SU1616987A1 - Detergent for cleaning surface of electronic articles - Google Patents

Abstract

The invention relates to detergent compositions, in particular, to a detergent for cleaning the surface of radio electronic equipment. In order to improve the quality of surface cleaning and increase the duration of use of the detergent in a boiling state, it contains the following components, wt%: ethyl alcohol 3.5-4.5

C ₈ -C ₉ monohydric alcohol 2.5-3.5

nitromethane 0.04-0.06

trichlorotrifluoroethane to 100. The new composition improves the quality of cleaning, increases the duration of use of detergent / 1200 min. 1 tab.

Description

The invention relates to the soldering and tinning of electrical assembly, electronic equipment connections (REA), in particular, to means used for mechanized cleaning of the surfaces of REA products from residues of tar-containing fluxes, and can be used in any branch of the national economy where mechanized cleaning is used. 1 of the surfaces of products about g of resinous substances in organic solvents.

The purpose of the invention is to increase the quality of cleaning the surfaces of CEA products and increase the duration of use of detergent in a boiling state.

By introducing Cg-Cg alcohol as a surfactant into the detergent composition, the quality of cleaning the surface of REA products is improved by completely removing white flux residues.

By introducing nitromethane into the detergent composition, an increase in the quality of cleaning is achieved by eliminating the formation of darkening of the metal surfaces and an increase in the duration of use by eliminating the oxidation of the detergent

facilities.

Thus, only the joint introduction of the monohydric alcohol Cg-C and nitromethane into the known composition allows one to achieve the goal.

The minimum content of alcohol z.tylovogo detergent vl 05

X

-h

is 3j, 5J5. With a further decrease in its content, the ability of the detergent to remove residues of rosin fluxes from the surface of products decreases.

The maximum ethyl alcohol content in the detergent is 4.5%. With its further increase the mixture becomes flammable and explosive.

The minimum nitromethane content in the detergent is 0.04%. With a further decrease in its content, acidification of the detergent takes place when used in a boiling state.

The maximum content of nitromete per century. detergent is 0.06%. A further increase in its content is inexpedient, since it does not create an additional positive effect, but it detracts from the process. I. The minimum content of high-molecular monohydric alcohols in the detergent is 2.5%. A further decrease in its content worsens the quality of cleaning of the soldered surfaces from residues of activated rosin resin.

The maximum content of high molecular weight monohydric alcohols in the detergent is 3.5%. Its further increase causes foaming that interferes with cleaning and does not create an additional positive effect.

The detergent is prepared as follows.

The calculated amounts of ethyl alcohol, nitromethane, and high molecular weight monohydric alcohol Gg-C are alternately added to the calculated amount of trichlorotrifluoroethane with stirring.

Technological characteristics of the proposed detergent composition are illustrated with specific examples (table).

From the data in the table it follows that the composition with the minimum content of components is the composition according to Example 3. The quality of cleaning of the propane surfaces meets the requirements, i.e. there are no visible traces of residual flux or other contaminants on the surface, there are permissible punctate (with a diameter of not more than 0.1 mm) inclusions of

0

five

0

five

0

five

0

roasted rosin, but no more than two points on one paann connection. The duration of the use of the detergent is 1200 minutes and is limited by its marginal saturation with flux FCTC residues to 0.25%.

A further decrease in the content of components (Example 2) impairs the quality of cleaning, i.e. white bloom of flux residues remains on the surface. In addition, the duration of use of the MS is reduced to 546 minutes due to its acidification to pH 6.9, and the flux residues are not completely limited.

The optimal composition of the detergent is the composition given in Example 4. The quality of the cleaning meets the requirements. The duration of use is 1.200 minutes, i.e. to the maximum saturation of the MS with flux residues.

The composition with the maximum maintenance of the components is the composition shown in Example 5. The cleaned surface of the propane boards with ERE meets the requirements,., The duration of use is 1200 minutes, i.e. to the maximum extent by flux residues.

With a further increase in the content of components (Example 6), foaming appears, which interferes with the cleaning process, and the fire hazard of the use of the composition increases.

Claims (1)

The advantages of the proposed detergent over the known ones are an improvement in the cleaning quality, an increase in the duration of use. Invention Formula MyUnder is a means for cleaning the surface of electronic equipment, containing trichlorotrifluoroethane and ethyl alcohol, about the fact that, in order to increase the quality of surface cleaning and increase the duration of using a detergent in a boiling state, it additionally contains monoatomic alcohol Cg-C and nitromethane at the following ratio- - Scientific Research Institute of Components, May.%: t 3.5-4.5 2.5-3.5 0.04-0.06 Up to 100. 5 - - - 95 2 one 0.02 Rest four 3 0.05 - The rest A, 5 3.5 0.06 5 0.1 Ostal- Else Noah 7 s On a surface there is white raid Pa surface detected flux residues Does not match 240 16.5 546 38.5 Limited by acidification of MS to p1 6.9 No visible traces of flux residues were found on the surface. No residual flux Complies 1200 82.5 Limited by saturation of MS with flux residues up to 0.25%