CS219105B1 - Lubricant with anticorrosion effects for electromechanical products - Google Patents

Abstract

Lubricant having anticorrosive properties for electromechanical components comprises a C20-35 ester of a dicarboxylic acid and 1 x 10<-4> to 10 g./l. of at least one pyrazolidine of formula <IMAGE> where R1 to 6 are C10 alkyl or aryl, NH2 or H. The lubricant enables a reduction of the thickness of coatings of precious metal on their contact surfaces, improving the resistivity to corrosion and prolonging their life time.

Description

The invention relates. the composition of a lubricant for electromechanical components with anticorrosive effects, which allows reducing the coating thickness of the precious metal to. contact surfaces greatly increases the corrosion resistance of these components and extends their service life by reducing mechanical wear.

An electromechanical component here is considered to be a component used for switching, connecting & disconnecting an electrical circuit. Thus, it always performs a mechanical function and transmits electrical current, for example a connector or a switch.

In practice, it is known to use a variety of friction reducing and corrosion reducing agents for electromechanical components. Usually mineral oils, salts and esters of fatty acids and dicariboxylic acids, etc. are used for this purpose. These substances are usually combined with weakening substances or substances! with anticorrosive effect. Usually, the phenothiazine or substituted phenol type is used for stabilization. However, these mixtures generally act only mechanically and do not have corrosion effects under the test conditions of electromechanical components. This also applies to a number of substances that are in other areas. . successfully. Use as corrosion inhibitors.

Measurements have shown that substances commonly used to stabilize lubricants and some substances commonly used as corrosion inhibitors, on the contrary, strongly accelerate corrosion, especially when conducting corrosion tests with pure substances without the presence of intrinsic lubricants which largely overlap their corrosion action, then manifest under extreme conditions. According to the invention, good lubricant stability is also assured in mixtures containing only substances which, under the conditions of testing and use of electromechanical components, have markedly inhibitory corrosion effects.

The disadvantages of the lubricants previously used are eliminated by the composition according to the invention containing only substances with a significant anti-corrosion effect, which at the same time has good stability and is particularly suitable for electromechanical parts covered wholly or partially with a nobler metal than the base material or interlayer material. Measurements have shown that especially by combining two corrosion inhibitors of different types, the anticorrosive effect is substantially increased.

Lubricinite consists essentially of a dicarboxylic acid ester having 5 to 12 carbon atoms in the molecule and its ester having a total of 20 to 28 carbon atoms in the molecule, with the addition of a substance. . from the group. pyrazolidine. v. a concentration of 0,01 to 1% by weight, which satisfies one of the three possible structures:

wherein R 1 to R 5 is methyl or phenyl, or H.

The composition may further comprise an additive of paraffin which alters the mechanical properties of the lubricant and an additive of benzotriazole or tolyltriazole.

For practical testing of the lubricants of the invention, compositions having the compositions shown in Examples 1 to 9 were prepared. Further compositions containing frequently used antloxidants (Examples 10-11) were prepared for comparing the anticorrosive effects, in other compositions. they are in combination with other agents frequently used as corrosion inhibitors (Examples 12-13).

EXAMPLE 1 Di-3,5,5 Triethyl Azelate 84 wt.

(1-phenyl-4-pyrazolidone 1 wt.% Paraffin 15 wt.

dioctyl sebacate 98.9% - methyl-4-pyrazolidone 1 ·% tolyCriazole 0.1%

Example 3

Bis-2-methylhexyl adipate 93.9% 1-phenyl-5-methyl-3-pyrazxlidone 1% benzotriazole 0.1% paraffin. 5%

Example 1! -1 4 d -1-3,5,5-trimethylhexyl azelate 99% 1-phenyl-S-imethyl-4-pyrazolidone 1% benzotriazole 10 ^_ 4 од

Example 5 Dioctyl sebacate 99.5%

5-methyl-3-pyrazole lidoin 0.5%

Example 6 Dioctyl sebacate 99.99%

5-Methyl-3-pyrazolidone 0.01%

Example 7 di-3,5,5-trimethylhexyl azelate 99.49% 1-phenynyl-3-pyrazolidone 0.01% tolyiltriazole 0.5%

EXAMPLE 8 • Di-3,5,5-thiimethylethexyl azelate 99% 5-Triethyl-3-pyrazolone 1% bcinisoljazol 10% ⁴ %

EXAMPLE 1, Doctyl dcdecandiate 59% 1-Phenyl-3-pyrazolidone 1% Paraffin 40%

Example 10 dibktyliadipalt 58%

2,6-Di-tert-butyl-4-methyl-phenol 1% 1-phenyl-3-pyrazolidoin 1% paraffin 40%

Example 11 dioctyl adipate 93%

2.6- child ^| tert-butyl-4-methylphenol 1% -1-phenyl-3-pyrazole: don 1% paraffin 5%

Example 12 Dioctyl sebacate 98%

2,6-di-tert-butyl-4-methylphenol. 1% octadecylamine 1% w / w

Example 13 di-3,5,5-tirii'met ^| liylhexyl azlate 98% Phenothiazine 1% triethanioilamin 1%

In all the examples, the composition was rounded to hundredths of a percent.

All prepared mixtures were tested under the same conditions. As a corrosion test, a contact resistance measurement after the test in a hydrogen sulphide atmosphere, which is the usual test for this kind of components, was used. Lubricants were applied to the contacts from a 4% solution in xylene. Contacts with an outer contact surface of an indirect row connector with circular contacts with approximately 0.25 micrometers of gold in the contact portion were used for the tests. The contacts were mounted in the appropriate bodies after drying at 60 ° C. Corresponding gold-plated contact sockets were used for measurements only and were not subjected to corrosion testing. After measuring the initial transient resistance, the wells were pulled into 1% by volume hydrogen sulfide at 95% relative humidity at 25 ° C for 48 hours and the transient resistance was again measured.

30 contacts would be used for each sample and the percent increase in transient resistance after the corrosion test was calculated from the average values measured. Each contact was measured 5 times. The results are shown in Table 1. The results show that the lubricants of the invention (1 to 9) provide the best results. For comparison, the same test was performed with 'no lubricant contacts', in the table, this group is marked '0'.

To demonstrate the long-term stability of the lubricant of the present invention, the same test was performed after long-term heating (56 days) of the lubricated contacts to 100 ° C. The results are also in the table and are in good agreement with the foregoing, the lubricants of the invention again provide the best corrosion protection. The values of increase of the transient resistance are in all cases somewhat higher due to higher demands of the performed test.

Lubricant 0

Table 1

5 6 7 ld

13

Ki% 84 27 18 11 15 42 51 38 38 25 128 68 92 140

K ₂ ('%) 121 35 23 20 23 54 62 48 51 31 181 111 51 51 158

Ki is the increase in transient resistance in pro- cog is the increase in transient resistance in cents after 48 hours in hydrogen sulphide and 56 days of heating to 100 ° C and 48 hours in hydrogen sulphide atmosphere expressed as a percentage.

Claims (3)

Luibrikaint for electromechanical components with anticorrosive effects substantially reducing their corrosion and mechanical wear, characterized in that it consists of a dicarboxylic acid ester having from 6 to 12 carbon atoms per molecule and its ester from 22 to 28 «carbon atoms in the molecule a molecule with an additive of 0.01 to 1% by weight, based on the total weight of the lubricant, of a compound of the pyrazolidone group or a mixture thereof, the composition of which conforms to one of three possible structures: wherein R 1 to R 6 is methyl or phenyl or H, and optionally comprises an additive of paraffin, benzotriazole or tolyltriazole. 2. Lubricant for electromechanical components according to item 1. characterized in that it comprises a paraffin additive having a softening point above 40 ° C in an amount of up to 40% by weight, based on the total shear life of the lubricant. 3. Lubricant for electromechanical components according to claim 1 or 2, characterized in that it contains an additive of benzotriazole or tolyltriazole in an amount of 1 - ^{4 to} 0 - 5% by weight, based on the total weight of the lubricant.