RU2291176C1 - Compound and a method for preparation thereof - Google Patents

Abstract

FIELD: polymer materials in radio engineering.

SUBSTANCE: invention relates to preparing compounds suitable to seal radio and electric appliances containing parts sensitive to mechanical stress, including functional blocks, rectifiers, stabilizers, and the like. Compound comprises low-molecular weight rubber - oligodieneurethan-epoxide, organo-titanium-silicon oligomer, isomethyltetrahydrophthalic anhydride, and, additionally, epoxide resin (E-181). Preparation of compound involves: mixing oligodieneurethan-epoxide and organo-titanium-silicon oligomer preheated to 80-100°C for at least 1 h, evacuation at pressure between 0.6 and 1.3 kPa until active bubbling ceases (no longer than 20 min) and hardening takes place, while simultaneously mixing for 1 h with epoxide resin (E-181) preheated to 80-100°C, after which isomethyltetrahydrophthalic anhydride preheated to 80-100°C is added at careful mixing and above-indicated evacuation and hardening of the mixture is effected at 80-85°C during 48 to 60 h.

EFFECT: increased electric strength, imparted resistance to pressure shock, increased elasticity, and reduced shrinkage.

2 cl, 2 tbl

Description

The invention relates to the field of obtaining compounds used for sealing electronic equipment containing parts sensitive to mechanical stress, including functional blocks, rectifiers, stabilizers, etc.

At present, compounds 34-300, 30-300 and others based on low molecular weight PDI-3AK (oligodienurethane epoxide), epoxy diane resin, isomethyl tetrahydrophthalic anhydride, aerosil) and others are used for these purposes. [Sealing of products of electronic equipment with 4 polymer materials .054.213-76], a compound based on oligodienurethane epoxide, organotitanium silicon oligomer, vinyl glycidyl ether of ethylene glycol, isomethyl tetrahydrophthalic anhydride [RU 1838361]. However, these compounds have insufficient electrical strength (20-24.5 KV / mm) and significant shrinkage (1.5%), which leads to failure of parts sensitive to mechanical stress, unstable to baroud.

To prepare compound 34-300, low-molecular-weight PDI-ZAK rubber heated to a temperature of (60 ÷ 80) ° C is introduced with aerosil, preheated at a temperature of (90 ÷ 110) ° C for 2 hours. The mixture is stirred and vacuum at a pressure of from 0.6 to 1.3 kPa for 7-10 minutes. Then, isomethyltetrahydrophthalic anhydride is heated up to (60 ÷ 80) ° С, the mixture is stirred and vacuum at a pressure of 0.6 to 1.3 kPa for 7-10 minutes. Curing is carried out at a temperature of 90-105 ° C for 18 hours. Compound 30-300 is prepared similarly to compound 34-300 without the introduction of aerosil.

The closest in technical essence to the proposed compound for sealing electro-radio-technical products is a compound [RU 547463] based on oligodienurethane epoxide (low molecular weight PDI-ZAK), epoxy Diane resin ED-20 and organosilicon oligomer (TMFT product) of the following composition, wt.

Oligodienurethaneepoxide one hundred (Rubber low molecular weight PDI-ZAK) TU 38103410-85 Epoxy Dianovy resin ED-20 15-20 GOST 10587-84 Isomethyltetrahydrophthalic anhydride 5-12 TU-6-09-3321-73 Organosilicon oligomer 8-12 (product TMFT) TU-6-02-933-74

A method of manufacturing a compound [OST 4GO.054.213-76 p. 251 “Sealing of electronic equipment with polymer materials”] is that a mixture of oligodienurethane epoxide (low molecular weight PDI-3AK) and epoxy diane ED-20 is maintained at a temperature of 90 ÷ 100 ° C for 2 hours. Then, a titanium-silicon-organic oligomer (a product of TMFT) is introduced into it, everything is mixed and kept at the same temperature for 30 minutes. The resulting mixture is evacuated at a temperature of 70 ÷ 90 ° C and a pressure of from 0.6 to 1.3 kPa for at least 20 minutes. Then isomethyltetrahydrophthalic anhydride is introduced into it, heated to (70 ÷ 90) ° С, mix thoroughly and vacuum under pressure from 0.6 to 1.3 kPa for no more than 20 minutes. Curing is carried out at a temperature of (85 ÷ 105) ° C for 18 hours.

The disadvantage of this compound is insufficient dielectric strength (20 Sq / mm), instability to baroudar, insufficient elasticity (elongation of 230%), significant shrinkage (1.5%).

The technical result of the invention is to increase the electrical strength, ensuring resistance to baroudara, i.e. resistance to pressure changes from 100 kPa to 5.4 kPa for 0.3-0.4 seconds, increasing elasticity and reducing shrinkage.

The essence of the invention lies in the fact that the compound for sealing electro-radio-technical products contains oligodienurethane epoxide (low molecular weight rubber PDI-ZAK), an organo-titanium oligomer (TMFT product of the formula T _i {[OS _i (CH ₃ ) (C ₆ H ₅ )] _2-5 OH } ₄ ) and isomethyl tetrahydrophthalic anhydride.

New features in the proposed compound for sealing electronic equipment is the use of low viscosity (dynamic viscosity 0.07 Pas for ED-20 16-22) epoxy grade E-181, which is a product of the dehydrochlorination of dichlorohydrins obtained by condensation of epichlorohydrin with water, containing epoxy groups in %% 25-30, as an active reactive diluent for epoxy resins in the following ratio, parts by weight:

Oligodienurethaneepoxide 90-110 (Rubber low molecular weight PDI-ZAK) TU 3803410-85 Organosilicon oligomer 40-60 (product TMFT) TU 6-02-933-74 Isomethyltetrahydrophthalic anhydride 0.1-1.0 TU-6-09-3321-73 Epoxy resin E-181 15-25 TU 6-05-1747-76

The method of obtaining a compound for sealing electro-radio-technical products is based on mixing oligodienurethane epoxide and organosilicon oligomer preheated to a temperature of (80-100) ° C for at least 1 hour, evacuating at a pressure of 0.6 to 1.3 kPa until the active bubbling is stopped more than 20 minutes and curing.

New features of the proposed method for producing this compound is that simultaneously with preliminarily heated to a temperature of (80-100) ° C for at least 1 hour oligodienurethaneepoxide and an organotitanium oligomer are mixed preheated to a temperature of (80-100) ° C for at least 1 hour epoxy resin E-181. After that, isomethyltetrahydrophthalic anhydride heated to (80-100) ° С is introduced into the mixture with thorough mixing, then the aforementioned evacuation of the resulting mixture is carried out and cured at a temperature of 80-85 ° С for 48-60 hours. Table 1 shows the composition of the compound for sealing electronic equipment according to the invention:

Table 1 №№pp Components Example 1 Example 2 Example 3 one Oligodienurethaneepoxide (Low molecular weight rubber PDI-ZAK) TU 8.103410-85 90 one hundred 110 2 Organosilicon oligomer (product TMFT) TU 6-02-933-74 40 fifty 60 3. Isomethyltetrahydrophthalic anhydride TU-6-09-3321-73 0.1 0.3 1,0 four Epoxy resin E-181 TU 6-05-1747-76 fifteen twenty 25

The specified range is chosen due to the fact that with an increase in the amount of organosilicon oligomer, the viability of the compound decreases, and with a decrease in the required elasticity, the compound is not cured. With a decrease in the epoxy resin E-181, the compound becomes viscous, the removal of air bubbles is not ensured, which reduces the electric strength and resistance to baroudar, while increasing the optimum degree of curing is not achieved.

With a decrease in isomethyltetrahydrophthalic anhydride, the curing process is long, and with an increase in the viability of the compound is small, which does not allow to obtain a high-quality homogeneous compound. The high reactivity of the organosilicon oligomer, taken in large quantities in comparison with the prototype, leads to interaction not only with oligodienurethane epoxide, but also with the additionally introduced epoxy resin E-181, creating at the same time a homogeneous and elastic compound structure, which ensures resistance to baroudar and increased electrical shock durability.

In connection with the optimally selected amount of components (oligodienurethane epoxide, organosilicon oligomer, epoxy resin E-181), it was possible to obtain a compound for sealing electronic and radio engineering products with a sufficient degree of cure when using isomethyl tetrahydrophthalic anhydride in quantities significantly lower than known, which also led to resistance increase electric strength, elasticity and reduce shrinkage.

The compound for sealing electronic equipment is obtained in the following way: weighed samples of oligodienurethane epoxide, organosilicon oligomer, epoxy resin E-181 are heated at a temperature of 80-100 ° C for at least 1 hour, thoroughly mixed to a homogeneous mass, after which they are preheated to 80 -100 ° C isomethyl tetrahydrophthalic anhydride. The mixture is evacuated at a temperature of 80-100 ° C and a pressure of from 0.6 to 1.3 kPa until the active release of bubbles ceases, but no more than 20 minutes. Curing is carried out at a temperature of 80-85 ° C for 48-60 hours

The proposed method of obtaining a compound for sealing electronic equipment when mixing preheated components with an additionally included epoxy resin E-181 active reactive diluent provides the necessary viscosity of the compound, its homogeneity and the formation of a uniform structure when mixed, which provides resistance to baroudar, increased electrical strength, increased elasticity and reduced shrinkage.

Table 2 shows the comparative properties of the analogue and the proposed compound for sealing electrical and radio engineering products.

table 2
The results of comparative tests of the analogue and the claimed compound for sealing electro-radio products №№pp Indicators Analogue to RU 547463 Example 1 Example 2 Example 3 one Baroudar (resistance to pressure changes from 100 kPa to 5.4 kPa for 0.3-0.4 seconds) Not withstand Withstands Withstands Withstands 2 Electric strength, kV / mm twenty 33 36 34 3 Elasticity (elongation,%, N / m) 230 450 470 500 four Shrink% 1,5 0.8 0.85 0.9

As can be seen from the data given in table 2, the proposed compound and method for its preparation has several advantages:

- withstands bar impact, resistant to pressure changes from 100 kPa to 5.4 kPa for 0.3-0.4 seconds (analog does not withstand);

- has high dielectric strength (33-36 kV / mm versus 20 kV / mm);

- has high elasticity (not less than 450% against 230%);

- has less shrinkage (0.8-0.9% versus 1.5%).

Claims (2)

1. A compound for sealing electrical and radio-technical products, including oligodienurethane epoxide — low molecular weight rubber PDI-ZAK, organotitanium silicon oligomer — a product of TMFT, isomethyl tetrahydrophthalic anhydride, characterized in that it additionally contains an epoxy resin of grade E-181, with the following ratio of components: wt. Oligodienurethanoepoxide - low molecular weight rubber PDI-ZAK 90-110 Organosilicon oligomer - product TMFT 40-60 Isomethyltetrahydrophthalic anhydride 0.1-1.0 Epoxy resin E-181 15-25 2. A method of obtaining a compound for sealing electro-radio-technical products, based on mixing oligodienurethane epoxide and organosilicon oligomer preheated to a temperature of 80-100 ° C for at least 1 hour, evacuating at a pressure of 0.6 to 1.3 kPa until the active release of bubbles ceases not more than 20 minutes and curing, characterized in that simultaneously with preheated to a temperature of 80-100 ° C for at least 1 hour oligodienurethane epoxide and organosilicon oligomer are mixed beforehand E-181 epoxy resin heated to a temperature of 80-100 ° С for at least 1 hour, after which isomethyltetrahydrophthalic anhydride heated to 80-100 ° С is added to the mixture with thorough mixing, then the above-mentioned evacuation of the resulting mixture is carried out and cured at 80 -85 ° C for 48-60 hours