What kinds of adhesives are there?
Classification and application of adhesives
There are many kinds of adhesives. According to different standards, adhesives are simply classified as follows.
1. According to the chemical properties of adhesives, they can be divided into inorganic adhesives and organic adhesives. Such as water glass, cement, gypsum, etc. It can be used as an inorganic adhesive, while adhesives with polymer materials as adhesives belong to organic adhesives.
2. According to the physical state of adhesives, they can be divided into liquid adhesives, glue stick adhesives and paste adhesives. Among them, glue stick adhesives are in powder and film forms, while liquid adhesives can be divided into aqueous solutions, organic solutions, aqueous emulsions and non-aqueous medium dispersion types.
3. According to the source of adhesive, it can be divided into natural rubber and synthetic rubber. Such as natural rubber, asphalt, rosin, gelatin, cellulose, starch adhesive, etc. All belong to natural adhesives, and all kinds of adhesives synthesized by artificial polymerization belong to the category of synthetic adhesives.
4. According to the molecular structure, common organic adhesives can be divided into thermoplastic resin, thermosetting resin and rubber adhesive.
5. According to the application mode of adhesive, it can be divided into pressure-sensitive adhesive, rewetting adhesive, dry glue adhesive and delay adhesive.
6. According to the application temperature range of adhesive, it can be divided into high temperature resistant adhesive, low temperature resistant adhesive and normal temperature resistant adhesive. According to its curing temperature, it can be divided into normal temperature curing adhesive, medium temperature curing adhesive and high temperature curing adhesive.
7. According to the application fields of adhesives, adhesives are mainly divided into adhesives for civil construction, papermaking and plants, automobiles, airplanes and ships, electronics and electricity, and medical and health care.
8. According to the chemical composition of adhesives, they can be divided into various specific types of adhesives, such as epoxy resin adhesives, polyurethane adhesives and polyvinyl acetate adhesives.
9. Hardening adhesive, polyurethane adhesive, epoxy adhesive, sealant, hot melt adhesive, potting adhesive, silicone rubber, conductive adhesive, pressure-sensitive adhesive, white latex, all-purpose adhesive, anaerobic adhesive, polyamide adhesive, laminating adhesive, penetrating adhesive, waterproof glue, fireproof adhesive, speaker adhesive, automobile adhesive, electronic and electrical adhesive, photosensitive adhesive, building adhesive, solar adhesive and automobile maintenance adhesive.
Thermoplastic molding
Cellulose ester, vinyl polymer (polyvinyl acetate, polyvinyl alcohol, perchloroethylene, polyisobutylene, etc. ), polyester, polyether, polyamide, polyacrylate, α-cyanoacrylate, polyvinyl acetal, ethylene-vinyl acetate polymer, etc.
Thermosetting type
Epoxy resin, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, silicone resin, furan resin, unsaturated polyester, acrylic resin, polyimide, polybenzimidazole, phenolic-polyvinyl acetal, phenolic-polyamide, phenolic-epoxy resin, epoxy-polyamide, etc.
Synthetic rubber type
Neoprene rubber, styrene-butadiene rubber, butyl rubber, sodium butadiene rubber, isoprene rubber, polysulfide rubber, polyurethane rubber, chlorosulfonated polyethylene elastomer, silicone rubber, etc.
Rubber resin agent
Phenolic nitrile rubber, phenolic chloroprene rubber, phenolic polyurethane rubber, epoxy nitrile rubber, epoxy polysulfide rubber, etc.
Application of adhesive
1, instant bonding. When in use, it does not need to be heated or pressurized, and has the characteristics of fast curing and high bonding strength. A 6.45-square-centimeter sticky surface bears enough tension to lift a car. This kind of adhesive has greatly promoted the development of continuous production line.
2. Bonding of structural parts. The bonding of structural parts refers to the bonding of objects that can withstand long-term load and great stress, such as the bonding of structural parts such as buildings, vehicles, ships, airplanes and spacecraft. Increase the speed; At the same time, the surface of the bonding piece is smooth and smooth, which is beneficial to navigation; It also has the properties of sealing and corrosion resistance.
3, liquid sealing plugging. Some adhesives are liquid at room temperature, which are coated on various connecting or sealing parts to form an elastic adhesive layer, which can replace the usual gasket and play a sealing role.
4. Underwater bonding. In the construction of dams or bridges, shipbuilding industry and national defense industry, it can connect prefabricated components on land with underwater and underwater parts, thus greatly simplifying the construction technology and speeding up the construction progress.
5, oil surface bonding. The adhesive for oil surface does not need to remove oil stains on the surface first, which simplifies the process and has good bonding strength.
6. Hot melt bonding. Hot melt adhesive is a solid, which can only be bonded after being heated and melted into a fluid, and will be reduced to a solid after being bonded and cooled to form a solid adhesive. Hot melt adhesive is made of thermoplastic polymer and tackifier.
7. High temperature bonding and ultra-low temperature bonding. General adhesives can withstand temperatures below 100℃. Inorganic glue can resist about 600℃, among which ceramic glue is the best, and can resist the high temperature of 1300℃. The ultra-low temperature resistant adhesive can still maintain high strength and toughness at a lower temperature of-196℃ or even -269℃.
8. Pressure-sensitive bonding. This product is used for pasting commodity labels, sealing boxes, bundling wire harnesses and protecting the surface of high-gloss metal plates.
9. Medical integration. Medical glue has become an indispensable new material in medical treatment. For example, it can play a very good role in kidney adhesion, blood vessel connection, wound, esophageal or biliary anastomosis, dental adhesion repair, bone connection and so on.
10, in addition, it is also used for conductive bonding of electronic device leads, and there is conductive adhesive with silver powder as conductor. High transparency optical glass adhesive, photosensitive curing adhesive and electron beam curing adhesive used for optical glass bonding.