Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Process of treating scrap or waste product containing solid...
Patent
1996-06-21
1997-11-25
Dean, Ralph H.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Process of treating scrap or waste product containing solid...
521 49, C08J 1114
Patent
active
056913885
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention concerns a process for decomposing materials containing polycyanurate, especially polycyanurates, polycyanurate prepolymers and plastics containing polycyanurate.
BACKGROUND OF THE INVENTION
Polycyanurates can be produced by polycyclotrimerization of di- or polyfunctional cyanates. Because of their good electrical properties, especially insulating properties, their resistance to chemicals and moisture and their heat stability, they are used, inter alia, as inclusion products for electronic components and in adhesive, casting and laminating technology. To modify their properties, the polycyanurates are mixed with various additives, for example, soot, silicates or aluminum oxide and/or combined with other polymer compounds.
Direct recycling of materials containing polycyanurates, from plastic waste or production residues, is not possible due to the duroplastic properties of the polycyanurates. It is possible to mix finely ground production wastes in quantities of 15% to 30% with new products as fill. The usual method of disposal therefore consists of dumping or burning materials containing polycyanurate.
Methods of purposeful recycling of plastic materials have not been researched very much to date. Thermolysis, pyrolysis and hydrating methods are known, in which, depending on the reaction conditions (and catalysts added), synthesis gases and petroleum-like products are obtained, but, for the most part, they have lost the chemical structure present in the primary material. These products can be reused as primary materials in the chemical industry, but only by losing a high proportion of energy and chemical specificity compared to the original monomer primary materials.
For polyesters and polyamides, alcoholysis methods have become known, in which they are decomposed into monomers or oligomers. This method cannot be used on materials containing polycyanurates. A similar process for polycyanurate has not been known.
U.S. Pat. No. 2,545,049 describes a method of aminolysis of dissolved or suspended cyanuric acid triaryl esters, in which, depending on the reaction conditions, one to all aryl oxy groups can be exchanged for amino groups; see also D. Martin et al., Journal fur praktische Chemie 723:694 (1981). Moreover, partial aminolysis of melted cyanuric acid triaryl esters is known from H. Ahne et al., Synthesis 182:184 (1975). But the primary products and reaction conditions of these known reactions are extremely special, so that these methods do not appear to be usable in general on plastics containing groups of polycyanurates with complete aminolysis of all units.
In general, it would be desirable to find a method with which materials containing polycyanurate, i.e., polycyanurates, polycyanurate prepolymers and plastics containing polycyanurates, could be decomposed so that mainly monomer products with a definite chemical composition are obtained. It would also be desirable if the products occurring in this decomposition could be used, at least partially, as primary products for new polycyanurates or other polymers, especially those with related structures.
The invention is therefore based on the task of providing a method with which materials containing polycyanurate can be decomposed so that definite recyclable products can be obtained while largely maintaining the structure of the components present in the material containing polycyanurates.
SUMMARY OF THE INVENTION
This task is solved with a method in which the material containing polycyanurate is dissolved in a solvent or finely ground in a first step and thereby put into a finely distributed form and, in the second step, is subjected to aminolysis with an agent containing at least one reactive NH.sub.2 group.
The reactive NH.sub.2 or amino group in the sense of the invention is understood to be any amino group that is capable of inducing an aminolysis reaction on polycyanurate. These are, specifically, ammonia, hydrazine, primary amines and primary hydrazines with aliphatic or aromatic radicals, which can in
REFERENCES:
patent: 2545049 (1951-03-01), Schaefer et al.
patent: 3404103 (1968-10-01), Matsudaira et al.
patent: 3983087 (1976-09-01), Tucker et al.
patent: 4039568 (1977-08-01), Sakai et al.
patent: 4110266 (1978-08-01), Sheratte
patent: 4162995 (1979-07-01), Sheratte
Synthesis, 1975, Stuttgart, DE, "Partielle Aminolyse von 2,4,6-triazin. T 1: Herstellung von 2-Alkyl(-en)amino-4,6-diallyl-oxy-s-triazinen", H. Anhe et al., pp. 182-186.
Journal f. prakt. Chemie, 1981, Band 323, Heft 4, "Einfache Synthesen fur Amino-aroxy-1,2,5-tiazine", D. Martin et al., pp. 694-699.
Bauer Jorg
Bauer Monika
Gocks Karin
Dean Ralph H.
Fraunhofer-Gesellschaft Zur Forderung der Angewandten Forschung
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