What is epoxy adhesive?
is a kind of engineering adhesive formulated by epoxy resin base, curing agent, diluent, accelerator, and filler. Due to its excellent adhesive property, good functionality, comparatively low price, and a simple adhesion procedure, it has been used in a variety of applications in the fields of appliance, automotive, hydraulic and transport, electronic appliances, and the aerospace industry in recent decades. With the continuous development of high-tech and nanotechnology, in recent years, the modification of epoxy resin has been deepened, and the methods of the interpenetrating network, chemical copolymerization, and nanoparticle toughening are widely used, and there are more and more varieties of high-performance adhesives formulated by epoxy resin.Epoxy resin adhesives (epoxy adhesives or epoxy glue for short)
have been around since 1950, only 50 years ago. But with the middle of the 20th century, a variety of adhesive theory, as well as adhesive chemistry, adhesive rheology and adhesive damage mechanism and other basic research progress, so that the adhesive performance, variety and application has been a rapid development. Epoxy resin and its curing system with its unique, excellent performance and new epoxy resin, new curing agent and additives continue to emerge, become an important class of adhesives with good properties, wide range of varieties and widespread adaptation.
Application of epoxy adhesive
Application to automobiles: chassis primer, parts paint, tanker interior coating
Application to containers: food cans interior and exterior coating, storage tanks interior and exterior anti-corrosion coating, pressure tanks anti-corrosion
For factory equipment: equipment, pipeline anti-corrosion coating, refrigerator, washing machine outer layer coating, electrical equipment insulation coating
Application in other: steel furniture powder coating, resistance components powder coating, steel parts powder coating, valve body anti-corrosion, heavy anti-corrosion super wear-resistant ceramic, shielding vertical pipe pump, solar water heater, solar panels, weapons.
Epoxy adhesives can be used in automotive parts, factory equipment, insulation materials, and light-emitting diodes and photodiodes, laboratory countertops, etc.
Epoxy glue can be applied to room temperature fast curing toughness epoxy resin adhesive, conductive adhesive, room temperature curing electrostatic flocking adhesive, optical structural adhesive, shuffle ball adhesive, chemical anchoring adhesive, high functionalization of silk, artificial flower, magnetic writing board, car repair adhesive, stone adhesive, etc.
Application of toughened epoxy resin in adhesives
Based on toughened epoxy resin with functional filler and curing agent, the polymer alloy adhesive is formed to overcome its shortcomings such as brittleness, impact and poor heat resistance. It has been widely used in the fields of machinery, electronics, electrical appliances, aerospace, aviation, coatings, bonding, etc., and is known as the universal structural adhesive.
Epoxy adhesive composition
The basic components of epoxy resin adhesive
are epoxy resin and curing agent, according to the requirements of different properties, it can also include toughening agent, plasticizer, diluent, accelerator, antioxidant, filler, coupling agent, etc.1）Epoxy resin
The relative molecular
weight of epoxy resin used as adhesive is generally 300~7000, and the viscosity is 15~55 Pa-s. The main varieties are glycidyl epoxy resin and epoxy olefin.2）Curing agent
Since epoxy resin itself is a thermoplastic linear structure compound, it cannot be directly used as adhesive, it must be added with curing agent and curing cross-linking reaction under certain conditions to produce a non-melting, insoluble body type mesh structure.3) Toughening agent
Improve the brittleness, improve the impact strength and peel strength. Toughening agent is divided into: active toughening agent, inactive toughening agent.
Inactive toughening agent does not participate in the curing reaction, but the free state in the cured adhesive layer, the amount should not be too much, commonly used dibutyl phthalate, dioctyl phthalate, triphenyl phosphite; active toughening agent involved in the curing reaction, toughening effect is better, the amount is relatively more than inactive toughening agent, commonly used low molecular polysulfone, liquid nitrile, liquid carboxyl nitrile and other rubber, polyurethane and low molecular polyamide and other resins.4) Diluent
Reduce the viscosity of the adhesive, improve the process, increase the wettability of the sticky material, such as acetone, toluene, ethyl acetate, etc..
(5) filler: has the role of reducing costs and improving the performance. Such as glass fiber, talcum powder, titanium dioxide, etc.
Advantages of epoxy adhesive
Epoxy glue has the following advantages compared to other types of adhesives.
1. Epoxy resin contains many kinds of polar groups and epoxy groups with great activity, thus it has strong adhesion with many kinds of polar materials such as metal, glass, cement, wood and plastic, especially those with high surface activity, and the cohesive strength of epoxy cured products is also great, so its adhesive strength is very high.
2. Basically, there is no low molecular volatiles generated when the epoxy resin is cured. The volume shrinkage of the adhesive layer is small, about 1% to 2%, which is one of the smallest varieties of curing shrinkage among thermosetting resins. It can be reduced to less than 0.2% after adding fillers. The linear expansion coefficient of epoxy curing material is also very small. Therefore, the internal stress is small, the impact on the adhesive strength is small. In addition, the creep of epoxy curing material is small, so the dimensional stability of the adhesive layer is good.
3. There are many varieties of epoxy resin, curing agent and modifier, which can be designed by reasonable and clever formulation, so that the adhesive has the required process (such as fast curing, room temperature curing, low temperature curing, curing in water, low viscosity, high viscosity, etc.), and has the required performance.
4. With a variety of organic materials (monomer, resin, rubber) and inorganic materials (such as fillers, etc.) have good compatibility and reactivity, easy to copolymerization, cross-linking, blending, filling and other modifications to provides improved performance of the adhesive layer.
5. Good corrosion resistance and dielectric properties. It can resist the corrosion of various media such as acid, alkali, salt and solvent. Volume resistivity 1013-1016Ω-cm, dielectric strength 16-35kV/mm.
6. General-purpose epoxy resin, curing agent and additives have many origins and large production volume, easy to prepare, can contact pressure molding, and can be applied on a large scale.
Types of epoxy adhesive
|Classification method||Specific name
|Classification by morphology||Solvent-free adhesives
(Organic) solvent-based adhesives
Epoxy adhesive film
|Classification by curing conditions||Cold curing adhesive
Heat curing adhesive
Other curing methods
|Classification by gluing strength||Structural adhesive
Sub-stress structural adhesive
|Classification by use||General purpose adhesives
Epoxy adhesive specifications
|Features||High strength, no collapse
|Viscosity||After mixing - high
|Suitable time||120 minutes
|Volume mixing ratio||2 to 1
How to use epoxy adhesive?
a. First, take dry cotton cloth or sandpaper to remove the dust, oil, and rust from the base surface, and then take acetone or trichloroethylene to clean the outer layer.
b. Open the epoxy resin adhesive, and according to the proportion of the proportion.
c. Then apply to the base surface gluing can, pay attention to the construction must be within the specified time with work, otherwise, it will dry up leading to unnecessary waste, a day after the strength will reach the highest.
d. The uncured epoxy glue can be cleaned with acetone, and the cured epoxy glue can only be removed by mechanical sanding.
e. It will be cured in 2 to 3 hours after application.
f. When gluing straight and inverted surfaces, the glue is applied without the aid of self-adhesive paper or 502 glue for positioning. It is usually used for bonding high-temperature metals, ceramics, and other materials, and the best working temperature is maintained between minus 50 and 180 degrees.
Precautions for using epoxy adhesive
1. Whether it is the main agent or the curing agent, keep it out of the air during storage and make sure that the container holding the epoxy adhesive is sealed. Avoid direct skin contact with the uncured mixture and wear protective gloves and glasses.
2. The glue can be applied by hand with a squeegee or roller, or by two-component machine. In general, a single-sided application is sufficient and the amount of glue applied depends on the material itself.
3. Materials just glued together with epoxy glue should be cured under 0.5kg/㎝ pressure so that the glue has good contact with both surfaces.
4. The surface to be bonded should be dry, free of grease, dust or other contaminants. If the metal surface is polished, or in some special cases epoxy primer is available, the bonding strength will be significantly increased.
5. Mix the main agent and curing agent well before proportioning, to ensure accurate proportioning and uniform mixing, in order to obtain the ideal mechanical and chemical properties. The amount of glue mixing at one time should not be too much, and should be used up within the applicable period.
6. It can be cured under natural conditions or accelerated by heating. Increasing the curing temperature and extending the pressurization time can improve the initial adhesive strength. If available, it is recommended that the heating temperature should be at least 60℃.
7. The uncured epoxy glue can be cleaned with acetone, and the cured epoxy glue can only be removed by mechanical sanding.
How to buy epoxy adhesive?
ANTITECK provide lab equipment, lab consumable, manufacturing equipment in life sciences sector.
If you are interested in our epoxy adhesive or have any questions, please write an e-mail to firstname.lastname@example.org, we will reply to you as soon as possible.