FILLING-IN PASTE FOR ELECTRONIC COMPONENTS

Abstract: The filling-in paste for electronic components is produced as the reaction product of anhydrous ricine-oil and polyizocyanate-resin in weight ratios from 100:5 to 100:25 and it is thermosetting in temperature range 0 to + 75 C and by duration from 20 minutes to 6 hours.

Description: Filling-in paste for electronic components Field of the invention The invention refers to the filling-in paste for elec¬ tronic components, which ensures tight and elastic filling -up of component, with perfect insulation from unfavourable influences of external environment, and at the same time it ensures the good thermal conductivity and the practical self-suppression. Background of the invention Epoxide-reεinε, asphalts, polyurethane-reεinε and simi¬ lar compounds are used as filling-in pastes for electronic components. These compounds are applied with various fil¬ lers, accelerators and dryers, which influence their elec¬ trical, mechanical and chemical features and also the self -suppression. The problem is complicated with filling-in paste preparation, high price and with harmonizing of all required properties. These compounds have mostly antagonis¬ tic properties - for example the good insulation properties, but the considerable internal stress during the hardening process for example at epoxide-reεinε, combined often with an exotherm reaction. The following example can the patent SU 430 124, which employs toluene as a solvent to the mix¬ ture of ricine-oil and aliphatic aromatic diizocyanate; that causes however the considerable extension of hardening time and toluene is into the bargain very harmful. The problems connected with ecology and safety standards occur by present -day filling-in pastes last but not least. Summary of the invention The disadvantages of till used filling-in pastes are sol- ved by the filling-in paste of this invention. Substance of the invention of the filling-in paste for electronic compo¬ nents iε, that it concerns product of reaction anhydrous ri¬ cine-oil and polyizocyanate-reεin; for this resin is advan¬ tageously used aromatic polyizocyanate with the main compo¬ nent triphenilmethan - 4,4?4" - triizocyanate in ratio 100 weight parts of ricine-oil and ?5 weight parts of polyizo- cyanate-resin. The filling-in paste is hardened at tempera¬ ture range 0 - 75°C for the duration 20 minutes till 6 hours as required. The advantage of the filling-in paste opposite the well-known mixtures iε, that it contains no harmful organic solvents as toluene, it shortens the hardening time at lower temperatures without demands on the following hardening: and it shows very good result properties, as dielectric and ele- ctroinsulating properties, heat conductivity and resistance, mechanical elasticity, gas and steam airtightnesε. and also very good adhesion to common used materials. The optimal result properties for the given use may be reached with the filling-in paste from the invention, by the various relative mixing ratio of ricine-oil and polyizocyana- te-reεin (with triizocyanate as its main component). At the same time it is not necessary to use fillers, dryers, accele¬ rators and it is possible to change the consistence from nearly liquid to solid. Detailed description of the invention The roll of capacitor made from polypropylene-folie with aluminium meta ization is filled-up in the case with filling-in paste which is prepared by mixing of vacuum dryed ricine-oil and low-polmered polyizocyanate-reεin (the main component of polyizocyanate-reεin iε triphenilmethan - 4,4 * 4" - triizocyanate), in ratio 100 weight parts of ricine- oil and 25 weight parts of polyizocyanate-resin. This mixtu¬ re iε solidified on the temperature + 75°C for 2 hours. The co pletation of the capacitor is made in normal way. The capacitcr without the filling-in paste and the ca¬ pacitor filled-up with epoxide-resin are used for comparison. After the life test was applied on capacitors (400 hours, + 85°C, 340 V, polypropylene-folie 6 yum thickness with alu¬ minium metalization) , the average decreases of capacitance are: a) the capacitor without filling-in paste: δC (% ) = 2.25 b) the capacitor filled-up with epoxide-reεin: δC (%) = 0.65 c) the capacitor filled-up with compound from the invention: SC {%) = 0.35 The teεt result shows considerable smaller decrease of the capacitance in the case of using the filling-in paste from the invention. The mentioned filling-in paste slackens the process of electrochemical oxidation of aluminium or other capacitor electrodes by loading of AC voltage, due to perfect- seal of the roll and hinder the access of external humidity and air-oxygen. Industrial applicability The filling-in paste from the invention enables to im¬ prove parameters of filling-up components, to increase the air-humidity resisting, moisture resisting, heat resisting and also thε mechanical shock and burn resiεting. It extends the range of application of components and enables to get- significantly longer life durability.

Claims: The claims 1. The filling-in paste for electronic components c h a r a c t e r i z e d as a product of the reaction of the anhydrous ricine-oil and the polyizocyanate-reεin. 2. The filling-i -paste fcr electronic components in the point 1, c h a r a c t e r i z e d by using with ad¬ vantage aromatic polyizocyanate with the main component triphenilm than - 4,4^4" - triizocyanate, as a polyizocya- nate-reεin. 3. The filling-in paste for electronic components in the point 2, c h a r a c t e r i z e d by using the reac¬ tion product of anhydrous ricine-oil and polyizocyanate- resin in weight ratio 100:5 to 100:25. 4. The filling-in paste for electronic components in the point 3 * c a r c t e r i z e d by using the reac¬ tion mixture of anhydrous ricine-oil and polyizocj^anate- reεin and itε hardening on the temperature in range of 0 to + 75°C 5. The filling-in paste for electronic components in the point 4, c h a r a c t e r i z e d by using the reac¬ tion mixture of anhydrous ricine-oil and polyizocyanate- reεin and its hardening by requirements from 20 minutes to 6 hours. AMENDED CLAIMS [received by the International Bureau on 4 February 1994 (04.02.94); original claims 1-5 replaced by amended claim 1 (1 page)] The filling-in paste for electronic components c h a r a c t e r i z e d as a product of the reaction of the anhydrous ricine-cil and the triphenil ethan - 4,4,4" - triizocyanate in the form of polyizocyanate-resin in weight ratios from 100:5 to 100:25 this product is thermosetting.

Inventors: DOKOUPIL JAROSLAV, JETMAR JAN, NOVOTNY CIR BEDR CIR ICH, ZAJIC CIR EK MILOSLAV, DOKOUPIL, JAROSLAV, JETMAR, JAN, NOVOTNY, BEDRICH, ZAJICEK, MILOSLAV
Applicants: TESLA LANS & CIR & KROUN A S, TESLA LANSKROUN A.S.
Application year: 1993
Main classification: H01B3
IPC codes: C08G18, H01B3