JPH0476025A - Biodegradable closed cell sponge body and its manufacturing method - Google Patents

Abstract

PURPOSE:To obtain the title sponge which does not pollute environments when discarded and is useful as an agricultural material or the like by mixing cellulose, chitosan, a blowing agent and a specified substance. CONSTITUTION:Cellulose is mixed with chitosan, a blowing agent (e.g. azodicarbonamide) and a coagulant (e.g. ammonium carbonate).

Description

[Detailed description of the invention] <Industrial application field> The present invention provides a biodegradable cellulose comprising cellulose and chitosan]
1. This article relates to a semi-sponge body and its manufacturing method.

<Prior art> J, Y's sponge bodies are made of synthetic polymers such as rubber and plastic, and when released into the natural environment as waste, they do not decompose, or even if they decompose, the rate of decomposition is extremely slow. It causes environmental pollution.

Currently, degradable plastics are being developed, but none have been made into sponges.

Biodegradable plastics whose main components are cellulose and chito-4-non, a type of chitin, have been proposed, but sheet-like plastics have only been produced. The method of using a surfactant for foaming is generally applied to latex sponges, but this method uses a system in which cellulose is dispersed in an aqueous chitosan solution, which is a step in the production of biodegradable plastics whose main components are cellulose and gitlin. There are no application examples.

<Problems to be Solved by the Invention> In light of the above, there is a need for a biodegradable single-cell sponge body that does not cause ring ift pollution and a method for producing the same.

The object of the present invention is to provide a biodegradable closed-cell foam sponge made of cellulose and chitosan that solves the problems described above, and a method for producing the same.

In order to achieve the above-mentioned objects, the present invention (sufficiently disintegrable single-cell sponge material containing cellulose, chitosan, a blowing agent, and a coagulant) has been developed. be.

In addition, 1. The method for producing the biodegradable single-cell sponge body according to the present invention consists of adding a liquid in which cellulose is dispersed in an aqueous solution of chitosan, and then sequentially adding a blowing agent and a coagulant. . The aqueous solution of chitosan is prepared by dissolving chitosan in a dilute acid such as acetic acid, but is not limited to acetic acid.

<Function> When the biodegradable single-cell sponge body constructed as described above is released into the natural environment as waste, it easily decomposes and does not cause environmental pollution.

<Example> To explain the example with reference to Figure 1, 1. First, 4%
250g of cellulose and 60m of 6.7% starch as a biodegradation accelerator! An aqueous cellulose solution A was prepared by adding 27 g of glycerin as a plasticizer.

Separately, dissolve glacial acetic acid in water to make a 1.3% acetic acid aqueous solution.
Chitosan in acetic acid aqueous solution B is prepared by dissolving 2 g of chitosan in 150 ml of the acetic acid aqueous solution.

Next, cellulose aqueous solution A and chitosan acetic acid aqueous solution B are mixed. This mixture was filtered to remove insoluble matter through a 150-mesh filter cloth, 400 g of the filtrate was taken, and a suspension of 15 ml of azodicarbonamide Ig was dispersed therein as a foaming agent. Then, 4.0 g of ammonium carbonate was added as a coagulant to form a gel After drying with air at 70°C, a biodegradable single cell sponge body is obtained.

Next, the effects of different compositions of the formulations will be explained. The solid content concentration of chitosan should be 0.5% or more, and 1 to 20%.
% is preferred for foaming. The biodegradation rate can be adjusted by adjusting the chitosan concentration and biodegradation accelerator (starch, etc.).

Although a plasticizer is not necessarily required, for example, if glycerin is added as a plasticizer at a solid content of 50 to 65%, a soft and elastic single cell sponge body can be obtained.

A high-quality foam cannot be obtained unless it is gelled with a coagulant before drying and foaming. When ammonium carbonate is used as a coagulant, its solid content concentration is preferably 0.5 to 2%.

When azodicarbonamide is used as a blowing agent, its solid content concentration is preferably 1 to 0.3%.

Note that other natural products may also be blended.

<Effects of the Invention> Since the present invention is configured as explained above, the present invention is a lightweight biodegradable single material with an apparent density of 0.05 g/cm3 or more, a water absorption rate of 1000% or less, and a thickness of 11 or more. A foam sponge body is obtained.

In addition, it is possible to produce materials suitable for agricultural materials, trays for food (fishery products), etc. by taking advantage of its biodegradability.

It is also possible to produce packaging cushioning materials for household and industrial use that do not cause environmental pollution.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing an embodiment of the present invention. Sub-agent of the Director of the Agency of Industrial Science and Technology Patent attorney 1) Gouki Nishikawa Rubber Industries Co., Ltd.

Claims (1)

[Scope of Claims] [1] A biodegradable single-cell sponge body containing cellulose, chitosan, a foaming agent, and a coagulant. [2] A method for producing a biodegradable single-cell sponge body, which comprises adding a dispersion of cellulose in an aqueous solution of chitosan, and then sequentially adding a blowing agent and a coagulant.