HIGH SOLIDS, SPRAYABLE SETTING TYPE JOINT COMPOUND
A high solids, sprayable, fast drying, ready-mixed setting-type joint compound comprising a blend of a joint compound mixture comprising: joint compound mixture ingredients comprising: calcium sulfate hemihydrate (e.g. US Gypsum's HYDROCAL C-Base), a chelating agent, and water; and an activator mixture, wherein the activator mixture comprises: activator mixture ingredients comprising: inert filler, set accelerator, and water, wherein a weight ratio of joint compound mixture:activator mixture is 1:1 to 100:1, wherein the activator mixture viscosity is the same as the joint compound mixture viscosity plus or minus 50 percent, and wherein the joint compound has about 55 to about 80 wt. % solids and a viscosity of 2,500-28,000 cps.
1 - 6 . (canceled)
7 . A system for making a joint compound comprising
a joint compound mixture and an activator mixture, said joint compound mixture being mixable with the activator mixture,
(A) wherein the joint compound mixture comprises
(a) joint compound mixture ingredients comprising in weight percent on a dry basis:
about 20 to about 99 wt. % calcium sulfate hemihydrate in an alpha morphological form having blocky cubic crystal microstructure with a D50 average particle size of about 15 to 50 microns, for example 15 to 20 microns or 20 to 50 microns,
about 0-4 wt. % thickening agent,
about 0-2 wt. % set retarder,
about 0.05-5 wt. % chelating agent, wherein the chelating agent is selected from tetra sodium pyrophosphate or tetra potassium pyrophosphate,
about 0-2 wt. % preservative,
optionally about 0-5 wt. % second chelating agent,
optionally about 0-80 wt. % filler, and
optionally about 0-5 wt. % binder,
and
(b) joint compound mixture water, wherein weight ratio of the joint compound mixture ingredients to the joint compound mixture water is within a range of 9:1 to 3:2, and
(B) wherein the activator mixture comprises:
(a) activator mixture ingredients comprising in weight percent on a dry basis:inert filler at about 0-95 wt. % of the activator mixture ingredients, set accelerator at about 5-99 wt. % of the activator mixture ingredients, thickening agent at about 0-4 wt. % of the activator mixture ingredients, preservative at about 0-2 wt. % of the activator mixture ingredients, and
(b) activator mixture water, wherein weight ratio of the activator mixture ingredients to the activator mixture water is within a range of 9:1 to 1:1, wherein a weight ratio of joint compound mixture:activator mixture is 1:1 to 100:1, wherein the activator mixture viscosity is the same as the joint compound mixture viscosity plus or minus 50%, preferably plus or minus 20%, most preferably plus or minus 10%,
wherein the joint compound mixture viscosity is between 2,500-28,000 cps,
wherein the activator mixture viscosity is between 2,500-28,000 cps,
wherein the joint compound viscosity is between 2,500-28,000 cps, and
wherein the joint compound has about 55 to about 88 wt. % solids,
wherein the joint compound mixture has about 55 to about 88 wt. % solids,
wherein the activator mixture has about 55 to about 88 wt. % solids.
8 . The system of claim 7 , wherein the weight ratio of joint compound mixture:activator mixture is 1:1 to 10:1.
9 . The system of claim 7 , wherein the joint compound has about 72 to about 78 wt. % solids.
10 . The system of claim 7 , wherein the joint compound mixture has a viscosity of about 4,000-5,600 cps and the activator mixture has a viscosity of about 4,000-5,600 cps.
11 . The system of claim 7 , wherein the joint compound consists essentially of the joint compound mixture and the activator mixture.
12 . The system of claim 11 , wherein the joint compound mixture consists essentially of the joint compound mixture ingredients and joint compound mixture water.
13 . The system of claim 11 , wherein the activator mixture consists essentially of the activator mixture ingredients and activator mixture water.
14 . A method of dispersing joint compound comprising
mixing a joint compound mixture and an activator mixture and
spraying the joint compound through a nozzle on a spray gun,
(A) wherein the joint compound mixture comprises
(a) joint compound mixture ingredients comprising in weight percent on a dry basis:
about 20 to about 99 wt. % calcium sulfate hemihydrate in an alpha morphological form having blocky cubic crystal microstructure with a D50 average particle size of about 15 to 50 microns, for example 15 to 20 microns or 20 to 50 microns,
about 0-4 wt. % thickening agent,
about 0-2 wt. % set retarder,
about 0.05-5 wt. % chelating agent, wherein the chelating agent is selected from tetra sodium pyrophosphate or tetra potassium pyrophosphate,
about 0-2 wt. % preservative,
optionally about 0-5 wt. % second chelating agent,
optionally about 0-80 wt. % filler, and
optionally about 0-5 wt. % binder,
and
(b) joint compound mixture water, wherein weight ratio of the joint compound mixture ingredients to the water is within a range of 9:1 to 3:2, and
(B) wherein the activator mixture comprises:
(a) activator mixture ingredients comprising in weight percent on a dry basis:
inert filler at about 0-95 wt. % of the activator mixture ingredients,
set accelerator at about 5-99 wt. % of the activator mixture ingredients, thickening agent at about 0-4 wt. % of the activator mixture ingredients, preservative at about 0-2 wt. % of the activator mixture ingredients, and
(b) activator mixture water, wherein weight ratio of the activator mixture ingredients to the activator mixture water is within a range of 9:1 to 1:1,
wherein a weight ratio of joint compound mixture:activator mixture is 1:1 to 100:1,
wherein the activator mixture viscosity is the same as the joint compound mixture viscosity plus or minus 50%, preferably plus or minus 20%, most preferably plus or minus 10%,
wherein the joint compound mixture viscosity is between 2,500-28,000 cps,
wherein the activator mixture viscosity is between 2,500-28,000 cps,
wherein the joint compound viscosity is between 2,500-28,000 cps, and
wherein the joint compound has about 55 to about 88 wt. % solids,
wherein the joint compound mixture has about 55 to about 88 wt. % solids,
wherein the activator mixture has about 55 to about 88 wt. % solids.
15 . The method of claim 14 , wherein the joint compound has about 72 to 78 wt. % solids.
16 . The method of claim 14 , wherein the weight ratio of joint compound mixture:activator mixture is 1:1 to 10:1.
17 . The method of claim 14 , wherein the joint compound mixture has a viscosity of about 4,000-5,600 cps, a ratio of joint compound mixture:activator mixture is 1:1 to 10:1 and the activator mixture has a viscosity of about 4,000-5,600 cps.
18 - 20 . (canceled)