Fiber board and its producing method

• US 20040096623A1
• Filed: 09/17/2003
• Published: 05/20/2004
• Est. Priority Date: 09/18/2002
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated, Toyota Boshoku Corporation (Toyota Motor Corporation)
• Original Assignee: Toyota Auto Body Company Limited (Toyota Motor Corporation), Toyota Boshoku Corporation (Toyota Motor Corporation)
• Inventors: Hashiba, Masanori, Kato, Takehiro, Sugiyama, Eiji, Inoh, Takashi, Mito, Osamu, Fujiyama, Tomomichi, Tamaki, Kousuke, Okuyama, Hisashi, Maeda, Yuhei, Urayama, Hiroshi, Matsumura, Kazuya
• Granted Patent: US 7,416,779 B2
• Time in Patent Office: Days
• US Class Current: 428/114
• 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 wherein polylactic acid resin is mixed in natural fiber as a binder and the apparent density is 0.2 g/cm³ or more.

2. The fiberboard according to claim 1, wherein the carboxyl-terminal quantity of the polylactic acid resin is an equivalent weight/t of 10 or less.

3. The fiberboard according to claim 2, wherein a polycarbodiimide compound is added to the polylactic acid resin.

4. The fiberboard according to any one of claims 1 to 3, wherein polylactic acid resin whose remaining monomer quantity under a raw pellet state is 500 ppm or less is used.

5. The fiberboard according to any one of claims 1 to 3, wherein a bending strength calculated in accordance with the following expression is 30 MPa or more as an initial value.

Bending strength (MPa)=3PL/ 2Wt²

P:

Maximum bending load (N)

L;

Distance between fulcrums (mm)

W;

Width of test piece (mm)

t;

Thickness of test piece (mm)

6. The fiberboard according to claim 5, wherein the retention rate of a bending strength to an initial value after leaving the board as it is for 1,200 hours at high temperature and high humidity of 50 °

C. and 95% RH is 20% or more.

7. The fiberboard according to any one of claim 1 to 3, wherein the mixing rate of the polylactic acid resin ranges between 10 and 90 wt %.

8. A fiber-board producing method comprising the steps of:

fibrosing polylactic acid resin whose remaining monomer quantity under a raw pellet state is 500 ppm or less through melt spinning;

mixing the fiber of the polylactic acid resin with natural fiber and forming them into a sheet, and molding by hot-pressing the sheet.

9. The fiber-board producing method according to claim 8, wherein the polylactic acid resin is kneaded with a polycarbodiimide compound and then fibrosed through melt spinning.