Stock material or miscellaneous articles – Composite – Of epoxy ether
Patent
1997-02-28
1998-09-22
Krass, Frederick
Stock material or miscellaneous articles
Composite
Of epoxy ether
428415, 428417, 428901, 525523, 525525, 528103, 528108, 528361, 528398, 528400, 427386, C08G 5914, C08L 6300
Patent
active
058111883
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to novel phosphorus-modified epoxy resins, a process for their preparation and their use. The novel phosphorus-modified epoxy resins are distinguished as flame retardant additives having very processing-friendly properties.
Epoxy resins are widely employed nowadays for the production of reactive resin molded materials and coatings having a high level of thermal, mechanical and electrical properties and for the production of laminates. The low molecular weight or oligomeric starting components can be reacted to high-quality thermosetting materials using the most diverse hardeners, such as, for example, carboxylic acid anhydrides, amines, phenols or isocyanates, or by ionic polymerization. The processing properties of epoxy resins is another of their advantages. In the starting state they are low molecular weight or oligomeric and have a low viscosity at processing temperatures. They are therefore particularly suitable for sealing complex electrical and electronic components and for soaking and impregnating processes. They have adequate pot lives in the presence of suitable reaction accelerators. They can also be filled to a high degree with customary inorganic inert fillers.
In order to protect persons affected in the event of a fire or a malfunction and in order to assure functioning of electrical and electronic equipment is maintained over a certain period of time, epoxy resin molded materials (cured epoxy resins) are often required to have flame resistance in electrical engineering. This means that epoxy resin molded materials must be self-extinguishing and should not transmit the fire. The detailed requirements are given in the standards relating to the particular product. For epoxy resin molded materials employed in electronics and electrical engineering, combustibility testing in accordance with UL 94V mainly applies here.
A summary of the possible methods for rendering epoxy resins flame resistant is to be found in the literature (for example Troitzsch, J., "International Plastics Flammability Handbook", 2nd Edition, Carl Hanser Verlag, Munich, 1990; Yehaskel, A., "Fire and Flame Retardant Polymers", Noyes Data Corporation, New Jersey, USA, 1979).
Epoxy resin molded materials are currently in general provided with a flame resistant finish by means of halogen-containing, specifically bromine-containing, aromatic components. The materials are usually molded materials which comprise intercalation components, for example fillers or glass fabric, and often comprise antimony trioxide as a synergist. The problem here is that in the event of a malfunction, decomposition products which are corrosive and under unfavorable conditions are ecologically or toxicologically unacceptable are formed owing to smouldering or combustion. There must be a considerable technical expenditure for hazard-free disposal by combustion.
There is therefore a considerable demand for epoxy resins which achieve the low combustibility required in the standards without the addition of halogenated components.
The use of organic phosphorus compounds has proven to be an effective way of achieving flame resistance in resinous substrates. Attempts have therefore already been made to modify epoxy resins with additives based on phosphoric acid esters such as, for example, triphenyl phosphate (DE 1 287 312). However, these compounds migrate out of the molded materials to the surface, especially at elevated temperature, affecting the dielectric properties and leading to E corrosion.
The object of the invention was therefore to provide novel phosphorus-containing additives for epoxy resins which, in addition to flame resistance, also have high storage stability, allow variations in the phosphorus content, are simple and inexpensive to prepare and above all are also suitable for use in electronics and electrical engineering where high filler contents are customary.
The present invention thus relates to novel phosphorus-modified epoxy resins of the formula (I) and/or of the formula (II) ##STR2## in which: R.sup.1, R.su
REFERENCES:
patent: 4164487 (1979-08-01), Martin
patent: 4195035 (1980-03-01), Kleiner et al.
patent: 4289812 (1981-09-01), Martin
patent: 4783345 (1988-11-01), Kleeberg et al.
patent: 4952646 (1990-08-01), Weil et al.
patent: 5319138 (1994-06-01), Roscher et al.
patent: 5364893 (1994-11-01), von Gentzkow et al.
patent: 5587243 (1996-12-01), Von Gentzkow et al.
Appendix I, Synthesis of Epoxy Resins, pp. 198-207.
Novel Thermosetting Epoxy Resins Based on Pentaerythritol, J. M. Jordan, pp. 1-15.
Handbook of Epoxy Resins, Chapter 2, Synthesis of Glycidyl-type epoxy resin, pp. 2-1-2-33.
K. Sasse: Phosphonsauren und Derivate, pp. 612, 613.
Die Angewandte Makromolekulare Chemie 44 (1975) pp. 151-163 Nr. 679 Thermisches Verhalten von Mono-, Bis-und Poly-2-oxazolidinonen.
Polyadditionscharze, pp.174-194.
International Plastics Flammability, 5.2 The most important fire retardant plastics, pp. 53-60.
Epoxies and Silicones, Adducts of Cyclic Urea Derivatives and Dialkyl Phosphites, pp. 119-131.
Huber Jurgen
Kapitza Heinrich
Kleiner Hans-Jerg
Rogler Wolfgang
Aventis Research & Technologies GmbH & Co. KG
Krass Frederick
Siemens Aktiengesellschaft
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