" " wisno wood furniture finishing: Cellulose acetate butyrate

Wednesday, October 14, 2009

Cellulose acetate butyrate

The butyrate or the cellulose acetate butyrate (CAB) lacquer is the non yellowing lacquer. It is a special lacquer that is developed to answer the problem of yellowing in the nitrocellulose system finish. It is formulated by using the cellulose acetate butyrate resin as the main ingredient. Cellulose acetate butyrate resin is cellulose (wood fibers)  that is processed by acetic acid and butyric acid. The cellulose acetate butyrate coating has high resistant to the UV light. It is simple, one component and quite easy in application as the nc coating, but its film won,t be yellowing.
The cellulose acetate butyrate resin is mixed with acrylic resin and some additive to make butyrate lacquer. The butyrate clear coating will give a film layer that has a better resistance to the ultraviolet light. As a lacquer the butyrate is quite similar with the nitrocellulose lacquer. It is one component coating, washable, fast dry, clear looked and easy to be handled.

Compare with Nitrocellulose coating, the cellulose acetate butyrate coating has less resistance to the alcohols and hydrocarbons solvents. The cellulose acetate butyrate film also has less compatibility with modifying resins and plasticizers. The butyrate lacquer also will give the "muddy looked") to the finishing film. The muddy looked is very slightly and will not affect the white or light color finish, but it could be visible for the dark brown or black finish. 
Normally the cellulose acetate butyrate is only used to the light color or white color when the yellowing film is not allowed. It is more complicated and more expensive then the nitrocellulose lacquer. The butyrate lacquer is the proper coating for the white color finished such as: white paint, white wash or antique white finish. It is also used for the natural for the light wood finish when the yellowing of the film coating is not allowed. 

The butyrate clear coating is available in the sealer and top coat. The butyrate sealer is rarely used. The addition of the sanding agent to the butyrate is limited. The small amount of the sanding agent will quickly increase the viscosity of the lacquer. In the finishing process the butyrate is used for the top coat and sealer for the white color and very light color finish. The combination with vinyl sealer is also can be used. The vinyl sealer is not yellowing sealer and will increase the coating adhesion. 
The butyrate lacquer mixed with white pigment is the white enamel. It will give the white paint color and can be used as the last coat layer.


butyrate coating for white color



white finish with butyrate lacquer

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