| (19) |
 |
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(11) |
EP 0 323 732 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
03.04.1991 Bulletin 1991/14 |
| (43) |
Date of publication A2: |
|
12.07.1989 Bulletin 1989/28 |
| (22) |
Date of filing: 21.12.1988 |
|
|
| (84) |
Designated Contracting States: |
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AT BE CH DE ES FR GB GR IT LI LU NL SE |
| (30) |
Priority: |
06.01.1988 JP 1588/88
|
| (71) |
Applicant: Japan as represented by Director-General,
Agency of Industrial Science and Technology |
|
Tokyo 100 (JP) |
|
| (72) |
Inventors: |
|
- Hosokawa, Jun
Takamatsu-shi
Kagawa-ken (JP)
- Nishiyama, Masahi
Kan-onji-shi
Kagawa-ken (JP)
|
| (74) |
Representative: Baverstock, Michael George Douglas et al |
|
BOULT, WADE & TENNANT
27 Furnival Street
London, EC4A 1PQ
London, EC4A 1PQ (GB) |
|
| |
|
| (54) |
Cellulosic fibre - and chitosan-based composite material and a method for the preparation
thereof |
(57) The composite material of the invention is a sheet of cellulose fibres impregnated
with chitosan of at least 40% deacetylation and further impregnated with a higher
fatty acid such as stearic acid by treatment with an organic solution thereof. The
composite sheet of the invention differs from conventional paper and films of plastic
resins in having a high strength even in a wet condition and still is biodegradable,
for example, in wet soils so that no problems of environmental pollution are caused
by the waste thereof left in the environment. Therefore, the composite sheet of the
invention is useful as a wrapping material for foods, a sheet material for agricultural
use and other temporary or seasonal uses.