JP3435492B2 - Solvent for dissolving polysaccharide substances - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a solvent used for dissolving a polysaccharide substance, a solution containing the polysaccharide substance, and a method for preparing the solution.

[0002]

2. Description of the Related Art It is known that a polysaccharide substance (polysaccharide) such as cellulose does not dissolve in a solvent under normal conditions because the hydroxyl groups in the crystal form hydrogen bonds. In order to dissolve such a polysaccharide substance into a solution, it is necessary to perform pretreatment such as high temperature steam treatment, mechanical treatment, and hydrolysis treatment for reducing the molecular weight. It is known that the polysaccharide substance subjected to such pretreatment is soluble in an amide-based polar solvent (dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, etc.) in which lithium chloride is dissolved. However, the above-mentioned conventional method of making a polysaccharide substance into a solution is unsatisfactory because it requires a pretreatment, resulting in high treatment cost.

[0003]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a solvent capable of directly dissolving a polysaccharide substance without pretreatment, a solution containing the polysaccharide substance and a method for preparing the solution. To do.

[0004]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the present invention, there is provided a solvent for dissolving a polysaccharide substance, which comprises a solution formed by dissolving at least one metal halide selected from alkali metal halides and alkaline earth metal halides in formic acid. It Also, according to the present invention, the polysaccharide substance solution obtained by dissolving a polysaccharide material into the solvent Ru are provided. Further, according to the present invention, there is provided a cellulose solution obtained by dissolving a cellulose substance in the solvent. Furthermore, according to the present invention, there is provided a method for producing a cellulose-containing solution, which comprises adding and dissolving a cellulose substance to the solvent.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The solvent for dissolving a polysaccharide substance according to the present invention dissolves in formic acid at least one metal halide selected from alkali metal halides and alkaline earth metal halides. In this case, halogen includes chlorine, bromine, iodine and fluorine. Alkali metal halides include sodium chloride (NaC
l), potassium chloride (KCl), lithium chloride (LiC
l), sodium bromide (NaBr), potassium bromide (K
Br), lithium bromide (LiBr) and the like can be preferably used. On the other hand, alkaline earth metals include calcium chloride (CaCl ₂ ), magnesium chloride (MgC
l ₂ ), calcium bromide (CaBr ₂ ), magnesium bromide (MgBr ₂ ) and the like can be preferably used.

To prepare the solvent of the present invention, the metal halide may be added to formic acid and dissolved. The amount of dissolved metal halide is 100 to 800 per liter of formic acid in the case of alkali metal halide.
g, preferably 250 to 700 g. On the other hand, in the case of an alkaline earth metal halide,
It is 100 to 800 g, preferably 250 to 600 g. The temperature at which the metal halide is dissolved is usually room temperature, but in order to increase the dissolution rate, it is, for example, 30 to 4
It is also possible to heat to 0 ° C.

The solvent of the present invention exhibits a dissolving action not only for water-soluble polysaccharide substances but also for various poorly water-soluble or water-insoluble polysaccharide substances. In this case, the polysaccharide substance
Included are natural and synthetic. Specific examples thereof include cellulose, starch, dextran, inulin,
Examples include mannan, pectin, pectic acid, alginic acid, chitin, chitosan, carrageenan, xanthan and the like. The polysaccharide substances also include modified products and processed products of the above-mentioned polysaccharide substances, for example, cotton or hemp pulp, linters, cellulose powder, regenerated cellulose such as cellophane and rayon, and carboxymethylcellulose.

In order to prepare the solution by dissolving the polysaccharide substance in the solvent of the present invention, the polysaccharide substance may be added to the solvent and stirred. In this case, the dissolution temperature is usually room temperature, but in order to increase the dissolution rate, it is 30 to 100 ° C.
It can also be heated to. The amount of the polysaccharide substance dissolved is 2% or more, preferably 4% or more in the solution. Its upper limit is usually about 30%, Ru different depending on the type of composition and the polysaccharide substance of the solvent.

[0009] The solution containing the polysaccharide material or cellulose material noted previously, can be used as a molding material and film-forming material. In order to obtain a molded product using this solution, this solution may be molded into a film-like or thread-like shape and dried. On the other hand, to form the coating film on paper or film,
The solution may be applied on paper or film and dried.

[0010]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 0.2 g of cotton linter dried at 115 ° C. was dissolved in 4 g of formic acid 4 g of lithium chloride.
Added to mL. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 2 0.2 g of cotton linter dried at 115 ° C. was added to 4 mL of formic acid in which 1 g of magnesium chloride was dissolved. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 3 0.2 g of cotton linter dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of calcium chloride was dissolved. The mixture was stirred at room temperature for 10 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 4 0.2 g of cotton linter dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of lithium bromide was dissolved. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 5 0.2 g of cotton linter dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of calcium bromide was dissolved. The mixture was stirred at room temperature for 10 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 6 0.2 g of cotton linter dried at 115 ° C. was added to 4 mL of formic acid in which 1 g of magnesium bromide was dissolved. The mixture was stirred at room temperature for 10 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 7 0.2 g of softwood pulp dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of lithium chloride was dissolved. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 8 0.2 g of hardwood pulp dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of lithium chloride was dissolved. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 9 0.2 g of cotton dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of lithium chloride was dissolved. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 10 0.2 g of softwood flour dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of lithium chloride was dissolved. The mixture was stirred at room temperature for 3 hours to obtain a transparent viscous liquid containing black insoluble matter. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 11 0.2 g of chitin dried at 115 ° C. was added to 2 parts of lithium chloride.
g was added to 4 mL of dissolved formic acid. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 12 0.2 g of chitosan dried at 115 ° C. was added to 4 mL of formic acid in which 2 g of lithium chloride was dissolved. The mixture was stirred at room temperature for 3 hours to give a clear viscous liquid. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed.

Example 13 0.2 g of cotton linter dried at 115 ° C. was added to a mixture of 2 mL of formic acid and 2 mL of acetic acid in which 2 g of lithium chloride was dissolved. The mixture is stirred at room temperature for 10 hours,
A clear viscous liquid was obtained. When the liquid was observed with a polarization microscope, no birefringence indicating the presence of a crystalline substance was observed .

[0024] The ratio Comparative Examples 1 lithium bromide 4g 100 ° C. in ethylene glycol 2g
Dissolved in. 0.3 g of cotton linter was added to this water-free solution and stirred for 5 hours, but no dissolution of cellulose was observed.

[0025]

EFFECTS OF THE INVENTION According to the present invention, there is provided a solvent capable of solubilizing a polysaccharide substance which is generally difficult to solubilize. The polysaccharide substance solution or cellulosic substance solution obtained by using the solvent of the present invention is used as a homogeneous reaction solution, or as a molding material, a coating film forming material, a fiber material, a film material or the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08L 1/00 C08L 1/00 1/02 1/02 (72) Inventor Hateiyama Hyoe Fukui Prefecture Niu Gun Koshihiromura Yatsumata 73- 8 (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08B 1/00 C08J 3/11 CEP C08K 3/16 C08K 5/053 C08K 5/09 C08L 1/00 C08L 1/02 CA (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A solvent for dissolving a polysaccharide substance, which comprises a solution formed by dissolving at least one metal halide selected from alkali metal halides and alkaline earth metal halides in formic acid. 2. A polysaccharide substance solution obtained by dissolving a polysaccharide substance in the solvent according to claim 1. 3. A cellulose solution obtained by dissolving a cellulose substance in the solvent according to claim 1 . 4. adding a solvent to the cellulose material according to claim 1, <br/> method for producing a cellulose-containing solution characterized by dissolving.