48results about How to "Improve surface toughness" patented technology

The invention relates to transparent matt polyurethane varnish. The preparation method of the varnish comprises the following steps: according to weight percentage, 40 to 60 percent of alkyd, 10 to 40 percent of elastic resin and 0.3 to 1.0 percent of a dispersant are sequentially added and are dispersed at the speed of 500 revolutions per minute for 3 to 5 minutes to evenness; while stirring, 2.0 to 5.0 percent of flatting powder, 3.0 to 10 percent of glass powder and 0.5 to 2.0 percent of wax powder are added and are dispersed for 15 minutes at the speed of 1,000 revolutions per minute till the fineness is less than or equal to 25 mu m; 0.2 to 0.5 percent of a leveling agent, 0.2 to 0.5 percent of an antisettling agent and 13.6 percent of a mixed solvent are sequentially added and are dispersed for 10 minutes at the speed of 800 revolutions per minute; 1.0 to 5.0 percent against 20 percent scratch resistant resin which is pre-dispersed is added into a varnish material obtained by the steps under the low-speed stirring; and after adding, the varnish material is dispersed for 10 to 15 minutes at the speed of 500 revolutions per minute to evenness and is filtered to obtain the transparent matt anti-scratch polyurethane varnish. The crosslinking density NCO/OH of the varnish and a curing agent is between 1.0 and 1.1; and the curing agent is mixed by the following compositions in weight percentage: 25 percent of aliphatic poly-isocyanate, 45 percent of aromatic poly-isocyanate and 30 percent of anhydrous butyl acetate. The varnish has good scratch resistance and high hardness; and a varnish film has smooth hand feeling, good transparence, does not blanch basically, has good storage stability and can be recoated.