Are appliedin radio and electrical engineering as dielectrics and insulating material; in varnishes, paints, putties, for adhesives, impregnations, etc.

It turns outliquid epoxy resins by condensation of epichlorohydrin with dihydric alcohols or phenols, more often with diphenylolpropane (dian various brands ED, E; abroad, EPON brand), with resorcinol (epoxyresorcinol, various RES brands). Hardeners - amines (hexamethylenediamine, polyethylenepolyamines, triethylenetetramine), acid anhydrides (maleic, phthalic, succinic), acids, diisocyanates.

Chemical properties.The reactive epoxy and hydroxyl groups of epoxy resins react with hardeners to cause crosslinking of the molecules. Uncured epoxy resins are soluble in some organic solvents, while cured epoxy resins are insoluble. The number of epoxy groups for resins ED-5, ED-6 *, ED-37 is 11-20%, the content of volatile substances (mainly toluene) is 0.5-2.5%. A feature of the use of epoxy resins is the need to cure them directly during application, which usually leads to the release of volatile ingredients into the air. Release of volatiles from paint coatings based on epoxy resins increases significantly when heated to 85 °. From coatings that are a mixture of epoxy resins with polyamide resin, volatile compounds are released already at 40 ° (Gorshunova et al.). Resins E-181 and ED-5, when used, emit epichlorohydrin, dibutyladipate and diphenylolpropane into the air. The release of volatiles noticeably decreases after heat treatment of the resin at 50 ° for 45-60 h (Ovcharenko). Initial monomers (epichlorohydrin and diphenylolpropane) migrate into water when the ED-5 resin is drained into wastewater (Boltromyuk).

Toxic effect.The resorptive effect of epoxy resorcinol resins is higher than that of dian ones; in the latter, the lower the toxicity, the higher the molecular weight. Cured resins appear to have little resorptive action if they do not contain starting material residues. The greatest danger is posed by skin diseases arising from direct contact and as a result of sensitization. Dermatitis is sometimes accompanied by irritation of the eyes and upper respiratory tract. The toxic effect is aggravated by the use of hardeners with irritating and sensitizing properties (Alekseeva, Terentyeva;; Mehl et al.).

Workers in the process of making and using epoxy resins complained of headache, nausea, poor appetite, burning eyes, swelling of the eyelids, irritation of the upper respiratory tract, skin diseases. (Hine et al .; they were found to have diseases of the upper respiratory tract (rhinitis, pharyngitis, etc.) with a relatively short length of service, growing with lengthening of it.In 20%, lesions of the bronchopulmonary system were detected, and with an experience of 5 and over 10 years, diseases were noted in 29% of the examined. Cases of bronchial asthma were also revealed, especially with the experience of 3-5 years. The disease was preceded by bronchitis, often with asthmoid attacks. In patients with bronchitis on the ECG, there are signs of damage to the heart muscle. The examined workers have disorders of the gastrointestinal tract and liver (violation of protein, pigment and carbohydrate metabolism) .Almost 20% of the surveyed suffered from conjunctivitis, for the most part in combination with skin lesions.

In the process of using epoxy resins and hardeners, skin diseases are observed both through direct contact with them, and when exposed to dust and volatile substances. Diseases manifest themselves in the form of itchy red spots, papular-vesicular rash, eczematous dermatitis, sometimes weeping eczema, as well as edema, especially of the facial skin. Not only open parts of the body are affected, but also parts of the body covered by clothing (Burn). The number of skin lesions, as a rule, is large: some authors believe that 75% of workers get sick (Burn et al .; Siboulet; Grandjean; Welker; Hine et al; Plescher et al .; Spassovskiy et al .;). Skin lesions were of an allergic nature, which was confirmed by positive skin tests with diluted Dianic gum in almost 68% of workers (Gulko; Surkova, Saperova; Kerimova, etc.). Some mastics on the basis of epoxy resins, for example, mastics KD-1, BI-2, are also the cause of skin diseases (Pushkar, Borisenko; Volodchenko).

When resins ED-5 and ED-6 were applied to the skin of female mice for 45 days, their estrous cycle was disrupted (Proshina).

Maximum Allowable Concentration.According to the recommendation of some authors, it should be set according to the content of epichlorohydrin in the air and somewhat lower than for epichlorohydrin itself. So, for epoxy resins, ED-5, ED-40 it is recommended for epichlorohydrin 1 mg / m 3; for E-181 and for EA-1 and DEG-1 resins 0.8 mg / m 3 (Korbakova et al.;).

Individual protection. Preventive measures.Respiratory protection from volatile substances and aerosols released from epoxy resins and all compositions containing it during curing, heating, processing. If it is necessary to work in poorly ventilated spaces - hose gas masks with forced supply of clean air. Sealed glasses. Gloves, sleeves, aprons made of polyethylene, chlorosulfone polyethylene. Application of protective pastes such as CHIOT-6, "invisible gloves", "biological gloves", siloxane ointments, IER-1 paste, etc. Remove adhered resin from the skin immediately (with soft paper), and then wash off with warm water and soap.

Mechanization of preparation of epoxy resins and their compositions and elimination of direct contact of workers with epoxy resins and all materials containing them; limiting the content of the most dangerous volatile impurities in epoxy resins. See Kardashov and others; “Safety regulations and prom. sanitation when working with epoxy resins and materials based on them ", approved. Central Committee of the trade union of workers of the aviation and defense industry on 9 / VIII 1962; "Sanitary rules when working with epoxy resins", M., 1961; methodological instructions "Issues of occupational health and toxicology in the production and use of epoxy resins", L., 1961.

Preliminary and periodic (by a therapist 1 time in 24 months and a dermatologist 1 time in 6 months) examinations when receiving and using epoxy resins, adhesives, etc.

In experiments on animals epoxy resins UP-612, UP-632, UP-629, diepoxy resinsdid not show irritating and sensitizing effects, but signs of their penetration through the skin were found (Kharchenko, Mishchenko).

For persons who have worked with epoxy compound EK-242,revealed chronic bronchitis. The concentration of epichlorohydrin in the air significantly exceeded the permissible level. Skin diseases manifested themselves in the form of dermatitis. EF compoundsand EPF-2have an irritating and sensitizing effect (Pushkar, Borisenko; Zagidullin). When heated compound EPM-2it is recommended to set the MPC for epichlorohydrin - 1 mg / m 3.

Metolon-E fiberglass(with 30% modified epoxy resin) when heated, releases epichlorohydrin and chlorinated hydrocarbons (Dvoskin et al.).

goodevil 22-05-2010 15:23

Good afternoon! I bought myself a knife, Spyderco tenanious. His linings are made of Zh-10. But since the clip is rearranged in 4 different positions, there are holes for fastening on 4 sides. I decided to close them up, since I was not going to rearrange the clip. To do this, I took epoxy, added paste from a gel pen for black. I removed the overlays and carefully filled in the holes for the screws. Then he sanded it. It turned out pretty well.
Only today I read that epoxy, even after drying, is terribly poisonous. And skin contact is dangerous. The question is, is it really that dangerous? My coverage area turns out to be small - holes the size of a match head. Or will you have to drill back now? Tell me what to do

DesignerHP 22-05-2010 15:30

:) I glued a wooden spoon with epoxy about 6 years ago. It seems to be alive and well.

Klingo 22-05-2010 15:33

The components of epoxy are highly carcinogenic. Polymerized epoxy is biologically inert. In your case, despite the fact that there is no certainty that the resin components have completely reacted, the contact area with the hand is so small that there is no reason to worry. It is more harmful to drive around the city in a car, there exhaust gases are MUCH more harmful.

DesignerHP 22-05-2010 15:39

quote: Originally posted by Klingo:

The components of epoxy are highly carcinogenic.

AleksBr 22-05-2010 17:50

After hardening, it is harmless, the domain is clearly annoying, what exactly I do not understand.

kazak354 22-05-2010 18:08

Everything is harmful in our life. The knife itself is very dangerous - it can cut itself and bring an infection into the wound.
And about epoxy - yes, it is not suitable for topcoat handle. But if you can't, but really want to, then you can.
Many trees are stabilized with epoxy (impregnated), then the handles are sharpened - and nothing; This, like hers, "self-made mikarta from dzhinsa" is glued with epoxy through and through and the lining on the handle is sharpened - and it's fine.

kemm 22-05-2010 18:29

quote: From the wiki:
Although an epoxy cured using the correct technology is considered completely harmless under normal conditions, its use is severely limited, since when cured in industrial conditions a certain amount of the sol fraction - a soluble residue - remains in the ES. It can cause serious damage to health, if washed with solvents and ingested... Uncured epoxy resins are poisonous enough and can also harm health.

22-05-2010 18:38

quote: Originally posted by Klingo:
The components of epoxy are highly carcinogenic.

Harmful resin itself or hardener?

both the one and the other component are poisonous, the resin itself is carcinogenic, the hardener is simply not useful. Least harmful polyamine hardener

quote: Polymerized epoxy is biologically inert

if there is no excess of one of the components, which is difficult to achieve at home. The good thing about polyamine is that even with few amino groups, it will react with epoxy groups of the resin.

quote: My coverage area turns out to be small - holes the size of a match head. Or will you have to drill back now? Tell me what to do

in your case, you can score, unless, of course, you are a fan of healthy lifestyle

chief 22-05-2010 21:02

I faced only one problem - from one of the components of the Dzerzhinsk EDP, the skin from the fingers peels off in a couple of days, if it did not notice and did not immediately wash it off with acetone

sheb 22-05-2010 21:10

I doubt the resin will neutralize the hardener. Anyway, he is there inside and gradually stands out IMHO. But the problem is that there is no alternative. Do not glue casein.

For household needs, creating models, repair work, in the manufacture of various adhesives and the plastics used epoxy. It consists of two components (base and hardener), securely fixes various materials together. However, many who use it for their own purposes wonder if epoxy is harmful to health and, if so, how much.

Is it harmful to wear epoxy jewelry

Recently, jewelry made from epoxy has become very popular. When hardened, it is not inferior in terms of reliability and durability precious stones... However, appearance much worse.

The hardened composition does not emit toxic odors and harmful substances that can harm the human body. If you experience discomfort when wearing epoxy jewelry for a long time, you need to give it up and consult a doctor.

Occupational diseases in the field of polymer compounds

Epoxy resins are synthetic compounds. People who constantly work with these compounds are characterized by occupational diseases. Resins are used in conjunction with hardeners. The second, in turn, are hexamethylenediamine, maleic anhydride and others.

Occupational diseases arise from the sensitizing properties of the parent products. Epoxy resin is made from them. List of ailments:

1. Dermatitis.
2. Itching.
3. Redness and inflammation upper layers epidermis.
4. Allergic reactions.
5. Respiratory tract diseases.
6. Bronchial asthma.
7. Irritation of the mucous membrane of the eyes.

Also, some of the components that make up epoxy resins can negatively affect the non-human nervous system.

Toxicity of various types of adhesives

With prolonged contact with adhesives, chronic intoxication of the body can occur.

This is due to the fact that the toxicity of epoxy resin and other adhesives increases over time. Against the background of chronic intoxication, the following health problems may occur:

• Conjunctivitis.
• Headache.
• Irritation of the mucous membrane of the eye.
• Disruption of the respiratory tract.
• Toxic hepatitis.
• Gastritis.
• Pain in the abdomen.
• Chronic cholecystitis.
• Swelling of the eyelids.
• Bronchial asthma.

If epoxy comes into contact with open areas of the body, the skin may turn red, start itching in places of contact with the adhesive.

Poisoning symptoms

After it became clear whether epoxy is harmful to the human body and what problems it can cause, it is necessary to talk about the most common problem that arises during prolonged work with this adhesive. It will focus on the symptoms of poisoning with chemical components contained in. They can be divided into symptoms of eye and respiratory tract poisoning.

Eye symptoms:

• Lachrymation.
• Redness and burning of the eyelid.
• Inability to focus vision.

Respiratory tract symptoms:

• Dyspnea.
• Airway edema.
• Voice change.
• Acrocyanosis.

After damage to the eyes and respiratory tract, painful and unpleasant symptoms can reach the gastrointestinal tract:

• Stomach ache.
• Decreased appetite.
• Nausea and vomiting.
• Stool disorders (discharge may be mixed with blood).

After the onset of symptoms associated with the work of the gastrointestinal tract, the activity of the whole organism decreases. The person feels thirsty and unwell. Muscle pains, drowsiness may appear.

If the resin enters the human body, ulcers may form, mechanical damage to the stomach and intestines, blockage. Patients in whom the resin has hardened in the body are prescribed surgical intervention in order to free the body from foreign matter.

Constant exposure to epoxy can lead to chronic poisoning. It is accompanied by bronchial asthma, allergic reactions, and digestive disorders. Over time, problems with the nervous system begin. Constant fatigue, increased nervousness or depression are direct symptoms of the effect of toxic substances on the nervous system.

After the information provided, it is clear how harmful epoxy resin is to humans.

Poisoning treatment and prevention

The harmfulness of epoxy resin to human health has been proven. However, in the event of poisoning or other problems with the body, a correct diagnosis is required. It is necessary to take a history of the patient in order to diagnose poisoning.

If the stomach and esophagus are affected by chemical damage, the doctor sends the patient for an x-ray. With its help, you can find out if there are chemical burns or ulcers on the walls of the stomach and esophagus. If problems are related to the intestines and the patient's condition becomes complicated, gastroscopy may be performed.

In case of chronic poisoning, mandatory diagnostic procedures are:

1. Blood analysis. The level of acid-base balance is checked.
2. Blood biochemistry.

Depending on the severity of the patient's condition and the presence of other symptoms, other types of examination may be prescribed.

If a person feels symptoms of poisoning, he needs to immediately perform a number of actions:

1. Stop all contact with adhesive completely. Leave the work area.
2. Flush eyes with plenty of warm water.
3. Unbutton your clothes.
4. Sit in a semi-sitting position.

If the condition worsens, you must call an ambulance. Doctors relieve swelling of the respiratory tract, remove eye mucous membrane irritation with drops. They can prescribe the use of antipyretic drugs and pain relievers.

It contains various chemicals that can harm human health. In order not to face unpleasant symptoms, it is required to work in goggles, a respirator, gloves and work clothes. If you experience a feeling of discomfort or pain, you need to immediately stop work and go to fresh air.

It is a synthetic resin that is a polycondensation product of epichlorohydrin and phenols. The epoxy resin is very resistant to alkalis, acids and halogens. Has a very high adhesion to metals. PCBs (carbon and fiberglass), electrical insulating varnishes, plastics are made from epoxy resins, epoxy adhesives, plastocements and potting compounds.

It is correct to call epoxy resins not only ED, but also all polyfunctional and bifunctional substances, which contain a glycine or epoxy group - a tense cycle, which includes an oxygen atom and two carbon atoms. Resins are obtained by polycondensation of epichloridehydrin with various organic compounds, ranging from phenol to edible oils such as soy. In Kazakhstan, resin is obtained from residues in the production of leather goods.

How epoxy resins are made

In addition to a process called "epoxidation", some types of resins are produced by catalytic oxidation of unsaturated compounds. This is how cycloaliphatic resins are made. The value of these resins is that they do not contain hydroxyl groups. Due to this, the resins have high arc resistance, tracking resistance and water resistance.

Depending on the brand epoxy resin It is a transparent yellow-orange liquid or solid brown mass, similar to tar. Liquid resin happens different color - from transparent white to wine-red (epsidated aniline).

Epoxy resin is used together with a hardener. These can be acids, anhydride or polyfunctional amine. Sometimes tertiary amines are used as curing catalysts, which are usually blocked by a complexing agent such as pyridine or Lewis acid.

After epoxy mixed with a hardener, it can be transformed into an infusible, insoluble solid. It takes about a day to cure polyethylene polyamine (PEPA) at room temperature. Anhydrite hardeners have to be heated to 180 ° C and kept in a thermostat for 10 hours. It is also necessary to take into account cascade heating from 150 ° C.

Application of epoxy resins

Based on these resins, various materials... Subsequently, these materials can be used in a wide variety of industries. Epoxy and carbon fiber combine to form carbon fiber. Boat hulls are made of epoxy resin fiberglass that can withstand the most severe impacts. The fastening bolts of the Earth-Air missiles use a composite based on ED 20. Epoxy resins used in the manufacture of material for body armor.

If the resin is cured with the correct technology, it is considered harmless under normal conditions. But its application is limited. This is due to the fact that during curing under industrial conditions, a soluble precipitate remains in the ES - the sol fraction. If it is washed with a solvent and ingested, it will cause serious harm to the body. Uncured epoxy resins are poisonous and harmful to humans.
With this in mind, there are a few rules to follow.
1. Dishes that are glued with ES cannot be used for eating and storing food.
2. It is necessary to work with ES in rubber gloves.
3. If ES gets into the eye, it is necessary to urgently rinse it with water and consult a doctor.
4. Wear a dust mask when working with solid hardeners and resins.
5. ES should not be cured in a household oven.

The compound obtained by synthesis is a synthetic substance with a complex chemical structure. The term "" (ES) is used more often. It has been used in industry since the fifties of the last century. Its unique properties - chemical and mechanical resistance, durability, low shrinkage, improved adhesion, etc. - ensured the widespread use of the polymer in various industries.

home distinctive feature - preparatory stage. ES is not available in finished form. First, it must be combined with a hardener. The contact of these two components initiates the polymerization reaction, as a result of which the finished product is formed. The resulting liquid substance gradually hardens (on average 24 hours), forming the strongest adhesive layer, or a product of the required parameters, or a durable protective coating.

There are two types: hot and cold curing. In production, a "hot" variety is used, the so-called "technical", which is characterized by increased operational properties. To obtain such a polymer, the temperature rises to 200C. It requires careful handling due to toxicity, high heating of the mass, and harmful fumes. Application technical kind in everyday life it is inconvenient and even dangerous due to the possibility of causing serious harm to health.

For domestic use, a "cold" variety has been developed - a jewelry compound. It is used for the manufacture of jewelry and interior items, as well as for household needs - repair, gluing. The composition is very popular. The combination of glass transparency and increased strength makes it possible to "brick up" in the depths of plastic whole plot pictures from nuts, pieces of glass and many other fillers.

Safety and operation

Unusual spectacular jewelry with various fillings and interior design developments (for example, self-leveling floors or furniture with various thematic compositions created in plastic) are very colorful and are in constant demand. Therefore, among professionals and amateurs of "hand-made" the interest in "epoxy" does not decrease.

Manufacturers offer modern brands with enhanced usability. After solidification, the mass is completely safe to use, odorless, and does not emit toxic elements. Caution should be exercised during the preparation and use of a liquid or viscous substance while it is poisonous. The degree of toxicity depends on the qualitative and quantitative composition of the mixture. Hot epoxy is especially dangerous. On contact with the skin, the drug can cause irritation, dermatitis and even burns. Inhalation of vapors irritates the mucous surfaces of the respiratory tract and eyes, the vapors can cause poisoning. But if you follow certain principles, working with the material is not dangerous.