Water-resistant gypsum formulations
AssigneesFleet Capital Corporation, Fllet Capital Canada Corporation, Fleet National Bank, London U.K., Branch
InventorsSteven Joseph Wantling, Bonnie Sherrard Zepka
Life of this patent
Estimating the term…
Abstract
Emulsions are provided which are useful in imparting water resistance to gypsum products. In one embodiment, the emulsions comprise a plurality of waxes, at least one saponified wax, a complexed starch, a polymerized alkyl phenol, and a small amount of a co-surfactant. In another embodiment, the emulsions comprise a single wax, a balanced dual surfactant system, a complexed starch and a polymerized alkyl phenol. Emulsions of this embodiment may be added to hot, even boiling, water without the emulsion separating or curdling. The emulsions of the present invention are stable for extended periods of time when stored at room temperature and do not require the addition of a bactericide. The emulsions of the present invention are pourable liquids at room temperature.
Claims30
An emulsion useful in providing water resistance to a gypsum product, the emulsion comprising:
- from about 30 to about 35 weight percent, based on the total weight of the emulsion, a first wax having a melting point of 120° F. or greater;
- from about 3 to about 10 weight percent, based on the total weight of the emulsion, a second wax having a melting point of 180° F. or greater the second wax having a saponification value;
- from about 0.5 to about 10 weight percent, based on the total weight of the emulsion, an alkyl phenol;
- from about 0.5 to about 5 weight percent, based on the total weight of the emulsion, a co-surfactant, selected from the group consisting of sodium lignosulfate, potassium lignosulfate and trisodium phosphate;
- from about 0.5 to about 3 weight percent, based on the total weight of the emulsion, an alkali metal hydroxide;
- from about 55 to about 65 weight percent, based on the total weight of the emulsion, water;
- and
- from about 0.25 to about 10 weight percent, based on the total weight of the emulsion, a complexed starch;
- wherein the alkali metal hydroxide saponifies the second wax to provide a surfactant.
An emulsion useful in providing water resistance to a gypsum product, the emulsion comprising:
- from about 33 to about 38 weight percent, based on the total weight of the emulsion, of a wax having a melting point of 135° F. or greater;
- from about 0.5 to about 10 weight percent, based on the total weight of the emulsion, an alkyl phenol;
- a dual surfactant system, the dual surfactant system comprising a mixture of two surfactants such that a HLB value of the mixture is from about 8.9 to about 14;
- from about 55 to about 65 weight percent, based on the total weight of the emulsion water;
- and from about 0.25 to about 10 weight percent, based on the total weight of the emulsion a complexed starch.
A method for making an emulsion, the emulsion useful in providing water resistance to a gypsum product, the method comprising:
- (a) providing:
- from about 30 to about 35 weight percent, based on the total weight of the emulsion, a first wax having a melting point of 120° F. or greater;
- from about 3 to about 10 weight percent, based on the total weight of the emulsion, a second wax having a melting point of 180° F. or greater, the second wax having a saponification value;
- from about 0.5 to about 10 weight percent, based on the total weight of the emulsion, an alkyl phenol;
- from about 0.5 to about 5 weight percent, based on the total weight of the emulsion, a co-surfactant selected from the group consisting of sodium lignosulfonate, potassium lignosulfonate and trisodium phosphate;
- from about 0.5 to about 3 weight percent, based on the total weight of the emulsion, an alkali metal hydroxide;
- from about 55 to about 65 weight percent, based on the total weight of the emulsion, water;
- and
- from about 0.25 to about 10 weight percent, based on the total weight of the emulsion, a complexed starch;
- (b) mixing the first wax, the second wax, the alkyl phenol and the co-surfactant to provide a first pre-mix;
- (c) mixing the alkali metal hydroxide, water and complexed starch to provide a second pre-mix;
- (d) combining the first pre-mix and the second pre-mix to provide a mixture;
- and
- (e) homogenizing the mixture;
- wherein the homogenized mixture contains a distribution of micelles;
- and
- wherein the alkali metal hydroxide saponifies the second wax to provide a surfactant.
A method for making an emulsion, the emulsion useful in providing water resistance to a gypsum product, the method comprising:
- (a) providing:
- a wax having a melting point of 135° F. or greater;
- an alkyl phenol;
- water;
- and
- a complexed starch;
- (b) mixing a plurality of surfactants to provide a dual surfactant system such that the HLB value of the dual surfactant system is from about 8.9 to about 14;
- (c) mixing the wax, the alkyl phenol and the dual surfactant system to provide a first pre-mix;
- (d) mixing the water and complexed starch to provide a second pre-mix;
- (e) combining the first pre-mix and the second pre-mix to provide a mixture;
- and
- (f) homogenizing the mixture;
- wherein the homogenized mixture contains a distribution of micelles.
Dependencies are inferred from the claim text.