JP5072265B2 - Pullulan derivatives and their uses - Google Patents

Description

  The present invention relates to a pullulan derivative, in particular, a pullulan derivative characterized in that it has a cationic group and an anionic group in the molecule, and each group is charged to a cation and an anion in an aqueous solvent. It relates to its use.

  As shown in the general formula 2, pullulan is a water-soluble polysaccharide having a structure in which maltotriose, which is a trimer of glucose, is linked by α-1,6 bonds, and is a kind of black yeast, aureobasidium. -An extracellular polysaccharide produced from sucrose, starch hydrolyzate, and the like by pullulans (Aureobasidium pullulans). Pullulan is used as a food thickener, binder, tissue improver, water-soluble film raw material, etc. due to its physicochemical properties, and in recent years it has also been used due to concerns such as mad cow disease and mouth-clotting. It is also attracting attention as a substitute for gelatin that is avoided.

General formula 2:
(In the formula, n represents an integer.)

  On the other hand, various attempts have been made to use pullulan derivatives modified by chemically modifying pullulan. Patent Documents 1 to 6 and the like include dialdehyde pullulan, aminoalkylated pullulan, carboxylated pullulan. Water-resistant pullulan, crosslinked pullulan, sulfate ester derivative of pullulan and the like are disclosed. However, there has been no pullulan derivative that can be used as an excellent emulsifying agent or colloid stabilizer in food, cosmetics, pharmaceuticals, or industrial products.

JP-A-51-90379 JP-A-53-58589 Japanese Patent Laid-Open No. 51-149388 JP 51-150590 A Japanese Patent Laid-Open No. 51-149883 JP-A 51-52484

  An object of the present invention is to provide a novel pullulan derivative that exhibits excellent emulsifying action and protective colloid ability, and is useful as a material for foods, cosmetics, pharmaceuticals, or industrial products as an emulsifying agent or colloid stabilizer, and its use. And

  In order to solve the above-mentioned problems, the present inventors diligently studied to establish a new pullulan derivative, and each of them has a cationic group and an anionic group in the molecule, and each group is an aqueous solvent. It was found that a pullulan derivative characterized by being charged with a cation and an anion is useful as an emulsifying agent or a colloid stabilizer for foods, cosmetics, pharmaceuticals or industrial products, and the present invention has been completed. It was.

  That is, the present invention relates to a pullulan derivative having a cationic group and an anionic group in the molecule, and each group is charged to a cation and an anion in an aqueous solvent, and the pullulan derivative. The above-mentioned problems are solved by providing a use as an emulsifying agent or a colloid stabilizer.

  According to the present invention, pullulan, which is a water-soluble polymer that has no electric charge, has both a substituent functioning as a cation (cationic group) and a substituent functioning as an anion (anionic group) in a solvent. It is possible to provide a pullulan derivative in which is introduced, and the protective colloid ability of the pullulan derivative makes it possible to prepare and use a uniform emulsion. Moreover, the pullulan derivative of the present invention can be applied to a substrate to form a coating film, and the industrial use of pullulan can be greatly expanded. The pullulan derivative of the present invention is useful as an emulsifying agent or colloid stabilizer, particularly as a gelatin substitute in photographic emulsions because it has the property of aggregating and precipitating depending on pH.

  The present invention has both a substituent functioning as a cation and an anion functioning as an anion in an aqueous solvent synthesized from a pullulan, an edible water-soluble polysaccharide, as a raw material (hereinafter referred to as the present specification). (Hereinafter simply referred to as “both charge”).

  The weight average molecular weight of pullulan used as a raw material for the amphoteric pullulan derivative of the present invention is usually 5,000 daltons or more, preferably 10,000 to 1,000,000 daltons, more preferably 50,000 to 500. Selected from the range of 1,000 daltons. As the pullulan that is a raw material, since it is usually advantageous in terms of easy availability and quality, a commercially available pullulan is advantageously used. For example, pullulan sold by Hayashibara Shoji Co., Ltd. , Number average molecular weight of about 200,000 daltons) can be preferably used. Although it depends on the use, a reagent grade pullulan prepared by the method disclosed in Japanese Examined Patent Publication No. 2-48561 and having a weight average molecular weight to number average molecular weight ratio (Mw / Mn) of 1.5 or less (product) A weight average molecular weight of 380,000 daltons (Mw / Mn 1.12), sold by Showa Denko KK, such as the name “P-400”, can also be used as a raw material. In addition, it is also possible to advantageously use a pullulan derivative having a cationic group, which has been chemically synthesized in advance, as a raw material for the amphoteric pullulan derivative of the present invention.

  The cationic group in the amphoteric pullulan derivative of the present invention is not particularly limited as long as it functions as a cation in an aqueous solvent, and even a quaternary ammonium group is an amino group that can be quaternized. May be. In particular, the group represented by the general formula 1 is preferably used.

General formula 1:
(In the formula, R ₁ represents an alkylene group, and the alkylene group may have a substituent. R ₂ and R ₃ are each a hydrogen atom or a hydrocarbon group that is the same or different from each other; (The hydrocarbon group may have a substituent.)

  In general formula 1, the number of carbon atoms of the alkylene group or carbon hydrogen group is usually in the range of 1 to 10, preferably 1 to 5. Specific examples of the cationic group include a dimethylaminoethyl group, a diethylaminoethyl group, a dimethylaminoisopropyl group, and a diphenylaminoethyl group.

  The anionic group in the amphoteric pullulan derivative of the present invention is not particularly limited as long as it functions as an anion in an aqueous solvent, but a substituent having a carboxyl group is preferably used. Among them, oxalic acid ester, malonic acid ester, succinic acid ester, glutaric acid ester, adipic acid ester, pimelic acid ester, suberic acid ester, azelaic acid ester, sebacic acid ester, maleic acid ester, fumaric acid ester, phthalic acid ester, A single ester group of a dicarboxylic acid such as octenyl succinate is preferably used.

  The degree of substitution of the cationic group in the bicharged pullulan derivative in the present invention means the number of substituted cationic groups per glucose residue constituting the pullulan, and the degree of substitution is determined by a known colloid titration method. Can be measured. The degree of substitution of the cationic group in the bicharged pullulan derivative of the present invention is usually in the range of 0.01 to 1, preferably 0.05 to 0.8, more preferably 0.1 to 0.6. It is preferable to adjust to. If the degree of substitution is less than 0.01, the effect as a cationic group in the solvent cannot be obtained, and if the degree of substitution exceeds 1, an excessive reaction is required to obtain a derivative having a high degree of substitution, and the reaction efficiency is also low. Turn into.

  The degree of substitution of the anionic group in the amphoteric pullulan derivative referred to in the present invention means the number of anionic groups substituted per glucose residue constituting the pullulan, and the degree of substitution is the case of a cationic group. Similarly, it can be measured by a known colloid titration method. The degree of substitution of the anionic group in the bicharged pullulan derivative of the present invention is usually in the range of 0.01 to 1, preferably 0.05 to 0.8, more preferably 0.1 to 0.6. It is preferable to adjust to. When the degree of substitution is less than 0.01, an effect as an anionic group in the solvent cannot be obtained, and when the degree of substitution exceeds 1, as in the case of the cationic group, an excessive amount for obtaining a derivative having a high degree of substitution. Reaction is required and the reaction efficiency is also lowered.

  The ratio of the degree of substitution between the cationic group and the anionic group in the amphoteric pullulan derivative of the present invention is within the range where the degree of substitution of the cationic group and the anionic group is 0.01 to 1, respectively. A range of 10: 1 is preferred. When the ratio exceeds this range and is biased to either a cationic group or an anionic group, the characteristic of the amphoteric pullulan derivative of the present invention exhibiting amphoteric properties in an aqueous solvent becomes difficult to be exhibited.

  The amphoteric pullulan derivative of the present invention can be produced by an organic chemical reaction. In order to introduce an aminoalkyl group as a cationic group, an aminoalkyl halide represented by the general formula 3 or an epoxyaminoalkyl represented by the general formula 4 may be reacted with pullulan in the presence of a strong alkali.

General formula 3:
(In the formula, X is a halogen atom, R ₁ represents an alkylene group, and the alkylene group may have a substituent. R ₂ and R ₃ are each a hydrogen atom or the same or different from each other. (It is a hydrocarbon group, and the hydrocarbon group may have a substituent.)

General formula 4:
(In the formula, R ₁ and R ₂ are hydrogen atoms or the same or different hydrocarbon groups, and the hydrocarbon groups may have a substituent.)

  As a method for introducing a substituent having a carboxyl group as an anionic group, the pullulan is oxidized using a known oxidizing agent such as sodium hypochlorite, hydrogen peroxide, potassium permanganate, Although there is a method of converting the carboxylic acid to a carboxyl group, in the synthesis of the bicharged pullulan derivative of the present invention, a dicarboxylic acid such as succinic anhydride, glutaric anhydride, phthalic anhydride, maleic anhydride, or the like is reacted, The method of introducing a single ester group is preferably used.

  As an example of the method for producing an amphoteric pullulan derivative of the present invention, a method for producing a pullulan derivative having a diethylaminoethyl (DEAE) group as a cationic group and a succinate group as an anionic group is schematically shown. Then, as shown in FIG. First, pullulan is reacted with diethylaminoethyl chloride or a salt thereof under alkaline conditions to synthesize a DEAE pullulan derivative having a DEAE group introduced as a cationic group. Next, the obtained DEAE pullulan derivative and succinic anhydride may be reacted in dimethyl sulfoxide (DMSO) in the presence of 4-dimethylaminopyridine (4-DMAP). By this method, a diethylaminoethylated pullulan succinic acid ester derivative in which a succinic acid ester group is further introduced as an anionic group, that is, an amphoteric pullulan derivative can be obtained.

  The bicharged pullulan derivative of the present invention thus obtained is excellent in water solubility and has a protective colloid ability in addition to the functions of pullulan such as thickening, water retention, suspension and dispersion. As an agent, it is useful in the field of food, cosmetics, pharmaceuticals or industrial products.

  The amphoteric pullulan derivative of the present invention depends on the type of the substituent, but may be a general food or drink such as mayonnaise, dressing, sauce, ketchup, curry roux, pudding, butter cream, custard cream, shoe cream, ice cream, It can be advantageously used as an emulsifying agent that can be blended in sherbet, flower paste, peanut paste, fruit paste, jam, juice, carbonated beverage, lactic acid beverage, lactic acid bacteria beverage, therapeutic food, drink, peptide food, frozen food, and the like.

Both charge of pullulan derivatives of the present invention, physiologically acceptable medium, e.g., water, or water and ethanol, isopropanol, n- butanol, 2-butanol, _C 1 -C ₈ alcohols such as tert- butanol; Polyols such as glycerol; glycols such as butylene glycol, isopropylene glycol, propylene glycol, polyethylene glycol, and polyol ethers, as well as anionic, cationic, amphoteric, zwitterionic or nonionic fixed or nonionic Fixed polymers, surfactants, brighteners, opacifiers, organic solvents, fragrances, thickeners, gelling agents, mineral, plant or animal derived or synthesized oils, fatty acid esters, dyes, volatile or non-volatile silicones , Inorganic or organic particles, pigments, excipients, preservatives, pH stabilizers, etc. Al with one or more additives selected may be used in the form of the cosmetic composition. Such cosmetic compositions include cosmetic creams, cleansing creams, shampoos, rinses, hair conditioners, lotions, mousses, styling lacquers, gels, sprays and the like.

  The bicharged pullulan derivatives of the present invention are physiologically acceptable, for example, antioxidants, preservatives, coloring agents, flavoring agents, diluents, emulsifiers, suspending agents, excipients, bulking agents, buffering agents. In addition, it can be blended into general pharmaceuticals, and can also be used in the form of pharmaceuticals administered orally or parenterally.

  The amphoteric pullulan derivatives of the present invention are, for example, thickeners, water retention agents, adhesives, concrete dispersants, printing pastes, paper strength enhancers, colloidal stability in paints, building materials, dyeing, paper processing and ceramic fields. It can also be used as an industrial composition such as an agent, a binder, or a cryogen. In particular, the amphoteric pullulan derivative of the present invention can be used as a substitute for gelatin in a photographic emulsion as described later in Example 6.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited only to these examples.

<Dual charge pullulan derivative>
An amply charged pullulan derivative having a diethylaminoethyl group as a cationic group and a succinic acid group as an anionic group was prepared.

<Example 1-1: Synthesis of diethylaminoethyl (DEAE) -derived pullulan derivative>
97.2 grams of commercially available pullulan (trade name “Pullulan PI-20”, Hayashibara Shoji Co., Ltd.) was dissolved in 730 ml of a 2.4 M aqueous sodium hydroxide solution prepared in advance. Next, 103.2 grams of diethylaminoethyl chloride hydrochloride was dissolved in 240 ml of deionized water and added dropwise to the pullulan solution at 40 ° C. over 30 minutes with stirring. After dropping, the mixture was further maintained at 40 ° C. for 3.5 hours and cooled to about 25 ° C. The resulting reaction solution was neutralized with acetic acid to pH 7.0, and then added dropwise to 64 L of isopropyl alcohol (IPA) to form a white precipitate. The resulting white precipitate was filtered off, dissolved in deionized water to about 900 ml, and purified again by dropwise addition to 64 L of IPA to produce a white precipitate. The resulting white precipitate was filtered off, washed with IPA, and then dried under reduced pressure at 58 ° C. overnight. The obtained dried product was pulverized with a blender to obtain 157 g of white DEAE-treated pullulan derivative powder.

<Example 1-2: Desalination and purification of DEAE pullulan derivative>
45 g of the DEAE pullulan derivative powder obtained in Example 1-1 was dissolved in deionized water to a concentration of 6% by mass, and dialyzed overnight against 24 times the amount of deionized water for desalting. The dialysate was concentrated to 550 grams, and the desalting treatment was repeated twice more in the same manner. The obtained dialysate was concentrated to a concentration of about 20% by mass to obtain a purified DEAE-treated pullulan derivative aqueous solution.

<Example 1-3: Synthesis of amphoteric pullulan derivative>
60 grams of the DEAE pullulan derivative powder obtained in Example 1-1 was dissolved in 1,500 ml of DMSO. Then 14.4 grams of 4-dimethylaminopyridine (4-DMAP) was dissolved in 150 ml of DMSO and added to the diethylaminoethylated pullulan derivative solution. Separately, a solution obtained by dissolving 28.4 grams of succinic anhydride in 186 ml of DMSO was added dropwise over 30 minutes while maintaining the obtained mixed solution at 56 to 61 ° C. while stirring. After dropping, the mixture was further maintained at 60 ° C. for 3.5 hours and cooled to about 35 to 40 ° C. The obtained reaction solution was dropped into 64 L of IPA to form a white precipitate. The resulting white precipitate was filtered off, dissolved in about 1,100 ml of deionized water, and purified again by dropwise addition to 64 L of IPA to produce a white precipitate. The obtained white precipitate was separated by filtration, washed with IPA and acetone, and then dried under reduced pressure at 58 ° C. overnight to obtain 68.5 g of white DEAE-treated pullulan succinate derivative powder.

<Example 1-4: Desalting and purification of amphoteric pullulan derivative>
420 grams of an aqueous solution in which the DEAE-treated pullulan succinate derivative powder obtained in Example 1-3 was dissolved to a concentration of 5% by mass was dialyzed overnight against 43 volumes of deionized water for desalting. The dialysate was concentrated to the same amount as before the treatment, and the same dialysis treatment was performed again. The resulting dialysate was concentrated to about 250 grams and added dropwise to 17 L IPA to form a white precipitate. The resulting white precipitate was filtered off, washed with IPA, and then dried under reduced pressure at 58 ° C. overnight to obtain 12.6 g of a white purified amphoteric pullulan derivative powder.

<Example 1-5: Confirmation of substituents and measurement of degree of substitution in bi-charged pullulan>
In the DEAE-derived pullulan succinate derivative obtained in Example 1-4, both a cationic group and an anionic group were introduced, indicating that a nuclear magnetic resonance apparatus (“JNM-AL300 type”, JEOL Ltd.). Proton Nuclear Magnetic Resonance ( ¹ H-NMR) analysis using a DEAE group in the vicinity of a chemical shift of 1 to 1.2 ppm (D ₂ O, TMS) and a chemical shift of about 2.7 ppm This was confirmed by the proton peak of the methylene group derived from the succinic acid group. Furthermore, by Fourier transform infrared absorption spectrum (FT-IR) analysis using a Fourier transform infrared spectrophotometer (“FTIR-8300 type”, manufactured by Shimadzu Corporation), an absorption peak of a carboxyl group is found near 1570 cm ⁻¹ . An absorption peak of ester was confirmed in the vicinity of 1730 cm ⁻¹ .

  The substitution degree of the cationic group and the anionic group was measured by a known colloid titration method, and found to be 0.16 and 0.38, respectively, per pullulan glucose residue. In addition, the viscosity at 40 ° C. of a 10% strength by weight aqueous solution of the resulting bi-charged pullulan derivative was measured using an EMD type viscometer, which was 56 mPa · s, which is slightly lower than the aqueous pullulan solution having the same concentration. It was a viscosity.

  The obtained DEAE pullulan succinate derivative can be used as an emulsifying agent or a colloid stabilizer for foods, cosmetics, pharmaceuticals or industrial products.

<Dual charge pullulan derivative>
DEAE-modified pullulan derivative powder (5.0 g) obtained by the method of Example 1-1 was dissolved in 30 ml of methanol (MeOH), and a solution prepared by dissolving 1.89 g of 4-DMAP in 5 ml of MeOH was mixed with anhydrous maleic acid. A solution of 1.52 grams of acid in 5 ml of MeOH was added dropwise. After dropping, the mixture was reacted at 60 ° C. for 3.5 hours, cooled to room temperature, and then dropped into 1 L of denatured ethanol (EtOH) to form a white precipitate. The resulting white precipitate was filtered off, washed with denatured EtOH, and then dried under reduced pressure at 58 ° C. overnight. By this operation, 4.4 g of DEAE-treated pullulan maleate derivative powder was obtained.

In the ¹ H-NMR analysis, the derivative showed a DEAE group-derived methyl group proton peak around a chemical shift of 1 to 1.2 ppm, and a maleic acid-derived alkene proton peak around a chemical shift of 6 to 7 ppm. Further, the FT-IR analysis, an absorption peak of a carboxyl group near 1570 cm ^-1, and an absorption peak of the ester in the vicinity of 1730 cm ^-1. The degree of substitution of the cationic group and the anionic group in this bi-charged pullulan derivative was 0.22 and 0.25, respectively.

  The resulting DEAE pullulan maleate derivative can be used as an emulsifying agent or colloid stabilizer for food, cosmetics, pharmaceuticals or industrial products.

<Dual charge pullulan derivative>
Instead of pullulan PI-20 used in Example 1, pullulan (trade name “P-400”, sold by Showa Denko KK) with Mw / Mn of 1.12 was used, and dimethylamino instead of diethylaminoethyl chloride hydrochloride The dimethylaminoisopropylated pullulan phthalate derivative powder was prepared by reacting and purifying isopropyl chloride hydrochloride in the same manner as in Example 1 except that phthalic anhydride was used instead of succinic anhydride and the reaction scale was reduced to 1/10. 7.1 grams were obtained. The degree of substitution of the cationic group and the anionic group in this bicharged pullulan derivative was 0.20 and 0.18, respectively.

  The obtained dimethylaminoisopropylated pullulan phthalate derivative can be used as an emulsifying agent or a colloid stabilizer for foods, cosmetics, pharmaceuticals or industrial products.

<Cosmetic cream>
15 parts by mass of a bi-charged pullulan derivative powder obtained by the method of Example 3, 2 parts by mass of polyoxyethylene glycol monostearate, 5 parts by mass of glyceryl monostearate, 1 part by mass of α-glucosyl rutin, liquid paraffin 1 part by mass, 10 parts by mass of glycerin trioctanoate and 5 parts by mass of ascorbic acid 2-glucoside are dissolved by heating in accordance with a conventional method, and 2 parts by mass of L-lactic acid, 5 parts by mass of 1,3-butylene glycol, preservatives and ions 60 parts by mass of exchanged water was added, emulsified with a homogenizer, and a proper amount of fragrance and coloring agent were added and mixed by stirring to prepare a cream. This cream contains an amphoteric pullulan derivative and α-glucosyl rutin, is smooth, has high component stability, and can be used as a high-quality sunscreen, fair skin cream, and the like.

<Shampoo>
20 parts by weight of an amphoteric pullulan derivative powder obtained by the method of Example 2, 15 parts by weight of ethyl alcohol, 2 parts by weight of glycerin, 85 parts by weight of ion-exchanged water, 0.3 part by weight of fragrance, polyoxyethylene sorbitan mono A shampoo containing 1.5 parts by weight of laurate, preservatives, antioxidants and colorants was prepared. This product is an excellent shampoo that expresses the emulsifying action of the bi-charged pullulan derivative.

<Photosensitive emulsion>
The protective colloid ability of the amphoteric pullulan derivative obtained by the method of Example 1-4 was measured in a conventional gold counting method, that is, in a colloidal red gold sol solution having a concentration of about 0.05 g / L. When 1 ml of the liquid was mixed and then 1 ml of 10% by mass saline was added and mixed, the evaluation was made by measuring the minimum dissolved mass in the sample liquid that causes the red gold sol to break and change color to blue. The number was 0.02. This value was equivalent to 0.02 of the gold number of gelatin used as a control. This result shows that the amphoteric pullulan derivative of the present invention has a protective colloid ability equivalent to gelatin.

  A silver bromide photosensitive emulsion was prepared by a general control double jet method using the purified amphoteric pullulan derivative powder obtained by the method of Example 1-4. That is, in a dark room, 260 ml of an aqueous solution of potassium bromide having a concentration of 0.0315 mol / L containing 0.128 gram of an amphoteric pullulan derivative, 19 ml of an aqueous solution of 0.235 mol / L silver nitrate and an odor of 0.235 mol / L in concentration. 190 ml of potassium halide aqueous solution was simultaneously added and mixed at 30 ° C. for 1 minute. During this period, the bromine ion concentration (pBr) was maintained at 1.5. Subsequently, 56 ml of a 10% by weight aqueous solution of a bicharged pullulan derivative was mixed and ripened at 70 ° C. for 15 minutes to obtain a seed emulsion. While maintaining the temperature at 60 ° C., 200 g of the obtained emulsion was simultaneously added with 60 ml of a 3 mol / L silver nitrate aqueous solution and 60 ml of a 3 mol / L potassium bromide aqueous solution over 1 hour while maintaining pBr at 2.0. Added and mixed. After adjusting the pH of the emulsion to about 4.0 with acetic acid, an aqueous solution of 20% surfactant (trade name “Demol N”, manufactured by Kao Corporation) in an amount of 20% is added to the emulsion. Form an aggregated precipitate, discard the supernatant, wash the aggregated precipitate with the same amount of deionized water as the supernatant and repeat desalting twice, then add the same amount of deionized water, An aqueous potassium carbonate solution having a concentration of 10% by mass was added to adjust the pH to 6.0, and the aggregated precipitate was dissolved to prepare a photographic emulsion. Aggregation of silver bromide crystal grains was not observed throughout the preparation of this photosensitive emulsion, and the dispersed state was kept stable. Note that a photosensitive emulsion prepared in the same manner as described above using gelatin instead of the bicharged pullulan derivative was used as a control. FIG. 2 shows the result of comparison of silver bromide crystal grains dispersed in both photosensitive emulsions with a scanning electron microscope (SEM). In FIG. Are each a photosensitive emulsion containing a diethylaminoethylated pullulan succinate derivative). The silver bromide crystal grains in the photosensitive emulsion prepared using the bicharged pullulan derivative were the same in size and shape as those in the gelatin-containing photosensitive emulsion.

Using RC paper as a mount, the above-prepared photosensitive emulsion containing a bi-charged pullulan derivative was applied at about 70 g / m ² , and further 15% by mass of the purified DEAE pullulan derivative obtained in Example 1-2. The aqueous solution was overcoated and dried by ventilation at room temperature to form a film. The film was then immersed in a 2% potassium alum solution for 30 seconds and dried by ventilation at room temperature to prepare a photographic paper.

  The photographic paper prepared above was exposed for 15 seconds at 3.54 lux through a continuous wedge, and then developed in a conventional manner. FIG. 3 shows a characteristic curve created by measuring the reflection density of the obtained test photographic paper and obtaining the reflection density with respect to the exposure amount (reference symbol ◯ in FIG. 3). The results of the same evaluation using a photographic paper prepared using a control gelatin-containing photosensitive emulsion are also shown in FIG. As is clear from the results in FIG. 3, the photosensitive emulsion prepared using the bicharged pullulan derivative is not inferior to the conventional photosensitive emulsion prepared using gelatin. It turns out that it can be used.

<Solid adhesive>
A mixture of 30 parts by mass of dimethyl sulfoxide, 25 parts by mass of water, 5 parts by mass of erucinane, 5 parts by mass of the bicharged pullulan derivative powder produced by the method of Example 2 and 2 parts by mass of dibenzylidene xylite was heated at 90 ° C. After stirring for 1 hour and dissolving, this is poured into a lipstick-type container equipped with a cylinder with a diameter of 14 mm and a height of 50 mm that can be lifted and lowered and allowed to cool at room temperature. Manufactured. When this adhesive was applied to kraft paper, it could be applied thinly and uniformly, and the initial adhesive strength was sufficient.

  As described above, since the chargeable pullulan derivative of the present invention is mainly composed of pullulan, which is an edible water-soluble polysaccharide, it is highly safe and has functions such as thickening, water retention, suspension and dispersion. In addition, since it has protective colloid ability, it can be advantageously used as an emulsifying agent or colloid stabilizer in a wide range of fields such as foods, cosmetics, pharmaceuticals, and industrial products. Furthermore, since the photographic emulsion produced using the emulsion has characteristics comparable to conventional photosensitive emulsions using gelatin, the bi-charged pullulan derivative of the present invention is an alternative to gelatin in photographic emulsions. It can be used as a product.

It is the figure which showed typically the manufacturing process of the chargeable pullulan derivative which has a diethylaminoethyl group as a cationic group, and a succinic acid ester group as an anionic group. The figure which compared the scanning electron microscope (SEM) photograph (magnification | multiplying_factor: 20,000 times) of the silver bromide grain in the photosensitive emulsion using the diethylamino ethylated pullulan succinate derivative | guide_body or gelatin which is a chargeable pullulan derivative of this invention. It is. 2 is a graph (characteristic curve) showing the relationship between the exposure amount and the reflection density of a test photographic paper prepared using a photosensitive emulsion using the diethylaminoethylated pullulan succinate derivative or gelatin of the present invention.

Explanation of symbols

In FIG. 1, n means an integer,
A: pullulan B: diethylaminoethylated pullulan derivative C: diethylaminoethylated pullulan succinate derivative In FIG.
A: Photosensitive emulsion containing gelatin (control)
B: Diethylaminoethylated pullulan succinate derivative-containing photosensitive emulsion In FIG.
●: Photosensitive emulsion containing gelatin (control)
○: Diethylaminoethylated pullulan succinate derivative-containing photosensitive emulsion

Claims (3)

As a cationic group, an aminoalkyl group selected from dimethylaminoethyl group, diethylaminoethyl group, dimethylaminoisopropyl group and diphenylaminoethyl group, and as anionic group, oxalic acid, malonic acid, succinic acid, glutaric acid, adipine Photosensitive comprising a bi-charged pullulan derivative in which a single ester of a dicarboxylic acid selected from acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid and octenyl succinic acid is introduced into the hydroxyl group emulsion.   2. The photographic emulsion according to claim 1, wherein the degree of substitution of the cationic group and the anionic group in each chargeable pullulan derivative is 0.01 to 1, respectively.   The photographic emulsion according to claim 1 or 2, wherein the both-charged pullulan derivative is a diethylaminoethylated pullulan succinate derivative.