Cementitious exterior sheathing product having improved interlaminar bond strength

• US 7,155,866 B2
• Filed: 01/15/2003
• Issued: 01/02/2007
• Est. Priority Date: 11/05/2002
• Status: Expired due to Term

• Current Assignee: Plycem USA, Inc. (Elementia SAB de CV)
• Original Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Inventors: Bezubic, William Paul Jr., Brown, Claude Jr.
• Primary Examiner(s): Katcheves; Basil
• Application Number:
  US10/342,529
• Publication Number:
  US 20040083677A1
• Time in Patent Office: 1,448 Days
• Field of Search: 523/16, 523/38, 525/20, 525/55, 525/18, 525/41, 524/55, 524/43, 527/481, 523/091.7, 524/08, 527/961, 522/871, 428/292.1, 428/294.7, 428/296.1, 428/296.4, 428/317.1, 428/317.3, 428/317.5, 428/317.7, 264/86, 264/333, 156/62.2, 156/285, 156/71.1
• US Class Current: 52/287.1
• 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 building product comprising:

a plurality of individual fibercement layers, said individual fibercement layers comprising, substantially gypsum free, cementitious material having respective reinforcing fibers therein; and

said individual fibercement layers being successively adhered to one another and strengthened by a water resistant, interlaminar bond therebetween, said interlaminar bond comprising, a substantially gypsum free, bond promoter material of an acrylic based resin and water.

2. The building product of claim 1, wherein said respective reinforcing fibers are oriented within corresponding said individual fibercement layers.

3. The building product of claim 1, wherein said individual fibercement layers further comprise, respective aggregate therein.

4. The building product of claim 1, wherein said individual fibercement layers are successively adhered to one another by having said bond promoter material thereon.

5. The building product of claim 1, wherein said cementitious material in a slurry form comprises said bond promoter material.

6. The building product of claim 1, wherein said interlaminar bond strength of said plurality of layers is increased at least about 10%.

7. The building product of claim 1, wherein said cementitious material comprises Portland cement and silica sand aggregate, and said reinforcing fibers comprise cellulose fibers.

8. The building product of claim 1, wherein said bond promoter material increases an Elongation at Break property of said building product by at least about 7%.

9. The building product of 1, wherein said plurality of individual layers comprise first, second and third layers, and said bond promoter material is disposed between said first and second layers, and between said second and third layers to improve the interlaminar bond strength of said first, second and third layers.

10. The building product of claim 9 wherein said building product comprises, one of a siding product or a roofing product;

said bond promoter material increases the interlaminar bond strength of said building product by at least 10%, and said bond promoter material increases an Elongation at Break of said building product by at least 7%.

11. A building product comprising:

a plurality of gypsum free, individual fibercement layers in one of, siding for a building or roofing for a building, each of said individual fibercement layers comprising, cement having therein respective, cellulosic fibers and silica sand;

one of said individual fibercement layers comprising an exterior for a building having said one of, said siding or said roofing;

a gypsum free, acrylic-based bond promoter material disposed at least within an interlaminar bond region between adjacent said individual fibercement layers; and

said one of, said siding or said roofing, having an interlaminar bond break stress of at least 10% greater than without said acrylic-based bond promoter material in said siding or said roofing.

12. The building product of claim 11 wherein said acrylic-based bond promoter material comprises at least about 0.1 wt. % acrylic portion thereof.

13. An exterior building product comprising:

a plurality of gypsum free, individual fibercement layers;

a gypsum free bond promoter material successively adhering together adjacent said individual fibercement layers, such that, said bond promoter material increases an interlaminar bond strength of an adhered together said individual fibercement layers;

wherein said bond promoter material comprises one or more of;

acrylic, polyvinyl alcohol, starch, polyvinyl acetate;

an exterior-facing side on one of said individual fibercement layers; and

a building-facing side on another of said individual fibercement layers.

14. An exterior cementitious building product comprising:

a plurality of successive, individual fibercement layers, wherein each of said fibercement layers contains a respective cementitious mixture, said cementitious mixture comprising, at least gypsum free cement and respective reinforcing fibers therein;

one of said individual fibercement layers having an exterior-facing side;

another of said individual fibercement layers comprising, a rearwardly facing side; and

a resinous, gypsum free bond promoter material comprised of one or more of;

acrylic, polyvinyl alcohol, starch and polyvinyl acetate, disposed between said successive said fibercement layers in sufficient quantity to increase the interlaminar bond strength of said building product while improving its resistance to water absorption.