Pouch

Abstract

The present invention pertains to a pouch comprising a water-soluble film that contains at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof.

Description

Pouch

[0001] The present invention relates to a pouch comprising a water-soluble film, a laminate comprising a water-soluble film and a support, and a coating agent for forming a water-soluble film.

[0002] A method is known in which a liquid drug is packaged in a water-soluble film to form a pouch, and when in use, the pouch is placed in water to dissolve the contents together with the film in water for use (Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2019-081901

[0004] For example, when the pouch is filled with laundry detergent or the like, if the pouch has low solubility in cold water, it takes a long time for the pouch to dissolve, which can result in some of the detergent remaining undissolved in the clothes. Furthermore, polysaccharides may have particularly low solubility in cold water. Furthermore, the pouch containing the contents also needs to have sufficient mechanical strength to prevent breakage during transportation.

[0005] Therefore, an object of the present invention is to provide a pouch comprising a water-soluble film that has excellent solubility and mechanical strength at low temperatures, a laminate comprising a water-soluble film and a support, and a coating agent for forming the water-soluble film.

[0006] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, leading to the completion of the present invention. That is, the present invention includes the following preferred embodiments.

[0007] [1] A pouch comprising a water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof. [2] The pouch according to [1], wherein the polysaccharide A is selected from tamarind seed gum and derivatives thereof. [3] The pouch according to [1] or [2], wherein the content of the polysaccharide A is 5 to 80% by mass relative to the mass of the water-soluble film. [4] The pouch according to any one of [1] to [3], wherein the water-soluble film further contains a plasticizer. [5] The pouch according to [4], wherein the plasticizer is at least one selected from the group consisting of polyhydric alcohols, hydroxy acids, monosaccharides, and disaccharides. [6] The pouch according to [4] or [5], wherein the plasticizer is at least one selected from the group consisting of glycerin, diglycerin, sorbitol, alkylene glycol, polyalkylene glycol, trimethylolpropane, erythritol, 2-methyl-1,3-propanediol, lactic acid, glucose, fructose, maltose, and trehalose. [7] The pouch according to any one of [4] to [6], wherein the plasticizer is at least one selected from the group consisting of glycerin, ethylene glycol, sorbitol, and fructose. [8] The pouch according to any one of [4] to [7], wherein the content of the plasticizer is 20 to 95% by mass relative to the mass of the water-soluble film. [9] The pouch according to any one of [1] to [8], wherein the water-soluble film further contains polysaccharide B different from polysaccharide A.

[10] The pouch according to [9], wherein the polysaccharide B is at least one selected from the group consisting of guar gum, locust bean gum, xanthan gum, carrageenan, alginic acid, pullulan, and derivatives thereof.

[11] The pouch according to [9] or

[10] , wherein the content of the polysaccharide B is 1 to 30% by mass relative to the mass of the water-soluble film.

[12] The pouch according to any one of [1] to

[11] , wherein the water-soluble film has a toughness of 400 or more.

[13] The pouch according to any one of [1] to

[12] , wherein the pouch dissolves in water at 10°C within 1,000 seconds.

[14] The pouch according to any one of [1] to

[13] , containing therein at least one selected from the group consisting of a cleaning agent, a fabric softener, and a fragrance.

[15] A water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof.

[16] A water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof, and a polysaccharide B different from the polysaccharide A.

[17] A water-soluble film for use in a pouch, containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof, and a plasticizer, wherein the plasticizer content is 45% by mass or less relative to the mass of the water-soluble film.

[18] The water-soluble film according to any one of

[15] to

[17] , which is a coating film formed from a coating agent containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof.

[19] A laminate comprising the water-soluble film according to any one of

[15] to

[17] and a support, wherein the support is paper or film.

[20] A packaging material comprising the water-soluble film according to

[15] .

[21] A coating agent containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof.

[0008] According to the present invention, it is possible to provide a pouch comprising a water-soluble film, which has excellent solubility at low temperatures and mechanical strength, a laminate comprising a water-soluble film and a support, and a coating agent for forming the water-soluble film.

[0009] Hereinafter, embodiments of the present invention will be described in detail. Note that the following description is merely illustrative of embodiments of the present invention, and is not intended to limit the present invention to the following embodiments. Note that the upper and lower limits described in this specification can be arbitrarily combined to form a suitable numerical range.

[0010] [Pouch] The pouch of the present invention comprises a water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof.

[0011] <Polysaccharide A> Tamarind seed gum is a polysaccharide obtained from the seeds of tamarind (Tamarindus indica), and has a structure in which glucose is the main chain and xylose and galactose are bonded to the side chains. As the tamarind seed gum, for example, commercially available products such as "Glyloid 6C (registered trademark)", "Glyate (registered trademark)", "Glyloid (registered trademark)", "Glyloid (registered trademark) 3S", "Glyloid (registered trademark) 2A" (manufactured by MP Gokyo Food & Chemical Co., Ltd.), and "TG120" (manufactured by Mitsubishi Chemical Corporation) may be used.

[0012] Locust bean gum is a polysaccharide obtained from the seeds of carob (Celatonia siliqua), and has a structure in which mannose is the main chain and galactose is bonded to the side chain. As locust bean gum, for example, commercially available products such as "Soarlocust A120," "Soarlocust A200," and "MC1000" (manufactured by Mitsubishi Chemical Corporation) and GRINSTED LBG 860 (manufactured by Sansho Co., Ltd.) may be used.

[0013] Tara gum is a polysaccharide obtained from the seeds of Caesalpinia spinosa, and has a structure in which mannose is the main chain and galactose is bonded to the side chain. Commercially available tara gum products such as "MT120" and "MT1000" (manufactured by Mitsubishi Chemical Corporation) and Spinogum D (manufactured by Sansho Co., Ltd.) may be used.

[0014] Examples of derivatives of these polysaccharides A include anionized products obtained by introducing a carboxymethyl group or the like and their sodium salts, potassium salts, and calcium salts; anionized products obtained by introducing a quaternary ammonium group or the like and their chlorides; etherified products with ethylene oxide or propylene oxide; enzyme-treated products; acid hydrolysates, etc. One type of polysaccharide A may be used alone, or two or more types may be used in combination.

[0015] In one embodiment of the present invention, the number-average molecular weight (sometimes referred to as Mn) of polysaccharide A is preferably 5 kDa to 50,000 kDa, more preferably 7 kDa to 10,000 kDa, even more preferably 10 kDa to 5,000 kDa, for example, 10 kDa to 3,000 kDa, 15 kDa to 1,000 kDa, or 20 kDa to 700 kDa. The weight-average molecular weight (sometimes referred to as Mw) of polysaccharide A is preferably 5 kDa to 150,000 kDa, more preferably 10 kDa to 50,000 kDa, even more preferably 20 kDa to 30,000 kDa, for example, 30 kDa to 10,000 kDa, 50 kDa to 7,000 kDa, or 70 kDa to 5,000 kDa. When the Mn and / or Mw of polysaccharide A are within the above ranges, the solubility and mechanical strength of the pouch at low temperatures can be improved. When polysaccharide A is composed of two or more polysaccharides, the Mn of polysaccharide A is a weighted average of the Mn of the two or more polysaccharides. The same applies to Mw.

[0016] In one embodiment of the present invention, the Mn of the tamarind seed gum is preferably 10 kDa to 3,000 kDa, more preferably 30 kDa to 1,000 kDa, and even more preferably 50 kDa to 500 kDa, and may be, for example, 100 kDa to 500 kDa. The Mw of the tamarind seed gum is preferably 10 kDa to 50,000 kDa, more preferably 30 kDa to 10,000 kDa, and even more preferably 50 kDa to 5,000 kDa, and may be, for example, 500 kDa to 4,500 kDa or 1,000 kDa to 4,000 kDa. The Mn of the locust bean gum is preferably 5 kDa to 50,000 kDa, more preferably 7 kDa to 10,000 kDa, and even more preferably 10 kDa to 5,000 kDa, and may be, for example, 15 to 1,000 kDa or 20 to 300 kDa. The Mw of locust bean gum is preferably 5 kDa to 150,000 kDa, more preferably 10 kDa to 30,000 kDa, and even more preferably 15 kDa to 15,000 kDa, and may be, for example, 20 kDa to 5,000 kDa, 30 kDa to 1,000 kDa, or 50 kDa to 500 kDa. The Mn of tara gum is preferably 5 kDa to 10,000 kDa, more preferably 7 kDa to 5,000 kDa, and even more preferably 10 kDa to 1,000 kDa, and the Mw of tara gum is preferably 5 kDa to 30,000 kDa, more preferably 10 kDa to 15,000 kDa, and even more preferably 15 kDa to 10,000 kDa. When the Mn and / or Mw of each polysaccharide is within the above range, the solubility and mechanical strength of the pouch at low temperatures can be improved. Polysaccharide A may contain polysaccharides of the same type but different in Mn and / or Mw. The Mn and Mw of these polysaccharides A can be determined by gel filtration HPLC, for example, by the method described in the Examples below.

[0017] The present inventors conducted research focusing on polysaccharides and unexpectedly found that films formed using at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and their derivatives exhibit both excellent low-temperature solubility and mechanical strength. While the reason for this is unclear, it is believed that these polysaccharides A have a steric hindrance structure in the side chain, which makes them more resistant to crystallization and advantageous in terms of water solubility. Furthermore, it is believed that these polysaccharides A are capable of forming a higher-order network through intermolecular interactions and hydrogen bonds, which increases mechanical strength. Furthermore, these polysaccharides A have high heat resistance, acid resistance, and salt resistance, which minimizes molecular weight loss upon heating and dissolution during film production. Furthermore, they exhibit minimal changes in physical properties even when exposed to acidic or salt-containing liquids, making them suitable for use in pouches. Furthermore, their high resistance to enzymes such as amylase makes them suitable for use in, for example, enzyme-containing detergent pouches.

[0018] The content of the polysaccharide A may be, for example, 0.1 to 100% by mass, 1 to 95% by mass, or 3 to 90% by mass, preferably 5 to 80% by mass, more preferably 10 to 70% by mass, even more preferably 20 to 60% by mass, still more preferably 25% by mass or more but less than 60% by mass, particularly preferably 30 to 58% by mass, especially more preferably 32 to 55% by mass, and particularly even more preferably 35 to 50% by mass or 37 to 48% by mass, relative to the mass of the water-soluble film. When the content of polysaccharide A is within the above range, the pouch will have excellent solubility at low temperatures and mechanical strength.

[0019] In a preferred embodiment of the present invention, the polysaccharide A is selected from tamarind seed gum and its derivatives. When the polysaccharide A is selected from tamarind seed gum and its derivatives, the pouch has better solubility at low temperatures and mechanical strength. In a more preferred embodiment, the polysaccharide A is selected from the group consisting of tamarind seed gum, sodium salts or potassium salts of anionized tamarind seed gum, and enzyme-treated tamarind seed gum.

[0020] <Plasticizer> In the pouch of the present invention, it is preferable that the water-soluble film further contains a plasticizer. When the water-soluble film contains a plasticizer, processability can be improved, such as facilitating film formation and pouch formation. The plasticizer used in the pouch of the present invention is preferably at least one selected from the group consisting of polyhydric alcohols, hydroxy acids, monosaccharides, and disaccharides. These compounds can aggregate polysaccharide A by dehydration. Furthermore, since they can form a high-order network by hydrogen bonding with polysaccharide A, they can not only improve processability but also further increase the mechanical strength of the pouch, particularly elongation. One type of plasticizer may be used alone, or two or more types may be used in combination.

[0021] Examples of the polyhydric alcohol include glycerin, diglycerin, sorbitol, alkylene glycols (e.g., alkylene glycols having 2 to 10 carbon atoms, such as ethylene glycol, propylene glycol, and neopentyl glycol), polyalkylene glycols (e.g., diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols having a molecular weight of up to 400, and polypropylene glycols having a molecular weight of up to 400), trimethylolpropane, erythritol, xylitol, 2-methyl-1,3-propanediol, maltitol, mannitol, and pentaerythritol.

[0022] Examples of the hydroxy acid include lactic acid, glycolic acid, malic acid, and tartaric acid.

[0023] Examples of the monosaccharides include glucose, mannose, galactose, fructose, and xylose.

[0024] Examples of the disaccharides include maltose, trehalose, sucrose, and lactose.

[0025] Among these, from the viewpoint of further increasing the mechanical strength of the pouch, the plasticizer is preferably at least one selected from the group consisting of glycerin, diglycerin, sorbitol, alkylene glycol, neopentyl glycol, trimethylolpropane, erythritol, 2-methyl-1,3-propanediol, lactic acid, glucose, fructose, maltose, and trehalose, and more preferably at least one selected from the group consisting of glycerin, ethylene glycol, sorbitol, and fructose.

[0026] The content of the plasticizer may be, for example, 0 to 99.9% by mass, 5 to 99% by mass, or 10 to 95% by mass, preferably 20 to 95% by mass, more preferably 30 to 90% by mass, even more preferably 40 to 80% by mass, still more preferably more than 40% by mass but not more than 75% by mass, particularly preferably 42 to 70% by mass, especially more preferably 45 to 68% by mass, and particularly even more preferably 50 to 65% by mass or 52 to 63% by mass, relative to the mass of the water-soluble film. When the content of the plasticizer is within the above range, the processability of the film and the mechanical strength of the pouch can be excellent.

[0027] In one embodiment of the present invention, the content ratio (mass ratio) of polysaccharide A to plasticizer is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, even more preferably 30:70 to 70:30, even more preferably 35:65 to 65:35, particularly preferably 36:64 to 60:40, or 37:63 to 58:42, particularly preferably 38:62 to 55:45, and extremely preferably 39:61 to 52:48, or 40:60 to 50:50. When the content ratio of polysaccharide A to plasticizer is within the above range, the water solubility, mechanical strength, and low-temperature solubility of the water-soluble film can be improved. Furthermore, when the water-soluble film further contains polysaccharide B (described below), the content ratio (mass ratio) of polysaccharide A and polysaccharide B to plasticizer is preferably within the above range.

[0028] <Polysaccharide B> In one embodiment of the present invention, in the pouch of the present invention, it is preferable that the water-soluble film further contains a polysaccharide B different from the polysaccharide A. When the water-soluble film further contains polysaccharide B, a higher-order network can be formed by hydrogen bonding with polysaccharide A, thereby further improving the mechanical strength of the pouch.

[0029] From the viewpoint of further increasing the mechanical strength of the pouch, polysaccharide B is preferably at least one selected from the group consisting of guar gum, locust bean gum, xanthan gum, carrageenan, alginic acid, pullulan, and derivatives thereof.

[0030] Guar gum is a polysaccharide obtained from the endosperm of guar beans (Cyamopsis tetragonoloba), and has a structure in which mannose is the main chain and galactose is bonded to the side chain. As the guar gum, for example, commercially available products such as "Guapak (registered trademark)" (manufactured by MP Gokyo Food & Chemical Co., Ltd.), "RG100" (manufactured by Mitsubishi Chemical Corporation), "JAGUAR C 17K" (manufactured by Sansho Co., Ltd., cationized guar gum), and "MEYPRO-BOND 111" (manufactured by Sansho Co., Ltd., cationized guar gum) may be used.

[0031] Xanthan gum is a polysaccharide produced by fermenting starch with the bacterium Xanthomonas campestris, and has a glucose backbone and a side chain containing one glucuronic acid between two mannose units. Commercially available xanthan gums may be used, such as "Echogum (registered trademark)" (manufactured by MP Gokyo Food & Chemical Co., Ltd.), "Soaxan," and "XG800" (manufactured by Mitsubishi Chemical Corporation).

[0032] Carrageenan is a polysaccharide obtained from red algae and contains repeating units of D-galactose or 3,6-anhydro-D-galactose and sulfate groups. Carrageenan is classified into κ (kappa) carrageenan, ι (iota) carrageenan, and λ (lambda) carrageenan. These may be used alone or in combination. Commercially available carrageenans include "GENUGEL carrageenan type JPE-126" (manufactured by Sansho Co., Ltd.), "GENUTINE VCS-J" (manufactured by Sansho Co., Ltd.), "MW210," "MV320," and "MW952" (manufactured by Mitsubishi Chemical Corporation).

[0033] Examples of derivatives of polysaccharide B include sodium salts, potassium salts, calcium salts, cationized forms and salts thereof, anionized forms and salts thereof, enzyme-treated products, acid hydrolysates, etc. Polysaccharide B may be used singly or in combination of two or more types.

[0034] In one embodiment of the present invention, the number-average molecular weight (sometimes referred to as Mn) of polysaccharide B is preferably 5 kDa to 50,000 kDa, more preferably 10 kDa to 10,000 kDa, even more preferably 10 kDa to 5,000 kDa, and may be, for example, 5 kDa to 1,000 kDa, 10 kDa to 500 kDa, or 15 kDa to 200 kDa. The weight-average molecular weight (sometimes referred to as Mw) of polysaccharide B is preferably 5 kDa to 150,000 kDa, more preferably 10 kDa to 50,000 kDa, and even more preferably 10 kDa to 30,000 kDa, and may be, for example, 10 kDa to 5,000 kDa, 30 kDa to 2,000 kDa, or 50 kDa to 1,000 kDa. When the Mn and / or Mw of polysaccharide B are within the above ranges, the mechanical strength of the pouch can be further increased. When polysaccharide B is composed of two or more polysaccharides, the Mn of polysaccharide B is a weighted average of the Mn of the two or more polysaccharides. The same applies to Mw.

[0035] In one embodiment of the present invention, the Mn of the guar gum is preferably 5 kDa to 20,000 kDa, more preferably 5 kDa to 10,000 kDa, even more preferably 7 kDa to 5,000 kDa, and may be, for example, 10 kDa to 1,000 kDa or 15 kDa to 100 kDa. The Mw of the guar gum is preferably 5 kDa to 100,000 kDa, more preferably 5 kDa to 50,000 kDa, and even more preferably 7 kDa to 20,000 kDa, and may be, for example, 10 kDa to 5,000 kDa, 30 kDa to 1,000 kDa, or 50 kDa to 500 kDa. The Mn of xanthan gum is preferably 5 kDa to 50,000 kDa, more preferably 7 kDa to 10,000 kDa, even more preferably 10 kDa to 5,000 kDa, for example, 10 kDa to 1,000 kDa or 15 kDa to 100 kDa. The Mw of xanthan gum is preferably 5 kDa to 150,000 kDa, more preferably 7 kDa to 50,000 kDa, even more preferably 10 kDa to 30,000 kDa, for example, 10 kDa to 5,000 kDa, 30 kDa to 1,000 kDa, or 50 kDa to 500 kDa. The Mn of carrageenan is preferably 5 kDa to 5,000 kDa, more preferably 10 kDa to 3,000 kDa, and even more preferably 20 kDa to 1,000 kDa, for example, 25 kDa to 500 kDa or 30 kDa to 200 kDa. The Mw of carrageenan is preferably 5 kDa to 15,000 kDa, more preferably 10 kDa to 10,000 kDa, and even more preferably 20 kDa to 5,000 kDa, for example, 50 kDa to 2,000 kDa or 100 kDa to 1,000 kDa. The Mn of alginic acid is preferably 5 kDa to 50,000 kDa, more preferably 7 kDa to 10,000 kDa, and even more preferably 10 kDa to 5,000 kDa, for example, 15 kDa to 1,000 kDa or 20 kDa to 300 kDa. The Mw of alginic acid is preferably 5 kDa to 150,000 kDa, more preferably 10 kDa to 30,000 kDa, and even more preferably 15 kDa to 15,000 kDa, and may be, for example, 20 kDa to 5,000 kDa, 30 kDa to 1,000 kDa, or 50 kDa to 500 kDa. When the Mn and / or Mw of each polysaccharide is within the above range, the mechanical strength can be further increased.Polysaccharide B may contain polysaccharides of the same type but different in Mn and / or Mw. The Mn and Mw of these polysaccharides B can be determined by gel filtration HPLC, for example, by the method described in the Examples below.

[0036] In the water-soluble film, it is preferred that the polysaccharide A is selected from tamarind seed gum or a derivative thereof, and the polysaccharide B is at least one selected from the group consisting of xanthan gum, guar gum, and locust bean gum. Such a water-soluble film tends to improve the mechanical strength of the pouch while maintaining the solubility at low temperatures.

[0037] The content of the polysaccharide B is preferably 1 to 30% by mass, more preferably 1.5 to 20% by mass, even more preferably 2 to 10% by mass, still more preferably 2.5 to 7% by mass, and particularly preferably 3 to 5% by mass, relative to the mass of the water-soluble film. When the content of polysaccharide B is within the above range, the pouch can have excellent solubility at low temperatures and mechanical strength.

[0038] In one embodiment of the present invention, the content ratio (mass ratio) of polysaccharide A to polysaccharide B is preferably 99:1 to 50:50, more preferably 98:2 to 55:45, even more preferably 95:5 to 60:40, 93:7 to 70:30, or 92:8 to 65:35, and still more preferably 91:9 to 70:30. When the content ratio of polysaccharide A to polysaccharide B is within the above range, the water solubility of the water-soluble film can be maintained while further improving the mechanical strength and processability.

[0039] <Additives> In the pouch of the present invention, the water-soluble film may contain additives other than the plasticizer and polysaccharide B (also referred to as additives A) to the extent that the effects of the present invention are not impaired. Examples of additives A include dispersants, moisture, antioxidants, UV absorbers, lubricants, colorants, preservatives, fillers, surfactants, anti-sticking agents, release agents, pigments, and crosslinking agents. One type of additive A may be used alone, or two or more types may be used in combination. In this specification, the plasticizer, polysaccharide B, and additive A may be collectively referred to simply as "additives."

[0040] The filler refers to a component that is incompatible with polysaccharide A. In a pouch, when a water-soluble film contains a filler, it can form a higher-order network by hydrogen bonding with polysaccharide A, thereby improving the stress of the resulting pouch. Furthermore, particularly when a water-soluble film is produced by coating, adding a filler to the coating agent increases the solids concentration, allowing the thickness of the coating film to be increased.

[0041] Examples of fillers include inorganic pigments such as kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica (swelling mica, synthetic mica, white mica (muscovite), sericite (sericite), phloxopite, biotite, fluorphlogopite (artificial mica), red mica, soda mica, vanadium mica, illite, zinc mica, paragonite, brittle mica, etc.), talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicates, bentonite (montmorillonite, beidellite, saponite, stevensite, hectorite, etc.), colloidal silica, and satin white, as well as solid, hollow, or core-shell organic pigments. These fillers may be used singly or in combination of two or more.

[0042] In a pouch, when the water-soluble film contains a filler, the total content of the filler relative to the mass of the water-soluble film is preferably 0.1 to 50% by mass, more preferably 0.5 to 35% by mass, even more preferably 1 to 30% by mass, even more preferably 1.5 to 20% by mass, even more preferably 2 to 18% by mass, even more preferably 2 to 15% by mass, even more preferably 2 to 10% by mass, and particularly preferably 2 to 6% by mass, from the viewpoint of improving the stress of the resulting pouch. Also, from the viewpoint of increasing the thickness of the coating film, it is preferably 1 to 90% by mass, more preferably 5 to 80% by mass, even more preferably 10 to 75% by mass, even more preferably 20 to 70% by mass, even more preferably 30 to 65% by mass, even more preferably 40 to 60% by mass, even more preferably 42 to 58% by mass, and particularly preferably 45 to 55% by mass.

[0043] Alternatively, a dispersant may be added separately to the coating agent used to form the water-soluble film in the pouch. Addition of a dispersant can improve the dispersibility of the filler. The dispersant is preferably a cationic polymer, and examples thereof include polyalkylene polyamines, polyamide compounds, polyamidoamine-epihalohydrin or formaldehyde condensation products, polyamine-epihalohydrin or formaldehyde condensation products, polyamide polyurea-epihalohydrin or formaldehyde condensation products, polyamine polyurea-epihalohydrin or formaldehyde condensation products, polyamidoamine polyurea-epihalohydrin or formaldehyde condensation products, polyamide polyurea compounds, polyamine polyurea compounds, polyamidoamine polyurea compounds, polyamidoamine compounds, polyethyleneimine, polyvinylpyridine, amino-modified acrylamide compounds, polyvinylamine, polydiallyldimethylammonium chloride, and modified polyvinyl alcohol. The dispersants may be used singly or in combination of two or more. When the water-soluble film in the pouch contains a dispersant, the content of the dispersant is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 1 to 5% by mass, relative to the mass of the water-soluble film.

[0044] Examples of crosslinking agents include tannic acid and its salts, tannins other than tannic acid, catechin, anthocyanin, gallic acid and its salts, phenols, and hydroquinone.

[0045] The content of additive A is not particularly limited as long as it does not interfere with the effects of the present invention, but it is, for example, about 0 to 10 mass %, preferably 0.001 to 10 mass %, more preferably 0.01 to 5 mass %, and even more preferably about 0.1 to 1 mass %, relative to the mass of the water-soluble film.

[0046] In one embodiment of the present invention, the content of the polyvinyl alcohol-based resin in the water-soluble film of the pouch of the present invention is preferably less than 30% by mass, more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, particularly preferably 1% by mass or less, particularly preferably 0.1% by mass, and even 0% by mass. That is, it is preferably 0 to less than 30% by mass, more preferably 0 to 20% by mass, even more preferably 0 to 10% by mass, even more preferably 0 to 5% by mass, particularly preferably 0 to 1% by mass, and particularly preferably 0 to 0.1% by mass. The polyvinyl alcohol-based resin used in the present invention can be made from vinyl acetate containing petroleum-derived carbon, vinyl acetate containing biomass-derived carbon, or a mixture thereof. Alternatively, a polyvinyl alcohol-based resin whose apparent biomass ratio has been changed using a mass balance method may be used.

[0047] In one embodiment of the present invention, the total content of polysaccharide A, plasticizer, and polysaccharide B contained in the water-soluble film of the pouch of the present invention is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, particularly preferably 95% by mass or more, and particularly preferably 98% by mass or more, based on the mass of the water-soluble film. That is, it is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, even more preferably 70 to 100% by mass, even more preferably 80 to 100% by mass, particularly preferably 90 to 100% by mass, particularly preferably 95 to 100% by mass, and particularly preferably 98 to 100% by mass. When the total content of polysaccharide A, plasticizer, and polysaccharide B contained in the water-soluble film is within the above range, the solubility and mechanical strength of the pouch at low temperatures can be further improved. Note that the above total content also includes cases where the plasticizer and / or polysaccharide B is 0% by mass.

[0048] <Water-Soluble Film> The pouch of the present invention comprises a water-soluble film. In the present invention, water-soluble means soluble in water, preferably meaning that the solubility in 90°C hot water is 90% by mass or more. That is, a water-soluble film can be evaluated as water-soluble if, after adding the film to 90°C hot water and stirring for 5 minutes to dissolve the film, the amount of solids that do not pass through a filter (21 μm) is 10% by mass or less. The mass of the water-soluble film to be dissolved in 90°C hot water is 0.1 parts by mass per 100 parts by mass of 90°C hot water. When the solubility of the water-soluble film in 90°C hot water is 90% by mass or more, preferably 95% by mass or more, and more preferably 98% by mass or more, residue is less likely to remain when a pouch containing the film is used. The upper limit of the solubility of the water-soluble film is 100% by mass. That is, the solubility of the water-soluble film is 90 to 100% by mass, preferably 95 to 100% by mass, and more preferably 98 to 100% by mass. The solubility of the water-soluble film can be adjusted to be equal to or higher than the above lower limit by, for example, appropriately adjusting the type and / or amount of components (for example, additives) contained in the water-soluble film.

[0049] In one embodiment of the present invention, the water-soluble film can be dissolved in water at 10°C preferably within 1000 seconds. That is, when a water-soluble film measuring 30 mm in length, 40 mm in width, and 50 μm in thickness is immersed in 500 mL of water at 10°C, the time required for complete dissolution is preferably within 1000 seconds, more preferably within 700 seconds, even more preferably within 600 seconds, and even more preferably within 500 seconds, and may be, for example, within 300 seconds or within 180 seconds. When the time for complete dissolution of the water-soluble film in water at 10°C is equal to or less than the upper limit, this is preferable because the contents are quickly released when a pouch containing the film is used, particularly when dissolved in cold water. Furthermore, residue is less likely to remain. The lower limit of the time for complete dissolution is not particularly limited, and the shorter the time required for complete dissolution, the better. The time for complete dissolution of the water-soluble film in water at 10°C can be adjusted to be equal to or less than the upper limit by, for example, appropriately adjusting the type and / or amount of components contained in the water-soluble film; the production conditions of the water-soluble film (e.g., drying conditions); etc. The time for complete dissolution in water at 10°C can be determined, for example, by the method described in the Examples below.

[0050] The thickness of the water-soluble film is preferably 1 to 500 μm, more preferably 5 to 300 μm, and even more preferably 10 to 100 μm. When the thickness of the water-soluble film is within the above range, the pouch can have good solubility at low temperatures and good mechanical strength. The thickness of the water-soluble film can be determined, for example, using a thickness meter, and can be determined by the method described in the examples below.

[0051] The maximum stress of the water-soluble film is preferably 5 MPa or more, more preferably 10 MPa or more, even more preferably 20 MPa or more, even more preferably 25 MPa or more, and particularly preferably 30 MPa or more, and may be, for example, 35 MPa, 40 MPa, 45 MPa, or 50 MPa or more. When the maximum stress of the water-soluble film is equal to or greater than the above-mentioned lower limit, the mechanical strength of a pouch containing the water-soluble film can be improved. The upper limit of the maximum stress of the water-soluble film is usually 150 MPa or less, preferably 140 MPa or less. That is, preferred ranges are 5 to 150 MPa, 10 to 150 MPa, 20 to 150 MPa, 25 to 150 MPa, 30 to 150 MPa, 35 to 150 MPa, 40 to 150 MPa, 45 to 150 MPa, or 50 to 140 MPa. The maximum stress of the water-soluble film can be adjusted to be equal to or greater than the lower limit by, for example, appropriately adjusting the type and / or amount of components contained in the water-soluble film; the manufacturing conditions of the water-soluble film (e.g., drying temperature and / or time); etc.

[0052] The breaking elongation of the water-soluble film is preferably 10% or more, more preferably 25% or more, even more preferably 35% or more, even more preferably 40% or more, particularly preferably 50% or more, especially more preferably 70% or more, especially more preferably 75% or more, and extremely preferably 80% or more or 85% or more. When the breaking elongation of the water-soluble film is at or above the lower limit, the mechanical strength of a pouch containing the water-soluble film can be improved. The upper limit of the breaking elongation of the water-soluble film is usually 150% or less, preferably 140% or less. That is, preferred ranges are 10 to 150%, 25 to 150%, 35 to 150%, 40 to 150%, 50 to 150%, 70 to 150%, 75 to 150%, 80 to 150%, or 85 to 140%. The breaking elongation of the water-soluble film can be adjusted to be equal to or higher than the above lower limit by, for example, appropriately adjusting the type and / or amount of components contained in the water-soluble film, the production conditions of the water-soluble film (e.g., drying temperature and / or time), etc. The maximum stress and breaking elongation of the water-soluble film can be determined by a tensile test, for example, by the method described in the Examples below.

[0053] The toughness of the water-soluble film is preferably 400 or more, more preferably 900 or more, even more preferably 1100 or more, even more preferably 1200 or more, particularly preferably 1300 or more, particularly more preferably 1400 or more, especially more preferably 1500 or more, and extremely preferably 1600 or more, for example, 1700 or more, 1800 or more, 1900 or more, or 2000 or more. When the toughness of the water-soluble film is above the lower limit, the mechanical strength of a pouch containing the water-soluble film can be improved. The upper limit of the toughness is usually 3000 or less. That is, preferred ranges are 400 to 3000, 900 to 3000, 1100 to 3000, 1200 to 3000, 1300 to 3000, 1400 to 3000, 1500 to 3000, 1600 to 3000, 1700 to 3000, 1800 to 3000, 1900 to 3000, or 2000 to 3000. The toughness of the water-soluble film can be determined by multiplying the maximum stress in a tensile test by the elongation at break.

[0054] In one embodiment of the present invention, the water-soluble film has excellent homogeneity without bleeding out of the plasticizer. The surface of the water-soluble film may be flat, or one or both sides of the water-soluble film may be textured, such as with an embossed or textured pattern, to prevent adhesion between products. Such textured processing can be performed using methods known in the art.

[0055] <Method for Producing Water-Soluble Film> The method for producing the water-soluble film used in the pouch of the present invention is not particularly limited, and the film can be produced by a method known in the art. For example, the water-soluble film can be produced by a method including: (1) a step of obtaining a coating liquid (coating agent) by stirring at a predetermined temperature at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof, a solvent, and optionally an additive; (2) a step of forming a coating film; and (3) a step of drying the coating film to form a dried coating film.

[0056] The solids concentration of the coating solution is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, where the solids concentration indicates the total mass of components other than the solvent (e.g., polysaccharide A, additives, etc.) relative to the mass of the coating solution.

[0057] The temperature at which polysaccharide A, and optionally additives and a solvent are stirred is usually 15 to 100° C., preferably 30 to 98° C. The stirring method is not particularly limited, and stirring can be carried out by a conventionally known method.

[0058] The solvent is not particularly limited, but water, ethanol, methanol, 1-propanol, 2-propanol, etc. are preferred because they easily dissolve polysaccharide A and facilitate subsequent drying.

[0059] The coating film can be formed, for example, by applying the coating liquid to a substrate, such as a polyolefin (e.g., polyethylene, polypropylene, etc.), a polyester (e.g., polyethylene terephthalate, etc.), a polyamide (e.g., nylon 6, nylon 66, etc.), a fluororesin (e.g., Teflon (registered trademark)), or a metal plate.

[0060] Examples of a method for applying the coating liquid to a substrate or the like include known methods such as spin coating, extrusion, bar coating, applicator, etc. Examples of coaters that can be used include blade coaters, bar coaters, roll coaters, gravure coaters, reverse gravure coaters, comma coaters, air knife coaters, reverse roll coaters, curtain coaters, spray coaters, size press coaters, and gate roll coaters.

[0061] The solvent is then removed by drying or the like to form a dried coating film. Drying methods include natural drying, ventilation drying, heat drying, and reduced pressure drying. Conventional dryers can be used, including steam heaters, gas heaters, infrared heaters, electric heaters, hot air heaters, microwaves, and cylinder dryers. The dried coating film is a water-soluble film.

[0062] Alternatively, the water-soluble film can be produced by a melt extrusion film-forming method in which a film-forming solution obtained using an extruder or the like is extruded through a T-die or the like to form a film, or by an inflation molding method.

[0063] After forming the water-soluble film on the substrate, the substrate can be removed to obtain the water-soluble film. Alternatively, the substrate may be used as is without being peeled off. When the substrate is not peeled off, a laminate including the substrate (support) and the water-soluble film can be obtained. When peeling off is required, it is preferable that a release agent is applied to the coating surface.

[0064] [Laminate] The present invention also encompasses a laminate comprising a support and a water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof. The support is preferably paper or film. In such an embodiment, the laminate of the present invention contains the specific polysaccharide A, and therefore has excellent solubility at low temperatures and mechanical strength.

[0065] In a laminate containing a water-soluble film and a support, examples of the support include paper or film (hereinafter also referred to as "support film").

[0066] When the support is paper, examples of the paper include kraft paper, one-side glossy kraft paper, one-side glossy bleached kraft paper, bleached kraft paper, unbleached kraft paper, fine paper, medium-quality paper, coated paper, one-side glossy paper, construction paper, glassine paper, graphene paper, parchment paper, synthetic paper, white cardboard, manila cardboard, milk carton base paper, cup base paper, ivory paper, silver paper, tissue paper, paperboard, rayon paper, wax paper, liner paper, etc. The basis weight of the paper is 20 to 400 g / m from the viewpoint of suitability for packaging applications. ２ It is preferable that the density is 25 to 150 g / m ２ From the viewpoint of suitability for use as a flexible packaging material, which will be described later, the basis weight of the paper is 30 to 100 g / m ２ More preferably, it is 40 to 70 g / m ２ The basis weight of the paper is measured in accordance with JIS P 8124:2011.

[0067] The above-mentioned paper can generally be produced by papermaking a stock containing pulp, fillers, and various auxiliaries. Examples of pulp include chemical pulps such as bleached hardwood kraft pulp (LBKP), bleached softwood kraft pulp (NBKP), unbleached hardwood kraft pulp (LUKP), unbleached softwood pulp (NUKP), and sulfite pulp; mechanical pulps such as stone-ground pulp and thermomechanical pulp; wood fibers such as deinked pulp and recycled paper pulp; and non-wood fibers obtained from kenaf, bamboo, hemp, etc. These can be used alone or in combination of two or more. Among these, chemical pulp from wood fibers and mechanical pulp are preferred, and chemical pulp is more preferred, from the viewpoints of reducing the possibility of foreign matter being mixed into the base paper and the possibility of discoloration over time when recycled after use, achieving good printing due to high brightness, and increasing the useful value (especially when used as a packaging material). Materials other than pulp can also be used as the secondary paper material as long as they do not impair the effects of the present invention. Examples of such materials include synthetic fibers such as rayon and nylon.

[0068] Examples of fillers include white carbon, talc, kaolin, clay, heavy calcium carbonate, light calcium carbonate, titanium oxide, zeolite, and synthetic resin fillers. These can be used alone or in combination of two or more. Examples of various auxiliaries include aluminum sulfate, various anionic, cationic, nonionic, or amphoteric retention aids, drainage aids, paper strength agents, and internal sizing agents, which can be used alone or in combination of two or more. Optionally, dyes, fluorescent whitening agents, pH adjusters, defoamers, pitch control agents, slime control agents, and additives consisting of two or more of these can also be used.

[0069] The method for producing paper is not particularly limited, and paper can be produced, for example, according to the following procedure. First, a stock is prepared by mixing a pulp slurry with a filler and various auxiliaries. The pulp slurry can be prepared by beating pulp in the presence of water. The pulp beating method and beating device are not particularly limited, and known beating methods and beating devices can be used. The pulp content in the stock is not particularly limited. For example, it is 60% by mass or more but less than 100% by mass relative to the total mass of the stock. Next, the prepared stock is made into paper by an acidic, neutral, or alkaline papermaking method using a known Fourdrinier former, on-top hybrid former, gap former, or the like. Multiple sheets of wet paper obtained after dewatering are stacked as necessary, and one or more sheets of wet paper are pressed and dried to obtain paper. In this case, if multiple wet paper sheets are not stacked, a single-layer paper is obtained, and if multiple wet paper sheets are stacked, a multi-layer paper is obtained. When multiple wet papers are stacked, adhesive may be applied to the surface of the wet paper (the surface on which other wet papers are stacked).

[0070] The paper surface may be treated with various chemicals. Examples of such chemicals include oxidized starch, hydroxyethyl etherified starch, enzyme-modified starch, polyacrylamide, polyvinyl alcohol, surface sizing agents, water-resistant agents, water-retention agents, thickeners, and lubricants. These may be used alone or in combination. Furthermore, these chemicals may be used in combination with pigments. Examples of pigments include inorganic pigments such as kaolin, clay, engineered kaolin, delaminated clay, ground calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicates, colloidal silica, and satin white, as well as organic pigments such as solid, hollow, and core-shell pigments. These may be used alone or in combination.

[0071] The method for treating the surface of paper is not particularly limited, and can be performed using a known coating device such as a rod metering size press, a pond type size press, a gate roll coater, a spray coater, a blade coater, or a curtain coater.

[0072] When the support is a film, examples of the film include films (polyolefin films such as polyethylene, polypropylene, and norbornene-based polymers; polyvinyl alcohol films; polyethylene terephthalate (PET) films; poly(meth)acrylic acid ester films; cellulose ester films such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polylactic acid films; ethylene-vinyl alcohol copolymer films, etc.), sheets, etc.

[0073] The average thickness of the paper or film used as the support is, for example, about 1 to 500 μm, or about 10 to 300 μm.

[0074] In the laminate, the water-soluble film may be a single layer or multiple layers. When the water-soluble film is a multiple layer, the layers may be the same or different from each other. The laminate may also include any layer. The laminate may have one or more layers selected from the group consisting of a barrier layer, a protective layer, and a heat-sealing layer at any location in the layer structure. When the laminate has a protective layer and / or a heat-sealing layer, it is preferable that the layer is disposed as the outermost layer of the laminate.

[0075] The barrier layer may be a gas barrier layer or a water vapor barrier layer, and such barrier layers are known in the art. Examples of barrier layers include resin layers and metal foils, and more specific examples include resin layers containing polyvinyl alcohol, ethylene-vinyl alcohol copolymers, and / or polyvinylidene chloride, layers containing polysaccharide A but not corresponding to the water-soluble film of the present invention, aluminum foils, aluminum vapor-deposited films (aluminum vapor-deposited on a substrate such as polyethylene, polypropylene, nylon, polyethylene terephthalate, or ethylene-vinyl alcohol copolymer), alumina vapor-deposited films (alumina vapor-deposited on a substrate such as polyethylene, polypropylene, nylon, polyethylene terephthalate, or ethylene-vinyl alcohol copolymer), and silica vapor-deposited films (silica vapor-deposited on a substrate such as polyethylene, polypropylene, nylon, polyethylene terephthalate, or ethylene-vinyl alcohol copolymer).

[0076] The protective layer is a layer that, by being present as at least a part of the outermost layer of the laminate, can reduce the influence of the surrounding environment on the components present below the protective layer (deterioration of the components). Therefore, the protective layer may have one or more functions selected from the group consisting of barrier properties, oil resistance, solvent resistance, heat resistance, abrasion resistance, impact resistance, weather resistance, and light resistance. By covering the entire outermost layer of the laminate with the protective layer, the above functions can be more effectively exhibited. Examples of the protective layer include a resin layer, a paper layer, and a metal foil.

[0077] The heat-sealing layer may be any layer known in the art. The heat-sealing layer is preferably a resin layer having heat-sealing properties. The heat-sealing layer preferably contains a water-dispersible resin and, optionally, additives. Examples of water-dispersible resins include polyolefin resins, styrene / acrylic copolymers, acrylic resins such as ethylene-(meth)acrylic acid copolymers, ethylene-vinyl acetate copolymers, polyester resins, rubber-based resins, urethane resins, polyamide resins, and combinations thereof. Examples of optional additives include lubricants such as paraffin wax, carnauba wax, and polyolefin waxes, pigments such as silica and kaolin, and combinations thereof. The heat-sealing layer may have barrier properties, in which case it can function as both a heat-sealing layer and a barrier layer. When the support is a film having barrier or protective properties, the film can also function as a barrier or protective layer.

[0078] Specific layer configurations of the laminate of the present invention, which includes a water-soluble film and a support and may have any layer (barrier layer, protective layer, heat seal layer), include, for example, the following configurations. Note that the following configurations are each described starting from the layer that will become the outermost layer (the layer on the opposite side to the layer that comes into contact with the contents) when used as, for example, a packaging material. Water-soluble film / paper or support film or metal foil, Gas barrier layer or water vapor barrier layer / water-soluble film / paper or support film or metal foil, Water vapor barrier layer / gas barrier layer / water-soluble film / paper or support film or metal foil, Gas barrier layer / water vapor barrier layer / water-soluble film / paper or support film or metal foil, Protective layer / water-soluble film / paper or support film or metal foil, Protective layer / gas barrier layer or water vapor barrier layer / water-soluble film / paper or support film or metal foil, Protective layer / water vapor barrier layer / gas barrier layer / water-soluble film / paper or support film or metal foil, Protective layer / gas barrier layer / water vapor barrier layer / water-soluble film / paper or support film or metal foil, Protective layer / water-soluble film / gas barrier layer or water vapor barrier layer / paper or support film or metal foil, Protective layer / water-soluble film / gas barrier layer / water vapor barrier layer / paper or support film or metal foil, Protective layer / water-soluble film / gas barrier layer / water vapor barrier layer / paper or support film or metal foil, Protective layer / gas barrier layer or water vapor barrier layer / water soluble film / paper or support film or metal foil / gas barrier layer or water vapor barrier layer, Protective layer / water vapor barrier layer / gas barrier layer / water soluble film / paper or support film or metal foil / gas barrier layer or water vapor barrier layer, Protective layer / gas barrier layer / water vapor barrier layer / water soluble film / paper or support film or metal foil / gas barrier layer or water vapor barrier layer, Protective layer / water vapor barrier layer / gas barrier layer / water soluble film / paper or support film or metal foil / gas barrier layer / water vapor barrier layer, Protective layer / water vapor barrier layer / gas barrier layer / water soluble film / paper or support film or metal foil / water vapor barrier layer / gas barrier layer, Protective layer / water vapor barrier layer / gas barrier layer / water soluble film / paper or support film or metal foil / water vapor barrier layer / gas barrier layer,protective layer / gas barrier layer / water vapor barrier layer / water-soluble film / paper or support film or metal foil / water vapor barrier layer / gas barrier layer; a layer configuration in which a heat seal layer is provided on the side opposite to the outermost layer in the above layer configuration; a layer configuration in which a heat seal layer is provided in place of a protective layer in the above layer configuration, for example, heat seal layer / water-soluble film / paper or support film or metal foil; a layer configuration in which an adhesive layer is provided in one or more locations between each layer in the above layer configuration, for example, heat seal layer / adhesive layer / water-soluble film / paper or support film or metal foil.

[0079] More specific examples of the layer structure include the following: Water-soluble film / paper, LLDPE / water-soluble film / paper, LLDPE / adhesive layer / water-soluble film / paper, LDPE / water-soluble film / paper, LDPE / adhesive layer / water-soluble film / paper, HDPE / water-soluble film / paper, HDPE / adhesive layer / water-soluble film / paper, CPE (non-oriented polyethylene) / water-soluble film / paper, CPE (non-oriented polyethylene) / adhesive layer / water-soluble film / paper, Polyethylene formed from polyethylene emulsion / water-soluble film / paper, Polyethylene formed from polyethylene emulsion / adhesive layer / water-soluble film / paper, Uniaxially oriented polyethylene / water-soluble film / paper, Uniaxially oriented polyethylene / adhesive layer / water-soluble film / paper, Biaxially oriented polyethylene / water-soluble film / paper, Biaxially oriented polyethylene / adhesive layer / water-soluble film / paper, Polypropylene / water-soluble film / paper, Polypropylene / adhesive layer / water-soluble film / paper, Uniaxially oriented polypropylene / water-soluble film / paper, Uniaxially oriented polypropylene / adhesive layer / water-soluble film / paper, Biaxially oriented polypropylene / water-soluble film / paper, Biaxially oriented polypropylene / adhesive layer / water-soluble film / paper, PLA / water-soluble film / paper, PLA / adhesive layer / water-soluble film / paper, PHA / water-soluble film / paper, PHA / adhesive layer / water-soluble film / paper, PHBH / water-soluble film / paper, PHBH / adhesive layer / water-soluble film / paper, PCL / water-soluble film / paper, PCL / adhesive layer / water-soluble film / paper, PBAT / water-soluble film / paper, PBAT / adhesive layer / water-soluble film / paper, PBS / water-soluble film / paper, PBS / adhesive layer / water-soluble film / paper.

[0080] <Method for Producing Laminate> The method for producing the laminate of the present invention is not particularly limited, and it can be produced by a method known in the art. The laminate of the present invention can be produced, for example, by a method including the same steps (1) to (3) as those described in the method for producing a water-soluble film above. The coating film in the laminate may be a single layer or multiple layers. By repeatedly coating a support with a coating liquid (coating agent) and removing the solvent, it is also possible to produce a multilayer laminate containing any layers in any stacking order.

[0081] The laminate of the present invention can also be produced by integrating a water-soluble film produced by, for example, a melt extrusion film-forming method, in which a film-forming solution (water-soluble film-forming material) obtained using an extruder or the like is extruded through a T-die or the like, or an inflation molding method, with a support. The integration method is not limited, and examples include a method of applying water to the surface of the water-soluble film and adhering the coated surface to the support, a method of integrating the water-soluble film and the support by thermocompression bonding, a method of integrating the water-soluble film and the support via a pressure-sensitive adhesive or adhesive, and an inflation method in which the water-soluble film-forming material and the support (film) material are co-extruded. When integrating by thermocompression bonding, the conditions may be appropriately selected depending on the type of polysaccharide contained in the water-soluble film and the type and amount of plasticizer, if any. For example, integration can be achieved by compression bonding at a temperature of 100 to 200°C and a pressure of 0.1 to 30 MPa for 0.1 to 10 seconds. When integrating via a pressure-sensitive adhesive or adhesive, such pressure-sensitive adhesives or adhesives are known in the art. The laminate of the present invention can also be produced as a multi-layer laminate by laminating a plurality of water-soluble films obtained by melt extrusion film formation, inflation molding or the like onto a support by a known method.

[0082] When the laminate contains a plurality of water-soluble films, it may contain a combination of a water-soluble film produced by coating and a water-soluble film produced by a melt extrusion film forming method, an inflation molding method, or the like.

[0083] <Pouch> Because the pouch of the present invention comprises the water-soluble film, it has excellent solubility and mechanical strength at low temperatures. Therefore, the pouch of the present invention dissolves in water at 10°C preferably within 2000 seconds, more preferably within 1500 seconds, even more preferably within 1000 seconds, even more preferably within 700 seconds, particularly preferably within 600 seconds, and especially preferably within 500 seconds. The lower limit of the dissolution time is not particularly limited, and the shorter the dissolution time, the more preferable it is. The solubility of the pouch in water at 10°C can be adjusted to above the lower limit by, for example, appropriately adjusting the type and / or amount of components (e.g., additives) contained in the water-soluble film constituting the pouch; the pouch manufacturing conditions (e.g., the amount of water applied, temperature, and pressure during water sealing, the temperature and pressure during heat sealing), etc. The solubility of the pouch in water at 10°C can be determined, for example, by the method described in the Examples below.

[0084] The film contained in the pouch may be a monolayer film or a multilayer film. When the pouch comprises (or is composed of) a monolayer film, the monolayer film is the water-soluble film. When the pouch comprises (or is composed of) a multilayer film, the multilayer film may be a laminate of a plurality of the water-soluble films, or may be a laminate of the water-soluble film and another water-soluble film other than the water-soluble film. From the viewpoint of improving the solubility and mechanical strength of the pouch at low temperatures, the pouch is preferably composed of a monolayer or multilayer water-soluble film, and further from the viewpoint of production efficiency, it is more preferable that the pouch be composed of a monolayer water-soluble film.

[0085] The pouch of the present invention has excellent mechanical strength, and its compressive strength is preferably 50 N or more, more preferably 100 N or more, even more preferably 200 N or more, even more preferably 300 N or more, and particularly preferably 400 N or more, and may be, for example, 500 N, 600 N, 700 N, or 800 N or more. The upper limit of the compressive strength of the pouch is usually 2000 N or less, preferably 1000 N or less. That is, preferred ranges are 50 to 2000 N, 100 to 2000 N, 200 to 2000 N, 300 to 2000 N, 400 to 2000 N, 500 to 2000 N, 600 to 2000 N, 700 to 2000 N, or 800 to 1000 N. The compressive strength of the pouch can be adjusted to be equal to or greater than the lower limit by, for example, appropriately adjusting the type and / or amount of components contained in the water-soluble film that constitutes the pouch; the production conditions of the water-soluble film (e.g., drying temperature and / or time); the production conditions of the pouch (e.g., the amount of water applied, temperature, and pressure during water sealing, and the temperature and pressure during heat sealing); etc.

[0086] The pouch is not particularly limited as long as it is capable of packaging a substance (preferably a content), and may be sealed or partially open. The pouch may be, for example, a two-sided pouch, a three-sided pouch, a flat pouch, a standing pouch, a gusset pouch, a bottom gusset pouch, a twin pouch, a spout pouch, a side-seal pouch, a bottom-seal pouch, or the like, or may be in the form of a container, a cup, or the like. In one embodiment of the present invention, the pouch may be partially open, but is preferably sealed. In such an embodiment, the pouch more preferably contains a content and is sealed.

[0087] [Method for manufacturing a pouch] The method for manufacturing the pouch of the present invention from a water-soluble film is not particularly limited, and can be any method known in the art. The pouch of the present invention can be manufactured, for example, by a method including a step of sealing one or more sheets of water-soluble film to form a bag. Furthermore, a pouch containing a content can be manufactured, for example, by a method including a step of pouring the content into a film formed into a bag shape and a step of sealing the opening; a step of forming a recess in a first film, pouring the content into the recess, and laminating a second film and sealing it, etc.

[0088] Methods for sealing a water-soluble film include a method of applying water to the film surface and sealing the coated surface (also called water sealing), a method of sealing by thermocompression (also called heat sealing), a method of sealing with an adhesive, etc. Water sealing is preferred from the viewpoint of reducing thermal degradation of the film.

[0089] In one embodiment of the present invention, the water-soluble film has high adhesive strength due to moisture, and therefore can be suitably used for water sealing. In another embodiment of the present invention, the water-soluble film has high water-sealing properties and low heat-sealing properties. The low heat-sealing properties make it difficult for the film to adhere to the roll when the film is produced by a roll-to-roll method, effectively preventing damage during production. Furthermore, the high water-sealing properties allow the produced water-soluble film to be simply and easily formed into a pouch using moisture.

[0090] [Uses of the Pouch] The pouch of the present invention has excellent solubility and mechanical strength at low temperatures, and is therefore particularly suitable for use in applications where it is dissolved in cold water. Therefore, the pouch of the present invention preferably contains at least one selected from the group consisting of a cleaning agent, a fabric softener, and a fragrance. The physical properties of the contents are not particularly limited, and the contents may be acidic, neutral, or alkaline. Furthermore, the form of the contents may be any of powder, block, gel, and liquid.

[0091] [Water-soluble Film] The present invention also encompasses a water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof. Because the water-soluble film of the present invention in this embodiment contains a specific polysaccharide A, it has excellent solubility at low temperatures and mechanical strength, and can also be used to form a pouch having these properties. The water-soluble film is similar to the water-soluble film described above in the section [Pouch].

[0092] The present invention also encompasses a water-soluble film comprising at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof, and a polysaccharide B different from the polysaccharide A. The water-soluble film of the present invention in this embodiment contains specific polysaccharides A and B, and therefore has excellent solubility at low temperatures and mechanical strength, and can also be used to form a pouch having such properties. The water-soluble film is preferably similar to the water-soluble film described above in the section [Pouch], except that it contains the polysaccharide B as an essential component in addition to the polysaccharide A.

[0093] The present invention also encompasses a water-soluble film for use in a pouch, the water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof, and a plasticizer, the plasticizer content being 45% by mass or less relative to the mass of the water-soluble film. In this embodiment, the water-soluble film of the present invention contains at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof, and therefore has excellent solubility at low temperatures and mechanical strength, making it possible to form a pouch with these properties. Furthermore, the water-soluble film is less susceptible to bleeding of the plasticizer onto the film surface. The water-soluble film is preferably similar to the water-soluble film described above in the "Pouch" section, except for the essential requirement that the water-soluble film contains at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof, and a plasticizer, and that the plasticizer content is 45% by mass or less.

[0094] To prevent the plasticizer from bleeding out onto the film surface, the content of the plasticizer is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, relative to the mass of the water-soluble film. The lower limit of the plasticizer content is usually 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. Therefore, the preferred range is 1 to 40% by mass, 3 to 35% by mass, or 5 to 30% by mass.

[0095] [Packaging Material] The present invention also encompasses a packaging material comprising a water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof. The packaging material of the present invention in this embodiment contains a specific polysaccharide A, and therefore has excellent solubility and mechanical strength at low temperatures. The water-soluble film constituting the packaging material is preferably similar to the water-soluble film described in the above section [Pouch], and preferably has similar solubility and mechanical strength. Furthermore, the packaging material preferably has similar solubility and mechanical strength to the pouch described in the above section [Pouch].

[0096] The packaging material is a film used for packaging, and may include a thin film, a thick film, etc., and may be in the form of a container, a cup, a tube, a tray, a bottle, etc. In one embodiment of the present invention, the packaging material may contain a substance therein, similar to the above-mentioned pouch, preferably at least one selected from the group consisting of a cleaning agent, a fabric softener, and a fragrance.

[0097] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0098] Approximately 20 μg of each polysaccharide used in the Examples and Comparative Examples was subjected to gel filtration HPLC under the following conditions to measure the weight-average molecular weight (Mw) and number-average molecular weight (Mn). The measurement solvent was selected from water or dimethyl sulfoxide (DMSO) in consideration of the solubility of each polysaccharide.

[0099] (Gel filtration HPLC conditions) Eluent: 0.1 M aqueous sodium nitrate Column: One TSK GEL α-M column used Column temperature: 40°C Flow rate: 1 mL / min Sample concentration: 0.1 w / v% Sample preparation: The sample was dissolved by stirring at 80°C for 2.5 hours, and then stirred at 90°C for an additional 30 minutes. Filtration filter: 0.45 μm PP filter (Whatman) Injection volume: 100 μL Standard: PEO / PEG Measurement time: 18 minutes Solution delivery section: GPC-101 (Shodex) Detector: RI or

[0100] Eluent: 5 mM Na nitrate / DMSO Column: One TSK GEL α-M column used Column temperature: 60°C Flow rate: 0.8 mL / min Sample concentration: 0.2 w / v% Sample preparation: The sample was dissolved by stirring at 60°C for 1 hour, followed by further stirring at 65°C for 2.5 hours. Filtration: 0.45 μm PP filter (Whatman) Injection volume: 100 μL Standard: PMMA-R, Y, G Measurement time: 18 minutes Solution delivery section: GPC-101 (Shodex) Detector: RI

[0101] Preparation of Water-Soluble Film Example 1 6 g of tamarind seed gum (weight average molecular weight 3,700 kDa, number average molecular weight 429 kDa; "Glyloid 6C (registered trademark)" MP Gokyo Food & Chemical Co., Ltd.) was added to water and heated and stirred at 95°C for 2 hours to obtain a 4% aqueous solution. 4 g of glycerin was added to this to prepare a coating liquid. The coating liquid was applied to a polyethylene terephthalate film using a bar coater and dried with hot air at 60°C for 1 hour. The resulting dried coating film was peeled off from the polyethylene terephthalate film substrate to obtain a film with a thickness of approximately 50 μm.

[0102] Examples 2 to 6 Films were obtained in the same manner as in Example 1, except that the amounts of tamarind seed gum and glycerin were changed to those shown in Table 1.

[0103] Example 7 A film was obtained in the same manner as in Example 1, except that sorbitol was added in addition to glycerin when adding glycerin, and each component was added in the amount shown in Table 1.

[0104] Examples 8 to 10 Films were obtained in the same manner as in Example 1, except that tannic acid was added in addition to glycerin when adding glycerin, and each component was added in the amount shown in Table 1.

[0105] Examples 11 to 14 Films were obtained in the same manner as in Example 1, except that ethylene glycol was added instead of glycerin and each component was added in the amount shown in Table 1.

[0106] Examples 15 to 17 Films were obtained in the same manner as in Example 1, except that fructose was added instead of glycerin and each component was added in the amount shown in Table 1.

[0107] Example 18 A film was obtained in the same manner as in Example 1, except that xanthan gum (weight average molecular weight 92 kDa, number average molecular weight 16 kDa; "Kimika Xanthan PH-R3EC" (manufactured by Kimika Co., Ltd.) was added in addition to glycerin when adding glycerin, and each component was added in the amount shown in Table 1.

[0108] Example 19 A film was obtained in the same manner as in Example 1, except that guar gum (weight average molecular weight 93 kDa, number average molecular weight 17 kDa; "SUPERGEL CSA200 / 50" manufactured by Sansho Co., Ltd.) was added in addition to glycerin when adding glycerin, and each component was added in the amount shown in Table 1.

[0109] Example 20 A film was obtained in the same manner as in Example 1, except that locust bean gum (weight average molecular weight 96 kDa, number average molecular weight 26 kDa; "GENU (registered trademark) GUM type RL-200Z" manufactured by Sansho Co., Ltd.) was added in addition to glycerin when adding glycerin, and each component was added in the blending amount shown in Table 1.

[0110] Example 21 A film was obtained in the same manner as in Example 1, except that xanthan gum and guar gum were added in addition to glycerin when adding glycerin, and the components were added in the amounts shown in Table 1.

[0111] Example 22 A film was obtained in the same manner as in Example 1, except that when glycerin was added, xanthan gum and locust bean gum were added in addition to glycerin in amounts shown in Table 1.

[0112] Example 23 A film was obtained in the same manner as in Example 17, except that locust bean gum was used instead of tamarind seed gum and glycerin was used instead of fructose.

[0113] Comparative Example 1 A film was obtained in the same manner as in Example 3, except that κ-carrageenan (weight average molecular weight 826 kDa, number average molecular weight 48 kDa; "GENUGEL carrageenan type JPE-126" manufactured by Sansho Co., Ltd.) was used instead of tamarind seed gum.

[0114] Comparative Examples 2 to 4 Films were obtained in the same manner as in Comparative Example 1, except that glycerin was added in the amount shown in Table 1.

[0115] Comparative Examples 5 and 6 Films were obtained in the same manner as in Comparative Example 1, except that sorbitol was used instead of glycerin and each component was added in the amount shown in Table 1.

[0116] <Comparative Examples 7 and 8> Films were obtained in the same manner as in Comparative Examples 5 and 6, except that sodium alginate (weight average molecular weight 104 kDa, number average molecular weight 43 kDa; "Kimica Algin I-8" manufactured by Kimica Co., Ltd.) was used instead of κ-carrageenan.

[0117] <Comparative Examples 9 and 10> Films were obtained in the same manner as in Comparative Examples 5 and 6, except that guar gum (weight average molecular weight 93 kDa, number average molecular weight 17 kDa; "SUPERGEL CSA200 / 50" manufactured by Sansho Co., Ltd.) was used instead of κ-carrageenan.

[0118] Comparative Example 11 A film was obtained in the same manner as in Comparative Example 5, except that gum arabic (weight average molecular weight 237 kDa, number average molecular weight 45 kDa; "TIC Pretested Gum Arabic Spray Dry Powder" manufactured by Ingredion) was used instead of κ-carrageenan.

[0119] Comparative Example 12 A film was obtained in the same manner as in Comparative Example 5, except that gum arabic (weight average molecular weight 192 kDa, number average molecular weight 71 kDa; "TIC Pretested Gum Arabic FT" manufactured by Ingredion) was used instead of κ-carrageenan.

[0120] Comparative Examples 13 and 14 Films were obtained in the same manner as in Comparative Examples 5 and 6, except that cation-modified starch ("CATO304", manufactured by Ingredion) was used instead of κ-carrageenan.

[0121] Comparative Example 15 A film was obtained in the same manner as in Example 1, except that nonionic modified starch ("National 208", Ingredion) was used instead of tamarind seed gum, and glycerin was added in the amounts shown in Table 1.

[0122] Comparative Examples 16 to 19 Films were obtained in the same manner as in Comparative Example 15, except that nonionic modified starch ("National 208", Ingredion) and glycerin were added in the amounts shown in Table 1.

[0123] Comparative Example 20 A film was obtained in the same manner as in Comparative Example 15, except that sorbitol was used instead of glycerin.

[0124] Comparative Example 21 A film was obtained in the same manner as in Comparative Example 17, except that sorbitol was used instead of glycerin.

[0125] Comparative Example 22 A film was obtained in the same manner as in Comparative Examples 9 and 10, except that glycerin was used instead of sorbitol.

[0126] Comparative Examples 23 and 24 Films were obtained in the same manner as in Example 1, except that xanthan gum (weight average molecular weight 92 kDa, number average molecular weight 16 kDa; "Kimika Xanthan PH-R3EC" manufactured by Kimika Co., Ltd.) was used instead of tamarind seed gum.

[0127]

[0128]

[0129] Evaluation of Water-Soluble Films <Film Thickness of Water-Soluble Films> The film thickness was measured using a micrometer. The thickness was measured at five or more random points on the film, and the average value was taken as the film thickness.

[0130] <Water Solubility of Films> The films prepared in the Examples were added to 90°C hot water and stirred for 5 minutes to dissolve. The amount of solids that did not pass through a filter (21 μm) was measured, and found to be 10% by mass or less in all Examples 1 to 23. The mass of the film added was 0.1 parts by mass per 100 parts by mass of 90°C hot water. <Time to Complete Dissolution in Cold Water> The films prepared in the Examples and Comparative Examples were cut into 30 mm x 40 mm rectangles and sandwiched between slide mounts. A 600 ml glass beaker containing 500 ml of distilled water was placed in a separate thermostatic bath adjusted to 10°C, and stirring was performed at 400 rpm using a 5 cm rotor. After the distilled water in the beaker reached 10°C, the slide mount was immersed in the stirred water. The dissolution state of the film was visually observed, and the time (seconds) until the film was completely dissolved was measured and evaluated according to the following evaluation criteria. When a film having a thickness other than 50 μm was used, the time was converted to a value for a film having a thickness of 50 μm according to the following formula: Converted complete dissolution time (seconds) = [50 / film thickness (μm)] ２ x Sample complete dissolution time (seconds) When the converted complete dissolution time was within 600 seconds, it was marked as A, and when it was over 600 seconds, it was marked as B.

[0131] <Film Toughness> The films prepared in the Examples and Comparative Examples were stored for 7 days in an environment of 23°C and 50% RH, and then five test pieces measuring 10 mm in width and 120 mm in length were cut out. For each prepared test piece, the maximum stress and breaking elongation were measured using an autograph (apparatus name: AG-5000B, Shimadzu Corporation) at a chuck distance of 70 mm and a tensile speed of 500 mm / min, and the average value was calculated. The value of the maximum stress x the breaking elongation was taken as the toughness of the film.

[0132] The evaluation results are shown in Table 2.

[0133]

[0134] Pouch Fabrication Example 24 A benchtop pouch molding machine (DD-SR12-1, manufactured by Dada) was used to form the pouch. The film obtained in Example 1 was cut into two pieces measuring 15 x 15 cm, which were used as the bottom film and the top film, respectively. The bottom film was placed in a pouch mold with a base of 40 x 45 mm and a depth of 18 mm, and heated at 100°C for 4 seconds. A vacuum was then created between the bottle film and the pouch mold to form the bottom of the pouch. Water was then brushed onto the four edges of the bottom film, and the top film was placed on top of it, overlapping the four edges of each film. The overlapping portion of the bottom film and top film was heated and compressed at 100°C for 10 seconds to bond the top film to the bottom film. Air was then injected between the pouch mold and the bottom film, and the formed pouch was removed from the mold. The surrounding film was then cut and removed, leaving a 1.5 cm adhesive area. Examples 25 to 27 Pouches were obtained in the same manner as in Example 24, except that the films obtained in Examples 5, 14, and 23 were used. Comparative Examples 25 to 32 Pouches were obtained in the same manner as in Example 24, except that the films obtained in Comparative Examples 1, 11, 12, and 14 to 18 were used.

[0135] Evaluation of Pouch <Condition of Bottom Film in Pouch> The condition of the bottom film during bottom molding was visually evaluated. If the film strength is insufficient, the film will be damaged during bottom film molding. When there was no damage to the film, it was marked as A, and when there was damage to the film, it was marked as B.

[0136] <Air Leakage from Pouch> The obtained pouch was left for 24 hours in an environment of 23°C and 50% RH, and air leakage from the pouch was evaluated. Cases where there was no air leakage were marked A, and cases where there was air leakage were marked B.

[0137] <Water Solubility of Pouch> A water solubility test was conducted using the obtained pouch. The obtained pouch was placed in a wire frame cage (10 cm x 9 cm x 6.4 cm, wire gauge 1.25 mm, opening 1.27 cm). 1200 ml of distilled water was placed in a 2-liter beaker and stirred at 400 rpm using a 5 cm rotor. After the distilled water in the beaker reached 10°C, the wire frame cage and pouch were placed in the beaker so that the cage was 1 inch (2.54 cm) from the bottom. The state of dissolution of the film was visually observed to confirm whether the film was completely dissolved. Cases with no residue were marked A, and cases with residue were marked B.

[0138] The evaluation results are shown in Table 3.

[0139] Preparation of Laminate Example 28 7 g of tamarind seed gum (Greate (registered trademark)) and 3 g of glycerin were added to pure water to a total concentration of 15% by mass, and the mixture was heated and stirred at 90°C for 1 hour to dissolve, yielding a coating liquid (coating agent). The resulting coating liquid was cooled to 25°C and applied to a paper support (Solide Lucent 78 gsm) using a bar coater, so that the coating liquid thickness after application (hereinafter sometimes simply referred to as "coating liquid thickness") was 133 μm. The wet coating film on the support was dried in a hot air dryer at 80°C for 30 minutes to obtain a laminate comprising the support and the coating film.

[0140] Examples 29 to 42 and Comparative Examples 33 to 36 Laminates containing a support and a coating film were obtained in the same manner as in Example 28, except that the materials and manufacturing conditions were changed as shown in Table 4 below. When coating was performed twice, the dried coating film on the support obtained by the first coating and drying was coated in the same manner as the first coating, and the resulting wet coating film was then dried for 30 minutes in a hot air dryer at 80°C.

[0141] <Coating Film Thickness> The coating film thickness was calculated using the following formulas: Coating film thickness [μm] = Concentration of coating liquid [mass %] × Thickness of coating liquid [μm] / 100 Concentration of coating liquid [mass %] = {(Mass of coating liquid [g] - Mass of water contained in coating liquid [g]) / Mass of coating liquid [g]} × 100 The total thickness of the coating film when coating was performed twice was calculated by substituting "thickness of coating liquid" in the above formulas with "total thickness of coating liquid."

[0142] <Flexibility> The laminate was folded with the coated side facing inward. A 2 kg rubber roller was rolled back and forth once from one end of the folded area (crease) to the other to create a crease. Toluene colored with food coloring was applied to a 10 cm area of ​​the crease on the coated side, and then the back side (uncoated side) was checked for bleed-through (small red spots or full coloring of the coated surface). If no bleed-through was found, the same procedure was repeated to check for bleed-through. The maximum number of folds without bleed-through was defined as flexibility [times], with a maximum value of 5. The higher this value, the better the mechanical strength of the coating layer and the less likely it is to crack when bent.

[0143] <Oxygen Transmission Rate (OTR)> The oxygen transmission rate (cc / m) of the laminate was measured using an oxygen transmission rate measuring device (OXYSENSE MODEL 8101e manufactured by Systech Illinois) under the following conditions: ２ The oxygen pressure was measured at 1.0 atm. The oxygen pressure was 1.0 atm. The oxygen supply humidity was 50% RH at 23°C, the carrier gas humidity was 50% RH at 23°C, the carrier gas flow rate was 10 mL / min, and the carrier gas pressure was 1.0 atm.

[0144] The evaluation results are shown in Table 4.

[0145]

Claims

1. A pouch comprising a water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum and derivatives thereof.

2. The pouch according to claim 1, wherein said polysaccharide A is selected from tamarind seed gum and its derivatives.

3. The pouch according to claim 1, wherein the content of said polysaccharide A is 5 to 80% by mass relative to the mass of said water-soluble film.

4. The pouch of claim 1, wherein the water-soluble film further comprises a plasticizer.

5. The pouch of claim 4, wherein the plasticizer is at least one selected from the group consisting of polyhydric alcohols, hydroxy acids, monosaccharides, and disaccharides.

6. The pouch of claim 5, wherein the plasticizer is at least one selected from the group consisting of glycerin, diglycerin, sorbitol, alkylene glycol, polyalkylene glycol, trimethylolpropane, erythritol, 2-methyl-1,3-propanediol, lactic acid, glucose, fructose, maltose, and trehalose.

7. The pouch of claim 6, wherein the plasticizer is at least one selected from the group consisting of glycerin, ethylene glycol, sorbitol, and fructose.

8. The pouch according to claim 4, wherein the content of the plasticizer is 20 to 95% by weight based on the weight of the water-soluble film.

9. The pouch of claim 1, wherein said water-soluble film further comprises a polysaccharide B different from said polysaccharide A.

10. The pouch according to claim 9, wherein said polysaccharide B is at least one selected from the group consisting of guar gum, locust bean gum, xanthan gum, carrageenan, alginic acid, pullulan and derivatives thereof.

11. The pouch according to claim 9, wherein the content of said polysaccharide B is 1 to 30% by mass relative to the mass of said water-soluble film.

12. The pouch of claim 1, wherein the water-soluble film has a toughness of 400 or more.

13. The pouch of claim 1, which dissolves in water at 10°C within 1000 seconds.

14. The pouch of claim 1, containing therein at least one selected from the group consisting of cleaning agents, fabric softeners, and fragrances.

15. A water-soluble film containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum and derivatives thereof.

16. A water-soluble film comprising at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum and derivatives thereof, and a polysaccharide B different from said polysaccharide A.

17. A water-soluble film for use in a pouch, comprising at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum and derivatives thereof, and a plasticizer, the plasticizer content being 45% by mass or less relative to the mass of the water-soluble film.

18. The water-soluble film according to any one of claims 15 to 17, which is a coating film formed from a coating agent containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum, and derivatives thereof.

19. A laminate comprising the water-soluble film according to any one of claims 15 to 17 and a support, wherein the support is paper or film.

20. A packaging material comprising the water-soluble film of claim 15.

21. A coating agent containing at least one polysaccharide A selected from the group consisting of tamarind seed gum, locust bean gum, tara gum and derivatives thereof.

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