JPH0739509B2 - Water-soluble seaweed polysaccharide composition having water resistance function - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition containing a water-soluble seaweed-based polysaccharide as a main component, and more specifically, using a means harmful to an enzyme or a living body. The present invention relates to a water-soluble seaweed-based polysaccharide composition which can be made resistant to water and has excellent processability.

[Prior Art] Water-soluble seaweed-based polysaccharides such as alginic acid (salt), agar, and carrageenan have been conventionally used as fibers due to their unique water-solubility, thickening and gelling properties, and nontoxicity to enzymes and living bodies. It has been put to practical use in a wide range of applications such as an industrial sizing agent, a dispersant for the paper industry, a food thickener, a gel-like food material, and a culture substrate for microorganisms.

In recent years, especially focusing on the nontoxicity of these water-soluble seaweed polysaccharides to enzymes and living organisms, we have developed new functional materials such as wound wound coating materials, immobilized enzyme substrates, and biosensors and biochips. The application of is attracting attention. (For example, Kobayashi: Chemistry and industry 39 (7) 521-523, protein nucleic acid, enzyme 31
(11) 1066-1077).

In these new fields of application, improving the processability of water-soluble seaweed polysaccharides into films, coatings, fibers or fiber sheets, etc., and making them water resistant without using any means harmful to enzymes or living organisms. Is strongly demanded.

Conventionally, as a water-resistant method for water-soluble seaweed polysaccharides, treatment with a water-soluble salt of calcium or other polyvalent metal (excluding mercury and magnesium) used in the production of alginate fibers is known. ing. (Large Organic Chemistry, 20
Vol., Pp. 228-229, published in 1959).

Further, generally, as a method of making a water-soluble polymer water resistant, a chemical method such as a method of introducing a crosslinkable functional group into the polymer, a method of using a crosslinking agent suitable for the polymer, and heat treatment, Many methods are known, including physical methods such as radiation treatment and surface treatment with a hydrophobic substance.

[Problems to be Solved by the Invention] However, when the above-mentioned heavy metal salts are used for making the water-soluble seaweed-based polysaccharides resistant to water, coloring of the fiber or fiber sheet after drying is remarkable or opaque Moreover, depending on the type of metal, toxicity to the enzyme or living body may become a problem. Further, there is a limit to the coordination of metal ions, and it is considered impossible to expect a large water resistance effect.

Further, it is not easy to introduce a functional group having a cross-linking property, which is known as a water-resistant method for general water-soluble polymers, into a water-soluble seaweed polysaccharide without impairing its water-solubility or processability, Even if it could be introduced, it has a drawback that it thickens or gels over time and impairs processability.When water resistance is obtained using a crosslinking agent, a special catalyst or heat treatment is required for the crosslinking reaction. However, there are drawbacks such that these cross-linking agents, catalysts, and heat treatments are often harmful to enzymes and living bodies.

Furthermore, even if the water-soluble seaweed polysaccharide is subjected to heat treatment, radiation treatment, or the like, it has almost no effect on improving the water resistance, and excessive heat treatment or radiation treatment causes decomposition of molecules, which is not preferable.

The object of the present invention is to provide a water-soluble seaweed polysaccharide composition which is improved in stability and processability of an aqueous solution and can be made water resistant without using a harmful means to an enzyme or a living body. Therefore, another object of the present invention is to provide various molded products containing enzymes and microorganisms, coating films, and materials harmless to living bodies.

[Means for Solving Problems] As a result of intensive studies to achieve the above-mentioned object, the present inventors have blended a water-soluble seaweed-based polysaccharide with a water-soluble acetoacetylated polyvinyl alcohol-based resin. By doing so, it was found that water resistance can be achieved without using an enzyme or a means harmful to the living body, and the film-forming ability is remarkably improved, and the present invention has been completed.

[Action] The water-soluble seaweed-based polysaccharides referred to in the present invention include alginic acid and its water-soluble salts, agar, carrageenan and 2 of these.
It is a mixture of two or more species.

Among these, alginic acid (salt) is particularly useful because it has excellent film and fiber forming properties.

The water-soluble acetoacetylated polyvinyl alcohol-based resin in the present invention is produced, for example, by the method described in JP-B-57-45761 and JP-A-55-137107, but is not limited to these methods. However, it can also be obtained by subjecting a water-soluble polyvinyl alcohol resin to an acetoacetic acid ester exchange reaction.

The content of the acetoacetyl group in the water-soluble acetoacetylated polyvinyl alcohol resin is 0.05 mol% or more, and can be selected within the range of the water solubility of the resin, but usually 0.1
It is preferable to select from the range of -40 mol%, especially 0.2-20 mol%.

If the content of the acetoacetyl group is too low, the water resistance effect is insufficient and the object of the present invention cannot be achieved. Further, even if it is higher than necessary, the water resistance efficiency is not improved, and the water solubility is out of the range. Will increase.

The saponification degree of the acetoacetylated polyvinyl alcohol resin is preferably 70 to 100 mol%, and the preferable degree of polymerization is 3
It is from 00 to 2,000.

Toxicity to the living body of the above-mentioned water-soluble acetoacetylated polyvinyl alcohol resin is low, for example, the content of the acetoacetyl group 5 mol%, the acute toxicity for saponification degree of 99 mole% of the acetoacetylated polyvinyl alcohol, LD ₅₀ 8 g / Values above Kg (rats) have been obtained. (Institute for Life Science, test report, dated May 10, 1984) In the present invention, the compounding ratio of the water-soluble acetoacetylated polyvinyl alcohol resin to the water-soluble seaweed polysaccharide depends on the purpose of water resistance. The content ratio of acetoacetyl groups based on the total dry solid content of the water-soluble seaweed polysaccharide and the water-soluble acetoacetylated polyvinyl alcohol resin is 3 × 10 ^-2. ~ 5
It is selected to be × 10 ^-1 mmol / g. If the content of the acetoacetyl group in the composition is too low, it is difficult to obtain a sufficient water resistance effect, while even if higher than necessary, the water resistance effect does not improve further, water-soluble seaweed The properties of the polysaccharides are lost.

The composition of the present invention is usually provided as an aqueous solution, but the aqueous solution is formed into a granular, film-like, sponge-like or the like, or a plastic film / fiber / other molded article having hydrophilic surface, paper / nonwoven fabric. -Water resistance can be easily obtained by applying to a porous base material such as woven cloth or a base material such as metal or ceramics and then air drying or vacuum drying.

Further, the composition of the present invention, if the content thereof is 20% by weight or more, preferably 30% by weight or more, if the active ray is irradiated,
The water resistance effect can be obtained more easily. As the type of actinic rays, in addition to artificial rays such as electron rays, α rays, β rays, γ rays, and X rays, sunlight can also be used, but usually, due to the simplicity of equipment, work safety, etc. UV light is used. Any light source may be used, and a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a xenon lamp or the like can be used.

Irradiation dose required for water resistance of the composition of the present invention, for example, 100
In the case of a film having a thickness of μm, it is suitable to set the light amount to 3 × 10 ^{4 to} 3 × 10 ⁵ μW / sec · cm ² for about 0.5 to 10 seconds. Upon irradiation, if necessary, a publicly known light source sensitizer may be selected and used in combination for the purpose.

Further, the water resistance of the composition of the present invention, the irradiation of actinic rays in the above-mentioned drying process, or after performing actinic ray irradiation, such as drying, dehydration drying and actinic ray irradiation appropriately It can also be performed in combination.

[Effect] As described above, the composition of the present invention is water-soluble, and can be made water resistant without the need for a crosslinking agent, a catalyst or heat treatment harmful to enzymes and living bodies, and has a film-forming ability. Since it is also excellent in fiber forming ability, it is highly useful as a molding material or coating material such as a film containing an enzyme or a microorganism, a fiber or a fiber sheet, or a molding material or coating material having low biotoxicity.

[Examples] Next, the characteristics of the composition of the present invention will be described more specifically based on Examples. Hereinafter, "parts" or "%" are based on weight unless otherwise specified.

The "dry solid content of the composition" of the present invention in the following examples can be determined by the following method.

Method for measuring the dry solid content of the composition: 1 to 3 g of a sample was precisely weighed (Ag), and 3 in a hot air dryer at 110 ° C.
After drying for an hour, let it cool in silica gel and weigh it after drying (B
g) is measured, and the dry solid content (%) = (B / A) x 100 is calculated.

Example 1 117 parts of sodium alginate having a water content of 15% (manufactured by Kimitsu Chemical Industry Co., Ltd., grade H), degree of acetoacetylation 5
Mol%, saponification degree 99 mol%, degree of polymerization 1,100, water content 7%
Acetoacetylated polyvinyl alcohol 108 parts, water 2,6
A composition consisting of 00 parts (content of acetoacetyl group relative to dry solid content of the composition: 0.1 mmol / g) was cast on a horizontal glass plate and allowed to stand at room temperature for 2 days to give an average thickness of 100.
A film having μ and a water content of 30% was prepared. A part of this film was dehydrated and dried at room temperature for 15 hours using a vacuum dryer to obtain a dried film. Moisture the remaining part of this film to a water content of 60%, then add 3 × 10 ⁴ μW
After UV irradiation for 2 sec / sec · cm ² , it was dehydrated and dried for 15 hours in a vacuum dryer to obtain a UV irradiation film.

These films were conditioned at 20 ° C. and 65% RH for 8 days, and then the dry strength and wet strength were determined by the following methods. The results are summarized in Table 1.

Method for measuring dry strength and wet strength: After measuring the average thickness of the film after humidity control, a test piece for measurement (width 10 mm, length 80 mm) was prepared from the film, and the dry strength was the same as the wet strength. Test piece
After soaking in water at 20 ° C for 30 seconds, tensile strength was determined using a Tensilon at a chuck distance of 50 mm and a pulling speed of 20 mm / min. The number of repeated measurements n = 6.

Examples 2 to 4 The dry strength and wet strength of the film obtained in the same manner as in Example 1 were determined except that the compounding ratio of acetoacetylated polyvinyl alcohol to sodium alginate was changed.

Control Example 1 The dry strength and wet strength of the film obtained in the same manner as in Example 1 except that acetoacetylated polyvinyl alcohol was not mixed with sodium alginate were determined.

The results are summarized in Table 2.

Examples 5 to 6 Example 1 was repeated except that acetoacetylated polyvinyl alcohols having different degrees of acetoacetylation were used.
The dry strength and wet strength of the film obtained in the same manner as above were determined.

Examples 7 and 8 The dry strength and wet strength of the film obtained in the same manner as in Example 1 except that acetoacetylated polyvinyl alcohols having different degrees of polymerization were used were obtained.

The results are summarized in Table 3.

Examples 9 and 10 A mixture of sodium alginate and agar in place of sodium alginate in Example 1 (dry solid content ratio 60/4
0) or the dry strength and wet strength of the film obtained in the same manner as in Example 1 except that a mixture of sodium alginate and κ-carrageenan (dry solid ratio 60/40) was used.

Control Examples 2 and 3 In Control Example 1, instead of sodium alginate, a mixture of sodium alginate and agar (dry solids ratio 60/4
0) or a mixture of sodium alginate and κ-carrageenan (dry solid ratio 60/40) was used, and the dry strength and wet strength of the film obtained in the same manner as in Control Example 1 were determined.

The results are summarized in Table 4.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Kageyama 2-6-18 Manoren, Ikeda-shi, Osaka (72) Inventor Shuji Tsutsumi 759-11 Nomura-cho, Kusatsu-shi, Shiga Examiner Hiroshi Josho

Claims (3)

[Claims] 1. A water-soluble seaweed-type polysaccharide composition having a water resistance function, which is obtained by blending a water-soluble seaweed-type polysaccharide with a water-soluble acetoacetylated polyvinyl alcohol-type resin. 2. The content of acetoacetyl groups relative to the total amount of dry solids of the water-soluble seaweed polysaccharide and the water-soluble acetoacetylated polyvinyl alcohol resin is 3 × 10 ^{−2 to} 5 × 10 ⁻¹ m. The composition according to claim (1), which is blended so as to be mol / g. 3. The composition according to claim 1, wherein the water-soluble seaweed polysaccharide is alginic acid and / or an alkali metal alginate.