Low dust joint compound and method of making the same
A joint compound or wall repair composition and the method of making the same is disclosed that reduces the amount of airborne dust emitted during traditional sanding processes. Generally, such a reduction can be achieved by combining a first binder that has a high glass transition temperature and a second binder that has a low glass transition temperature with conventional joint compound compositions.
1. A joint compound composition capable of reducing the amount of dust produced during sanding of the joint compound composition, said joint compound composition comprising:
a filler material selected from the group consisting of calcium carbonate, calcium sulfate dihydrate, talc, and calcium sulfate hemihydrate; and
at least a first binder and a second binder, wherein the first binder comprises a styrene-butadiene polymer and has a glass transition temperature that is equal to or greater than about −10 degrees Celsius, the second binder comprises an ethylene vinyl acetate polymer and has a glass transition temperature in the range of about −80 degrees Celsius to about 10 degrees Celsius, and the glass transition temperature of the first binder is at least about 5 degrees Celsius greater than the glass transition temperature of the second binder.
2. The joint compound composition of claim 1 wherein the first binder has a glass transition temperature in the range of about 0 degrees Celsius to about 40 degrees Celsius.
3. The joint compound composition of claim 1 wherein the filler material comprises between about 25% to about 95% of the total wet weight of the joint compound composition.
4. The joint compound composition of claim 1 wherein the second binder comprises an emulsion comprising water, an ethylene vinyl acetate latex polymer, and a plasticizer capable of depressing the glass transition temperature of the latex polymer.
5. The joint compound composition of claim 1 wherein the first binder comprises at least about 0.5% of the total wet weight of the joint compound composition and the second binder comprises at least about 0.05% of the total wet weight of the joint compound composition.
6. A method for producing a joint compound composition capable of reducing the amount of dust produced during sanding of the joint compound composition, the method comprising the steps of:
providing at least one filler material selected from the group consisting of calcium carbonate, calcium sulfate dihydrate, talc, and calcium sulfate hemihydrate;
adding a first binder comprising a styrene-butadiene polymer and that has a glass transition temperature that is equal to or greater than about −10 degrees Celsius to the at least one filler material; and
adding a second binder comprising an ethylene vinyl acetate polymer and that has a glass transition temperature in the range of about −80 degrees Celsius to about 10 degrees Celsius to the at least one filler material, wherein the glass transition temperature of the first binder is at least 5 degrees Celsius greater than the second binder.
7. The method of claim 6 further comprising the step of mixing the filler, first polymer binder and second polymer binder.
8. The method of claim 6 further comprising the steps of: mixing the filler and second polymer binder; and adding the first polymer binder after mixing the filler and second polymer binder.
9. The method of claim 6 further comprising the steps of: mixing the filler and first polymer binder; and adding the second polymer binder after mixing the filler and first polymer binder.
10. The method of claim 6 wherein the second binder comprises an emulsion comprising water, an ethylene vinyl acetate latex polymer, and a plasticizer capable of depressing the glass transition temperature of the latex polymer.
11. A joint compound composition, comprising:
a filler selected from the group consisting of: calcium carbonate, calcium sulfate dihydrate, talc, and calcium sulfate hemihydrate;
a first binder comprising a styrene-butadiene polymer and having a glass transition temperature that is equal to or greater than about −10° C., and comprising between about 0.5 wt % to about 5 wt % of the composition; and
a second binder comprising an ethylene vinyl acetate polymer and having a glass transition temperature in the range of about −80° C. to about 10° C., and comprising between about 3.0 wt % to about 7.0 wt % of the composition;
wherein the glass transition temperature of the first polymeric binder is at least about 5° C. greater than the glass transition temperature of the second polymeric binder.
12. The joint compound composition of claim 11 , wherein the first polymeric binder comprises between about 1.0 wt % to about 1.3 wt % of the composition, and the second polymeric binder comprises between about 3.9 wt % to about 4.9 wt % of the composition.
13. The joint compound of claim 11 , wherein the second polymeric binder is a latex that further comprises a plasticizer.