Rubber adhesive is a type of adhesive that has good adhesion properties to various substances and has strong initial adhesion. At the same time, the elasticity of rubber has an excellent buffering effect on the volume shrinkage of materials with different expansion coefficients, and on impact and vibration. Therefore, it can be used to prepare adhesives.
1. Neoprene adhesive
Neoprene is an addition polymer of 2-chloro-1,3-butadiene. The adhesive made of chloroprene rubber is referred to as chloroprene adhesive. Due to its high crystallinity, high polarity and excellent adhesion, it is the most widely used rubber adhesive. Its dosage Accounting for more than 70% of the total amount of synthetic rubber adhesives.
(1) Types of chloroprene rubber adhesives
①Contact adhesives generally use high crystallinity AC type or AD type chloroprene It is composed of gel polymer and alkyl-substituted phenolic resin, with additives such as zinc oxide, magnesium oxide and antioxidants added, and aliphatic hydrocarbons, aromatic hydrocarbons, ketone or ester solvents are used to prepare the solution.
②AF adhesive The AF type polymer of chloroprene rubber contains hydroxyl groups. Because it contains hydroxyl groups, the rubber masticating temperature must be controlled below 25°C to prevent interaction with additives and magnesium oxide. reaction, in addition, if only aromatic hydrocarbon solvents are used, the solution will produce stringing phenomenon, so a small amount of water must be added to the mixture.
③HC adhesive Neoprene HC polymer is highly crystalline. If a polymer heated to 70°C is cooled and kept at room temperature, its hardness will increase rapidly within a few minutes, while other types of chloroprene rubber will take at least two hours to completely crystallize. HC polymer hardly softens below 50°C, but softens rapidly when it exceeds 50°C, and has low viscosity when melted at high temperatures. These characteristics indicate that it is particularly suitable for making heat-sealing adhesives.
(2) Advantages and applications of chloroprene rubber adhesive Neoprene rubber adhesive has the following advantages:
① It has outstanding flexibility Flexibility;
②Good oil resistance and chemical resistance, non-toxic or low toxicity, non-flammable;
③Good aging resistance;
④ Because it contains polar groups, it has high bonding strength and a wide range of applications;
⑤ generally does not require vulcanization, and can be made into a one-component adhesive, which is easy to use.
Neoprene rubber adhesives have excellent flame resistance, ozone resistance, aging resistance, oil resistance, water resistance, solvent resistance and chemical resistance, so they are widely used in construction, shoemaking, electronics, textiles, automobiles, and shipbuilding. It has a wide range of applications.
The application of neoprene adhesive requires a clean site, no dust, dry adherends and no oil stains, and the application temperature should be within 15~35°C. Relative humidity is less than 80%, pressurize appropriately.
