Cementitious exterior sheathing product having improved interlaminar bond strength

• US 8,192,658 B2
• Filed: 11/29/2006
• Issued: 06/05/2012
• Est. Priority Date: 11/05/2002
• Status: Active Grant

• Current Assignee: Plycem USA, Inc. (Elementia SAB de CV)
• Original Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Inventors: Bezubic, William Paul Jr.
• Primary Examiner(s): Hill, Jr., Robert J
• Assistant Examiner(s): LE, NINH V
• Application Number:
  US11/564,517
• Publication Number:
  US 20070098907A1
• Time in Patent Office: 2,015 Days
• Field of Search: 264/86, 264/87, 264/112, 264/113
• US Class Current: 264/113
• CPC Class Codes: B28B 1/526 by delivering the materials on a conveyor of the endless-belt type
• CPC Class Codes: B28B 1/527 by delivering the materials on a rotating drum, e.g. a sieve drum, from which the materials are picked up by a felt
• CPC Class Codes: B28B 7/46 for humidifying or dehumidifying
• CPC Class Codes: B32B 13/02 with fibres or particles being present as additives in the layer
• CPC Class Codes: B32B 2038/0076 Curing, vulcanising, cross-linking
• CPC Class Codes: B32B 2250/05 5 or more layers
• CPC Class Codes: B32B 2307/7265 Non-permeable
• CPC Class Codes: B32B 2419/00 Buildings or parts thereof
• CPC Class Codes: C04B 14/06 Quartz; Sand
• CPC Class Codes: C04B 14/10 Clay sepiolite C04B14/042; grog C04B18/025
• CPC Class Codes: C04B 18/24 Vegetable refuse, e.g. rice husks, maize-ear refuse; Cellulosic materials, e.g. paper , cork
• CPC Class Codes: C04B 20/0048 Fibrous materials
• CPC Class Codes: C04B 2111/00612 as one or more layers of a layered structure
• CPC Class Codes: C04B 2111/00637 as glue or binder for uniting building or structural materials
• CPC Class Codes: C04B 2111/1018 Gypsum free or very low gypsum content cement compositions
• CPC Class Codes: C04B 24/24 Macromolecular compounds C04B24/14 takes precedence; macromolecular compounds comprising sulfonate or sulfate groups C04B24/16
• CPC Class Codes: C04B 24/2641 Polyacrylates; Polymethacrylates
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 28/04 Portland cements
• CPC Class Codes: C04B 40/006 involving the elimination of excess water from the mixture
• CPC Class Codes: C04B 40/0064 : Processes of the Magnini or Hatscheck type
• CPC Class Codes: C04B 40/0071 : making use of a rise in pressure
• CPC Class Codes: C04B 41/009 : characterised by the material treated
• CPC Class Codes: C04B 41/4578 : Coating or impregnating of green ceramics or unset concrete
• CPC Class Codes: C04B 41/483 : Polyacrylates
• CPC Class Codes: C04B 41/5076 : with masses bonded by inorganic cements sulfur compositions C04B41/5097
• CPC Class Codes: C04B 41/63 : Macromolecular compounds
• CPC Class Codes: E04C 2/04 : of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibresE04C2/26 takes precedence; material or manufacture B28, C04
• CPC Class Codes: E04D 1/16 : of ceramics, glass or concrete, with or without reinforcement
• CPC Class Codes: E04F 13/0733 : for corners
• CPC Class Codes: E04F 13/141 : with an outer layer of concrete E04F13/147 takes precedence
• CPC Class Codes: E04F 13/16 : of fibres or chips, e.g. bonded with synthetic resins , or with an outer layer of fibres or chips E04F13/0864 takes precedence
• CPC Class Codes: E04F 15/10 : of other materials, e.g. fibrous or chipped materials, organic plastics, magnesite tiles, hardboard , or with a top layer of other materials
• CPC Class Codes: Y02W 30/91 : Use of waste materials as fillers for mortars or concrete

Abstract

The present invention provides exterior building products, such as roofing and siding, shake, shingles, siding, sheathing, panels, planks, vertical siding, soffit panels, fencing, decking, fascia, corner posts, column corners and trim boards in which a plurality of cementitious layers are provided with an improved interlaminar bond by employing a resinous bond promoter, a rheological agent, mechanical means to distribute fibers in a direction which is perpendicular to the machine direction so as to bridge between layers in the product, or a combination thereof. These techniques help to increase interlaminar bond strength to improve the mechanical properties of the product. When certain resinous bond promoters are used, the additional benefits of water absorption resistance and pigmentation throughout the product can be provided with minimal expense. Improvements in interlaminar bond strength of about 10 46% were observed with a percent elongation improvement of about 7%.

Claims

1. A method of manufacturing an exterior building product comprising:

a) forming a slurry of substantially non-gypsum cementitious material with reinforcing fibers;

b) forming the slurry into successive fibercement layers;

c) incorporating a resinous bond promoter of substantially non-gypsum, acrylic emulsion in an interlaminar region formed between the successive fibercement layers, and spraying a rheological agent of nano-sized magnesium alumino silicate onto the fibercement layers;

d) applying pressure and a wood grain impression in the slurry by a method step of molding the slurry with a mold having the wood grain impression and molding at a pressure of at least about 100 psi-500 psi, and dewatering and curing the slurry with the resinous bond promoter in the interlaminar region to bond the successive fibercement layers to one another with an increased interlaminar bond strength.

2. The method of claim 1 wherein said resinous bond promoter further comprises one or more of, starch, polyvinyl acetate, and derivatives thereof.

3. The method of claim 1, further comprising:

spraying the bond promoter onto one of the successive fibercement layers, and layering thereon another of the successive fibercement layer such that the bond promoter promotes better adhesion between the successive fibercement layers.

4. The method of claim 1 wherein first and second successive fibercement layers define a region therebetween, and said resinous bond promoter is applied to at least about 50% of the region.

5. The method of claim 1, and further comprising:

displacing individual fibers on the fibercement layers from an orientation in a machine direction to an orientation perpendicular to the machine direction, wherein the fibers join the fibercement layers together.

6. A method of manufacturing an exterior building product comprising:

a) forming a slurry of substantially non-gypsum cementitious material with reinforcing fibers;

b) forming the slurry into successive fibercement layers;

c) incorporating a resinous bond promoter of substantially non-gypsum, acrylic emulsion in an interlaminar region formed between the successive fibercement layers, and displacing individual fibers on the fibercement layers from an orientation in a machine direction to an orientation perpendicular to the machine direction, wherein the fibers join the fibercernent layers together;

d) spraying a rheological agent of nano-sized magnesium alumino silicate onto the fibercement layers; and

d) applying pressure and a wood grain impression in the slurry by a method step of molding the slurry with a mold having the wood grain impression and molding at a pressure of at least about 100 psi-500 psi, and dewatering and curing the slurry with the resinous bond promoter in the interlaminar region to bond the successive fibercement layers to one another with an increased interlaminar bond strength.