Composition for forming a composite material
A composition and method for forming a composite material comprising a mixture of component A and component B, component A comprising gypsum and an inhibitor; and component B comprising an accelerator, wherein at least one of component A and component B further comprises a polymer binder having a T g of below −23° C. or wherein the Shore D hardness of the composite material when cured is less than 70; the method comprising providing a first slurry mixture of component A and a second slurry mixture of component B and blending the first slurry mixture and the second slurry mixture to form a soft composite using a weight ratio of from 10:1 to 1:2.
1. A composition for forming a composite material comprising a mixture of component A and component B,
component A comprising:
gypsum; and
an inhibitor; and
component B comprising:
an accelerator;
wherein at least one of component A and component B further comprises a predominantly acrylic aqueous emulsion polymer binder having a T g of below −23° C.
2. The composition of claim 1 wherein component A further comprises:
a defoamer;
a surfactant; and
a pH adjuster.
3. The composition of claim 1 wherein component B further comprises:
an extender;
a defoamer;
a surfactant;
a thickener; and
an activator.
4. The composition of claim 1 wherein component A comprises 60-75 weight % gypsum based on a total weight of the component A.
5. The composition of claim 1 wherein
component A comprises:
60-75 weight % gypsum;
0.1-3 weight % inhibitor;
10-30% polymer binder; and
0-14.9 weight % component A additives selected from the group consisting of a defoamer, a surfactant, a pH adjuster, and combinations thereof; and
component B comprises:
5-50 weight % polymer binder;
1-15 weight % accelerator; and
35-94 weight % component B additives selected from the group consisting of an extender, a defoamer, a surfactant, a thickener, an activator, and combinations thereof.
6. The composition of claim 1 further comprising a colorant.
7. The composition of claim 1 wherein the gypsum comprises calcium sulfate hemihydrate, the inhibitor comprises aqueous polycarboxylate, the polymer binder comprises an acrylic copolymer, and the accelerator comprises aluminum sulfate.
8. The composition of claim 2 wherein the defoamer comprises a polysiloxane, the surfactant comprises a nonionic surfactant, and the pH adjuster comprises calcium hydroxide.
9. The composition of claim 3 wherein the polymeric binder comprises an acrylic copolymer, the extender comprises alumina trihydrate, the defoamer comprises polysiloxane, the surfactant comprises a nonionic surfactant, the thickener comprises hydroxyethyl cellulose, and the activator comprise aluminum sulfate.
10. A composition for forming a composite material comprising a mixture of component A and component B,
component A comprising:
gypsum; and
an inhibitor; and
component B comprising:
an accelerator;
wherein at least one of component A and component B further comprises a polymer binder and wherein a Shore D hardness of the composite material when cured is less than 70.
11. The composition of claim 10 wherein component A further comprises:
a defoamer;
a surfactant; and
a pH adjuster; and
component B further comprises:
an extender;
a defoamer;
a surfactant;
a thickener; and
an activator.
12. The composition of claim 10 wherein the Shore D hardness is 50-70.
13. A method of forming a composite material with a polymer binder having a T g below −23° C. comprising:
providing a first slurry mixture of gypsum and an inhibitor and a second slurry mixture of at least an accelerator, at least one of the first slurry mixture and the second slurry mixture comprising a predominantly acrylic aqueous emulsion polymer binder; and
blending the first slurry mixture and the second slurry mixture to form a soft composite using a weight ration of from 10:1 to 1:2.
14. The method of claim 13 further comprising: mixing the soft composite with a hard composite material.
15. The composition of claim 1 wherein the polymeric binder is has a Tg of −35° C. to −60° C.
16. The composition of claim 1 wherein the predominantly acrylic aqueous emulsion polymer is a styrene/acrylic polymer.
17. The composition of claim 1 wherein the predominantly acrylic aqueous emulsion polymer is an all-acrylic polymer.
18. The composition of claim 1 wherein the composite material exhibits a Shore D hardness of about 50 to about 60.
19. A composition for forming a composite material comprising a mixture of component A and component B, wherein
component A comprises:
60-75 weight % gypsum;
0.1-3 weight % inhibitor;
10-30% polymer binder; and
0-14.9 weight % component A additives selected from the group consisting of a defoamer, a surfactant, a pH adjuster, and combinations thereof; and
component B comprises:
5-50 weight % polymer binder;
1-15 weight % accelerator; and
35-94 weight % component B additives selected from the group consisting of an extender, a defoamer, a surfactant, a thickener, an activator, and combinations thereof;
wherein the polymeric binder of at least one of component A and component B is a predominantly acrylic aqueous emulsion polymer having a T g of below −23° C., wherein the polymer comprises greater than 50%, by weight, of copolymerized units deriving from (meth)acrylic comonomers selected from the group consisting of(meth)acrylate esters, (meth)acrylamides, meth)acrylonitrile), (meth)acrylic acid, and combinations thereof; and
wherein the composite material exhibits a Shore D hardness when cured of less than 70.
20. The composition of claim 19 , wherein the polymer binder of component A has a T g of −35° C. to −60° C., is an all-crylic or styrene/acrylic polymer, and wherein the composite material exhibits a Shore D hardness when cured of about 50 to about 60.