Patent ID: 9238748
Filing Date: 2016-01-19
CPC Classification: C08F,C08L,C09D

Claim Text:
1. A baking type water-based automobile finishing varnish having improved acid resistance, wherein, the baking type water-based automobile finishing varnish is prepared by following steps: a) weighing raw materials according to the component A, the component A comprises 20-30 wt. % of a methacrylate monomer, 35-45 wt. % of a nacrylate monomer, 5-15 wt. % of a non-acrylate monomer, 5-15 wt. % of an acrylic monomer, 10-20 wt. % of a hydroxyl-containing acrylate monomer, and 0.5-1.5 wt. % of a chain transfer agent; mixing the weighed raw materials to yield a first solute, dissolving the first solute in a solvent whereby obtaining a first solution having a mass percentage concentration of 50-70%; adding an initiator accounting for 1.4-3 wt. % of the solute to the first solution, uniformly mixing to yield a solution A; conducting a solution polymerization reaction on the solution A to yield an acryl resin A; cooling the solution A to a temperature of between 50 and 60° C., adding a neutralizer to the cooled solution A to regulate a neutralization value of the acryl resin A to 60-100%, whereby obtaining a water-based acryl resin A with a number-average molecular weight of about 10000; b) weighing raw materials according to the component B, the component B comprises 5-15 wt. % of the methacrylate monomer, 35-45 wt. % of the acrylate monomer, 5-15 wt. % of the non-acrylate monomer, 5-15 wt. % of the acrylic monomer, 25-35 wt. % of the hydroxyl-containing acrylate monomer, and 0.5-1.5 wt. % of the chain transfer agent; mixing the weighed raw materials to yield a second solute, dissolving the second solute in the solvent whereby obtaining a second solution having a mass percentage concentration of 50-70%; adding the initiator accounting for 0.3-1.1 wt. % of the solute to the second solution, uniformly mixing to yield a solution B; conducting the solution polymerization reaction on the solution B to yield an acryl resin B; cooling the solution B to a temperature of between 50 and 60° C., adding the neutralizer to the cooled solution B to regulate a neutralization value of the acryl resin B to 60-100%, whereby obtaining a water-based acryl resin B with a number-average molecular weight of about 20000; c) uniformly mixing the water-based acryl resin A obtained from step a) and the water-based acryl resin B obtained from step b) with a mass ratio thereof of 1-4:1, whereby yielding a mixed water-based acryl resin, adding hexamethoxy methyl melamine-formaldehyde resin as a crosslinking agent to the mixed water-based acryl resin, a mass ratio of the mixed water-based acryl resin to the crosslinking agent being 2-3:1, and diluting the mixed water-based acryl resin using water to reach a required viscosity, whereby yielding the baking type water-based automobile finishing varnish having improved acid etching resistance;