Water-soluble composition, package, and aqueous composition

Abstract

Provided is a water-soluble composition which comprises a PVA-based polymer and a naturally derived component sufficiently compatible with the PVA-based polymer and which has tensile strength, elongation, and water solubility which are in practically acceptable ranges. The water-soluble composition comprises a PVA-based polymer and a water-soluble branched polysaccharide, wherein the content of the PVA-based polymer is 60 wt% or higher with respect to the total weight of the water-soluble composition.

Description

Water-soluble composition, package, and aqueous composition

[0001] The present disclosure relates to a water-soluble composition, a package, and an aqueous composition.

[0002] Polyvinyl alcohol (PVA) is used in various applications due to its excellent water solubility, adhesiveness, film-forming property, and chemical stability. Since PVA is a petroleum-derived biodegradable plastic, from the perspective of improving sustainability, it is required to replace part of PVA with naturally derived components to reduce the environmental load during production and disposal.

[0003] Patent Document 1 describes a vinyl alcohol polymer composition composed of at least one saccharide (A) selected from monosaccharides, disaccharides and oligosaccharides, and a vinyl alcohol polymer (B), wherein the weight blending ratio of component (A) to component (B) is 0.01:99.99 to 50:50.

[0004] Patent Document 2 describes a water-soluble film made of polyvinyl alcohol containing 1 to 40% by weight (based on the total amount with polyvinyl alcohol) of at least one of carrageenan, water-soluble cellulose, α-starch or water-soluble polysaccharide.

[0005] Patent Document 3 describes a water-soluble film characterized by containing pullulan and a modified polyvinyl alcohol resin modified with a hydrophilic group.

[0006] Patent Document 4 describes a resin composition containing a water-soluble branched polysaccharide in a dispersed state, wherein the weight average molecular weight of the water-soluble branched polysaccharide is 1000 to 10000, and the absorbance of an aqueous solution of the water-soluble branched polysaccharide (water-soluble polysaccharide concentration 1.0% by mass, ethanol concentration 40% by mass) at 25°C is 0.7 or less.

[0007] Patent Document 5 describes an α-glucan in which glucose is linked by α-glucoside bonds, wherein the total ratio of α-1,4-linked glucose residues and α-1,6-linked glucose residues, and the ratio of α-1,6-linked glucose residues to α-1,4-linked glucose residues fall within predetermined ranges.

[0008] Patent Document 6 describes an α-glucan mixture obtained by a manufacturing method that includes the steps of gelatinizing waxy starch and liquefying it by reacting it with amylase, the α-glucan mixture having the following characteristics (1) and (2): (1) having a weight-average molecular weight (Mw) in the range of 150 kDa to 3,000 kDa; and (2) having a value obtained by dividing the weight-average molecular weight (Mw) by the number-average molecular weight (Mn) (Mw / Mn) of 35.1 or less.

[0009] Japanese Patent Publication No. 10-324785, Japanese Patent Publication No. 05-001198, International Publication No. 2024 / 106541, Japanese Patent Publication No. 2021-070794, International Publication No. 2008 / 136331, International Publication No. 2017 / 094895

[0010] It is desirable that PVA-based resin compositions with added naturally derived components have tensile strength, elongation, and water solubility within an acceptable range depending on the application, equivalent to or better than conventional PVA-based resin compositions. Furthermore, it is desirable that the naturally derived components added to the PVA-based resin composition be sufficiently compatible with the PVA-based polymer, from the viewpoint of reducing variations in physical properties and avoiding manufacturing problems. This allows the aqueous solution containing the naturally derived components and the PVA-based polymer to form a single phase.

[0011] In view of these points, this disclosure provides a water-soluble composition containing a PVA-based polymer and a naturally derived component that is sufficiently compatible with the PVA-based polymer, and having practically acceptable tensile strength, elongation, and water solubility.

[0012] The embodiments of this disclosure include the following: [Embodiment 1] A water-soluble composition comprising a PVA-based polymer and a water-soluble branched polysaccharide, wherein the PVA-based polymer content is 60% by weight or more of the total weight of the water-soluble composition. [Embodiment 2] The water-soluble composition according to Embodiment 1, further comprising a disaccharide. [Embodiment 3] The water-soluble composition according to Embodiment 2, wherein the disaccharide is one or more selected from the group consisting of trehalose and maltose. [Embodiment 4] The water-soluble composition according to Embodiment 3, wherein the PVA-based polymer content is 90% by weight or less of the total weight of the water-soluble composition. [Embodiment 5] The water-soluble composition according to Embodiment 3, wherein the PVA-based polymer content is less than 90% by weight of the total weight of the water-soluble composition. [Embodiment 6] The water-soluble composition according to Embodiment 3, wherein the PVA-based polymer content is 85% by weight or less of the total weight of the water-soluble composition. [Aspect 7] A water-soluble composition according to any one of aspects 3 to 6, wherein the water-soluble branched polysaccharide content is 1% to 25% by weight relative to the total weight of the water-soluble composition. [Aspect 8] A water-soluble composition according to any one of aspects 2 to 7, wherein the disaccharide content is 1% to 20% by weight relative to the total weight of the water-soluble composition. [Aspect 9] A water-soluble composition according to any one of aspects 1 to 8, wherein the water-soluble branched polysaccharide is a branched α-glucan mixture. [Aspect 10] A water-soluble composition according to any one of aspects 1 to 9, further containing pullulan. [Aspect 11] A water-soluble composition according to any one of aspects 1 to 10, wherein the water-soluble composition is a water-soluble film. [Aspect 12] A package comprising: a water-soluble film according to aspect 11; and a drug contained in the water-soluble film. [Aspect 13] A package according to aspect 12, wherein the drug is a detergent, a pesticide, or a disinfectant. [Aspect 14] A package according to aspect 12 or 13, wherein the drug is in liquid form. [Aspect 15] An aqueous composition comprising the water-soluble composition described in any one of aspects 1 to 10 and an aqueous solvent.

[0013] The water-soluble composition of this disclosure contains a PVA-based polymer and a naturally derived component that is well compatible with the PVA-based polymer, and has practically acceptable tensile strength, elongation, and water solubility.

[0014] The embodiments described below are not limited to those described herein. Various modifications, changes, additions, omissions, and / or combinations of the embodiments described below are possible without departing from the technical scope of the claims.

[0015] In this application, a numerical range represented by the symbol "~" includes the numerical values ​​before and after the symbol "~" as the lower and upper limits, respectively, unless otherwise specified. The upper and lower limits described in this application may be used individually or in any combination.

[0016] In this application, "containing" and "containing" mean that additional components or elements may be included unless otherwise specified, and encompass "essentially made of" and "consisting of." "Essentially made of" means that additional components or elements may be included that do not substantially adversely affect the product. "Consisting of" means that only the described material or element is included, but does not exclude the inclusion of unavoidable impurities.

[0017] In this application, the term "and / or" refers to at least one of the enumerated items and all possible combinations thereof.

[0018] I. Water-soluble composition The water-soluble composition according to the embodiment contains a polyvinyl alcohol (PVA)-based polymer and a water-soluble branched polysaccharide.

[0019] In this application, a water-soluble composition means a composition that, when placed in 100 g of stirred water at 5°C, dissolves completely within 150 seconds, with dimensions of 20 mm x 20 mm x 0.03 mm.

[0020] Water-soluble compositions may be in solid or liquid form. Solid water-soluble compositions may have any shape depending on the application, such as film, sheet, bag, pipe, tube, bottle, rod, strand, fiber, lump, tablet, granule, powder, or pellet form. Water-soluble compositions can be molded by any method, such as extrusion molding (e.g., T-die casting or inflation molding), injection molding, or blow molding.

[0021] A film-like water-soluble composition (i.e., a water-soluble film) can be manufactured by any method such as casting or melt extrusion. Specifically, for example, a raw material solution is prepared by dissolving each component of the water-soluble film in an aqueous solvent (e.g., water). The raw material solution is cast onto the surface of a plate or roll to form a coating film, and the aqueous solvent is evaporated from the coating film. This yields a water-soluble film. The coating film may be dried using a heater, hot air, etc., or it may be air-dried. The water-soluble film may have any thickness set appropriately depending on the application, for example, 5 to 200 μm, preferably 10 to 150 μm, and more preferably 20 to 100 μm.

[0022] Each component of the water-soluble composition used in preparing the raw material solution may be in any form, such as powder, granules, or pellets, before being dissolved in an aqueous solvent. Granules or pellets containing two or more components of the water-soluble composition may be used. For example, an aqueous solution of a sugar mixture may be prepared using granules or pellets containing water-soluble branched polysaccharides and optionally further containing at least one selected from the group consisting of disaccharides, water-soluble linear polysaccharides, and sugar alcohols, and the raw material solution may be prepared by mixing this with an aqueous solution of a separately prepared PVA-based polymer. Compared to powders, granules or pellets have a lower risk of ignition during handling, storage, or transportation, and health hazards from inhalation. Also, while the mixing ratio of powders may be uneven due to vibrations during transportation, the mixing ratio can be maintained uniformly with granules or pellets.

[0023] (1) PVA-based polymers PVA-based polymers are water-soluble polymers obtained by saponifying (i.e., alkaline hydrolysis) polyvinyl ester polymers (e.g., polyvinyl acetate) obtained by polymerizing vinyl ester monomers (e.g., vinyl acetate). PVA-based polymers may be unmodified PVA or modified PVA in which a modifying group has been introduced. Furthermore, PVA-based polymers may be homopolymers obtained by saponifying vinyl ester homopolymers in which vinyl ester monomers are polymerized alone, or copolymers obtained by saponifying vinyl ester copolymers in which vinyl ester monomers are copolymerized with other monomers.

[0024] Examples of vinyl ester monomers include aliphatic vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl versatate, and vinyl trifluoroacetate, as well as aromatic vinyl esters such as vinyl benzoate. These vinyl ester monomers may be used individually or in combination of two or more. Examples of modifying groups in modified PVA include carboxyl groups, sulfonic acid groups, phosphate groups, acetoacetyl groups, and diacetone groups.

[0025] Examples of other monomers copolymerizable with vinyl ester monomers include ethylene; olefins having 3 to 30 carbon atoms such as propylene, 1-butene, and isobutene; acrylic acid and its salts; acrylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and octadecyl acrylate; methacrylic acid and its salts; methyl methacrylate, ethyl methacrylate, methac Methacrylic acid esters such as n-propyl lylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate; acrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide, diacetoneacrylamide, acrylamidepropanesulfonic acid and its salts, acrylamidopropyldimethylamine and its salts, N-methylolacrylamide and its Acrylamide derivatives such as derivatives; methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, methacrylamidepropanesulfonic acid and its salts, methacrylamidepropyldimethylamine and its salts, N-methylolmethacrylamide and its derivatives and other methacrylamide derivatives; N-vinylamide such as N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl Vinyl ethers such as nyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, and stearyl vinyl ether; vinyl cyanides such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid, and its salts, esters, and acid anhydrides; itaconic acid, and its salts, esters, and acid anhydrides; vinylsilyl compounds such as vinyltrimethoxysilane; isopropenyl acetate;Examples include diol compounds and their salts such as 1,4-butanediol, 2-butene-1,4-diol, and 3,4-dihydroxy-1-butene; and diol esters such as 1,4-diacetoxybutane, 1,4-diacetoxy-2-butene, and 3,4-diacetoxy-1-butene. Vinyl ester copolymers may have structural units derived from at least one of the above-mentioned other monomers.

[0026] PVA polymers are typically unmodified PVA obtained by saponifying polyvinyl acetate, which is produced by polymerizing vinyl acetate.

[0027] The PVA-based polymer may have any degree of saponification set appropriately depending on the application, for example, an average degree of saponification of 64 mol% or more, 70 to 99 mol%, 82 to 99 mol%, or 85 to 90 mol%. The PVA-based polymer may have any average degree of polymerization set appropriately depending on the application. The average degree of polymerization can generally be indirectly expressed by the viscosity of the aqueous solution. The viscosity of a 4 wt% PVA-based polymer aqueous solution at 20°C is preferably 2 to 50 mPa·s, more preferably 3 to 45 mPa·s, and even more preferably 4 to 40 mPa·s. The average degree of saponification of the PVA-based polymer and the viscosity of the PVA-based polymer aqueous solution are measured in accordance with JIS K 6726:1994.

[0028] The water-soluble composition according to the embodiment may contain one type of PVA-based polymer alone, or it may contain two or more types of PVA-based polymers with different degrees of polymerization, saponification, modification, etc.

[0029] The water-soluble composition according to the embodiment has a PVA-based polymer content of 60% by weight or more relative to the total weight of the water-soluble composition. As a result, the water-soluble composition can have sufficient tensile strength, as shown in the examples described later. The PVA-based polymer content of the water-soluble composition may be 65% by weight or more, 70% by weight or more, 99% by weight or less, 95% by weight or less, or 90% by weight or less, or 60 to 99% by weight, 65 to 95% by weight, or 70 to 90% by weight, relative to the total weight of the water-soluble composition. If the water-soluble composition contains disaccharides (especially trehalose and / or maltose) as described later, the PVA polymer content of the water-soluble composition may be 60% by weight or more, 65% by weight or more, or 70% by weight or more, and may be 99% by weight or less, 95% by weight or less, 90% by weight or less, less than 90% by weight, 85% by weight or less, or 80% by weight or less, and may be 60 to 99% by weight, 60 to 95% by weight, 60 to 90% by weight, 60% by weight or more and less than 90% by weight, 60 to 85% by weight, 65 to 85% by weight, or 70 to 80% by weight. If the water-soluble composition does not substantially contain disaccharides, the PVA polymer content of the water-soluble composition may be 60% by weight or more, 65% by weight or more, 70% by weight or more, 80% by weight or more, or 85% by weight or more, and may be 99% by weight or less, 95% by weight or less, or 90% by weight or less, and may be 60-99% by weight, 60-95% by weight, 65-95% by weight, 70-95% by weight, 80-95% by weight, 85-95% by weight, or 85-90% by weight.

[0030] (2) Water-soluble branched polysaccharides In this application, water-soluble branched polysaccharides mean branched polysaccharides that dissolve within 30 minutes when 1 g of branched polysaccharide is placed in 30 mL of distilled water and shaken vigorously for 30 seconds every 5 minutes at 25 ± 5°C. "Dissolved" means that the water to which the branched polysaccharide has been added is clear without any insoluble matter visible to the naked eye, or if any insoluble matter is observed, it is only a very small amount. Water-soluble branched polysaccharides can be obtained from biomass raw materials such as starch. Water-soluble branched polysaccharides are sufficiently compatible with PVA-based polymers, as shown in the examples described later.

[0031] The water-soluble composition according to the embodiment may have a water-soluble branched polysaccharide content of 1 to 40% by weight, 1 to 30% by weight, 1 to 25% by weight, 2 to 24% by weight, 3 to 22% by weight, 4 to 20% by weight, or 5 to 18% by weight, based on the total weight of the water-soluble composition.

[0032] Examples of water-soluble branched polysaccharides include branched α-glucan mixtures, indigestible dextrin, indigestible glucans, branched β-glucan mixtures, water-soluble cellulose derivatives, chitin derivatives, xyloglucan, glucomannan, polydextrose, inulin, guar gum, xanthan gum, tamarind gum, fucoidan, etc., with branched α-glucan mixtures being particularly preferred. The water-soluble composition according to the embodiment may contain one type of water-soluble branched polysaccharide alone, or it may contain two or more types of water-soluble branched polysaccharides. Preferred specific examples of branched α-glucan mixtures include isomaltodextrin (Fiberixa®) manufactured and sold by Nagase Vita Co., Ltd., and the α-glucan mixture described in Patent Document 6. A preferred specific example of indigestible glucan is Fitfiber® manufactured and sold by Nippon Shokuhin Kako Co., Ltd. A preferred specific example of indigestible dextrin is Fibersol 2 manufactured and sold by Matsutani Chemical Industry Co., Ltd.

[0033] In one embodiment, the branched α-glucan mixture may be a branched α-glucan mixture that produces a digest containing isomaltose in amounts of more than 3% by weight and up to 50% by weight, more than 3% by weight and up to 45% by weight, more than 3% by weight and less than 22% by weight, 25% by weight and up to 50% by weight, 30% by weight and up to 50% by weight, or 35% by weight and up to 45% by weight, relative to the solid weight of the digest. In this application, isomaltodextranase digestion means hydrolysis by acting with isomaltodextranase. Isomaltodextranase is an enzyme to which the International Union of Biochemistry and Molecular Biology has been assigned enzyme number (EC) 3.2.1.94, and hydrolyzes any of the α-1,2, α-1,3, α-1,4, or α-1,6 bonds adjacent to the reducing end of the isomaltose structure in α-glucan. As the isomaltodextranase, isomaltodextranase derived from Arthrobacter globiformis can be used (see, for example, Sawai et al., Agricultural and Biological Chemistry, Vol. 52, No. 2, pp. 495-501 (1988)). The isomaltose content of the digest produced by isomaltodextranase digestion, relative to the solid weight of the digest, indicates the proportion of isomaltose structures in the branched α-glucans constituting the branched α-glucan mixture.

[0034] The branched α-glucan mixture may have a weight-average molecular weight Mw of 500 to 3,000,000, 3,000 to 3,000,000, or 4,000 to 3,000,000, and a dispersion degree Mw / Mn of 35.1 or less, less than 25, 20 or less, 10 or less, or 5 or less. The weight-average molecular weight Mw and dispersion degree Mw / Mn of the branched α-glucan mixture can be measured by size exclusion chromatography.

[0035] Isomaltodextrin is a highly branched α-glucan mixture disclosed in Patent Document 5. Isomaltodextrin has a branched structure with a glucose polymerization degree of 1 or higher, in which glucose is used as the constituent sugar and a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or higher, linked via α-1,4 bonds, is linked via bonds other than α-1,4 bonds (e.g., α-1,2 bonds, α-1,3 bonds, or α-1,6 bonds). The term "non-reducing terminal glucose residue" refers to a glucose residue located at the end of a glucan chain linked via α-1,4 bonds that does not exhibit reducing properties. Isomaltodextrin is usually a mixture of multiple types of branched α-glucans having various branched structures and glucose polymerization degrees. An example of the structure of isomaltodextrin is shown below.

[0036]

[0037] Isomaltodextrin can be produced using starch as a raw material and by reacting it with various enzymes, as disclosed in Patent Document 5. For example, isomaltodextrin can be produced by reacting starch with α-glucosyltransferase. The α-glucosyltransferase used here is an enzyme that acts on α-1,4-glucan with a degree of polymerization of 3 or more of maltose and / or glucose, and catalyzes α-glucosyl transfer without substantially hydrolysis. In addition to α-glucosyltransferase, amylases such as liquefied α-amylase (EC 3.2.1.1), saccharifying α-amylase (EC 3.2.1.1), maltotetraose-producing amylase (EC 3.2.1.60), and maltohexaose-producing amylase (EC 3.2.1.98), and / or starch debranching enzymes such as pullulanase (EC 3.2.1.41) and isoamylase (EC 3.2.1.68) may be used in combination, thereby adjusting the molecular weight and / or glucose polymerization degree of isomaltodextrin. Furthermore, cyclomaltodextrin glucanotransferase (EC 2.4.1.19), starch branching enzyme (EC 2.4.1.18), and / or enzymes having the activity to transfer α-1,6 glucans with a degree of polymerization of 2 or more to glucose residues inside starch, as disclosed in Japanese Patent Publication No. 2014-54221, may also be used in combination. This allows for highly branching of isomaltodextrin and increases the water-soluble dietary fiber content of isomaltodextrin. In addition, the water-soluble dietary fiber content of isomaltodextrin can be further increased by treating isomaltodextrin with carbohydrate hydrolases such as glucoamylase. Furthermore, by treating isomaltodextrin with glycosyltrehalose-producing enzyme (EC 5.4.99.15), a trehalose structure can be introduced to the reducing end of isomaltodextrin, or the reducing end of isomaltodextrin can be reduced by hydrogenation, thereby reducing the reducing power of isomaltodextrin. The produced isomaltodextrin can also be fractionated by size exclusion chromatography or the like to obtain isomaltodextrin with a molecular weight distribution within a desired range.

[0038] Isomaltodextrin can be digested with isomaltodextranase to produce digests containing 5-70% by weight, 10-70% by weight, 15-70% by weight, 20-70% by weight, 20-60% by weight, and 20-50% by weight of isomaltose relative to the solid content weight of the digest.

[0039] Isomaltodextrin may have a weight-average molecular weight Mw of 500 to 10,000 or 3,000 to 7,000, and a dispersion degree Mw / Mn of 20 or less, 15 or less, 1 to 10, 1 to 5, or 1 to 3. Isomaltodextrin may have an average degree of glucose polymerization of 8 to 500, 15 to 400, or 20 to 300.

[0040] Furthermore, isomaltodextrin may have a water-soluble dietary fiber content of 40% by mass or more, 60% by mass or more, or 75% by mass or more. The water-soluble dietary fiber content indicates the content of α-glucan that is not broken down by α-amylase or glucoamylase. The water-soluble dietary fiber content is determined by high-performance liquid chromatography (enzyme-HPLC method) (hereinafter simply referred to as "enzyme-HPLC method").

[0041] The enzyme-HPLC method is a method described in item 8, "Dietary Fiber," of the Nutritional Labeling Standards, "Analytical Methods for Nutritional Components, etc. (Methods Listed in Column 3 of Appendix 1 of the Nutritional Labeling Standards)," issued by the Ministry of Health and Welfare on May 20, 1996 (Notification No. 146). A brief explanation of this method is as follows: The sample is decomposed by a series of enzymatic treatments using heat-stable α-amylase, protease, and glucoamylase, and a sample solution for gel filtration chromatography is prepared by removing proteins, organic acids, and inorganic salts from the treatment solution using an ion exchange resin. Next, the sample is subjected to gel filtration chromatography, and the peak areas of undigested glucan and glucose in the chromatogram are determined. Based on these peak areas and the amount of glucose in the sample solution, which has been separately determined by the glucose oxidase method using a conventional method, the water-soluble dietary fiber content of the sample is calculated.

[0042] In addition, the isomaltdextrin may have at least any one of the following characteristics. (i) The ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is in the range of 1:0.6 to 4. (ii) The sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 55% or more of all glucose residues. (iii) The α-1,3-linked glucose residues account for 0.5% or more and less than 10%, or 1% to 3% of all glucose residues. (iv) The α-1,3,6-linked glucose residues account for 0.5% or more, 1% to 10%, or 1% to 7% of all glucose residues.

[0043] Whether the isomaltdextrin has the characteristics (i) to (iv) can be confirmed by methylation analysis. Methylation analysis is a widely used method for determining the linkage mode of monosaccharides constituting polysaccharides or oligosaccharides (Ciucanu et al., Carbohydrate Research, Vol. 131, No. 2, pp. 209-217 (1984)). When methylation analysis is applied to the analysis of glucose linkage modes in glucan, first, all free hydroxyl groups in the glucose residues constituting the glucan are methylated, and then the fully methylated glucan is hydrolyzed. Next, the methylated glucose obtained by hydrolysis is reduced to eliminate the anomeric form, yielding methylated glucitol. By acetylating the free hydroxyl groups in this methylated glucitol, partially methylated glucitol acetate (hereinafter, "partially methylated glucitol acetate" may be simply referred to as "partially methylated product") is obtained. By analyzing the resulting partially methylated product by gas chromatography, a chromatogram having peaks of the partially methylated product corresponding to the glucose residues of each linkage mode in the glucan is obtained. The proportion of glucose residues of each linkage mode in the glucan is determined from the ratio of the peak area of the partially methylated product corresponding to the glucose residues of that linkage mode to the total sum of the peak areas of all partially methylated products.

[0044] The term "α-1,4-linked glucose residue" means a glucose residue linked to another glucose residue only via the hydroxyl groups bonded to the carbon atoms at positions 1 and 4, and is detected as 2,3,6-trimethyl-1,4,5-triacetylglucitol in methylation analysis.

[0045] The term "α-1,6-linked glucose residue" means a glucose residue linked to another glucose residue only via the hydroxyl groups bonded to the carbon atoms at positions 1 and 6, and is detected as 2,3,4-trimethyl-1,5,6-triacetylglucitol in methylation analysis.

[0046] The term "α-1,3-linked glucose residue" means a glucose residue linked to another glucose only via the hydroxyl group at the C-1 position and the hydroxyl group at the C-3 position, and is detected as 2,4,6-trimethyl-1,3,5-triacetylglucitol in methylation analysis.

[0047] The term "α-1,3,6-linked glucose residue" means a glucose residue linked to another glucose via the hydroxyl group at the C-3 position and the hydroxyl group at the C-6 position in addition to the hydroxyl group at the C-1 position, and is detected as 2,4-dimethyl-1,3,5,6-tetraacetylglucitol in methylation analysis.

[0048] The α-glucan mixture described in Patent Document 6 may have the following characteristics (1) to (3). (1) The weight average molecular weight Mw is in the range of 200 to 3000 kDa. (2) The dispersity Mw / Mn is 35.1 or less, or less than 25. (3) It has an isomaltose structure at the non-reducing end.

[0049] This α-glucan mixture can produce a digest containing more than 3 wt% and less than 22 wt% of isomaltose relative to the solid content weight of the digest through isomaltdextranase digestion.

[0050] Furthermore, this α-glucan mixture may have a glucose equivalent of 2.0 or less, 1.8 or less, or 1.6 or less. In this application, "glucose equivalent" is an indicator of the degree of hydrolysis in starch sugar (partially hydrolyzed starch product) obtained by hydrolyzing starch with acid or enzyme. The glucose equivalent is expressed by the following formula: Glucose equivalent = [Amount of reducing sugar (measured as glucose) / Total solid content] × 100

[0051] The amount of reducing sugars is quantified using the conventional modified Park-Johnson method (see Hinoki et al., "Carbohydrate Research," Vol. 94, pp. 205-213 (1981)), with D-glucose as the standard substance. The total solid content is determined by the conventional drying method.

[0052] Glucose equivalent is a relative measure with the reducing power of D-glucose (dextrose, glucose) set at 100. A glucose equivalent value closer to 0 indicates a lower degree of hydrolysis and properties closer to starch, while a glucose equivalent value closer to 100 indicates a higher degree of hydrolysis and properties closer to glucose.

[0053] Such α-glucan mixtures are obtained by gelatinizing waxy starch, liquefying it with amylase, and then acting on the partially hydrolyzed starch with an α-glucosyltransferase that has the activity to transfer α-1,6-glucosyl to the non-reducing terminal glucose residue. The α-glucosyltransferase used here is an enzyme that acts on the partially hydrolyzed starch and has the activity to transfer α-1,6-glucosyl to the non-reducing terminal glucose residue.

[0054] "Waxy starch" refers to starch obtained from waxy (glutinous) plants, such as waxy rice, barley, wheat, adlay, corn, millet, foxtail millet, and sorghum. Waxy starch is substantially free of amylose, which is a linear α-1,4-glucan, and consists almost entirely of amylopectin, which has a branched structure.

[0055] Gelatinization refers to the phenomenon in which, when starch granules are heated in the presence of water, the hydrogen bonds within the starch granules are broken, causing the granules to irreversibly swell (or hydrate, dissolve). Gelatinization causes starch to lose its crystallinity and birefringence, its viscosity to increase, and its reactivity to enzymes (amylase) and chemicals to increase dramatically. Gelatinization is also known as alpha-gelatinization.

[0056] "Liquefaction" refers to the process of partially hydrolyzing gelatinized starch with amylase, causing it to become liquid. The more hydrolyzed the gelatinized starch, the lower its molecular weight and viscosity.

[0057] (3) Disaccharides In one embodiment, the water-soluble composition further contains disaccharides. Disaccharides are well compatible with PVA-based polymers, as shown in the examples described later. As shown in the examples described later, the inclusion of disaccharides in the water-soluble composition can improve the elongation of the water-soluble composition.

[0058] Examples of disaccharides include trehalose, maltose, sucrose, lactose, and isomaltose. The water-soluble composition according to the embodiment may contain one type of disaccharide alone, or it may contain two or more types of disaccharides.

[0059] The water-soluble composition according to the embodiment may have a disaccharide content of 1 to 20% by weight, 1 to 19% by weight, 1 to 17% by weight, or 1 to 15% by weight based on the total weight of the water-soluble composition. This allows the water-soluble composition to have sufficient tensile strength and elongation.

[0060] In one embodiment, the water-soluble composition contains one or more disaccharides selected from the group consisting of trehalose and maltose. As a result, the water-soluble composition can have high tensile strength, as shown in the examples described later. In this embodiment, the PVA polymer content of the water-soluble composition may be 60% by weight or more, 65% by weight or more, or 70% by weight or more, and may be 99% by weight or less, 95% by weight or less, 90% by weight or less, less than 90% by weight, 85% by weight or less, or 80% by weight or less, and may be 60 to 99% by weight, 60 to 95% by weight, 60 to 90% by weight, 60% by weight or more and less than 90% by weight, 60 to 85% by weight, 65 to 85% by weight, or 70 to 80% by weight. Furthermore, as shown in the examples described later, by including one or more selected from the group consisting of trehalose and maltose in the water-soluble composition, a water-soluble composition with excellent tensile strength and elongation can be obtained even when the PVA-based polymer content in the water-soluble composition is reduced to less than 90% by weight, 85% by weight or less, or 80% by weight or less, relative to the total weight of the water-soluble composition. In this embodiment, the water-soluble branched polysaccharide content of the water-soluble composition may be 1 to 25% by weight, 2 to 24% by weight, 3 to 22% by weight, 4 to 20% by weight, or 5 to 18% by weight, relative to the total weight of the water-soluble composition. As a result, the water-soluble composition can have excellent tensile strength and elongation.

[0061] (4) Other Additives In one embodiment, the water-soluble composition may contain other additives. Examples of other additives include water-soluble linear polysaccharides (e.g., pullulan, amylose, carrageenan, modified cellulose), sugar alcohols (e.g., maltitol, sorbitol), plasticizers, surfactants, antioxidants, UV absorbers, lubricants, colorants, fragrances, preservatives, antifungal agents, water-soluble polymers other than PVA polymers, and fillers. Examples of water-soluble polymers other than PVA polymers include dextrin, gelatin, glue, casein, shellac, gum arabic, polyacrylamide, sodium polyacrylate, polyvinyl methyl ether, copolymer of methyl vinyl ether and maleic anhydride, copolymer of vinyl acetate and itaconic acid, polyvinylpyrrolidone, cellulose, acetylcellulose, acetylbutylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, sodium alginate, etc. Other additives may be included in a range that does not interfere with the effects of the water-soluble composition according to the embodiment.

[0062] II. Uses of Water-Soluble Compositions The water-soluble compositions according to the embodiment can be used for a variety of purposes. Examples of uses for the water-soluble compositions include films such as pharmaceutical packaging films, base films for hydraulic transfer, embroidery substrate films, release films for artificial marble molding, seed packaging films, food packaging films, and waste collection bags. The water-soluble compositions according to the embodiment are particularly suitable for use as pharmaceutical packaging films. Furthermore, the water-soluble compositions according to the embodiment can also be used as adhesives, emulsifiers, turbidifiers, coating agents, paper processing agents, fiber processing agents, additives to paper or fibers, binders, etc.

[0063] A drug packaging can be manufactured using the water-soluble composition according to the embodiment. The packaging comprises a film-like water-soluble composition (i.e., a water-soluble film) and a drug contained within the water-soluble film. Examples of drugs include detergents (e.g., laundry detergents, dishwashing detergents, bleaches), pesticides (e.g., insecticides, fungicides, herbicides), and disinfectants. The drug may be in liquid, powder, lump, or gel form, and may be particularly liquid.

[0064] When the package is placed in water, the water-soluble film dissolves, and then the drug encapsulated within the film flows into the water, dissolves or disperses, and the drug's effect is released. Because the water-soluble film has sufficient tensile strength and elongation, the package is less likely to break and is easy to handle.

[0065] III. Aqueous Compositions The aqueous composition according to the embodiment is a composition in which each component of the above-described water-soluble composition (which may be referred to as "solid content" in this application) is dissolved in an aqueous solvent (for example, water or a mixed solvent containing water). In this application, an aqueous composition means a composition containing water. The water content in the aqueous composition may be 10% by weight or more, 20% by weight or more, 30% by weight or more, 40% by weight or more, or 50% by weight or more, and may be 99% by weight or less, 95% by weight or less, or 90% by weight or less, based on the total weight of the aqueous composition.

[0066] The composition of the solids in the aqueous composition is the same as that of the water-soluble composition described above, so no explanation is provided.

[0067] The aqueous composition can be used in the manufacture of the above-mentioned water-soluble composition. Furthermore, the aqueous composition can also be used as an adhesive, emulsifier, turbidifier, coating agent, paper processing agent, fiber processing agent, additive to paper or fiber, binder, etc.

[0068] The aqueous composition according to the embodiment exhibits excellent storage stability. PVA-based polymers generally gel when left at low temperatures, and their viscosity increases over time. However, the aqueous composition according to the embodiment shows little to no increase in viscosity over time. Furthermore, the aqueous composition according to the embodiment also exhibits excellent thermal stability. The aqueous composition according to the embodiment shows little to no change in properties and appearance even after storage at high temperatures. Moreover, even when a water-soluble composition is manufactured using the aqueous composition after high-temperature storage, a water-soluble composition with sufficient mechanical properties can be manufactured.

[0069] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these examples.

[0070] A. Film-like water-soluble composition (1) Materials <Polyvinyl alcohol (PVA)> G-type Gosenol GL-05 manufactured by Mitsubishi Chemical Corporation (average saponification degree 86.5 to 89.0 mol%, viscosity of 4.8 to 5.8 mPa·s at 20°C for a 4% by weight PVA aqueous solution)

[0071] <Water-soluble branched polysaccharides> PS1: Fiberixa (registered trademark) manufactured by Nagase Vita Co., Ltd. (Mw = 4100, Mn = 2000, Mw / Mn = 2.1) PS2: α-glucan mixture prepared using α-glucosyltransferase in the same manner as in Patent Document 6 (Mw = 1,160,000, Mn = 69,000, Mw / Mn = 21.2)

[0072] <Water-soluble linear polysaccharides> Pullulan: Food additive manufactured by Nagase Vita Co., Ltd. Pullulan amylose: Starch from corn manufactured by Sigma-Aldrich

[0073] <Disaccharides> Trehalose: Treha (registered trademark) manufactured by Nagase Vita Co., Ltd. Sucrose: Sucrose reagent grade manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Maltose: Maltose HH manufactured by Nagase Vita Co., Ltd.

[0074] <Sugar Alcohols> Maltitol: Manufactured by Nagase Vita Co., Ltd. (99.6% purity)

[0075] (2) Film Preparation Each of the above materials was added to water being stirred in a hot bath to prepare aqueous solutions of each material at a concentration of 20% by weight. The aqueous solutions of each material were mixed in the weight ratios shown in Table 1 to obtain a mixture (hereinafter referred to as "raw material solution"), which was then cast onto a PET film placed on a hot plate at a temperature of 80°C and allowed to air dry. A film was thus prepared. The average thickness of the obtained film was approximately 40 μm. The tensile strength and elongation of this film were evaluated as described below.

[0076] Food coloring was added to the raw material solution prepared in the same manner as described above, and a film was prepared in the same manner as described above. The water solubility of the obtained film was evaluated as described below.

[0077] (3) Evaluation of compatibility The compatibility of the raw material solutions described above was evaluated by visual inspection. The results are shown in Table 1. In Table 1, "A" indicates that the components in the raw material solution were completely compatible and formed a single phase, and "B" indicates that phase separation was observed in the raw material solution.

[0078] (4) Evaluation of tensile strength and tensile elongation Ten or more 45 mm x 15 mm test pieces were cut from the prepared film and left to stand in a constant temperature and humidity chamber at 22°C and 50% RH for 5 days to adjust the moisture content in the test pieces. Then the tensile strength (N / mm) of the test pieces was evaluated. ２ The pressure (%) and elongation (%) were measured in accordance with JIS K7127. The measurements were performed using the following equipment under the following conditions.

[0079] Tensile testing machine: CR-500DX manufactured by Sun Science Co., Ltd. Tensile speed: 300 mm / min Gauge distance: 30 mm

[0080] In each example and comparative example, the average values ​​of the tensile strength and elongation of the measured test specimens were determined. The average tensile strength and average elongation of Comparative Example 1 were set to 100, and the relative tensile strength and relative elongation of each example and comparative example were determined. The results are shown in Table 1. Regarding relative tensile strength, in Table 1, "A" represents greater than 100, "B" represents 70 or more and 100 or less, "C" represents 50 or more and less than 70, and "D" represents less than 50. A to C are within the range that is practically acceptable, and D is within the range that is not practically acceptable. Regarding relative elongation, in Table 1, "A" represents greater than 65, "B" represents greater than 12 and 65 or less, and "C" represents 3 or more and 12 or less. A to C are within the range that is practically acceptable.

[0081] (5) Evaluation of water solubility Three or more 20 mm x 20 mm test pieces were cut from the prepared film. The test pieces were placed in 100 g of 5°C water being stirred at 500 RPM, and the time until the test pieces completely dissolved was measured. For each example and comparative example, the average dissolution time of the measured test pieces was calculated. The average dissolution time of Comparative Example 1 was set to 100, and the relative dissolution times of each example and comparative example were calculated. The results are shown in Table 1. Regarding relative dissolution time, "A" in Table 1 represents less than 60, and "B" represents 60 or more and 100 or less. A and B are within the range that is practically acceptable. All of the films in the examples and comparative examples had sufficiently short dissolution times and possessed practically acceptable water solubility.

[0082]

[0083] (6) Examination of evaluation results 6-1) Films composed of PVA and water-soluble branched polysaccharides (Examples 1 and 2, Comparative Example 2) The films of Examples 1 and 2, which had a PVA content of 90% by weight or 80% by weight, showed practically acceptable tensile strength and elongation. The film of Comparative Example 2, which had a PVA content of 50% by weight, had low tensile strength.

[0084] 6-2) Films composed of PVA and water-soluble linear polysaccharides (Comparative Examples 3-5) In all of Comparative Examples 3-5, the raw material solutions for the films separated into two phases.

[0085] 6-3) Films composed of PVA and disaccharides (Comparative Examples 6-8) The films of Comparative Examples 6 and 7, which had a PVA content of 90% by weight or 80% by weight, showed a tensile strength that was practically acceptable but lower than that of Comparative Example 1. Furthermore, the films of Comparative Examples 6 and 7 showed elongation at or above the same level as the film composed solely of PVA (Comparative Example 1). The film of Comparative Example 8, which had a PVA content of 50% by weight, had low tensile strength.

[0086] 6-4) Films composed of PVA, water-soluble branched polysaccharides, and disaccharides (Examples 3-13, Comparative Examples 9-11) The films of Examples 3-13, which had a PVA content of 70-90% by weight, all showed practically acceptable tensile strength and elongation. In contrast, the films of Comparative Examples 9-11, which had a PVA content of 50% by weight, had low tensile strength.

[0087] The films of Examples 3-5, which contained 90% by weight of PVA, showed higher elongation than the film of Example 1, which had the same PVA content but did not contain disaccharides. Similarly, the films of Examples 6-11, which contained 80% by weight of PVA, showed higher elongation than the film of Example 2, which had the same PVA content but did not contain disaccharides. Furthermore, the films of Examples 7 and 8 showed higher tensile strength than the film of Example 2. Therefore, it was shown that by combining PVA, water-soluble branched polysaccharides, and disaccharides, a film with superior elongation can be obtained, and furthermore, by selecting an appropriate amount of water-soluble branched polysaccharides, the tensile strength of the film can also be improved.

[0088] The films of Examples 3 to 12, which contained 5 to 18% by weight of water-soluble branched polysaccharides, showed higher tensile strength and elongation compared to the film of Example 13, which contained 27% by weight of water-soluble branched polysaccharides.

[0089] The films of Examples 6 and 10, which contained trehalose or maltose as the disaccharide, showed higher tensile strength compared to the film of Example 11, which contained sucrose as the disaccharide. Furthermore, when the film composed of PVA and water-soluble branched polysaccharides and the film composed of PVA and disaccharides had a PVA content of 90% by weight, the tensile strength or elongation of the film was evaluated as B (see Example 1 and Comparative Example 6). However, when the film composed of PVA, water-soluble branched polysaccharides, and trehalose or maltose had a PVA content of 90% by weight, it showed excellent tensile strength and elongation, receiving an evaluation of A (see Examples 3 to 5). Furthermore, when a film composed of PVA and water-soluble branched polysaccharides, and a film composed of PVA and disaccharides had a PVA content of 80% by weight, the tensile strength or elongation of the film was evaluated as C (see Example 2 and Comparative Example 7). However, a film composed of PVA, water-soluble branched polysaccharides, and trehalose or maltose was able to achieve excellent tensile strength and elongation, with an evaluation of B or higher, even with a PVA content of 70-80% by weight (see Examples 6-10 and 12).

[0090] 6-5) Film composed of PVA, water-soluble branched polysaccharides, and sugar alcohols (Example 14) The film of Example 14 exhibited practically acceptable tensile strength and elongation. Compared to the films of Examples 6 and 10, which contained trehalose or maltose, the film of Example 14 had lower tensile strength.

[0091] 6-6) Films composed of PVA, water-soluble linear polysaccharides, and disaccharides (Comparative Examples 12, 13) In Comparative Example 12, which used amylose as the water-soluble linear polysaccharide, partial phase separation occurred in the raw material solution of the film. The tensile strength of the film of Comparative Example 13, which contained pullulan as the water-soluble linear polysaccharide, was practically acceptable, but it was lower than the tensile strength of the films of Examples 1, 3-5 and Comparative Examples 3, 6, which had the same PVA content.

[0092] 6-7) Film composed of PVA, water-soluble branched polysaccharides, water-soluble linear polysaccharides, and disaccharides (Example 15) and film composed of PVA, water-soluble branched polysaccharides, and water-soluble linear polysaccharides (Example 16) The films of Examples 15 and 16 showed practically acceptable tensile strength and elongation. The film of Example 15, which contained disaccharides, showed higher tensile strength and elongation than the film of Example 16, which did not contain disaccharides.

[0093] B. Aqueous composition (1) Materials <Polyvinyl alcohol (PVA)> G-type Gosenol GL-05 manufactured by Mitsubishi Chemical Corporation (average saponification degree 86.5 to 89.0 mol%, viscosity of 4.8 to 5.8 mPa·s at 20°C for a 4% by weight PVA aqueous solution)

[0094] <Water-soluble branched polysaccharides> PS1: Fiberixa (registered trademark) manufactured by Nagase Vita Co., Ltd. (Mw = 4100, Mn = 2000, Mw / Mn = 2.1)

[0095] <Water-soluble linear polysaccharides> Pullulan: Food additive pullulan manufactured by Nagase Vita Co., Ltd.

[0096] <Disaccharides> Trehalose: Treha (registered trademark) manufactured by Nagase Vita Co., Ltd.

[0097] (2) Preparation of aqueous compositions PVA and pullulan were dispersed in stirred water, respectively, and then dissolved in a warm bath to prepare 10% by weight aqueous solutions of PVA and pullulan. PS1 and trehalose were added to stirred water, respectively, to prepare 10% by weight aqueous solutions of PS1 and trehalose. The aqueous solutions of each material were mixed in the weight ratios shown in Table 2 to obtain aqueous compositions.

[0098] (3) Stability Test The viscosity of the aqueous composition was measured immediately after preparation. The aqueous composition was then left to stand in a constant temperature and humidity chamber at 22°C and 50% RH, and the viscosity of the aqueous composition was measured after 3 days, 7 days, 10 days, and 14 days. The viscosity immediately after preparation was set to 100, and the viscosity change rate was calculated. The results are shown in Table 2. The viscosity was measured at 30°C using a Brookfield B-type viscometer.

[0099] (4) Evaluation of Adhesion A 10 μL aqueous composition was dropped onto a 3 cm x 3 cm x 0.1 mm thick sheet of copy paper, another sheet of copy paper was placed on top and pressed down with a finger, and then left to stand overnight. After that, it was checked whether the sheets of copy paper were adhered to each other. The results are shown in Table 2. In Table 2, "A" indicates that the sheets of copy paper were well adhered to each other.

[0100]

[0101] (5) Examination of evaluation results The aqueous solution of PVA alone in Comparative Example 14 showed an increase in viscosity over time. On the other hand, the aqueous solutions of Examples 17 to 20 containing PVA and sugars showed less change in viscosity over time than Comparative Example 14, indicating good stability. Furthermore, the aqueous compositions of Examples 17 to 20 showed good adhesion, similar to Comparative Example 14.

[0102] C. Preparation of film-like water-soluble compositions using granulated or pelletized sugars (1) Materials <Polyvinyl alcohol (PVA)> G-type Gosenol GL-05 manufactured by Mitsubishi Chemical Corporation (average saponification degree 86.5 to 89.0 mol%, viscosity of 4.8 to 5.8 mPa·s at 20°C for a 4% by weight PVA aqueous solution)

[0103] <Water-soluble branched polysaccharides> PS1: Fiberixa (registered trademark) manufactured by Nagase Vita Co., Ltd. (Mw = 4100, Mn = 2000, Mw / Mn = 2.1)

[0104] <Water-soluble linear polysaccharides> Pullulan: Food additive pullulan manufactured by Nagase Vita Co., Ltd.

[0105] <Disaccharides> Trehalose: Treha (registered trademark) manufactured by Nagase Vita Co., Ltd.

[0106] Furthermore, all of the above sugars were in powder form.

[0107] (2) Preparation of powdered, granular, or pelletized sugar mixtures The above sugars were mixed in the weight ratios shown in Table 3A to obtain powdered sugar mixtures. In Examples 21, 24, 27, and 30, granules with a diameter of 1 mm or less were formed from the powdered sugar mixture by fluid bed granulation. In Examples 22, 25, 28, and 31, cylindrical pellets with a diameter of 3 mm and a length of 3 to 8 mm were formed from the powdered sugar mixture using Nagase & Co., Ltd.'s semi-wet granulation technology Ultibatch®. Gel permeation chromatography was used to confirm that the sugars were uniformly mixed in the granules and pellets.

[0108] (3) Film Preparation PVA was added to stirred water and dispersed, then dissolved in a hot bath to prepare a 20% by weight PVA aqueous solution. Each sugar mixture was added to water and dissolved to prepare a 20% by weight aqueous solution of each sugar mixture. The PVA aqueous solution and the sugar mixture aqueous solution were mixed in a weight ratio of 80:20 to obtain a mixed solution (hereinafter referred to as "raw material solution"). The raw material solution was cast onto a PET film placed on a hot plate at a temperature of 80°C and allowed to air dry. A film was thus prepared. The average thickness of the obtained film was 40 to 47 μm. Tensile strength and elongation were evaluated using these films as described below.

[0109] Food coloring was added to the raw material solution prepared in the same manner as described above, and a film was prepared in the same manner as described above. The average thickness of the obtained film was 38 to 48 μm. The water solubility of the obtained film was evaluated as described below.

[0110] (4) Evaluation of compatibility The compatibility of the raw material solutions described above was evaluated by visual inspection. The results are shown in Table 3B. In Table 3B, "A" indicates that the components in the raw material solution were completely compatible and formed a single phase.

[0111] (5) Evaluation of tensile strength and tensile elongation The tensile strength and tensile elongation of the film were evaluated using the same methods and evaluation criteria as described in Section A. Film-like water-soluble compositions above. The results are shown in Table 3B.

[0112] (6) Evaluation of water solubility The water solubility of the film was evaluated using the same method and evaluation criteria as described in section A. Film-like water-soluble compositions above. The results are shown in Table 3B.

[0113]

[0114]

[0115] (7) Examination of evaluation results When the sugar mixture was granulated or pelletized, it showed sufficient compatibility with PVA, similar to the case of the powder. Films made using the granulated or pelletized sugar mixture showed sufficient tensile strength, tensile elongation, and water solubility, equivalent to the film made using the powdered sugar mixture.

[0116] D. Film-like water-soluble compositions containing various PVA-based polymers <Polyvinyl alcohol (PVA)-based polymers> Standard unmodified PVA: G-type Gosenol GL-05 manufactured by Mitsubishi Chemical Corporation (average saponification degree 86.5-89.0 mol%, viscosity of 4.8-5.8 mPa·s at 20°C for a 4% by weight PVA aqueous solution, pH 5-7 at 30°C for a 4% by weight PVA aqueous solution) High viscosity unmodified PVA: G-type Gosenol GH-20R manufactured by Mitsubishi Chemical Corporation (average saponification degree 86.5-89.0 mol%, viscosity of 40.0-46.0 Pa·s at 20°C for a 4% by weight PVA aqueous solution, pH 5-7 at 30°C for a 4% by weight PVA aqueous solution) Low-viscosity unmodified PVA: G-type Gosenol GL-03 manufactured by Mitsubishi Chemical Corporation (average saponification degree 86.5-89.0 mol%, viscosity of 4% by weight PVA aqueous solution at 20°C 3.0-3.7 Pa·s, pH of 4% by weight PVA aqueous solution at 30°C 5-7) Fully or semi-fully saponified unmodified PVA: N-type Gosenol NL-05 manufactured by Mitsubishi Chemical Corporation (average saponification degree 98.5 mol% or more, viscosity of 4% by weight PVA aqueous solution at 20°C 4.6-6.0 mPa·s, pH of 4% by weight PVA aqueous solution at 30°C 5-7) Partially saponified unmodified PVA: K-type Gosenol NK-05R manufactured by Mitsubishi Chemical Corporation (average saponification degree 71.0-75.0%, viscosity of 4% by weight PVA aqueous solution at 20°C 4.5-5.5 mPa·s, pH of 4% by weight PVA aqueous solution at 30°C 5-7) Sulfonic acid group modified PVA1: Gosenex L CKS-50 manufactured by Mitsubishi Chemical Corporation (average saponification degree 99.0 mol% or more, viscosity of 4% by weight PVA aqueous solution at 20°C 2.5-3.0 mPa·s, pH of 4% by weight PVA aqueous solution at 30°C 2.3-2.7) Sulfonic acid group modified PVA2: Gosenex L manufactured by Mitsubishi Chemical Corporation L3266 (average saponification degree 86.5–89.0 mol%, viscosity 2.3–2.7 mPa·s at 20°C for a 4% by weight PVA aqueous solution, pH 5–7 at 30°C for a 4% by weight PVA aqueous solution)Carboxylate-modified PVA1: Kuraray POVA 25-88KL manufactured by Kuraray Co., Ltd. (average saponification degree 85.0-90.0 mol%, viscosity of 4% by weight PVA aqueous solution at 20°C 20.0-30.0 mPa·s, pH of 4% by weight PVA aqueous solution at 30°C 5-7) Carboxylate-modified PVA2: Kuraray POVA 3-86SD manufactured by Kuraray Co., Ltd. (average saponification degree 83.0-88.0 mol%, viscosity of 4% by weight PVA aqueous solution at 20°C 2.4-3.4 mPa·s, pH of 4% by weight PVA aqueous solution at 30°C 5-7) Butenediol vinyl alcohol copolymer (BVOH): Nichigo G Polymer AZF8035Q manufactured by Mitsubishi Chemical Corporation (viscosity of BVOH aqueous solution at 20°C is 3.0 mPa·s, with an average saponification degree of 98.5 mol% and a concentration of 4% by weight)

[0117] <Water-soluble branched polysaccharides> PS1: Fiberixa (registered trademark) manufactured by Nagase Vita Co., Ltd. (Mw = 4100, Mn = 2000, Mw / Mn = 2.1)

[0118] <Disaccharides> Trehalose: Treha (registered trademark) manufactured by Nagase Vita Co., Ltd.

[0119] (2) Film Preparation High viscosity unmodified PVA and carboxyl group modified PVA1 were dispersed in stirred water, and then dissolved in a hot bath to prepare 10% by weight aqueous solutions of high viscosity unmodified PVA and carboxyl group modified PVA1. In addition, each of the above PVA-based polymers, excluding high viscosity unmodified PVA and carboxyl group modified PVA1, was added to stirred water and dispersed, and then dissolved in a hot bath to prepare 20% by weight aqueous solutions of each material. In addition, PS1 and trehalose were added to stirred water and dissolved to prepare 20% by weight aqueous solutions of PS1 and trehalose. The aqueous solutions of each material were mixed to obtain a mixture containing each material in the weight ratio shown in Table 4A (hereinafter referred to as "raw material solution"). The raw material solution was cast onto a PET film placed on a hot plate at a temperature of 80°C and air-dried. A film was thus prepared. The average thickness of the obtained film was 23 to 67 μm. These films were used to evaluate tensile strength and elongation, as described below.

[0120] Furthermore, aqueous solutions of the various PVA-based polymers prepared as described above were cast onto a PET film placed on a hot plate at 80°C and allowed to air dry. This resulted in the production of individual films of each PVA-based polymer.

[0121] (3) Evaluation of compatibility The compatibility of the raw material solutions described above was evaluated by visual inspection. The results are shown in Table 4B. In Table 4B, "A" indicates that the components in the raw material solution were completely compatible and formed a single phase.

[0122] (4) Evaluation of Tensile Strength and Tensile Elongation The average values ​​of the tensile strength and tensile elongation of the films in each example were determined using the same method as described in section "A. Film-like Water-soluble Compositions" above. Similarly, the average values ​​of the tensile strength and tensile elongation of the films of each PVA polymer alone were determined in the same manner. The relative tensile strength and relative elongation of each example were determined by setting the average tensile strength and average elongation of the PVA polymer alone used in each example to 100. The results are shown in Table 4B. Regarding relative tensile strength, "B" in Table 4B represents 70 or more and 100 or less. B is within a practically acceptable range. Regarding relative elongation, "A" in Table 4B represents greater than 65. A is within a practically acceptable range.

[0123]

[0124]

[0125] (5) Review of evaluation results All PVA-based polymers were sufficiently compatible with water-soluble branched polysaccharides and trehalose. Furthermore, films containing any of the PVA-based polymers along with water-soluble branched polysaccharides and trehalose exhibited tensile strength and tensile elongation equivalent to those of films containing only the PVA-based polymer.

[0126] E. Thermal stability of aqueous compositions (1) Materials <Polyvinyl alcohol (PVA)> G-type Gosenol GL-05 manufactured by Mitsubishi Chemical Corporation (average degree of saponification 86.5 to 89.0 mol%, viscosity of 4.8 to 5.8 mPa·s at 20°C for a 4% by weight PVA aqueous solution)

[0127] <Water-soluble branched polysaccharides> PS1: Fiberixa (registered trademark) manufactured by Nagase Vita Co., Ltd. (Mw = 4100, Mn = 2000, Mw / Mn = 2.1) PS2: α-glucan mixture prepared using α-glucosyltransferase in the same manner as in Patent Document 6 (Mw = 1,160,000, Mn = 69,000, Mw / Mn = 21.2)

[0128] <Water-soluble linear polysaccharides> Pullulan: Food additive pullulan manufactured by Nagase Vita Co., Ltd.

[0129] <Disaccharides> Trehalose: Treha (registered trademark) manufactured by Nagase Vita Co., Ltd.

[0130] (2) Film Preparation PVA and pullulan were dispersed in stirred water, and then dissolved in a hot bath to prepare 20% by weight aqueous solutions of PVA and pullulan. PS1, PS2, and trehalose were added to stirred water and dissolved to prepare 20% by weight aqueous solutions of PS1, PS2, and trehalose. The aqueous solutions of each material were mixed in the weight ratios shown in Table 5 to obtain a mixed solution (hereinafter referred to as "raw material solution"). The raw material solution of Comparative Example 15 separated into two phases. The raw material solutions of Examples 42 to 44 were colorless and transparent and formed a single phase. The raw material solutions were each cast onto a PET film placed on a hot plate at a temperature of 80°C and air-dried. Films were thus prepared. In addition, the PVA aqueous solution prepared as described above was cast onto a PET film placed on a hot plate at a temperature of 80°C and air-dried. A PVA-only film was thus prepared. These films will be referred to below as "films from non-heated solutions."

[0131] Furthermore, the raw material solutions were heated at 90°C for one day. The raw material solutions of Examples 42 to 44 remained colorless and transparent after heating. Subsequently, the raw material solutions were cast onto PET films placed on a hot plate at 80°C and allowed to air dry. Films were then produced. The average thickness of the obtained films was 41 to 47 μm. In addition, the PVA aqueous solution prepared as described above was heated at 90°C for one day. The PVA aqueous solution remained colorless and transparent after heating. Subsequently, the PVA aqueous solution was cast onto PET films placed on a hot plate at 80°C and allowed to air dry. Films of PVA alone were then produced. These films will be referred to as "films from heated solutions" below.

[0132] The films of Examples 42-44 and Comparative Example 15 were all colorless regardless of whether the raw material solution was heated or not, and there were no differences in appearance due to heating. Tensile strength and elongation were evaluated using these films.

[0133] (3) Evaluation of Tensile Strength and Tensile Elongation The average values ​​of tensile strength and tensile elongation were determined for the films from the unheated solution and the films from the heated solution of each example and comparative example, as well as for the films from the unheated solution and the films from the heated solution of PVA alone, using the same method as described in section "A. Film-like Water-soluble Compositions" above. The relative tensile strength and relative elongation of the films from the unheated solution of PVA alone were set to 100, and the relative tensile strength and relative elongation of the films from the unheated solution of each example and comparative example were determined. Similarly, the relative tensile strength and relative elongation of the films from the heated solution of PVA alone were set to 100, and the relative tensile strength and relative elongation of the films from the heated solution of each example and comparative example were determined. The results are shown in Table 5. With respect to relative tensile strength, "A" in Table 5 represents a value greater than 100, and "B" represents a value between 70 and 100. A and B are within the practically acceptable range. With respect to relative elongation, "A" in Table 5 represents a value greater than 65, and "B" represents a value between 12 and 65. A and B are within practically acceptable limits.

[0134]

[0135] (4) Examination of evaluation results In all of Examples 42 to 44 and Comparative Example 15, no significant effect of heating the raw material solution on the relative tensile strength was observed. In Example 42, a decrease in the relative elongation of the film was observed due to heating the raw material solution, but it was within a range that did not pose a practical problem. In Examples 43 and 44, no significant effect of heating the raw material solution on the relative elongation of the film was observed.

[0136] Because the water-soluble composition of this disclosure contains naturally derived ingredients, it can be used as a sustainable material, reducing the environmental burden during production and disposal.

[0137] This specification includes the disclosures of Japanese Patent Application No. 2025-066601, which forms the basis of the priority claim of this application. All publications, patents and patent applications referenced herein are incorporated herein by direct reference.

Claims

1. A water-soluble composition comprising a PVA-based polymer and a water-soluble branched polysaccharide, wherein the PVA-based polymer content is 60% by weight or more of the total weight of the water-soluble composition.

2. The water-soluble composition according to claim 1, further containing a disaccharide.

3. The water-soluble composition according to claim 2, wherein the disaccharide is one or more selected from the group consisting of trehalose and maltose.

4. The water-soluble composition according to claim 3, wherein the PVA-based polymer content is 90% by weight or less relative to the total weight of the water-soluble composition.

5. The water-soluble composition according to claim 3, wherein the PVA-based polymer content is less than 90% by weight of the total weight of the water-soluble composition.

6. The water-soluble composition according to claim 3, wherein the PVA-based polymer content is 85% by weight or less relative to the total weight of the water-soluble composition.

7. The water-soluble composition according to claim 3, wherein the water-soluble branched polysaccharide content is 1% by weight to 25% by weight relative to the total weight of the water-soluble composition.

8. The water-soluble composition according to claim 2, wherein the disaccharide content is 1% by weight to 20% by weight relative to the total weight of the water-soluble composition.

9. The water-soluble composition according to claim 1, wherein the water-soluble branched polysaccharide is a branched α-glucan mixture.

10. The water-soluble composition according to claim 1, further comprising pullulan.

11. The water-soluble composition according to any one of claims 1 to 10, wherein the water-soluble composition is a water-soluble film.

12. A package comprising: a water-soluble film according to claim 11; and a drug contained in the water-soluble film.

13. The packaging according to claim 12, wherein the agent is a detergent, a pesticide, or a disinfectant.

14. The packaging according to claim 12, wherein the drug is in liquid form.

15. An aqueous composition comprising the water-soluble composition according to any one of claims 1 to 10, and an aqueous medium.

Images