Expanding rust-preventing spot welding structural sealant for car, and preparation method thereof

Abstract

The invention provides an expanding rust-preventing spot welding structural sealant for a car, and a preparation method thereof. The preparation method comprises the following steps: preparing 7-20 parts of master batch, 8 parts of aluminium hydroxide, 3 parts of calcium oxide and 3 parts of TXIB, kneading the prepared raw materials for 30 minutes on a kneader; adding in 6 parts of aluminium hydroxide, 5 parts of a rust inhibitor, 8 parts of conductive carbon black and 5 parts of TXIB for kneading for 15 minutes in the kneader to enable materials to be conglomerated; adding in 7 parts of nano-calcium, 3.5-10 parts of liquid butadiene, 3-25 parts of bisphenol F epoxy resin and 3 parts of TXIB for kneading for 25 minutes in the kneader; adding in 5 parts of coarse whiting, 0.3-0.5 part of DCP-40, 0.2-0.5 part of DM, 1-4 parts of superfine dicyandiamide and 3 parts of an ethenyl physical foaming agent for kneading for 20 minutes in the kneader; adding in 6-27.5 parts of acrylate mixed epoxy resin in the core-shell structure for kneading for 10 minutes in the kneader; adding in 1.5 parts of TXIB; reserving 1.5 parts of TXIB for adjusting viscosity. The structural sealant after curing is high in strength, good in tenacity and excellent in rust prevention.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to an intumescent automobile antirust spot welding structure sealant and a manufacturing method thereof. Background technique [0002] The main function of spot welding glue for automobiles is to seal, absorb shock and disperse the stress around the solder joints, so as to achieve the functions of dustproof, waterproof, anticorrosion and shock absorption, thereby prolonging the service life of automobiles. It is mainly used in automobile welding production lines. Before the paint treatment of the car body, the joints of the parts composed of steel plates are pre-coated with anti-rust spot welding sealant, and then spot welded after lamination, and then go through degreasing, water washing, phosphating, electrophoresis and other treatment processes together with the car body Finally, it is baked and cured together with the electrophoretic paint. [0003] Since October 1, 2...

AI Technical Summary

Problems solved by technology

[0004] At present, the anti-rust spot welding structure sealant is used on the fender, the side of the car body and the bottom plate, the wheel cover, the instrument panel, etc. The spot welding glue for the car needs to have good elasticity in order to absorb shock, and the general requirements Shore C-type hardness is between 20 and 50. Polyvinyl chloride resin is added to the resin. Although the elasticity is improved, it will release toxic gas containing chlorine when spot welding is decomposed, polluting the environment and harming the operator. Health poses a threat, and when the temperature exceeds 170 ° C, it will release hydrogen chloride gas and corrode the steel plate; the foaming anti-rust sealant is added with a chemical foaming agent during use, and the pores and foaming uniformity are difficult to obtain during the foaming process. Control, the foamed cells absorb moisture, which reduces the corrosion resistance of the foamed anti-rust sealant, and the non-foamed anti-rust sealant is difficult to solve the welding gap caused by the mold precision problem, how to make the spot welding sealant It has good elasticity, vibration resistance, sealing, and aging resistance to adapt to the environment of the car in the wild, and it will not release harmful gases during welding. This is a problem that we need to solve urgently

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