RU2543186C2 - Polymer composition for absorbing high-frequency energy - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to polymer compositions having shielding properties, intended for improving electrical containment of detachable flange couplings of microwave devices, especially for on-board equipment. The polymer composition for absorbing high-frequency energy contains synthetic low-molecular dimethylsiloxane rubber SKTN 15-25 pts.wt; absorbing filler - nickel powder PNK-1L5 30-50 pts.wt; cold curing catalyst N18 1.5-2.5 pts.wt.

EFFECT: invention provides low volume resistivity, reduces the curing time of the composition and provides high electrical containment of microwave devices.

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Description

The invention relates to electronic equipment, in particular to the production of polymer compositions with good shielding properties, designed to improve the electrical tightness of detachable flange connections of microwave devices, especially for on-board equipment.

Absorbing elastic materials are known [compositions No. 34, 35, 36 OST107.460007.006-92 Materials for volume absorbers of high-frequency energy] based on polyurethane and carbonyl iron. However, they have insufficient operating temperature range (-60 ÷ + 150) ° C and insufficient shielding properties.

Known polymer composition for absorption of radio waves [patent JP 2008282862 A, publ. November 20, 2008] based on ethylene propylene rubber, aluminum powder, and soot.

However, this multicomponent composition with a complex technology of manufacturing an absorber and at the same time has insufficient absorption properties, a narrower temperature range (-50 + 150) ° C, and its additional moisture protection is required.

The closest in technical essence to the proposed polymer composition for the absorption of high-frequency energy is [RF patent 2349615 C1, publ. 03/20/2009] a polymer composition for absorbing high-frequency energy, containing polymer - synthetic rubber, low molecular weight dimethylsiloxane SKTN, the catalyst is a cold curing catalyst No. 68, as well as an absorbing filler, characterized in that it contains radio carbon iron P-10 brand as an absorbing filler , in the following ratio of components, parts by weight:

Synthetic rubber, low molecular weight dimethylsiloxane SKTN 15-25 Iron carbonyl radio engineering brand P-10 78-83 No. 68 Cold Curing Catalyst 0.6-1.0

The disadvantages of the prototype are high resistivity, low electrical leakage of detachable flange connections of microwave devices and a long curing time, which leads to heterogeneity of the structure and instability of the properties.

The technical result of the invention is to obtain a polymer composition with a low specific volume resistance, improve the electrical tightness of microwave devices, reduce the curing time.

The essence of the invention lies in the fact that the proposed polymer composition for absorbing high-frequency energy contains a polymer - rubber, synthetic low molecular weight dimethylsiloxane SKTN, an absorbing filler and a cold curing catalyst.

New in the proposed solution is that the polymer composition for absorbing high-frequency energy as an absorbing filler contains nickel powder grade PNA-1L5, and as a cold curing catalyst - cold curing catalyst No. 18 in the following ratio, wt.h .:

Synthetic rubber, low molecular weight dimethylsiloxane SKTN (TU2294-002-00152000-96, GOST 13835-73) 15-25 Catalyst for cold curing No. 18 (TU6-02-805-78) 1.5-2.5 Nickel powder of the PNK-1L5 brand (GOST 9722-79) 30-50

A polymer composition for absorbing high-frequency energy is made by simply mixing the components and curing them at room temperature for 6 hours.

Table 1 shows the compositions of the proposed composition for the absorption of high-frequency energy.

Table 1 No pp Components Example 1 Example 2 Example 3 one Synthetic rubber low molecular weight dimethylsiloxane SKTN (TU2294-002-00152000-96, GOST 13835-73) fifteen twenty 25 2 Nickel powder grade PNK-1L5 (GOST 9722-79) thirty 40 fifty 3 The catalyst for cold curing No. 18 (TU6-02-805-78) 1,5 2.0 2,5

The indicated range of components was chosen due to the fact that with a decrease in the amount of nickel PNK-1L5 powder it is impossible to achieve the required electrical tightness of the waveguide flange connections of microwave devices, and with an increase in the amount of nickel PNK-1L5 powder it is impossible to obtain the proposed polymer composition due to an increase in viscosity and heterogeneity.

With an increase in the number of cold curing catalyst No. 18, the viability decreases, the viscosity of the polymer composition increases, and the presence of unallocated air bubbles leads to a decrease in electrical leakage. With a decrease in the number of cold curing catalyst No. 18, the curing time increases and the composition becomes heterogeneous due to settling of the filler.

Table 2 shows the results of comparative tests of the analogue and the inventive polymer composition for the absorption of high-frequency energy in the waveguide tract.

table 2 No pp Indicators Prototype (patent 2949615) Example 1 Example 2 Example 3 one Electrical leakage, dB 5 70 60 65 2 Volume resistivity, Ohm × cm 1.4 × 10 ⁸ 1 × 10 ^-1 9 × 10 ^-2 1 × 10 ^-1 3 Curing time, h 24 6 6 6

As can be seen from the data shown in table 2, the proposed polymer composition for absorbing high-frequency energy has several advantages:

- electrical tightness is an order of magnitude higher (“60-70 dB” versus “5 dB”);

- lower specific volume resistance (“1 × 10 ^-1 Ohm × cm” versus “1.4 × 10 ⁸ Ohm × cm”);

- shorter curing mode ("6 hours" versus "24 hours").

Claims (1)

A polymer composition for absorbing high-frequency energy, containing polymer - synthetic rubber, low molecular weight dimethylsiloxane SKTN, an absorbing filler and a cold curing catalyst, characterized in that it contains PNK-1L5 nickel powder as an absorbing filler, and No. 18 cold curing catalyst as a catalyst the following ratio, parts by weight:
synthetic rubber low molecular weight dimethylsiloxane SKTN 15-25 No. 18 cold curing catalyst 1.5-2.5 nickel powder, grade PNK-1L5 30-50