All about epoxy resin ED-20

The ED-20 epoxy-diane resin brand has been produced in Russia for over 60 years. Initially, it was a product intended for the defense industry, and today the resin is used in everyday life and in production. The two-component composition has a high degree of quality and reliability, but the most important thing is its low cost and availability. You can buy epoxy at any hardware store.

Epoxy resin ED-20 is produced at the Russian FPC "Plant named after Sverdlov", the manufacturer supplies its products not only to the domestic market, but also abroad. The plant is located in the city of Dzerzhinsk, Nizhny Novgorod region. Also, epoxy-diane resin is produced at a number of enterprises located in the CIS countries.

According to GOST 10587-84 grade ED-20 includes epichlorohydrin and diphenylolpropane. According to the description, it is a polymer condensation product of these components in an alkaline medium, which has fusibility and plasticity. In addition to the alkaline condensate, there is a toluene resin on the market, but the properties of both products are identical. Since ED-20 is most in demand in industry, it is packaged in flasks or steel drums, the volume of which is 50 kg. The product intended for domestic use is bottled in small containers. Dian epoxy resin is a two component product. Its main part looks like thick and transparent colorless honey. A hardener (thick consistency and amber color) is added to this composition.

If we consider in more detail the chemical composition of epoxy-diane resin, it looks like this:

• epoxy components - from 20 to 22.4%;
• saponifiable chlorine - from 0.3 to 0.8%;
• volatile components - from 0.3 to 0.7%;
• hydroxyl group of substances - 1.8%;
• chlorine ions - from 0.002 to 0.006%.

No plasticizers are added during the manufacture of ED-20 epoxy-diane resin, therefore, under the influence of vibration or mobility of the base, the frozen resin layer can become covered with cracks. Until the moment of polymerization, the product has good viscosity and plasticity. The resin is sometimes dissolved with an organic solvent to reduce the viscosity level before combining with the hardener.

The epoxy-diane product has the following physical properties:

• the resin is polymerized after 90 minutes. after mixing with a hardener;
• the composition will fully strengthen after 24 hours;
• bending resistance is 85-145 MPa;
• working temperature range - from 55 to 170 degrees;
• the dynamic viscosity of the material is from 13 to 20 Pa * s;
• density at + 20 ° C is from 1.16 to 1.25 kg / m³.

Manufacturers indicate that the shelf life of the resin is at least 18 months. from the date of manufacture of the product, while the hardener has a longer shelf life of 2 years. It is necessary to store ED-20 in dark places at a temperature not exceeding 40 ° C. The resin can be handled at 20 ° C - this is called the cold method.In an industrial setting, thick sheets of resin harden when exposed to higher temperatures, and this hardening method is called hot hardening.

The polymer product ED-20 is widely used. In almost every area of ​​production, this composition may be in demand.

• Instrumentation. In the form of an electrical insulator, as well as for creating frame structures and their walls, which have a low degree of thermal conductivity.
• Radio engineering sphere. For the manufacture of boards, chips, microcircuits.
• Shipbuilding. Manufacturing and repair of frames for boats, yachts, boats, as well as composite materials for various purposes.
• Aircraft construction. For the manufacture of the frame of the fuselage, wing and other composite elements.
• Defense industrial complex. As a constituent element for the production of lightweight models of body armor.
• Mechanical engineering. Manufacturing and repair of hinged body parts and interior trim elements.
• Furniture manufacturing. For decorative finishing and manufacturing of exclusive furniture models as imitation of stone, wood, metal.
• Construction. As a waterproofing material for various technical structures.

Taking an epoxy resin as a basis and adding one or another plasticizer to it, various types of glue that are used in everyday life are obtained from this polymer. Such glue has a high degree of strength and a different time period for polymerization. Most often, epoxy glue is used in everyday life to carry out repair work.

Uncured resin has the appearance of a plastic substance that is perfectly transparent. Without adding a hardener, it retains its original properties. The hardener acts as a catalyst for the chemical polymerization process, during which the composition gradually and evenly hardens. The speed and quality of the polymerization process is influenced by the proportion in which the resin is mixed with the hardener, as well as the ambient temperature. Manufacturers usually attach detailed instructions to their product indicating the ratio of the two components for mixing them. For work, 10 parts of resin and 1 part of hardener are taken.

The use of ED-20 is carried out in stages.

If you plan to harden the resin at room temperature (cold method), then preliminary preparation for this process is not required. When using the hot method, you will need to warm up the epoxy with a water bath. To do this, the resin is poured into the container and placed in a container with hot water, while it is necessary to ensure that water does not get into the resin, otherwise the polymer will be irretrievably damaged. The composition should be heated moderately and in no case should it be brought to a boil. The heating temperature of the epoxy must not exceed 55 ° C.

If the resin thickens during storage for a long time, it is also preheated, but in this case the temperature should not exceed 40 ° C. In the process of heating in a water bath, the resin must be slowly and gently stirred with a wooden or glass stick.

If it is required that the surface of the cured epoxy resin be resistant to mechanical stress, then a special plasticizer is added to the polymer composition, and then a hardener. This method is used, for example, for making connecting seams in order to give them elasticity. As a plasticizer, DBP (dibutyl phthalate) can be used, which is added in order to increase the resistance of the cured epoxy resin to low temperatures and mechanical damage.DBP is added in an amount from 2 to 5% to the total volume of the resin component.

Another common plasticizer is DEG-1 (diethylene glycol). This component is added in a volume of 3 to 10%, and this additive allows to achieve high elasticity of the hardened epoxy resin. The more DEG-1 is contained in ED-20, the more the finished product will resemble rubber. But the plasticizer has a drawback - it colors the resin in a rich orange color.

After the plasticizer is added to the epoxy resin, the catalyst is introduced into it in the form of a hardener. From this moment, an irreversible polymerization process starts. According to the instructions, the hardener is introduced either into a cold resin or into a resin heated to a temperature not exceeding 40 ° C. Exceeding this indicator can lead to the fact that during the introduction of the hardener, the composition will boil. The hardener should be added very slowly and evenly, stirring constantly. When epoxy resin and hardener are mixed, a chemical reaction occurs, during which heat energy is released. If the hardener is injected too quickly, the resin will overheat and harden immediately.

The following types of catalysts are used as a hardener for epoxy resin:

• PEPA;
• THETA;
• DEET;
• ETAL-45.

When using a hardener of the ETAL-45 brand, you do not have to add a plasticizer to the resin mixture, since this catalyst already contains all the necessary components.

A set for household use of epoxy resin ED-20 is completed directly at the manufacturing plant, it contains resin and a hardener, so these components do not have to be purchased separately from each other. Most often, the cold method is used at home, that is, these two components are mixed at room temperature. In the kit, which is on sale in retail chains, the resin is completed with a PEPA hardener (polyethylene polyamine), although sometimes a TETA hardener (triethylenetetramine) may also be included in the kit instead.

The prevalence of sets with PEPA hardener is explained by the fact that this substance assumes a cold method of application, so the consumer does not have to create additional conditions for heating the components. Besides, PEPA hardener does not tend to cure like an avalanche if the user starts to add hardener too quickly to the resin.

As for the hardener TETA, in the middle of the polymerization time, it is necessary to create conditions for the product where the ambient air temperature will be approximately 80 ° C. In this case, the curing of the material is better and faster.

Full curing of the polymer resin, regardless of which type of hardener was used, at room temperature occurs within an hour. This stage of polymerization is called primary solidification or gelation. In addition to the primary, secondary hardening must also occur. Its duration is from 1 to 2 days. At this time, it is still too early to use the product, since it is necessary to wait for the complete end of the chemical reaction of the polymers.

Polymerization begins after the introduction of a hardener into the resin - it is no longer possible to stop it. For this reason, it is recommended that before performing a large amount of work, mix a test batch of epoxy resin and visually assess its cure rate in order to properly plan all your work.

Working with chemical polymer substances that react with each other requires careful and careful handling from the user. Safety precautions must be followed to protect your own health and preserve the well-being of the environment. The fact is that the components of epoxy resin do not affect people, animals and wildlife only in the case of complete polymerization. In other cases (being in liquid form, separately, as well as during mixing of these substances), chemical elements that are harmful to health are released into the environment.

Epoxy resin has been assigned a hazard class 2 when exposed to the body of humans and animals. If, during the preparation of the mixture, the components of the resin get on the skin, they will cause allergic reactions. To prevent this, the skin must be washed under running water with the addition of soap, and then wiped with a swab dipped in alcohol. After completing these steps, petroleum jelly, castor oil or an emollient cream are applied to the skin.

When working with epoxy-diane resin, it is necessary to protect the organs of vision and breathing. To do this, wear protective goggles, rubber gloves and a respirator. The larger the working area of ​​the resin coating, the more effective personal protection should be. To quickly neutralize chemical components, you should have clean water, alcohol and emollient cream on hand.

For production purposes, epoxy resin is packaged in containers from 50 to 200 kg, it can also be poured into cans, cans or bottles of 0.5 liters. The resin is transported only if the cargo is protected from direct sunlight. The polymer composition ED-20 can be stored in a tightly closed container at temperatures from +15 to + 40 ° C. On contact with air, the resin thickens and dries. It is not recommended to store this product near oxidizing or acidic substances. The shelf life of such a resin is 12 months.

The following video explains the tricks for using epoxy.