The selection of adhesive is crucial in the assembly process of electronic components. In order to pursue efficiency and speed, many users hope that adhesives can cure quickly. Manufacturers of chloroprene rubber have developed many varieties with medium to high crystallization rates to meet this demand. For example, companies such as DuPont in the United States, NEC in Japan, Toyo Soda in Japan, and Bayer in Germany have all launched a variety of chloroprene rubber varieties that are suitable for different needs.

crystallization rate 🏎️

The crystallization rate directly affects the curing time of the adhesive. Adhesives with fast crystallization rates, such as G-40S from Toyo Soda Corporation in Japan and A-90 from Nippon Electric, have strong initial adhesion and short adhesion retention time, achieving maximum adhesion within approximately 2-3 hours. The slower crystallization rate of adhesive species, such as M-40, although has a longer time for the increase of adhesive strength, the adhesion retention time is longer, about 60-80 hours, and the low-temperature performance is better.

The softness and hardness of the adhesive film 💪

The softness and hardness of the adhesive film is also an important consideration factor. When bonding electroacoustic equipment, users often want the adhesive film to be hard and tough in order to reduce distortion during sound propagation. But in the field of damping, the adhesive film needs to be softer. The softness and hardness of the rubber film vary among different specifications and models of chloroprene rubber. For example, the G-40S-1 adhesive film from Tosa in Japan is harder than the Y-30S. Generally speaking, the faster the crystallization rate of chloroprene rubber, the harder the rubber film. Therefore, when selecting rubber varieties, it is necessary to choose suitable chloroprene rubber varieties according to different application purposes.

Application of different types of adhesive in combination 🔄

In some special occasions, in order to meet the comprehensive performance requirements of the product, different types of chloroprene rubber can be used together, or chloroprene rubber can be used in combination with other rubbers. For example, in order to achieve better low-temperature resistance, it is possible to consider using chloroprene rubber models with low crystallization rates; In order to improve processability, enhance adhesive strength, and improve flexural and tear resistance, it may be considered to use it in combination with natural rubber; Combining with nitrile rubber can improve its oil resistance.

solvent selection 🌐

The solubility of chloroprene rubber in solvents, the initial viscosity of adhesives, the stability of viscosity, layer separation, coating, adhesion retention, impregnation of the bonded material, initial adhesion force, and bonding strength are all closely related. In addition, toxicity, volatilization rate, and impact on the atmospheric ozone layer are also factors that need to be considered. With the increasingly strict environmental regulations and the strengthening of people's health awareness, the production and use of environmentally friendly chloroprene adhesives is the trend. According to the latest patent report, the VOC of the newly invented low VOC chloroprene rubber adhesive is less than 250g/L.

When selecting adhesives, it is necessary to comprehensively consider factors such as crystallization speed, film softness and hardness, compatibility of different adhesive types, and solvent selection based on specific application scenarios and requirements, in order to select the most suitable adhesive type.