Joint compound

Abstract

A joint compound for use on joints between adjacent wall panels without the need for tape, the joint compound comprising a filler, a binder, carbon fibres and/or carbon nanotubes.

Claims

1. A joint compound for use on joints between adjacent wall panels, the joint compound comprising: a filler selected from the group consisting of calcium carbonate, calcium sulphate dihydrate, calcium sulphate hemihydrate, calcium magnesium carbonate, magnesium silicate, and combinations thereof; a binder selected from the group consisting of acrylic co-polymer emulsions, polyvinyl acetate, polyvinyl alcohol, ethylene vinyl acetate co-polymers, vinyl acrylic copolymers, styrene-butadiene polymers, polyacrylamides, other acrylic polymers, latex emulsions, caseins, and combinations thereof; carbon fibres; and from 5% to 20% by weight fibre additive selected from the group consisting of cellulose fibres, polymer fibres, mineral fibres, synthetic organic fibres and synthetic inorganic fibres, and combinations thereof, wherein the ratio of carbon fibres to filler is from about 1:1000 to about 1:50 by weight, and wherein the ratio of fibre additive to filler is from 1:1 to about 1:10 by weight.

2. The joint compound according to claim 1, wherein the ratio of binder to filler is from about 5:1 to about 1:1 by weight.

3. The joint compound according to claim 1, wherein the ratio of carbon fibres to filler is from about 1:500 to about 1:300 by weight.

4. The joint compound according to claim 1, wherein the carbon fibres are from about 10 μm to about 10 mm in length.

5. The joint compound according to claim 4, wherein the carbon fibres are fibres from about 1 mm to about 5 mm in length.

6. The joint compound according to claim 1, wherein the carbon fibres are selected from the group consisting of pitch based, polyacrylonitrile (PAN) based, rayon (viscose) based, and combinations thereof.

7. The joint compound according to claim 1, wherein the fibre additive comprises cellulose fibres.

8. The joint compound according to claim 7, wherein the ratio of cellulose fibres to filler is from about 1:1 to about 1:10 by weight.

9. The joint compound according claim 1, wherein the fibre additive comprises polymer fibres.

10. The joint compound according to claim 9, wherein the ratio of polymer fibres to filler is from about 1:1000 to about 1:50 by weight.

11. The joint compound according to claim 1, further comprising one or more additives.

12. The joint compound according to claim 11, wherein the one or more additives are selected from the group consisting of water, defoamers, thickeners, gelling agents, pigments, surfactants, neutralising agents, coalescing agents, surfactants, wetting agents, non-levelling agents, biocides, fungicides, and combinations thereof.

13. The joint compound according to claim 1 comprising: 5 to 40% by weight filler; 5 to 50% by weight binder; 0 to 30% by weight additives; 0.001 to 5% by weight carbon fibres; and 5 to 20% by weight fibre additive.

14. The joint compound according to claim 13 comprising: 5 to 40% by weight filler; 30 to 50% by weight binder; 0.001 to 5% by weight carbon fibres; 0.001 to 1% by weight polymer fibres; and 0.01 to 10% by weight cellulose fibres.

Description

DESCRIPTION OF EMBODIMENTS

(1) An embodiment of the invention will now be described, by way of example only, with reference to the following examples.

(2) Examples 1 to 3 below show examples of formulations prepared utilising 3 mm long carbon fibres and a cellulose fibre additive. Properties of the carbon fibres and paper fibres used in Examples 1 and 2 are shown in Tables 1 and 2, respectively.

(3) TABLE-US-00001 TABLE 1 Carbon Fibre Properties Single fibre diameter 7.0 to 10 μm Tensile strength 3.0 to 3.6 GPa Tensile modulus 220 to 240 GPa Carbon content >93%  Elongation percent 1.5% Density 1.6 to 1.76 g/cm.sup.3 Colour Black Volume resistivity 1.5 × 10.sup.−3 ohms/cm

(4) TABLE-US-00002 TABLE 2 Cellulose Fibre Properties Diameter (ave) 20 μm Specific gravity 1.1  Moisture content (ave)  3% Oil absorption 3.71 Retention 325 mesh 28%

Example 1

(5) A tapeless joint compound was made in accordance with the formulation shown in Table 3.

(6) TABLE-US-00003 TABLE 3 Formula F4-A1 Ingredient Quantity Water 250 KG Liquid Defoamer (Foamaster DF 50) 1.5 KG Thickener (Mecellose PMC 40 HS) 2 KG Pigment Dispersant (Orotan 731 DP) 2 KG Neutralising Agent (Vantex-T) 1 L Wetting Agent (Carbowet GA 100) 1 L Mix until dissolved Non-Leveling Agent (Celite 281) 50 KG Cellulose Fibre (Gel-Cel Fibre W10) 25 KG Filler (Omyacarb 10) 200 KG Filler (Omyacarb 20) 100 KG Mix at high speed for 10 minutes Wetting Agent (Envirogem 360/Dynol 360) 5 KG Smoothing Agent (Dowanol DPnB) 5 KG Binder (Hydrocryl 360) 400 KG Binder (Hydrocryl 440) 100 KG Biocide (Acticide MBS) 1.5 KG Biocide (Acticide EP (W)) 4 KG Thickener (Acryltix CP) 2 KG Change mixer to putty mixer Cellulose Fibre (Gel-Cel Fibre W10) 100 KG Carbon Fibre (3 mm) 1 KG

Example 2

(7) A joint compound was prepared in accordance with the formulation shown in Table 4.

(8) TABLE-US-00004 TABLE 4 Formula F4-A2 Ingredient Quantity Water 250 KG Liquid Defoamer (Foamaster DF 50) 1.5 KG Thickener (Mecellose PMC 40 HS) 2 KG Pigment Dispersant (Orotan 731 DP) 2 KG Neutralising Agent (AMP 95) 1 L Wetting Agent (Teric N9) 1 L Mix until dissolved Non-Leveling Agent (Celite 281) 50 KG Cellulose Fibre (Gel-Cel Fibre W10) 25 KG Filler (Omyacarb 10) 400 KG Filler (Omyacarb 20) 100 KG Mix at high speed for 10 minutes Coalescing Agent (Texanol) 5 KG Smoothing Agent (Butyl Icinol) 5 KG Binder (Hydrocryl 360) 400 KG Binder (Hydrocryl 440) 100 KG Biocide (Acticide FS(N)) 1.5 KG Biocide (Acticide EP(W))) 4 KG Thickener (Acryltix CP) 2 KG Change mixer to putty mixer Cellulose Fibre (Gel-Cel Fibre W10) 100 KG Carbon Fibre (3 mm) 1 KG

Example 3

(9) A joint compound was prepared in accordance with the formulation shown in Table 5.

(10) TABLE-US-00005 TABLE 4 Formula F9-A Ingredient Quantity Water 50 KG Liquid Defoamer (Foamaster MO 2134) 500 mL Gelling Agent (Palygel Omya) 2 KG Thickener (Mecellose PMC 40 HS) 600 g Pigment Dispersant (Orotan 731 DP) 1 KG Neutralising Agent (AMP 95) 300 mL Surfactant (Strodex TH 100) 1 L Mix until dissolved Coalescing Agent (Texanol/K Flex) 3 KG Binder (Hydrocryl 399) 140 KG Binder (Hydrocryl 440) 50 KG Biocide (Acticide MB(S)) 600 mL Biocide (Acticide EP(W))) 400 mL Mix at high speed for 10 minutes Carbon Fibre 3 KG Cellulose Fibre (Gel-Cel Fibre W10) 30 KG Polymer Fibre (Mini Fiber ESS50F) 2 KG Non-Leveling Agent (Celite 281/Wollsatonite 30 KG 425) Filler (Omyacarb 10/Mica 260C) 75 KG Pigment (TiO.sub.2) 10 KG Liquid Defoamer (Foamaster MO 2134) 1 L Change mixer to putty mixer Filler (Limestone 60-16) 100 KG Liquid Defoamer (Foamaster MO 2134) 1 L Thickener (Acryltyx CP) 5 L

Strength Testing

(11) For a tapeless joint compound to be a viable alternative to current joint compounds utilising tape, it is important that joints formed with the tapeless compound are at least as strong as those using traditional joint compounds with tape. The above formulations were tested for strength and compared with industry standard for joints made with joint compounds and tape in the following manner.

(12) A substrate is prepared joining two sheets of fibre cement sheet or plasterboard. The joint is treated with two coats of the joint compound and one coat of a topping compound. The prepared substrate is affixed to a frame with screws at the top left and right corners and chains attached to the bottom left and right corners suspending a wooden platform. 25 kg weights are added at 30 second intervals to the wooden platform until breaking point.

(13) TABLE-US-00006 TABLE 6 Strength testing results Maximum weight Joint compound Substrate held Comment Industry standard Fibre cement 75 kg Substrate breaking at 100 (with paper tape) sheet kg Formula F4-A1 Fibre cement 150 kg Substrate breaking at 150 (with no tape) sheet kg, joint did not fail No cracking or deteriora- tion of compound evident Formula F4-A2 Fibre cement 175 kg Substrate breaking at 150 (with no tape) sheet kg, joint did not fail No cracking or deteriora- tion of compound evident Industry standard Plasterboard 120 kg (with paper tape) Formula F4-A1 Plasterboard 180 kg Substrate breaking at 180 (with no tape) kg, joint did not fail No cracking or deteriora- tion of compound evident Formula F4-A2 Plasterboard 180 kg Substrate breaking at 180 (with no tape) kg, joint did not fail No cracking or deteriora- tion of compound evident

(14) As can be seen from Table 6 above, the tapeless joints formed with Formula F4-A1 and Formula F4-A2 matched and exceeded the industry standard joints using paper tape for strength.

(15) It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.