Method for preparing stable bleached shellac
AssigneeMantrose-Haeuser Co., Inc.
InventorsStephen A. Santos, Joseph F. Cotter, Sr., Margaret M. McWeeney
Life of this patent
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Abstract
A stable bleached shellac and an improved method for making stable bleached shellac is provided which involves precipitating bleached stable shellac from a pre-shellac solution at a pH of from 5.0 to 6.8, preferably from 5.0 to 6.5, most preferably from 5.0 to 6.0. The stable particulate shellac and the stable shellac solution, have a longer shelf life than conventional shellac. The stable shellac solution is comprised of solubilized particulate shellac in a solvent, most preferably ethanol. The stable particulate shellac and the stable shellac solution have a pH of from 4 up to less than 5 or from 5.0 to 6.8, more preferably from 5.0 to 6.5, even more preferably from 5.0 to 6.3, most preferably from 5.0 to 6.0.
Claims37
A bleached, stable shellac having a pH of from 5.0 to 6.8;
- and selected from the group consisting of:
- bleached, stable particulate shellac;
- a de-lipidized, bleached, stable shellac solution characterized in that when said solution is heated to 100° F. for 6 weeks, the pH drops less than 15%;
- and
- a lipidized, bleached stable shellac solution characterized in that when said solution is heated to 100° F. for 6 weeks, the pH drops less than 30%.
A bleached, stable shellac solution, having a pH of from 4.0 up to less than 5.0;
- selected from the group consisting of:
- lipidized, bleached, stable shellac solution, when heated to 40° C. for 30 days, the pH drops and to not less than 3.7;
- and de-lipidized, bleached, stable shellac solution,
- characterized in that said solution when heated to 40° C. for 30 days, the pH drops to not less than 4.2;
- said shellac solution comprising:
- from 40% to 95% by weight, of a solvent;
- from 5% to 60% by weight, of a stable particulate shellac dissolved in said solvent.
A method of making stable shellac comprising the following steps:
- providing a liquid pre-shellac;
- and
- precipitating a stable shellac from the liquid pre-shellac at a pH of from 5.0 to 6.8 to provide a stable particulate shellac.
A method of coating a substrate comprising the following steps:
- providing a bleached stable shellac solution selected from the group consisting of:
- a lipidized, bleached stable shellac solution having a pH of from 4 up to less than 5.0 characterized in that when heated to 40° C. for 30 days, the pH drops to not less than 3.7;
- a de-lipidized, bleached stable shellac solution having a pH of from 4 up to less than 5.0 characterized in that when heated to 40° C. for 30 days, the pH drops to not less than 4.2;
- and
- a lipidized bleached stable shellac solution having a pH of from 5 to 6.8 characterized in that when heated for 6 weeks at 100° F. the pH drops not greater than 30%;
- a de-lipidized bleached stable shellac solution having a pH of from 5 to 6.8 characterized in that when heated for 6 weeks at 100° F. the pH drops not greater than 15%;
- said bleached stable shellac solution comprising:
- from 40% to 95% by weight, of a solvent;
- from 5% to 60% by weight, of a stable particulate shellac dissolved in said solvent,
- applying the stable shellac solution to the substrate;
- evaporating solvent in the stable shellac solution.
A coated substrate comprising:
- a substrate;
- a bleached stable shellac coating disposed on the substrate wherein the coating has a hardness of from 100 to 200 Konig units, a pH of greater than 4, and a Gardner color of less than 18.
Dependencies are inferred from the claim text.