JPS632911A - Mildew-proofing agent - Google Patents

Abstract

PURPOSE:To provide a mildew-proofing agent containing a low-molecular weight chitosan as an essential component, effective in forming a chitosan film and preventing growth of mildew by directly applying or spraying to the objective part of kitchen, bath room, etc., and having extremely excellent safety. CONSTITUTION:The objective agent contains a low-molecular weight chitosan as an essential component. A low-molecular weight chitosan is dissolved in an acid such as hydrochloric acid, formic acid, adipic acid, etc., and used as an aqueous solution containing 0.01-10% low-molecular weight chitosan. A chitosan having a molecular weight of from several tens thousands to several hundred thousands can be produced by treating crust of an invertebrate such as crust of crab, krill, etc., with hydrochloric acid to effect the removal of calcium, treating the product with sodium hydroxide to remove protein and heattreating the resultant chitin in concentrated sodium hydroxide solution. The objective low-molecular weight chitosan can be produced by hydrolyzing the chitosan e.g. with hydrogen peroxide.

Description

[Detailed description of the invention] (Industrial application field) TECHNICAL FIELD The present invention relates to a fungicide.

(Conventional technology) In recent years, the airtightness of residences has increased with the adoption of aluminum sash, etc., and indoor areas with relatively high humidity such as kitchens and bathrooms are prone to mold growth. Mold removers, mold preventive agents, etc. are used.

Conventionally used mold removers include, for example, sodium hypochlorite and sodium pyl acetate, and mold preventive agents include, for example, thiabendazole (TBZ).

(Problems to be Solved by the Invention) These conventionally used mold removers, mold preventive agents, etc. all have stronger effects than disinfectants and are spray-type, so when using them, Because these substances diffuse into the air, there are safety issues, such as eye and throat pain, feeling unwell, difficulty speaking, and difficulty breathing.

(Means for Solving the Problems) The present inventors have conducted extensive research into safer fungicides that can replace these chemicals, and have found that these problems can be solved by using chitosan. The present invention has been provided based on this discovery. That is, it is an antifungal agent characterized by containing low molecular weight chitosan as an essential component.

Examples of the low molecular weight chitosan used in the present invention include those obtained as follows.

Ttg! is obtained by decalcifying crustaceans such as crab shells, shrimp shells, and krill with hydrochloric acid and deproteinizing them with caustic soda. Chitin is then heat-treated with high concentration caustic soda and deacetylated. Chitosan having an amino group and a molecular weight of tens of thousands to hundreds of thousands is obtained.

The degree of acetylation of this chitosan is 0 to 7 oz, preferably 10 to 50%.

Next, chitosan with a molecular weight of tens of thousands to hundreds of thousands is hydrolyzed with hydrogen peroxide, the enzyme lysozyme, or the enzyme chitosanase, etc., and oligomers with a molecular weight of 20,000 or less or low molecular weight oligosaccharides such as glucosamine bis-daily oligosaccharides are prepared. Obtain chitosan.

The antifungal agent according to the present invention contains the low molecular weight chitosan as an essential component.

When using low molecular weight chitosan, it is dissolved in an acid such as hydrochloric acid, acetic acid, lactic acid, adipine, sorbic acid, etc., and used as a 0.01 to 10% aqueous solution of low molecular weight chitosan.

When used as a fungicidal agent, it may be applied either directly to the area where it is used or by spraying or the like.

In the antifungal agent of the present invention, conventionally used antifungal agents such as TBZ may be used in combination in any proportion within the range of safety.

(Effects of the Invention) The anti-mold agent obtained according to the present invention is extremely safe compared to conventional anti-mold agents, and is therefore most suitable as an anti-mold agent for kitchens, bathrooms, etc. If this anti-mold agent is applied to the kitchen, bathroom, etc., a chitosan film will be formed after air-drying, thereby preventing the growth of mold.

(Example) Synthesis Example 1 Chitosan hydrolyzate with a degree of acetylation of 15% and a molecular weight of 1
Ten thousand oligomers were dissolved in the same weight of acetic acid to prepare a 1% aqueous solution.

Synthesis Example 2 Molecular weight 1 with 30% acetylation degree Ki]-san hydrolyzate
．． 000 oligosaccharides were dissolved in the same weight of acetic acid, and 10%
After preparing the aqueous solution, it was further diluted 100 times.

Example.

Low molecular weight chitosan of each of the above synthesis examples was added as a mold preventive agent to 20 g of potato dextrose agar '6 with 50 g g/m of chloramphenicol inoculated with Cladosporium and Alternaria molds collected from the kitchen or bathroom. Add 1g of aqueous solution to 23-2
The animals were placed in stirrups in a room at 5°C.

The results are shown in Table 1.

A control example was one in which no antifungal agent was used.

Table 1 However, 3: No growth of mycelium on petri dish & 5.

2; Growth of mycelium with a diameter of 1 mm or less is observed on the petri dish.

1; Mycelium with a diameter of 1 cm or more on a petri dish Growth is observed.

Claims (1)

[Claims] An antifungal agent characterized by containing low molecular weight chitosan as an essential ingredient.