Fiber board and its producing method

• US 7,416,779 B2
• Filed: 09/17/2003
• Issued: 08/26/2008
• Est. Priority Date: 09/18/2002
• Status: Expired due to Term

• Current Assignee: Toray Industries Incorporated, Toyota Boshoku Corporation (Toyota Motor Corporation)
• Original Assignee: Toray Industries Incorporated, Toyota Auto Body Company Limited (Toyota Motor Corporation), Toyota Boshoku Corporation (Toyota Motor Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation), Toyota Tsusho Corporation
• Inventors: Hashiba, Masanori, Kato, Takehiro, Okuyama, Hisashi, Inoh, Takashi, Maeda, Yuhei, Matsumura, Kazuya, Sugiyama, Eiji, Urayama, Hiroshi, Mito, Osamu, Fujiyama, Tomomichi, Tamaki, Kousuke
• Primary Examiner(s): Cano; Milton I.
• Assistant Examiner(s): THOMPSON, CAMIE S
• Application Number:
  US10/663,672
• Publication Number:
  US 20040096623A1
• Time in Patent Office: 1,805 Days
• Field of Search: 428/35.8, 428/36.4, 428/182, 428/532, 428/220, 428/152, 428/906, 428/323, 428/373, 428/370, 428/375, 428/394, 428/218, 428/36.3, 428/36.91, 428/411.1, 156/296, 156/332, 156/307.1, 264/109, 264/121, 264/257
• US Class Current: 428/292.1
• CPC Class Codes: B27N 3/002 characterised by the type of binder compositions of macromolecular compounds C08L
• CPC Class Codes: C08L 2666/26 Natural polymers, natural resins or derivatives thereof according to C08L1/00 - C08L5/00, C08L89/00, C08L93/00, C08L97/00 or C08L99/00
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: Y10T 428/1369 Fiber or fibers wound around each other or into a self-sustaining shape [e.g., yarn, braid, fibers shaped around a core, etc.]
• CPC Class Codes: Y10T 428/1372 Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
• CPC Class Codes: Y10T 428/1393 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/24132 including grain, strips, or filamentary elements in different layers or components parallel
• CPC Class Codes: Y10T 428/249924 Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
• CPC Class Codes: Y10T 428/3179 Next to cellulosic

Abstract

To provide a fiberboard capable of reducing a load on the environment at all states of producing, using, and abolishing and moreover having a high degree of bending strength and a high bending-strength retention rate at high temperature and high humidity so as to be usable for an automobile interior material or building material and a fiber-board producing method. The fiberboard is formed by mixing natural fiber with polylactic acid resin serving as a binder and has an apparent density of 0.2 g/cm³.

Claims

1. A fiberboard comprising natural fiber and polylactic acid resin mixed in said natural fiber as a binder, said fiberboard

(1) having a density of 0.2 g/cm³ or more,

(2) comprising an initial bending strength of 30 MPa or more, said bending strength being calculated in accordance with the following expression

bending strength (MPa)=3PL/2Wt²

wherein P is the maximum bending load (N) to a test piece, L is the distance between fulcrums (mm) of the test piece, W is the width of the test piece (mm), and t is the thickness of the test piece (mm), and

(3) retaining 20% or more of said initial bending strength after subjecting said fiberboard to a high temperature of 50°

C. and a high humidity of 95% RH for 1,200 hours,

wherein the polylactic acid resin comprises a carboxyl-terminal quantity of 10 or less equivalent weight/ton and a polycarbodiimide compound which is added to the polylactic acid resin.

2. The fiberboard according to claim 1, wherein the polylactic acid resin comprises a remaining monomer quantity under a raw pellet state of 500 ppm or less.

3. The fiberboard according to claim 1, wherein the polylactic acid resin is mixed with the natural fiber at a range between 10 and 90 wt %.