Hydrophobic finish compositions with extended flow time retention and building products made thereof

Patent metadata

Field	Value
Publication number	US-10399898-B2
Application number	US-201615066417-A
Country	US
Kind code	B2
Filing date	Mar 10, 2016
Priority date	Mar 13, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

Disclosed are hydrophobic finish compositions and cementitious articles made with the hydrophobic finish compositions. In some embodiments, the article is a waterproof gypsum panel surface reinforced with inorganic mineral fibers that face a flexible and hydrophobic cementitious finish possessing beneficial waterproofing properties. These waterproof gypsum panels have many uses, such as, tile backer board in wet or dry areas of buildings, exterior weather barrier panel for use as exterior sheathing, interior wall and ceiling, and roof cover board having water durability and low surface absorption. The flexible and hydrophobic cementitious finish can include fly ash, film-forming polymer, preferably silane compound (e.g., alkyl alkoxysilane), an extended flow time retention agent including either one or more carboxylic acids, salts of carboxylic acids, or mixtures thereof, and other optional additives. Preferably a pre-coated non-woven glass fiber mat is employed to provide the inorganic mineral fibers for the surface reinforcement.

First claim

The invention claimed is:

1. A mat-faced cementitious board comprising:
a cementitious core;
a fibrous mat having a first inner surface facing at least one face of the cementitious core, and a second opposite outer surface, wherein the fibrous mat comprises a glass mat substrate having non-woven glass fibers, a uniformly distributed binder comprising a first polymer binder but no inorganic filler, and a binder coating comprising a second polymer binder and inorganic filler, wherein the inorganic filler is selected from at least one member of the group consisting of inorganic pigment and inorganic binder,
the binder coating is present in an amount of about 40 lbs./MSF to about 165 lbs./MSF to overlay the fibrous mat comprising the uniformly distributed binder,
the fibrous mat having opposed first and second sides,
wherein the binder coating uniformly penetrates the glass mat substrate from the first side of the coated glass mat substrate to a depth which is a fraction of the thickness of the coated glass mat substrate; and
a layer of hydrophobic finish composition to overlay the first side of the fibrous mat comprising the uniformly distributed binder and the binder coating comprising;
(i) hydraulic component comprising fly ash, the fly ash comprising Class C fly ash in an amount from about 50% to about 85% by weight of the hydrophobic finish composition on a water inclusive basis;
(ii) film-forming polymer in an amount of about 5% to about 25% by weight of the hydrophobic finish composition on a water inclusive basis; and
(iii) an extended flow time retention agent comprising at least one member of the group consisting of carboxylic acids, salts of carboxylic acids, and mixtures thereof,
wherein said carboxylic acids have the chemical formula (II):

wherein R is an organofunctional group;
wherein the salts of carboxylic acid have the chemical formula (III)

wherein R is as defined in formula (II) and X + is a cation,
wherein the extended flow time retention agent is in an amount of 0.05% to 1.00% by weight of the hydrophobic finish composition on a dry basis;
wherein the layer of the hydrophobic finish composition adheres to the first side of the fibrous mat having the uniformly distributed binder and coated with the binder coating and the cementitious core adheres to the opposed second side of the fibrous mat, wherein at least a portion of the binder coating is between the glass mat substrate having the uniformly distributed binder and the layer of hydrophobic finish composition, and
wherein penetration of the binder coating into the glass mat substrate thickness is 10 percent to 75 percent.

2. The mat-faced cementitious board of claim 1 ,
wherein the second polymer binder comprises a member of the group consisting of
urea formaldehyde,
melamine formaldehyde,
stearated melamine formaldehyde,
polyester,
acrylics,
polyvinyl acetate,
urea formaldehyde modified or blended with polyvinyl acetate or acrylic,
melamine formaldehyde modified or blended with polyvinyl acetate or acrylic,
styrene acrylic polymers,
Styrene-Butadiene-Rubber,
Styrene-Butadiene-Styrene polymer,
Ethylene-Vinyl-Chloride polymers,
Poly-Vinylidene-Chloride,
Poly-Vinyl-Alcohol,
Ethylene-Vinyl-Acetate polymer, and any combination thereof.

3. The mat-faced cementitious board of claim 1 ,
wherein the inorganic binder is selected from at least one member of the group consisting of calcium oxide, calcium silicate, limestone containing quicklime (CaO), clay containing calcium silicate, sand containing calcium silicate, aluminum trihydrate containing aluminum oxide, and magnesium oxide containing either the sulfate or chloride of magnesium, or both, calcium sulfate hemi-hydrate, magnesium oxychloride, magnesium oxysulfate, complexes of alkaline earth metals, and aluminum hydroxide; and
wherein the inorganic pigment is selected from at least one member of the group consisting of ground limestone (calcium carbonate), clay, sand, mica, talc, gypsum (calcium sulfate dihydrate), aluminum trihydrate (ATH), antimony oxide, microspheres, pumice, crushed or expanded perlite, volcanic ash, rice husk ash, diatomaceous earth, slag, metakaolin, fly ash and other pozzolanic materials.

4. The mat-faced cementitious board of claim 1 , wherein the layer of hydrophobic finish composition further comprises at least one silane compound selected from the group consisting of:
(a) silane compounds having a molecular weight of at least about 150,
(b) silane compounds having a general chemical formula (I):
(R 1 O) m —Si—X 4-m   (I)

wherein R 1 O is an alkoxy group, X is an organofunctional group, and m ranges from 1 to 3, and
(c) mixtures of silane compounds (a) and (b).

5. The mat-faced cementitious board of claim 4 , wherein
the Class C fly ash is about 55% to about 75% by weight of the layer of hydrophobic finish composition based on the weight of the layer of hydrophobic finish composition including water;
the film-forming polymer is about 7.5% to about 22.5% by weight of the layer of hydrophobic finish composition based on the weight of the layer of hydrophobic finish composition including water;
the silane compound is 0.1-3% by weight of the layer of hydrophobic finish composition based on the weight of the finish composition including water; and
the extended flow time retention agent is 0.075% to 0.75% by weight of Class C fly ash on a dry basis, wherein the extended flow time retention agent is at least one member selected from the group consisting of tricarboxylic acids, dicarboxylic acids, sugar acids, aldonic acids, aldaric acids, uronic acids, aromatic carboxylic acids, amino carboxylic acids, alpha hydroxy acids, beta hydroxy acids, sodium salts of said acids, and potassium salts of said acids.

6. The mat-faced cementitious board of claim 1 , wherein the binder coating of the fibrous mat has a thickness of 0.002 to 0.050 inches, the second polymer binder of the binder coating comprising latex binder, the binder coating being only partially permeated into the glass mat substrate such that 25% to 90% of the thickness of the glass mat substrate is not coated by the binder coating and the remainder of the glass mat substrate is coated by the binder coating.

7. The mat-faced cementitious board of claim 1 , wherein the cementitious core on a dry basis is 50 wt. % or greater gypsum and/or 20 wt. % or greater Portland cement.

8. The mat-faced cementitious board of claim 1 , having an absence of silane.

9. The mat-faced cementitious board of claim 1 , wherein the extended flow time retention agent comprises tartaric acid or a tartaric acid salt, and optionally further comprises citric acid or a salt of citric acid.

10. The mat-faced cementitious board of claim 1 , wherein the extended flow time retention agent is at least one member selected from the group consisting of tricarboxylic acids, dicarboxylic acids, sugar acids, aldonic acids, aldaric acids, uronic acids, aromatic carboxylic acids, amino carboxylic acids, alpha hydroxy acids, beta hydroxy acids, sodium salts of said acids, and potassium salts of said acids.

11. The mat-faced cementitious board of claim 1 , wherein the film-forming polymer of the layer of hydrophobic finish composition comprises at least one member of the group consisting of:
acrylic polymers and copolymers,
styrene-butadiene rubber copolymers,
copolymers of styrene and acrylic,
copolymers of vinyl acetate and ethy

Assignees

• United States Gypsum Co

Inventors

• Peng Yanfei
• Dubey Ashish
• Blackburn David R
• Lee Chris C
• Donelan Jeffrey W

Classifications

• D06N3/0063

  Inorganic compounding ingredients, e.g. metals, carbon fibres, Na2CO3, metal layers; Post-treatment with inorganic compounds · CPC title

• D06N3/0022

  Glass fibres · CPC title

• D06M2200/12

  Hydrophobic properties · CPC title

• D06M13/513

  with at least one carbon-silicon bond · CPC title

• D06M13/192

  Polycarboxylic acids; Anhydrides, halides or salts thereof {(D06M13/1845 takes precedence)} · CPC title