RU2493627C1 - Method of painting and drying radio electrical articles - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: articles are painted by preparing epoxy enamel EPIMAL^®-9114 by adding 30% solution of 2-methylimidazole in diethylene glycol in amount of 0.5-1.0% of the weight of enamel. The enamel is dried for 16-22 minutes at temperature of 180-200°C to obtain a coating.

EFFECT: method improves the quality of coating and provides the required degree of drying.

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Description

The invention relates to a method of painting, and more specifically to a technology for preparing the starting material, which is used for applying a protective paint coating, as well as its drying, which has the ability to form a defect-free solid film in a short time, and can be used for painting radio and electronic products, including cylindrical resistors with axial terminals (hereinafter - cylindrical resistors).

An analogue of the method of painting and drying of radio products is enamel painting EP-922 [1] with subsequent drying. This enamel can be used for applying multilayer coatings to cylindrical resistors, designed for operating temperatures up to 200 ° C, using automatic machines of the 08LP type in the following mode:

- drying temperature - (180 ± 20) ° С;

- drying time - (22 ± 2) min.

The disadvantage of this method is that when using this enamel for painting cylindrical resistors in the above mode, a coating with an insufficient degree of drying is obtained. So, when wiping the markings on top of the enamel coating with a cloth moistened with cyclohexanone (an enamel solvent) and (or) an alcohol-nephras mixture, sufficiently bright enamel traces remain on the fabric, and digital signs partially lose their readability, which is unacceptable. It is impossible to raise the drying temperature above the indicated one due to the formation of oxide films on the coating of the terminals of the resistors, as well as due to the design features of the used paint machines.

The prototype of the proposed method of painting and drying of electrical products is painting with electrical insulating enamel EPIMAL ^® -9114 [2], designed for operating temperatures up to 200 ° C, followed by drying. This enamel gives an opaque coating and has good decorative properties, but when used to paint cylindrical resistors, an insufficiently dried coating is obtained, which is why when wiping the digital markings on the enamel with a cloth moistened with ethyl cellosolve (enamel solvent) and (or) alcohol- nefrasovym mixture, traces of enamel remain on the fabric, and the brightness of the markings is also reduced.

The invention is aimed at improving the quality of a multilayer paint coating and increasing the speed of its formation (achieving the required degree of drying).

A method for applying and drying a coating is proposed, characterized by the use of enamel with the introduction of an additional component, an accelerator for drying epoxy resins, 2-methylimidazole [3]. 2-Methylimidazole is proposed to be used as a 30% solution in dihydric alcohol - diethylene glycol [4], introduced into the enamel directly when preparing it for work.

The technical result of the invention is to improve the quality of applying a multilayer paint coating and achieving the required degree of drying.

In the claimed invention, the hallmark distinguishing from the prototype is an additional component - 2-methylimidazole, dissolved in diethylene glycol with a mass fraction of 30%. Its introduction ensures the achievement of the required technical result, namely, improving the quality of applying a multilayer paint coating.

As a result of the information retrieval, a method for coloring and drying of radio and electronic products containing all the mentioned distinctive features was not found, which allows us to conclude about the novelty.

2-Methylimidazole is proposed to be used as a 30% solution in diethylene glycol by introducing EPIMAL ^® -9114 enamel immediately before use into the prepared enamel.

To 70 mass fractions of diethylene glycol add 30 mass fractions of 2-methylimidazole, then mix until it is completely dissolved. The resulting 30% solution of 2-methylimidazole in diethylene glycol is introduced into the prepared enamel EPIMAL ^® -9114 in an amount of 0.5-1.0% by weight of enamel and mix thoroughly.

The proposed method of painting and drying can be used for painting cylindrical resistors or other electrical and radio products, followed by drying. The application of enamel on cylindrical resistors can be carried out by dipping using automatic machines of the 08LP type.

The quality of EPIMAL ^® -9114 enamel coated with the proposed method with an added component (30% solution of 2-methylimidazole in diethylene glycol), characterized by a semi-gloss uniform surface, good hiding power and the required degree of drying, which forms during 16-22 minutes at a temperature of 180 -200 ° C, indicates the superiority of the proposed method over previously known.

The results of the practical use of the proposed method of coloring and drying using a 30% solution of 2-methylimidazole in diethylene glycol with a different percentage of the solution in the prepared enamel (0.5-6.0% by weight of enamel), as well as various time and temperature of drying are presented in the table.

From the results obtained [5], it follows that the selected method of painting and drying of electrical products in the mode:

- drying temperature - 180-200 ° C;

- drying time - 16-22 min (depending on the size of the products and the design of the machine);

with a mass ratio of components of a solution of 2-methylimidazole in diethylene glycol: 30% 2-methylimidazole and 70% diethylene glycol, when introduced into the EPIMAL ^® -9114 enamel in an amount of 0.5-1% by weight of the enamel before its use, it provides high quality painting and the required degree of drying of the resulting coating.

The content of a 30% solution of 2-methylimidazole in diethylene glycol in enamel,% Mode Coating quality Drying temperature, ° С Drying time, min Appearance Degree of drying 0.5 160 16 good sufficient 180 16 180 22 200 22 1,0 160 16 good sufficient 180 16 180 22 200 22 6.0 160 16 good (test results are positive) sufficient 180 16 180 22 good (according to the test results, a crack along the cap on one sample of 20 pieces) sufficient 200 22

Literature

[1] Enamel EP-922 TU 6-10-1649-77.

[2] Enamel EPIMAL ^® -9114 TU 2312-057-05758799-2004.

[3] 2-Methylimidazole TU 6-09-10-1836-90.

[4] GOST 10136-77.

[5] Acts No: 286,287 of February 9, 2011; 291 from 02/18/2011.

Claims (1)

A method of coloring and drying of electronic products, including the operation of preparing the EPIMAL ^® -9114 epoxy enamel by introducing an additional component into it, characterized in that a 30% solution of 2-methylimidazole in diethylene glycol with a quantitative content of 0.5-1 is used as an additional component of enamel, 0% by weight of enamel, and drying of the applied coating is carried out for 16-22 minutes at a temperature of 180-200 ° C.