RU2422485C2 - Acrylic composition for plugging threaded joints - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to an acrylic composition for plugging threaded joints, particularly for fixing high frequency connectors of inter-block cables. The acrylic composition consists of an acrylic amide-containing resin, an organic colour pigment and a solvent. The acrylic amide-containing resin is a copolymer of butylmethacrylate and acrylamide. The solvent used is a mixture of acetone, xylene and butylacetate. The acrylic composition has high adhesion to different metals, long working life and a wide range of working temperature from minus 40 to plus 50°C. The composition can be used on vertical surfaces.

EFFECT: use of the composition prevents self-unfastening of low-loaded threaded joints subjected to vibration loads and, if needed, enables dismantling of assembled elements.

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Description

The invention relates to visco-plastic materials based on an acrylic copolymer, in particular to compositions of amide-containing acrylic resins, and can be used to stop lightly threaded connections, in particular for fixing RF connectors of interconnect cables. The proposed invention allows to protect threaded connections from self-unscrewing under vibration, while allowing, if necessary, disassembly of threaded connections.

It is known that anaerobic sealants are recommended as the main material for locking threaded joints using polymeric materials. In addition, adhesives, fillers, enamels, and primers are also used as an additional polymeric material for locking threaded joints. For example, for protection against self-unscrewing of lightly threaded connections that are not exposed to vibration loads, EP-51 enamels, primer AK-070 (OST 92-1542-83 “Threaded connections. Methods of protection against self-unscrewing”, p.2, table 3 can be used , p.22).

However, enamels and primers have insufficient viscosity when applied to vertical surfaces. Glues and putties have high joint strength during locking, which eliminates the subsequent disassembly of the joint elements.

Known acrylic composition used as a sealing composition or sealant (IPC7: C09K 3/10, application RU No. 93050548, 08/10/1996; EP 0587332, 08/19/1993) and taken by the authors as a prototype. This composition includes a binder of an acrylic emulsion copolymer mixed with zinc oxide, taken in an amount of from about 0.5% to 5% (wt.) Based on the weight of the dry copolymer binder, and with solid silica, taken in an amount of from about 0 , 05% to 10% (wt.) Based on the weight of the dry copolymer binder.

The disadvantage of this composition is the inability to disassemble the fixed elements.

The objective of the invention is to obtain a viscous, not flowing down from the vertical surface of the polymer composition, which allows to prevent self-loosening of lightly threaded connections, for example, RF connectors subjected to vibration loads, allowing disassembly of the fixed elements, having high adhesion to various metals. In addition, the resulting composition should be technologically advanced - easy to apply, have high viability.

The technical result of the invention is:

- the possibility of applying an acrylic composition to vertical surfaces (the viscosity of the composition is 700-800 centipoise);

- the ability to disassemble the fixed elements (locking moment of the composition 9-12 kgf · cm);

- high viability of the acrylic composition (3 months);

- a large range of operating temperatures (from minus 40 to plus 50 ° C);

- curing at a temperature of from 15 to 35 ° C for 24 hours.

The technical result is achieved in that the acrylic composition for locking threaded joints consists of an acrylic amide-containing resin, which is a copolymer of butyl methacrylate and acrylamide, an organic color pigment, and a solvent, which is a mixture of acetone, xylene and butyl acetate, in the following ratio of components, parts by weight :

acrylic amide resin (in terms of dry residue) - 31-33;

organic color pigment - 1.5-3.5;

a mixture of acetone, xylene and butyl acetate - 62-66.

The invention consists in the following.

The composition is prepared on the basis of a highly viscous solution of acrylic resin, which is a copolymer of butyl methacrylate and acrylamide (for example, grade AC TU 6-02-101-90) in a mixture of organic solvents (for example, R-5A according to GOST 7827-74 (mixture of acetone, xylene and butyl acetate)) with the addition of organic colored pigment (for example, the organic pigment dye rhodamine "C" according to TU 6-14-1088-74 or red varnish GB according to GOST 8573-77 "Organic dyes. Red varnish GB. Technical conditions"). The color of the pigment does not matter.

Then the resulting composition is filtered, tightly closed with a lid and used for three months. The acrylic composition should be homogeneous, without impurities and should not be delaminated during storage.

The resulting acrylic composition is an adhesive viscous (rubber-like) mass. The viability of the acrylic composition for 3 months. The viscosity of the resulting composition is determined by a Geppler viscometer - 700-900 centipoise. Using the locking key determine the locking moment of the composition: 9-12 kgf · s. According to the tests of the acrylic composition in the chamber of heat and moisture (KTV), they conclude about its range of operating temperatures from minus 40 to plus 50 ° C.

The technology for applying the composition is as follows.

Before applying the composition to the surface, the following technical requirements must be observed: tighten the flare nut of the RF connector with a wrench with the required tightening torque, then the surfaces of the RF connector designed for applying the material are degreased with gasoline (nefras-C2-80 / 120 according to TU 38.401-67- 108-92). After degreasing the connector, it is held for 15 to 30 minutes at a temperature of 15 to 35 ° C. The time between degreasing and applying the composition should be no more than 2 hours.

The acrylic composition is applied to the flare nut of the RF connector with access to the block and cable parts at a width of at least 5-6 mm around the entire circumference, in hard-to-reach places it can be applied to 2/3 of the circumference of the connector. The composition is applied in a continuous layer without gaps and air bubbles. Then the composition is dried at a temperature of from 15 to 35 ° C for 24 hours.

Example.

To prepare the acrylic composition, a mixture of acetone, xylene and butyl acetate (solvent R-5A according to GOST 7827-74) is poured into a glass container in an amount of 65 parts by weight. and with constant stirring, AS resin is gradually introduced according to TU 6-02-101-90 in an amount of 32 parts by weight (in terms of dry residue) until it is completely dissolved (2-3 hours). After that, a colored pigment is added to the resulting solution - red concrete varnish, according to GOST 8573-77 “Organic dyes. Varnish red reinforced concrete. TU "in the amount of 3 parts by weight

Then the resulting product is filtered, tightly closed with a lid and used for three months; it should be homogeneous, without impurities and should not be delaminated during storage. The viscosity of the resulting composition is determined by a Geppler viscometer - 800 centipoise. Using the locking key determine the locking moment of the composition: 10 kgf · s.

Thus, the obtained acrylic composition has sufficient strength to prevent self-unscrewing of threaded joints when exposed to vibrational loads and, if necessary, allows disassembly of threaded joints; the material does not drain from vertical surfaces (viscosity 700-800 centipoise), has a high viability (3 months), a wide range of operating temperatures (from minus 40 to plus 50 ° C), curing at a temperature of 15 to 35 ° C for 24 hours .

Claims (1)

An acrylic composition for locking threaded joints, consisting of an acrylic amide-containing resin, which is a copolymer of butyl methacrylate and acrylamide, an organic color pigment and a solvent, which is a mixture of acetone, xylene and butyl acetate, in the following ratio of components,%:
acrylic amide resin (calculated on the dry residue) 31-33 organic color pigment 1,5-3,5 a mixture of acetone, xylene and butyl acetate 62-66