Preparation Of Low Irritation And Non-benzene Chloroprene Adhesive

Neoprene adhesives have advantages in high adhesive strength,good impact resistance and good dielectric resistance,etc.Accordingly,they have been widely used in many industries.Usually,the traditional solvent chloroprene adhesives use benzene,toluene,xylene,chlorinated and other organic solvents as the solvent.These solvents are not only harmful to human health,but also pollute the environment.With the increasing consideration for environmental protection,there is a growing demand for environmentally friendly neoprene adhesives.Therefore,environmentally friendly neoprene adhesive were prepared and studied recently,where ketones,esters and other low toxicity solvent were used instead of the traditional solvents.The toxicity problem has been improved,however,the strong irritation of solvents brings another problem to the construction environment.In this paper,three kinds of low toxicity and non-irritating solvents were studied by “solubility parameter and hydrogen bond index” method,which considers the development status,actual operating conditions and construction environment of chloroprene adhesives.The neoprene adhesives were prepared by the pre-reaction of 4-tert-butyl phenolic resin with light Magnesium Oxide.Then the content of chloroprene rubber,resin and the pre-reaction conditions were optimized.The results are shown as follows:(1)The mixed solvents can dissolve the chloroprene rubber when the sum of their solubility parameters and hydrogen bond indexes are in the range of 10.7-14.0,and vice versa.When the volume ratio of cyclohexane/solvent oil/dimethyl-carbonate is 3:4:3,the mixed solvents have good solubility.(2)The viscosity and nonvolatile content of chloroprene adhesive prepared by the optimized proportion are 10980 mPa·s and 27.5%,respectively.The peel strength and shear strength are 3.55 kN/m and 1.88 MPa,respectively.It is in accordance with HGT3738-2004 Industry Standard.(3)Compared with the domestic and foreign products,the neoprene adhesive prepared by the formula does not contain benzene solvents,and the irritating odor is small,making the operating environment more comfortable.