Perlite-free, lightweight setting-type joint compound compositions
Perlite-free, lightweight setting-type joint compounds which comprise calcium sulfate hemihydrate with a dry density of less than 50 lb/ft 3 , a foaming agent having a HLB value of at least 10 and preferably comprising an alkylbenzene sulfonic acid having a linear alkyl chain containing 8 to 14 carbons and/or a salt thereof, and a combination of rheology modifiers. Methods for building wallboard assemblies and methods for wall patch and repair projects that include applying the perlite-free, lightweight setting-type joint compounds to a substrate.
1 . A composition for perlite-free, lightweight setting-type joint compound, wherein the composition comprises:
calcium sulfate hemihydrate with a dry density of less than 50 lb/ft 3 and water consistency of at least 50 cc of water per 100 grams of calcium sulfate hemihydrate;
a foaming agent having a hydrophilic-lipophilic balance (HLB) value of at least 10, the foaming agent comprising an alkylbenzene sulfonic acid having a linear alkyl chain containing 8 to 14 carbons and/or a salt thereof;
a co-surfactant, wherein the co-surfactant includes a betaine, alkanolamide, alkylpolyglucoside, alkyl ethoxylate, or any combination thereof;
a rheology modifier including one or more of the following: modified cellulose, starch, and/or attapulgite clay; and
wherein the composition does not comprise perlite.
2 . The composition of claim 1 , wherein calcium sulfate hemihydrate includes alpha calcium sulfate hemihydrate in an amount ranging from about 50 wt % to about 95 wt %.
3 . The composition of claim 2 , wherein alpha calcium sulfate hemihydrate is obtained by autoclaving gypsum in a saturated steam atmospheric pressure, and wherein alpha calcium sulfate hemihydrate has a dry density of about 45 lb/ft 3 and water consistency of about 60 cc per 100 grams of alpha calcium sulfate hemihydrate.
4 . The composition of claim 1 , wherein the composition comprises from about 0.01 wt % to about 0.5 wt % of the foaming agent.
5 . The composition of claim 1 , wherein the composition comprises dodecyl benzene sulfonic acid or any salt thereof, and/or the composition comprises cocoamidopropyl betaine, or any combination thereof.
6 . The composition of claim 1 , wherein the composition comprises from about 0.1 wt % to about 1.0 wt % of the co-surfactant.
7 . The composition of claim 1 , wherein the composition comprises modified cellulose and/or starch in an amount from about 0.1 wt % to about 2 wt %.
8 . The composition of claim 1 wherein the composition comprises carboxymethyl cellulose, hydroxypropyl methyl cellulose, xanthan gum, methyl hydroxyethyl cellulose, attapulgite clay, or any combination thereof.
9 . The composition of claim 1 , wherein the composition comprises one or more of the following: mica, talc, calcium carbonate, and/or any combination thereof.
10 . The composition of claim 1 , wherein the composition comprises water in an amount ranging from about 40 cc to 70 cc of water per 100 grams of the composition.
11 . The composition of claim 1 , wherein the composition further comprises a binder which includes one or more of the following: polyvinyl alcohol, polyvinyl acetate, styrenebutadiene, ethylenevinyl acetate co-polymer, vinyl-acrylic co-polymer, and/or any combination thereof.
12 . The composition of claim 1 , wherein the composition is a ready-mixed composition which further comprises water and one or more of phosphate compounds.
13 . The composition of claim 1 , wherein the composition comprises one or more of foaming adjuvants and/or foam stabilizers, or any combination thereof.
14 . The composition of claim 1 , wherein the composition further comprises one or more of the following: diethylenetriamine pentaacetic acid, tartaric acid, citric acid, maleic acid or salts thereof.
15 . The composition of claim 1 , wherein the composition further includes one or more set accelerators enclosed in a separate container.
16 . The composition of claim 1 , wherein the composition comprises:
about 60 wt % to about 90 wt % of alpha calcium sulfate hemihydrate having a dry density in the range from about 30 to about 50 lb/ft 3 and having a water consistency of at least about 50 cc of water per 100 grams of calcined gypsum;
about 2 wt % to about 30 wt % of calcium carbonate;
about 0.01 wt % to about 0.5 wt % of sodium dodecyl benzene sulfonate;
optionally, about 0.1 wt % to about 1 wt % of cocamidopropyl betaine;
optionally, about 1 wt % to about 10 wt % mica and/or talc;
about 2 wt % to about 10 wt % of attapulgite clay;
about 0.1 wt % to about 2 wt % of one or more pregelatinized starches;
about 0.1 wt % to about 2 wt % of one or more of the following: carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl hydroxyethyl cellulose, or any combination thereof;
optionally, about 0.1 wt % to about 2 wt % of xanthan gum; and
about 0.1 wt % to about 10 wt % of a binder.
17 . A method for finishing a seam between two adjacent gypsum panels attached to a stud, the method comprising filling the seam with the composition of claim 1 , and/or applying the composition as a top-coat.
18 . A wall assembly comprising the composition of claim 1 .
19 . A method for making a perlite-free, lightweight setting-type joint compound, the method comprising: mixing the composition of claim 1 with water forming the perlite-free, lightweight setting-type joint compound.