Colored building boards, manufacturing methods thereof

• US 6,740,423 B2
• Filed: 01/31/2001
• Issued: 05/25/2004
• Est. Priority Date: 01/31/2000
• Status: Expired due to Fees

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Murase, Naoki
• Primary Examiner(s): Kiliman, Leszek B
• Application Number:
  US09/772,871
• Publication Number:
  US 20010014402A1
• Time in Patent Office: 1,210 Days
• Field of Search: 428/537.1, 428/536, 428/537.7, 428/535, 427/393, 427/393.6, 427/397, 427/403, 427/408
• US Class Current: 428/537.1
• CPC Class Codes: B32B 21/04 comprising wood as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/042; next to a bituminous or tarry layer B32B11/042; next to a water setting substance layer B32B13/10; next to a metal layer B32B15/10; next to a glass layer B32B17/062; next to a layer formed of natural mineral fibres or particles B32B19/042; next to a cellulosic plastic layer B32B23/044
• CPC Class Codes: B32B 7/02 Physical, chemical or physicochemical properties
• CPC Class Codes: Y10T 428/31982 Wood or paper
• CPC Class Codes: Y10T 428/31986 Regenerated or modified
• CPC Class Codes: Y10T 428/31989 Of wood
• CPC Class Codes: Y10T 428/31996 Next to layer of metal salt [e.g., plasterboard, etc.]

Abstract

There is provided a building board which is colored by mixture of a pigment(s) into the raw materials and exhibiting an excellent color development effect. A pigment and a resin(s) are incorporated into the raw materials of the front layer to form a resin film simultaneously with cement curing, thereby blocking the inflow or outflow of water through the surface of the substrate to provide a cement board with good waterproofness. The cement board obstructs the efflorescence generation and exhibits an excellent pigment color development effect.

Claims

1. A colored building board comprising:

a dry formed front layer having a first density, the front layer having main components including wood material and self-curing inorganic material;

a dry formed back layer having a second density, the back layer having main components including wood material and self-curing inorganic material; and

a dry formed core layer having a third density that is lower in density when compared with said first density and said second density, the core layer having main components including wood material and self-curing inorganic material;

wherein at least said front layer contains pigment and at least one anti-efflorescence agent which produces a colored layer and insoluble salts simultaneously with curing of the self-curing inorganic material contained therein.

2. The colored building board according to claim 1, wherein said anti-efflorescence agent comprises at least one material selected from the group consisting of fluoride, carbonate, polyaminocarboxylic acid and maleic acid.

5. The building board according to claim 1, wherein the first finished density is substantially the same as the second finished density.

3. A manufacturing method for manufacturing a colored building board by a dry forming process, comprising the steps of:

forming a front layer to yield a first finished density in a finished board, the front layer having main components including wood material and self-curing inorganic material;

forming a core layer to yield a second finished density in a finished board that is lower in density than the first finished density, the core layer having main components including wood material and self-curing inorganic material; and

forming a back layer to yield a third finished density in a finished board that is higher in density when compared with said second finished board density, the back layer having main components including wood material and self-curing inorganic material;

incorporating pigment and an anti-efflorescence agent into at least the front layer; and

curing the building board and simultaneously forming the colored effect and producing insoluble salts within the building board.

4. A manufacturing method for manufacturing a colored building board according to claim 3, wherein said anti-efflorescence agent comprises at least one material selected from the group consisting of fluoride, carbonate, polyaminocarboxylic acid and maleic acid.