtures of plastics, predominantly thermoplastics, as predominantly produced in the household, in commerce and also in industry and useful material collections, can be stabilized against thermooxidative degradation by adding a combination of a sterically hindered phenol with an organic phosphite or phosphonite and an inorganic compound from the series consisting of metal oxides, hydroxides and carbonates.
摘要:
Recycled plastics, predominanty thermoplastics, from domestic, commercial and industrial waste can be stabilized against thermooxidative degradation by adding a combination of a sterically hindered phenol with an organic phosphite or phosphonite and a metal salt of a fatty acid.
摘要:
An increase in the molecular weight of newly produced polyamides and recycled polyamide materials can be achieved by heating to above the melting point or glass transition point and adding of a bismaleimide and a sterically hindered hydroxyphenyl-alkyl-phosphonic acid ester or half-ester.
摘要:
A method is described for the decomposition of polymers, especially waste plastics and used plastics, in which so-called NOR--HALS compounds--that is, for example, compounds comprising the group ##STR1## in which R* is C.sub.1 -C.sub.20 alkyl, OH-substituted C.sub.1 -C.sub.20 alkyl, optionally C.sub.1 -C.sub.4 alkyl-substituted C.sub.5 -C.sub.12 cycloalkyl or O- or S-interrupted C.sub.2 -C.sub.20 alkyl--are added and heating is carried out at temperatures which lie above the customary processing temperatures for polymers (280.degree. C. or more).
摘要:
The invention relates to a process for increasing the molecular weight of polycondensates and at the same time stabilizing them, essentially without crosslinking, which comprises heating a polyamide, a polyester, a polycarbonate or a copolymer or blend of these polymers with addition of at least one diepoxide comprising terminal epoxide groups and as a further structural element a tetramethylpiperidine radical located centrally between the epoxide groups to a temperature which is above the melting point of the polymer in the case of crystalline polycondensates or above the glass point in the case of amorphous polycondensates. The invention additionally relates to mixtures comprising the corresponding diepoxides, to their use, and to polycondensates prepared from them.
摘要:
Plastic mixtures, in particular recycled plastic mixtures, comprising predominantly polyolefins and 0.05-20% by weight of PVDC can be stabilized against thermo-oxidative degradation by addition of a combination of an organic phosphite or phosphonite and a metal salt of a fatty acid.
摘要:
A process is disclosed for increasing the molecular weight of polyesters, polyester copolymers or polyester blends, which comprises heating a polyester blended with a tetracarboxylic acid dianhydride and a sterically hindered hydroxyphenylalkylphosphonic acid ester or half-ester to above the melting point (glass transition temperature) of the polyester.