Cellulose molded body and method for producing same

Abstract

This method for producing a cellulose molded body comprises: a step for producing a water dispersion that has a concentration of 10% or less and and that contains natural cellulose fibers containing cellulose microfibers having a fiber width of 1 μm or less; a step for producing a dehydrated body having a water content of 10 times or less the cellulose weight by press-molding the water dispersion while dehydrating the same at a press pressure of 30 kgf / cm2 or less; and a step for drying the dehydrated body at a temperature of 100-150°C and a press pressure of 10 MPa or lower. This produces a cellulose product in which the natural cellulose fibers are amorphized. The amorphization of the natural cellulose fibers is specified by using, as an indicator, the crystallinity calculated by the Segal method, the crystallinity calculated by the curve fitting method, the crystallinity index, the first crystallinity or the second crystallinity determined from the infrared absorption spectrum, the oxygen permeability, the maximum moisture content, etc.

Claims

1. An aqueous dispersion with a concentration of more than 0% and less than 10% is produced, containing at least one of natural cellulose fibers with a fiber width of more than 1 μm and less than or equal to 100 μm, and cellulose microfibers with a fiber width of 1 nm or more and less than or equal to 1 μm. Press pressure 0 kgf / cm ２ Over 30 kgf / cm² ２ The aqueous dispersion is press-molded while applying the following pressure to dehydrate it, thereby producing a dehydrated body with a water content of 0 to 10 times the weight of cellulose. The dehydrated body is dried by applying a pressing pressure of 0 MPa to 10 MPa at a temperature of 100°C to 150°C. A method for manufacturing a cellulose molded article.

2. An aqueous dispersion with a concentration of more than 0% and less than 10% is produced, containing at least one of natural cellulose fibers with a fiber width of more than 1 μm and less than or equal to 100 μm, and cellulose microfibers with a fiber width of 1 nm or more and less than or equal to 1 μm. The aqueous dispersion is applied in a sheet-like manner. The coated aqueous dispersion is dried at a temperature of 100°C to 150°C. A method for manufacturing a cellulose molded article.

3. From the natural cellulose fibers with a fiber width exceeding 1 μm and less than or equal to 100 μm, the cellulose microfibers are defibrillated and branched. As the natural cellulose fiber used to produce the aqueous dispersion, the natural cellulose fiber in which the cellulose microfibers are branched is used. A method for producing a cellulose molded article according to claim 1 or 2.

4. From the natural cellulose fibers with a fiber width of 1 nm or more and 1 μm or less, the cellulose microfibers are defibrated and branched. As the natural cellulose fiber used to produce the aqueous dispersion, the natural cellulose fiber in which the cellulose microfibers are branched is used. A method for producing a cellulose molded article according to claim 1 or 2.

5. The aforementioned natural cellulose fibers are defibrated to a fiber width of 1 nm or more and 1 μm or less to produce the aforementioned cellulose microfibers. The cellulose microfibers are defibrated until the axial portion is removed. As the natural cellulose fibers used to produce the aqueous dispersion, a mixture of the cellulose microfibers and the defibrated cellulose microfibers is used. A method for producing a cellulose molded article according to claim 1 or 2.

6. The aforementioned natural cellulose fibers are defibrated to a fiber width of 1 nm or more and 1 μm or less to produce the aforementioned cellulose microfibers. The cellulose microfibers are defibrated until the axial portion is removed. As the natural cellulose fibers used to produce the aqueous dispersion, the defibrated cellulose microfibers are used. A method for producing a cellulose molded article according to claim 1 or 2.

7. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. [Math 1] The degree of crystallinity obtained is between 0% and 80%. Cellulose molded body.

8. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. [Math 2] The degree of crystallinity obtained is between 0% and 55%. Cellulose molded body.

9. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. Using the integrated value of the signal obtained from the nuclear magnetic resonance spectrometer, [Math 3] The crystallinity index obtained from this is between 0% and 48%. Cellulose molded body.

10. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. Among the infrared absorption spectra measured by a Fourier transform infrared spectrometer, [Math 4] The first degree of crystallinity obtained from is between 0 and 1. Cellulose molded body.

11. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. Among the infrared absorption spectra measured by a Fourier transform infrared spectrometer, [Math 5] The second degree of crystallinity obtained from this is 0 or greater and 0.5 or less. Cellulose molded body.

12. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. The maximum moisture content is between 0% by mass and 5% by mass. Cellulose molded body.

13. The maximum moisture content is between 0% by mass and 3% by mass. The cellulose molded article according to claim 12.

14. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. The X-ray diffraction pattern measured by the X-ray diffractometer (source CuKα) is There are one or two peaks in the range of 13° ≤ 2θ ≤ 18°, There is one peak at 18° ≤ 2θ ≤ 30°, There is one peak at 30° ≤ 2θ ≤ 40°, It has, A cellulose molded article according to any one of claims 7 to 13.

15. It contains natural cellulose fibers containing cellulose microfibers with a fiber width of 1 nm to 1 μm. The oxygen permeability measured by an oxygen permeability measuring device (coulometric method) over a measurement period of 200 hours was 0.3 cc / m², which is equivalent to a thickness of 25 μm. ２ / day or more 7.0cc / m ２ / day or less, Cellulose molded body.

16. The aforementioned natural cellulose fibers include cellulose fibers with a fiber width of 1 μm to 100 μm, from which the cellulose microfibers branch off from the surface. A cellulose molded article according to any one of claims 7 to 13.

17. The aforementioned natural cellulose fibers are cellulose microfibers with a fiber width of 1 nm or more and 1 μm or less. The cellulose microfiber has fibers that branch off from the cellulose microfiber. A cellulose molded article according to any one of claims 7 to 13.

18. The aforementioned natural cellulose fiber is a mixture of cellulose microfibers with a fiber width of 1 nm or more and 1 μm or less, and cellulose microfibers without a shaft portion. A cellulose molded article according to any one of claims 7 to 13.

19. The aforementioned natural cellulose fiber is a cellulose microfiber that does not have a axial portion with a fiber width of 1 nm or more and 1 μm or less. A cellulose molded article according to any one of claims 7 to 13.

20. Density is 1.45 g / cm³ ３ 2.00g / cm or more ３ The following is: A cellulose molded article according to any one of claims 7 to 13.

21. The tensile modulus is 6 GPa or more and 100 GPa or less at 20°C. A cellulose molded article according to any one of claims 7 to 13.

22. The tensile modulus is 6 GPa or more and 100 GPa or less at 90°C. A cellulose molded article according to any one of claims 7 to 13.

23. The tensile stress is between 100 MPa and 10 GPa at 20°C. A cellulose molded article according to any one of claims 7 to 13.

24. The tensile stress is between 90 MPa and 10 GPa at 90°C. A cellulose molded article according to any one of claims 7 to 13.

25. The flexural modulus is 11 GPa or more and 100 GPa or less at 20°C. A cellulose molded article according to any one of claims 7 to 13.

26. The flexural modulus is 8 GPa or more and 100 GPa or less at 90°C. A cellulose molded article according to any one of claims 7 to 13.

27. The bending stress is between 80 MPa and 10 GPa at 20°C. A cellulose molded article according to any one of claims 7 to 13.

28. The bending stress is between 60 MPa and 10 GPa at 90°C. A cellulose molded article according to any one of claims 7 to 13.

29. The interlaminar strength is between 11 MPa and 10 GPa. A cellulose molded article according to any one of claims 7 to 13.

30. The Izod impact strength without notching is 36 kJ / m at 20°C. ２ More than 1000kJ / m ２ The following is: A cellulose molded article according to any one of claims 7 to 13.

31. The hardness D measured by a Rockwell durometer is between 80 and 100 at 20°C. A cellulose molded article according to any one of claims 7 to 13.

32. The tensile modulus after 24 hours of oil resistance evaluation was between 6 GPa and 100 GPa. A cellulose molded article according to any one of claims 7 to 13.

33. The tensile stress measured after 24 hours for oil resistance evaluation was between 100 MPa and 10 GPa. A cellulose molded article according to any one of claims 7 to 13.

34. The flexural modulus after 24 hours of oil resistance evaluation was between 13 GPa and 100 GPa. A cellulose molded article according to any one of claims 7 to 13.

35. The bending stress measured after 24 hours for oil resistance evaluation was between 100 MPa and 10 GPa. A cellulose molded article according to any one of claims 7 to 13.

Images