Water-soluble unit dose articles

Abstract

To reduce stickiness in water-soluble unit-dose products. [Solution] In the water-soluble unit dose article, granular material is held in a water-soluble resin substrate. The water-soluble unit dose article contains water-insoluble inorganic powder A held on the surface of the water-soluble resin substrate. The ratio of the mass of the water-insoluble inorganic powder A held on the surface of the water-soluble resin substrate to the surface area of ​​the water-soluble resin substrate is 1.0 × 10⁻⁶. -4 g / cm 2 The above 8.5 × 10 -4 g / cm 2 The following applies:

Description

[Technical Field]

[0001] This invention relates to a water-soluble unit-dose article. [Background technology]

[0002] A technology is known for constructing laundry detergent as a water-soluble unit-dose product (see, for example, Patent Document 1). With such a water-soluble unit-dose product, consumers can simply put a fixed amount of laundry detergent into the washing machine without having to measure it themselves, thus providing high convenience in daily laundry.

[0003] In the water-soluble unit-dose article described in Patent Document 1, particles of cleaning components such as surfactants are held by a water-soluble fiber structure formed of a water-soluble resin such as polyvinyl alcohol (PVA). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2020-505484 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, in water-soluble unit-dose articles using water-soluble fiber structures, stickiness is likely to occur in the water-soluble fiber structure due to moisture absorption during storage. As a result, such water-soluble unit-dose articles are more likely to have a poor texture when put into a washing machine and water-soluble components may stick to the user's hands.

[0006] This invention relates to a technology for reducing stickiness in water-soluble unit-dose articles. [Means for solving the problem]

[0007] In a water-soluble unit-dose article according to one embodiment of the present invention, granular material is held within a water-soluble resin substrate. The water-soluble unit dose article contains water-insoluble inorganic powder A held on the surface of the water-soluble resin substrate. The ratio of the mass of the water-insoluble inorganic powder A held on the surface of the water-soluble resin substrate to the surface area of ​​the water-soluble resin substrate is 1.0 × 10 -4 g / cm 2 The above 8.5 × 10 -4 g / cm 2 The following applies: [Effects of the Invention]

[0008] According to the present invention, it is possible to make water-soluble unit-dose articles less likely to become sticky. [Brief explanation of the drawing]

[0009] [Figure 1] This figure schematically shows an example of the structure of a water-soluble unit-dose article according to one embodiment of the present invention. [Figure 2] This figure schematically shows other examples of the above-mentioned water-soluble unit-dose articles. [Figure 3] This graph shows the results of the storage tests in the examples and comparative examples. [Modes for carrying out the invention]

[0010] The embodiments of the present invention will be described below. The present invention is not limited to the embodiments shown below, and various modifications can be made without departing from the spirit of the invention.

[0011] [Overall composition of water-soluble unit dose article W] A water-soluble unit-dose article W according to one embodiment of the present invention may be a unit-dose article of a laundry detergent used for washing clothes and the like. The water-soluble unit-dose article W comprises a water-soluble resin substrate X and granular material Y. In the water-soluble unit-dose article W, the granular material Y is held by the water-soluble resin substrate X. The water-soluble unit-dose article W also contains water-insoluble inorganic powder A. Furthermore, it is preferable that the water-soluble unit-dose article W further contains one or more selected from surfactant B and water-soluble inorganic salt C. The specific composition of the water-soluble unit-dose article W will be described below.

[0012] [Water-soluble resin base X and granular material Y] The water-soluble resin substrate X is mainly composed of a water-soluble resin and, from the viewpoint of ease of manufacture, is preferably configured as a sheet extending in an in-plane direction perpendicular to the thickness direction. In the water-soluble resin substrate X, the content of the water-soluble resin is preferably 10% by mass or more from the viewpoint of shapeability. The water-soluble resin is defined as the resin in which no insoluble matter is visible after adding 1 g of the resin to a 1 liter glass beaker containing 500 g of ion-exchanged water at 30°C, placing an 8 cm diameter Teflon® stirring bar inside, and stirring at 100 rpm for 30 minutes.

[0013] Examples of water-soluble resins usable for the water-soluble resin substrate X include polyvinyl alcohol (PVA), vinyl alcohol copolymers, polyvinylpyrrolidone, polyalkylene oxides, (modified) cellulose, (modified) cellulose ethers or esters or amides, polycarboxylic acids and their salts such as polyacrylate, maleic acid / acrylic acid copolymers, polyamino acids i.e., peptides, polyamides such as polyacrylamide, polysaccharides such as starch and gelatin, and natural rubbers such as xanthan gum and carragum. Vinyl alcohol copolymers include copolymers of vinyl alcohol with other monomers, such as ethylene and acrylic acid. For example, from the viewpoint of use as a water-soluble film forming a unit dose, the water-soluble resin is preferably selected from the group consisting of polyacrylate and water-soluble acrylate, methylcellulose, sodium carboxymethylcellulose, dextrin, ethylcellulose, hydroxyethylcellulose, maltodextrin, polymethacrylate, polyvinyl alcohol, vinyl alcohol copolymer, hydroxypropyl methylcellulose (HPMC), and combinations thereof. From a similar viewpoint, the water-soluble resin is more preferably selected from polyvinyl alcohol, vinyl alcohol copolymer, and hydroxypropyl methylcellulose. From a similar viewpoint, even more preferably, the water-soluble resin is polyvinyl alcohol, for example, Solbron, available from Aicello Corporation. Water-soluble resins that can be used for the water-soluble resin substrate X are, for example, described in U.S. Patent No. 6,995,126. From the viewpoint of effectively obtaining the effects of the present invention, it is preferable that the water-soluble resin substrate X contains polyvinyl alcohol.

[0014] Figure 1 is a schematic diagram showing an example of the structure of a water-soluble unit-dose article W. In the water-soluble unit-dose article W shown in Figure 1, the water-soluble resin substrate X is a water-soluble fiber structure composed of an aggregate of multiple water-soluble fibers. In the water-soluble unit-dose article W shown in Figure 1, the granular material Y is held between the water-soluble fibers that make up the water-soluble resin substrate X. As a result, in the water-soluble unit-dose article W, the water-soluble resin substrate X and the granular material Y are maintained as an integrated unit.

[0015] The water-soluble fiber structure used as the water-soluble resin substrate X can be composed of one or more water-soluble fabric materials selected from, for example, nonwoven and woven water-soluble fibers. The water-soluble resin substrate X may be configured as a laminate of multiple water-soluble fabric materials or as a folded water-soluble fabric material. Furthermore, in the water-soluble unit-dose article W, the granular material Y does not necessarily have to be held between the water-soluble fibers of the water-soluble resin substrate X; for example, some or all of the granular material Y may be held by adhering to the surface of the water-soluble resin substrate X. Also, as shown in Figure 2, in the water-soluble unit-dose article W, the granular material Y may be held by being contained in a bag-shaped water-soluble resin substrate X. In the water-soluble unit-dose article W shown in Figure 2, the water-soluble resin substrate X is configured as a flat bag, and the granular material Y is contained within the water-soluble resin substrate X. Note that Figure 2 shows the granular material Y inside the water-soluble resin substrate X by viewing it through the water-soluble resin substrate X.

[0016] In the water-soluble unit-dose article W, the water-soluble resin substrate X only needs to be composed mainly of a water-soluble resin and capable of holding granular material Y, and does not have to be a water-soluble fiber structure. For example, the water-soluble resin substrate X may be composed of one or more water-soluble films. In this case, the water-soluble unit-dose article W can be configured such that the granular material Y is attached to and held on the surface of the water-soluble resin substrate X, or that the granular material Y is contained and held in a bag-shaped water-soluble resin substrate X. Furthermore, the water-soluble resin substrate X can be a combination of a water-soluble fiber structure and a water-soluble film. In addition, the shape of the water-soluble resin substrate X is not limited to a sheet shape, but may be any three-dimensional shape.

[0017] A water-soluble film bag-shaped water-soluble resin substrate X can be manufactured by any suitable process known in the art, such as a known detergent pouch manufacturing process. Examples of pouch manufacturing processes are described in U.S. Patents 6,995,126, 7,127,874, 8,156,713, 7,386,971, 7,439,215, and U.S. Patent Application Publication 2009 / 199877.

[0018] In the water-soluble unit-dose article W, the granular material Y is composed of components other than those contained in the water-soluble resin base X. Each granular material Y may be composed of a single component, or it may be composed of a mixture or aggregation of multiple components. In the water-soluble unit-dose article W, the amount of granular material Y is preferably 5 g or more, more preferably 8 g or more, and even more preferably 10 g or more, from the viewpoint of obtaining the effect of the granular material Y more effectively (for example, from the viewpoint of improving washability if the granular material Y has washability), and preferably 48 g or less, more preferably 38 g or less, and even more preferably 28 g or less, from the viewpoint of economy and lightness. In addition, in the water-soluble unit-dose article W, the average particle diameter of the granular material Y is preferably 100 μm or more, more preferably 150 μm or more, even more preferably 200 μm or more, and from the viewpoint of improving solubility, preferably 800 μm or less, more preferably 750 μm or less, and even more preferably 700 μm or less. The average particle size of granular material Y is determined from the mass fraction based on the sieve mesh size after vibrating it for 5 minutes using a standard sieve specified in JIS Z 8801.

[0019] The preferred shape and size of each water-soluble unit-dose article W is not particularly limited, but for example, from the viewpoint of efficient packaging and ease of use, it is a quadrilateral shape, with the length of one side preferably being 1 cm to 10 cm, more preferably 2 cm to 9 cm, and even more preferably 3 cm to 8 cm. From the viewpoint of robustness and ease of handling, the thickness is preferably 0.2 cm to 4 cm, more preferably 0.4 cm to 3 cm, and even more preferably 0.6 cm to 2 cm. The mass of each water-soluble unit-dose article W is preferably 5 g or more, more preferably 8 g or more, even more preferably 10 g or more, and preferably 50 g or less, more preferably 40 g or less, and even more preferably 30 g or less.

[0020] (Water-insoluble inorganic powder A) The water-soluble resin that constitutes the water-soluble resin substrate X is likely to cause stickiness on the water-soluble resin substrate X by absorbing moisture. In contrast, in the water-soluble single-dose article W, in order to make it difficult for the water-soluble resin that constitutes the water-soluble resin substrate X to cause stickiness even when it absorbs moisture, a water-insoluble inorganic powder A is blended. The water-insoluble inorganic powder refers to an inorganic powder that does not dissolve 1 g or more in 100 g of water at 20°C. The water-insoluble inorganic powder A constitutes the granular body Y, is retained on the surface of the water-soluble resin substrate X that is easily touched by the user's hand, and imparts a smooth touch to the water-soluble resin substrate X, thereby reducing the stickiness of the water-soluble resin substrate X.

[0021] In the water-soluble single-dose article W, when a water-soluble fiber structure is used as the water-soluble resin substrate X and the surface of the water-soluble resin substrate X is not configured as a continuous surface, the surface layer region (including, for example, the region visually recognized between the water-soluble fibers in the water-soluble fiber structure) visually recognized from the appearance in the water-soluble resin substrate X is regarded as the surface. Also, when the surface of the water-soluble resin substrate X is not configured as a continuous surface, the surface area of the water-soluble resin substrate X is determined after regarding the surface as a continuous surface from the visually recognized external shape as a whole.

[0022] In the water-soluble single-dose article W, from the viewpoint of effectively reducing stickiness, it is preferable that the amount of the water-insoluble inorganic powder A is larger. On the other hand, in the water-soluble single-dose article W, in order to prevent an excessive amount of the water-insoluble inorganic powder A from adhering to the user's hand, it is preferable that the amount of the water-insoluble inorganic powder A is not too large. For this reason, in the water-soluble single-dose article W, the ratio M / S of the mass M (g) of the water-insoluble inorganic powder A retained on the surface of the water-soluble resin substrate X to the surface area S (cm 2 ) of the water-soluble resin substrate X is 1.0×10 -4 g / cm 2 or more and 8.5×10 -4 g / cm 2 or less. Also, from the viewpoint of economy, the ratio M / S is preferably 7.0×10 -4 g / cm 2 or less, more preferably 5×10 -4 g / cm 2More preferably 2.0 × 10 -4 g / cm 2 The following applies. If the water-soluble resin substrate X is in sheet form, the total surface area S of both surfaces (a pair of surfaces extending in the in-plane direction) of the water-soluble resin substrate X shall be considered as the surface area S.

[0023] Furthermore, in the water-soluble unit dose article W, it is preferable that the average particle size of the water-insoluble inorganic powder A is 3 μm or more and 4 μm or less in order to more effectively obtain the effect of reducing the stickiness of the water-soluble resin substrate X by the water-insoluble inorganic powder A.

[0024] The average particle size of water-insoluble inorganic powder A was measured using a laser diffraction / scattering particle size distribution analyzer (e.g., HORIBA LA-950). This average particle size is the D50 (median diameter) of the volume-based cumulative particle size distribution.

[0025] The water-insoluble inorganic powder A may be one or more selected from amorphous silica, calcium silicate, clay minerals, crystalline aluminosilicate, and amorphous aluminosilicate, preferably one or more selected from clay minerals and crystalline aluminosilicate, and more preferably crystalline aluminosilicate.

[0026] Examples of water-insoluble inorganic powder A include amorphous aluminosilicate (oil absorption capacity: 285 mL / 100 g) as described in Japanese Patent Publication No. 9-132794, Japanese Patent Publication No. 7-10526, Japanese Patent Publication No. 6-227811, Japanese Patent Publication No. 8-119622, etc.

[0027] More specifically, the crystalline aluminosilicate is preferably a zeolite. Specific examples of zeolites include crystalline aluminosilicates such as type A, type X, and type P zeolites. Type A zeolite (e.g., trade name "Toyobuilder": manufactured by Tosoh Corporation, oil absorption capacity according to JIS K 5101: 40 mL / 100 g or more) is preferred. Other preferred types include type P (e.g., trade names "Doucil A24", "ZSEO64", etc.; both manufactured by Crosfield; oil absorption capacity 60-150 mL / 100 g), type X (e.g., trade name "WessalithXD"; manufactured by Degussa; oil absorption capacity 80-100 mL / 100 g), and hybrid zeolites described in International Publication No. 98 / 42622.

[0028] As a water-insoluble inorganic powder calcium silicate, Fluorite R (manufactured by Tokuyama Corporation, oil absorption capacity: 400-500 mL / 100 g) can be used; as a water-insoluble inorganic powder amorphous silica, Toxil NR (manufactured by Tokuyama Corporation, oil absorption capacity: 210-270 mL / 100 g) and Silopure (manufactured by Fuji Silicia Chemical Co., Ltd., oil absorption capacity: 240-280 mL / 100 g) can be used; and as a water-insoluble inorganic powder amorphous aluminosilicate, TIXOREX25 (manufactured by Hanfutsu Chemical Co., Ltd., 220-270 mL / 100 g) can be used, etc.

[0029] Examples of water-insoluble inorganic powder clay minerals include bentonite. Bentonite with an ion exchange capacity of 50 to 100 meq / 100g is preferred. Bentonite can be one or more selected from the group consisting of alkali metal or alkaline earth metal montmorillonite, saponite, or hectorite (smectitic clay), illite, attapulgite, and kaolinite. Bentonite can be used in powdered or granulated form. For example, refer to Japanese Patent Publication No. 2008-189719 for granulated clay minerals.

[0030] [Surfactant B] The water-soluble unit-dose article W preferably contains a surfactant B to improve cleaning performance. Examples of surfactant B include one or more selected from anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, and from the viewpoint of improving cleaning performance, it is even more preferable that it be one or more selected from anionic surfactants and nonionic surfactants.

[0031] In the water-soluble unit-dose article W, when surfactant B is included, from the viewpoint of improving cleaning performance, the content of surfactant B is preferably 45% by mass or more, more preferably 48% by mass or more, even more preferably 50% by mass or more, and preferably 60% by mass or less, more preferably 57% by mass or less, and even more preferably 55% by mass or less.

[0032] In the water-soluble unit-dose article W, the surfactant B may be contained in either the water-soluble resin substrate X or the granular material Y, or in both, but from the viewpoint of improving solubility, it is preferably contained in the granular material Y.

[0033] (Anionic surfactant) As an anionic surfactant, from the viewpoint of improving the cleaning performance of particulate dirt, one or more selected from sulfate ester type surfactants, alkylaryl sulfonic acid type surfactants, alkane sulfonic acid type surfactants, olefin sulfonic acid type surfactants, alkyl sulfosuccinate ester type surfactants, sulfo fatty acid ester type surfactants, and fatty acids and their salts are preferred, one or more selected from sulfate ester type surfactants, alkylaryl sulfonic acid type surfactants, alkyl sulfosuccinate ester type surfactants, and fatty acids and their salts are more preferred, and one or more selected from sulfate ester type surfactants, alkylaryl sulfonic acid type surfactants, and fatty acids and their salts are even more preferred. Furthermore, the anionic surfactant is more preferably one or more selected from alkyl sulfate salts, alkyl ether sulfate salts, and alkylbenzene sulfonates, and even more preferably one or more selected from alkyl sulfate salts and alkyl ether sulfate salts.

[0034] When the anionic surfactant is a salt, examples of salts of the anionic surfactant include inorganic salts such as sodium salts, potassium salts, ammonium salts, and magnesium salts, and organic salts such as monoethanolamine salts, diethanolamine salts, triethanolamine salts, and morpholine salts. Preferably, the salt of the anionic surfactant is an inorganic salt selected from alkali metal salts such as sodium salts and potassium salts, and alkaline earth metal salts such as magnesium salts, more preferably an alkali metal salt, and even more preferably a sodium salt.

[0035] When surfactant B contains an anionic surfactant, the content of the anionic surfactant in the water-soluble unit dose article W is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, from the viewpoint of improving cleaning performance, and preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less, from the viewpoint of economic efficiency.

[0036] Examples of anionic surfactants include one or more compounds selected from the compounds represented by the following general formulas (1-1), (1-2), (1-3), and (1-4). From the viewpoint of improving cleaning performance, the anionic surfactant is preferably one or more compounds selected from the compounds represented by general formulas (1-1), (1-2), or (1-3), more preferably one or more compounds selected from the compounds represented by general formulas (1-1) or (1-2), and even more preferably one or more compounds selected from the compounds represented by general formula (1-1).

[0037] R 1a -O-(AO) n -SO3M (1-1) (In formula (1-1), R 1a (where A is an aliphatic hydrocarbon group having 10 to 18 carbon atoms, A is one or more alkylene groups selected from ethylene and propylene groups, n is a number between 0 and 20 representing the average number of moles of alkylene oxy groups AO, and M is a cation.)

[0038] R 2a -Φ-SO3M …(1-2) (In formula (1-2), R 2a Φ represents an alkyl group having 9 to 14 carbon atoms, Φ represents a phenylene group, and R is bonded to the carbon atom of Φ. 2a The carbon atoms are secondary carbon atoms, and M indicates a cation. R is bonded to Φ. 2a In contrast, the sulfonic acid group is bonded to the ortho, meta, or para position.

[0039] R 3a -COOM …(1-3) (In formula (1-3), R 3a (wherein represents an alkyl or alkenyl group with 9 to 17 carbon atoms, and M represents a cation.)

[0040] R 4a -CH(SO3M)COOR 5a (1-4) (In formula (1-4), R 4a R represents an alkyl group with 8 to 18 carbon atoms. 5a (wherein represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and M represents a cation.)

[0041] In formula (1-1), R 1a The aliphatic hydrocarbon group is preferably 10 or more, more preferably 11 or more, even more preferably 12 or more, and preferably 18 or less, more preferably 16 or less, and even more preferably 14 or less. 1a is a linear or branched aliphatic hydrocarbon group, preferably a linear aliphatic hydrocarbon group, and more preferably a linear alkyl group.

[0042] In formula (1-1), AO is one or more alkylene oxy groups selected from ethylene oxy groups and propylene oxy groups. When AO contains both ethylene oxy and propylene oxy groups, the ethylene oxy and propylene oxy groups may be in the form of block bonds or random bonds. From the viewpoint of improving washability, it is preferable that AO is a group containing an ethylene oxy group.

[0043] In formula (1-1), n ​​is 0 or greater, preferably 20 or less, more preferably 16 or less, even more preferably 12 or less, even more preferably 8 or less, and even more preferably 4 or less, from the viewpoint of improving cleanability.

[0044] In formula (1-1), when AO contains a propyleneoxy group, the average number of moles of propyleneoxy groups is preferably 4 or less, more preferably 3 or less, and preferably 0 or more.

[0045] In formula (1-1), the average number of moles of propyleneoxy groups may be 0.

[0046] In formula (1-1), when AO contains ethyleneoxy groups, the average number of moles of ethyleneoxy groups is preferably 0 or more, preferably 10 or less, more preferably 5 or less, and even more preferably 4 or less.

[0047] In formula (1-1), M is preferably an alkali metal ion such as a hydrogen ion, sodium ion, or potassium ion, an alkaline earth metal (1 / 2 atom) ion such as a magnesium ion or calcium ion, or an organic ammonium ion. The organic ammonium salt may be a salt of an amine such as monoethanolamine, diethanolamine, or triethanolamine. M is preferably an alkali metal ion such as a sodium ion or potassium ion, or an alkanol ammonium ion such as a monoethanolammonium ion or a diethanolammonium ion, and more preferably a sodium ion.

[0048] Surfactant B is represented by formula (1-1), where n represents the (non-average) number of moles n1 (integer value) of alkylene oxy group AO, and n1 is 1 or greater, R 1a When M contains compound ES as described above, the content of compound ES in the water-soluble unit dose article W is preferably 5% by mass or more, more preferably 6.5% by mass or more, from the viewpoint of improving cleaning performance, and preferably 20% by mass or less, more preferably 15% by mass or less, from the viewpoint of economic efficiency.

[0049] Surfactant B is represented by equation (1-1), where n is 0 and R 1a When M contains the same compound AS as described above, the content of compound AS in the water-soluble unit dose article W is preferably 6.5% by mass or more, more preferably 13% by mass or more, even more preferably 20% by mass or more, from the viewpoint of improving cleaning performance, and preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, from the viewpoint of economic efficiency.

[0050] In general formula (1-2), R 2a This is an alkyl group having 9 or more carbon atoms, more preferably 10 or more, and more preferably 14 or fewer carbon atoms, and more preferably 13 or fewer carbon atoms.

[0051] In general formula (1-2), M is preferably an alkali metal ion such as a hydrogen ion, sodium ion, or potassium ion, an alkaline earth metal (1 / 2 atom) ion such as a magnesium ion or calcium ion, or an organic ammonium ion. The organic ammonium salt may be a salt of an amine such as monoethanolamine, diethanolamine, or triethanolamine. M is preferably an alkali metal ion such as a sodium ion or potassium ion, or an alkanolammonium ion such as a monoethanolammonium ion or a diethanolammonium ion, and more preferably a sodium ion.

[0052] As compounds represented by general formula (1-2), p-alkylbenzenesulfonates with an alkyl group having 10 to 14 carbon atoms are preferred, and p-alkylbenzenesulfonate sodium salts with an alkyl group having 10 to 14 carbon atoms are more preferred. That is, compounds represented by general formula (1-1) are those in general formula (1-2), where R 2a Compounds in which C1 is an alkyl group having 10 to 14 carbon atoms and M is a sodium ion are preferred.

[0053] When surfactant B contains a compound represented by general formula (1-2), the content of the compound represented by general formula (1-2) in the water-soluble unit dose article W is preferably 5% by mass or more, more preferably 6.5% by mass or more, even more preferably 10% by mass or more, from the viewpoint of improving cleaning performance, and preferably 25% by mass or less, more preferably 20% by mass or less, from the viewpoint of economic efficiency.

[0054] In general formula (1-3), R 3a The alkyl or alkenyl group has preferably 9 or more carbon atoms, more preferably 10 or more, even more preferably 11 or more, and preferably 17 or fewer carbon atoms, more preferably 15 or fewer, and even more preferably 13 or fewer carbon atoms. 3a The group can be one or more groups selected from a linear alkyl group, a branched alkyl group, a linear alkenyl group, and a branched alkenyl group, with a linear alkyl group being preferred.

[0055] In general formula (1-3), M is preferably an alkali metal ion such as a hydrogen ion, sodium ion, or potassium ion, an alkaline earth metal (1 / 2 atom) ion such as a magnesium ion or calcium ion, or an organic ammonium ion. The organic ammonium salt may be a salt of an amine such as monoethanolamine, diethanolamine, or triethanolamine. M is preferably an alkali metal ion such as a sodium ion or potassium ion, or an alkanolammonium ion such as a monoethanolammonium ion or a diethanolammonium ion, and more preferably a sodium ion.

[0056] The compound represented by general formula (1-3) is preferably one or more selected from lauric acid, myristic acid, isostearic acid, palmitic acid, isopalmitic acid, oleic acid and their salts, more preferably one or more selected from lauric acid, myristic acid, palmitic acid and their salts, and even more preferably one or more selected from lauric acid, myristic acid and their salts.

[0057] Compounds represented by general formula (1-3) are those in general formula (1-3) where R 3a Compounds in which C1 is an alkyl group having 11 to 15 carbon atoms and M is a cation are preferred, and compounds in which M is a hydrogen ion or a sodium ion are more preferred.

[0058] In general formula (1-4), R 4a is preferably an alkyl group having 8 or more carbon atoms, more preferably 10 or more, even more preferably 12 or more, and preferably 18 or fewer, more preferably 16 or fewer. In general formula (1-4), R 5a The alkyl group is preferably one or more carbon atoms, preferably five or fewer, more preferably four or fewer, and even more preferably three or fewer.

[0059] In general formula (1-4), M is preferably an alkali metal ion such as a hydrogen ion, sodium ion, or potassium ion, an alkaline earth metal (1 / 2 atom) ion such as a magnesium ion or calcium ion, or an organic ammonium ion. The organic ammonium salt may be a salt of an amine such as monoethanolamine, diethanolamine, or triethanolamine. M is preferably an alkali metal ion such as a sodium ion or potassium ion, or an alkanolammonium ion such as a monoethanolammonium ion or a diethanolammonium ion, and more preferably a sodium ion.

[0060] Compounds represented by general formula (1-4) include, in general formula (1-4), R 4a is an alkyl group having 11 or more carbon atoms and 14 or fewer carbon atoms, R 5a A sodium methyl ester salt of α-sulfo fatty acid is preferred, in which is a methyl group and M is a sodium ion.

[0061] (Nonionic surfactant) Examples of nonionic surfactants that improve cleaning performance include one or more selected from polyoxyalkylene alkyl or alkenyl ethers, alkyl (poly)glycosides (glycoside-type nonionic surfactants), sorbitan-based nonionic surfactants, compounds in which alkylene oxides are added between the ester bonds of long-chain fatty acid alkyl esters, fatty acid monoglycerides, and sucrose fatty acid esters.

[0062] As a nonionic surfactant, a nonionic surfactant containing an alkylene oxy group, wherein the average number of added alkylene oxy groups is 1 or more and 30 or less, is preferred. The alkylene oxy group is preferably one or more groups selected from alkylene oxy groups having 2 to 4 carbon atoms, and more preferably one or more groups selected from ethylene oxy groups and propylene oxy groups. From the viewpoint of improving the cleaning performance against sebum stains, the average number of added alkylene oxy groups is preferably 1 or more, more preferably 6 or more, even more preferably 8 or more, and preferably 30 or less, more preferably 25 or less, even more preferably 20 or less, and even more preferably 15 or less.

[0063] When surfactant B contains a nonionic surfactant, the content of the nonionic surfactant in the water-soluble unit-dose article W is preferably 5% by mass or more, more preferably 6.5% by mass or more, from the viewpoint of improving cleaning performance, and preferably 20% by mass or less, more preferably 15% by mass or less, from the viewpoint of economic efficiency. The content of alkyl ether sulfate ester or its salt is preferably 5% by mass or more and 20% by mass or less, more preferably 6.5% by mass or more and 15% by mass or less, from the viewpoint of improving cleaning performance and economic efficiency.

[0064] Nonionic surfactants containing alkylene oxy groups, wherein the average number of added alkylene oxy groups is 1 or more and 30 or less, are preferably nonionic surfactants represented by the following general formula (2-1).

[0065] R 6a (CO) m O-(A 1a O) n -R 7a…(2-1) (In formula (2-1), R 6a R is an aliphatic hydrocarbon group having 8 to 18 carbon atoms, 7a is a hydrogen atom or a methyl group. CO is a carbonyl group, and m is a number, either 0 or 1. 1a n is one or more alkylene groups with 2 to 4 carbon atoms. 1a (This is the average number of moles of oxygen, and is between 1 and 30.)

[0066] In general formula (2-1), R 6a The number of carbon atoms is preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 18 or less, more preferably 16 or less, and even more preferably 14 or less, from the viewpoint of improving cleansing performance against sebum. 6a This is an aliphatic hydrocarbon group, preferably one or more groups selected from alkyl groups and alkenyl groups.

[0067] In general formula (2-1), A 1a O is one or more alkylene oxy groups having 2 to 4 carbon atoms, preferably one or more alkylene oxy groups having 2 to 3 carbon atoms, more preferably an ethylene oxy group. 1a If oxygen contains multiple different alkylene oxy groups, these different alkylene oxy groups may be either block-type or random-type bonds.

[0068] In general formula (2-1), n ​​is 1 or more, preferably 6 or more, more preferably 8 or more, and 30 or less, preferably 25 or less, more preferably 20 or less, and even more preferably 15 or less, from the viewpoint of improving cleanability against sebum stains.

[0069] In general formula (2-1), m is preferably 0 from the viewpoint of improving cleaning performance.

[0070] In general formula (2-1), R 7a From the viewpoint of improving cleaning performance, hydrogen atoms are preferred.

[0071] Specific examples of nonionic surfactants that do not have an alkylene oxy group include one or more selected from sucrose fatty acid esters, glycerin fatty acid esters, sorbitan fatty acid esters, alkyl glycosides, and glyceryl monoethers.

[0072] (cationic surfactant) Examples of cationic surfactants include quaternary ammonium salt type surfactants. Cationic surfactants may have one or more effects selected from bactericidal action, antibacterial action, and disinfectant action. As cationic surfactants, quaternary ammonium salt type surfactants, one or more selected from compounds represented by the following general formula (3-1) and compounds represented by the following general formula (3-2) are preferred.

[0073] [ka]

[0074] (In the formula, R 8a R is an aliphatic hydrocarbon group having 8 to 18 carbon atoms, 9a R is a group selected from aliphatic hydrocarbon groups having 8 to 18 carbon atoms, alkyl groups having 1 to 3 carbon atoms, and hydroxyalkyl groups having 1 to 3 carbon atoms. 10a and R 11a Each of these is independently selected from alkyl groups having 1 to 3 carbon atoms and hydroxyalkyl groups having 1 to 3 carbon atoms, X - It is an anion.

[0075] [ka]

[0076] (In the formula, R 12a R is an aliphatic hydrocarbon group having 8 to 18 carbon atoms, 13a and R 14a Each of these is independently selected from alkyl groups having 1 to 3 carbon atoms and hydroxyalkyl groups having 1 to 3 carbon atoms, X -It is an anion.

[0077] In general formula (3-1), R 8a The number of carbon atoms is preferably 9 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 16 or less, from the viewpoint of improving cleanability. 8a R is preferably an alkyl group or an alkenyl group, with alkyl groups being preferred. In general formula (3-1), 9a R is a group selected from aliphatic hydrocarbon groups having 8 to 18 carbon atoms, alkyl groups having 1 to 3 carbon atoms, and hydroxyalkyl groups having 1 to 3 carbon atoms. 9a However, if it is an aliphatic hydrocarbon group with 8 to 18 carbon atoms, R 9a From the viewpoint of improving cleaning performance, alkyl or alkenyl groups are preferably 8 or more, preferably 14 or less, and more preferably 12 or less, with alkyl groups being more preferred.

[0078] In general formula (3-1), R 10a and R 11a Each of these groups is independently selected from alkyl groups having 1 to 3 carbon atoms and hydroxyalkyl groups having 1 to 3 carbon atoms. 10a and R 11a Preferably, each of these groups is independently selected from alkyl groups having 1 to 3 carbon atoms. Examples of alkyl groups having 1 to 3 carbon atoms include methyl, ethyl, and propyl groups. Examples of hydroxyalkyl groups having 1 to 3 carbon atoms include hydroxymethyl, hydroxyethyl, and hydroxypropyl groups.

[0079] In general formula (3-1), X - It is an anion. Examples of anions include halogen ions and one or more anions selected from alkyl sulfate ions having 1 to 3 carbon atoms. Examples of halogen ions include chloride ions, bromide ions, and iodide ions. Examples of alkyl sulfate ions having 1 to 3 carbon atoms include methyl sulfate ions, ethyl sulfate ions, and propyl sulfate ions.

[0080] In general formula (3-2), R 12a R is an aliphatic hydrocarbon group having 8 to 18 carbon atoms. 12a The number of carbon atoms is preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 18 or less, and more preferably 16 or less, from the viewpoint of improving antibacterial properties. 12a The group is preferably an alkyl group or an alkenyl group, and more preferably an alkyl group.

[0081] In general formula (3-2), R 13a and R 14a Each of these groups is independently selected from alkyl groups having 1 to 3 carbon atoms and hydroxyalkyl groups having 1 to 3 carbon atoms. 13a and R 14a Preferably, each of these groups is independently selected from alkyl groups having 1 to 3 carbon atoms. Examples of alkyl groups having 1 to 3 carbon atoms include methyl, ethyl, and propyl groups. Examples of hydroxyalkyl groups having 1 to 3 carbon atoms include hydroxymethyl, hydroxyethyl, and hydroxypropyl groups.

[0082] In general formula (3-2), X - It is an anion. Examples of anions include halogen ions and one or more anions selected from alkyl sulfate ions having 1 to 3 carbon atoms. Examples of halogen ions include chloride ions, bromide ions, and iodide ions. Examples of alkyl sulfate ions having 1 to 3 carbon atoms include methyl sulfate ions, ethyl sulfate ions, and propyl sulfate ions.

[0083] Specific examples of compounds of general formula (3-2) include N-dodecyl-N,N-dimethyl-N-benzylammonium salt, N-tridecyl-N,N-dimethyl-N-benzylammonium salt, N-tetradecyl-N,N-dimethyl-N-benzylammonium salt, N-pentadecyl-N,N-dimethyl-N-benzylammonium salt, N-hexadecyl-N,N-dimethyl-N-benzylammonium salt, N-dodecyl-N,N-diethyl-N-benzylammonium salt, N-tridecyl-N,N-diethyl-N-benzylammonium salt, and N-tetradecyl-N,N-diethyl-N-benzylammonium salt. Examples include one or more compounds selected from ammonium salt, N-pentadecyl-N,N-diethyl-N-benzylammonium salt, N-hexadecyl-N,N-diethyl-N-benzylammonium salt, N-dodecyl-N-methyl-N-ethyl-N-benzylammonium salt, N-tridecyl-N-methyl-N-ethyl-N-benzylammonium salt, N-tetradecyl-N-methyl-N-ethyl-N-benzylammonium salt, N-pentadecyl-N-methyl-N-ethyl-N-benzylammonium salt, and N-hexadecyl-N-methyl-N-ethyl-N-benzylammonium salt.

[0084] The cationic surfactant is preferably one or more selected from benzalkonium chloride, dialkyldimethylammonium chloride, and alkyltrimethylammonium chloride. Benzalkonium chloride is preferably a compound represented by general formula (3-2). Dialkyldimethylammonium chloride, such as dioctyldimethylammonium chloride, and alkyltrimethylammonium chloride, such as dodecyltrimethylammonium chloride, are preferably compounds represented by general formula (3-1).

[0085] If surfactant B contains a cationic surfactant, the content of the cationic surfactant in the water-soluble unit-dose article W is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and may be greater than 0% by mass, from the viewpoint of economy and stability. From a similar viewpoint, the content of the cationic surfactant in the water-soluble unit-dose article W may be 0% by mass.

[0086] (Amphoteric surfactant) Examples of amphoteric surfactants include one or more selected from N-alkanoylaminopropyl-N,N-dimethylamine oxide, N-alkyl-N,N-dimethylamine oxide, N-alkanoylaminopropyl-N,N-dimethyl-N-carboxymethylammonium betaine, N-alkyl-N,N-dimethyl-N-carboxymethylammonium betaine, N-alkyl-N,N-dimethyl-N-sulfopropylammonium sulfobetaine, N-alkyl-N,N-dimethyl-N-(2-hydroxysulfopropyl)ammonium sulfobetaine, N-alkanoylaminopropyl-N,N-dimethyl-N-sulfopropylammonium sulfobetaine, and N-alkanoylaminopropyl-N,N-dimethyl-N-(2-hydroxysulfopropyl)ammonium sulfobetaine. In these, the alkanoyl group is, for example, lauroyl or myristyl. In these, the alkyl group is, for example, a lauryl group or a myristyl group.

[0087] In the water-soluble unit-dose article W, when an amphoteric surfactant is included, from the viewpoint of improving cleaning performance and foaming, the content of the amphoteric surfactant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.2% by mass or less.

[0088] [Water-soluble inorganic salt C] In the water-soluble unit-dose article W, it is preferable that a water-soluble inorganic salt C is included as an alkaline agent to obtain high cleansing properties against sebum and the like by improving the penetration action of surfactant B. Examples of water-soluble inorganic salt C include one or more selected from carbonates, bicarbonates, silicates, and tripolyphosphates, and from the viewpoint of improving cleansing properties, one or more selected from carbonates and bicarbonates are preferred.

[0089] Examples of carbonates include one or more selected from sodium carbonate and potassium carbonate, with sodium carbonate being preferred. Examples of bicarbonates include one or more selected from sodium bicarbonate and potassium bicarbonate. Examples of silicates include one or more selected from sodium silicate and potassium silicate. Examples of tripolyphosphates include alkali metal salts of tripolyphosphate.

[0090] In the water-soluble unit-dose article W, it is preferable to have a large amount of water-soluble inorganic salt C in order to obtain high cleaning performance by improving the penetration action of surfactant B, and it is preferable that the amount of water-soluble inorganic salt C is not too large in order to suppress the generation of undissolved residue. From these viewpoints, in the water-soluble unit-dose article W, when water-soluble inorganic salt C is contained, the content of water-soluble inorganic salt C is preferably 15% by mass or more, more preferably 17% by mass or more, even more preferably 18% by mass or more, and preferably 25% by mass or less, more preferably 24% by mass or less, and even more preferably 22% by mass or less.

[0091] In addition, in the water-soluble unit dose article W, the water-soluble inorganic salt C may be contained in either the water-soluble resin substrate X or the granular material Y, or it may be contained in both.

[0092] [Other ingredients] In the water-soluble unit-dose article W, components other than surfactant B and water-soluble inorganic salt C may be added as needed. For example, the water-soluble unit-dose article W may contain one or more selected from rheological modifiers, chelating agents, anionic polymers, and water.

[0093] (Rheological modifier) In the water-soluble unit-dose article W, for example, a rheological modifier is added to prevent the generation of undissolved material due to gelation when the water-soluble unit-dose article W is dissolved in water. The water-soluble unit-dose article W preferably contains an alkoxylated amine as the rheological modifier, more preferably an alkoxylated polyamine, even more preferably an alkoxylated polyethyleneimine, and even more preferably an ethoxylated polyethyleneimine.

[0094] In the water-soluble unit-dose article W, if a rheological modifier is included, the content of the rheological modifier is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, and from the viewpoint of ease of formulation, preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0095] In addition, in the water-soluble unit dose article W, the rheology modifier may be contained in either the water-soluble resin substrate X or the granular material Y, or it may be contained in both.

[0096] (Chelating agent) In water-soluble unit-dose article W, a chelating agent is added to enhance the action of surfactant B and improve cleaning performance. Specific examples of chelating agents include, for example, aminopolyacetic acids such as ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, and hydroxyethyliminodiacetic acid, or their salts; organic acids such as citric acid, lactic acid, tartaric acid, and malic acid, or their salts; 1-hydroxyethylidene-1,1-diphosphonic acid, diethylenetriaminepenta(methylenephosphonic acid), and alkali metal or lower amine salts thereof; one or more of these can be used. Examples of chelating agent salts include alkali metal salts such as sodium salts and potassium salts; and lower amine salts such as monoethanolamine, diethanolamine, and triethanolamine.

[0097] In the water-soluble unit-dose article W, if a chelating agent is included, from the viewpoint of improving washability, the chelating agent content is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more. From the viewpoint of ease of formulation, it is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less.

[0098] (Water-insoluble inorganic components) The water-soluble unit-dose article W may contain water-insoluble inorganic components other than water-insoluble inorganic powder A. The water-insoluble inorganic components may be held inside the water-soluble resin substrate X as granular bodies Y, or they may be contained within the water-soluble resin substrate X. As the water-insoluble inorganic components, powders similar to those of water-insoluble inorganic powder A can be used. When the water-insoluble inorganic components are used in a specific ratio with the water-soluble inorganic salt C, they have the effect of suppressing undissolved residue after washing the object to be washed with the water-soluble unit-dose article W and reducing the turbidity of the rinse water.

[0099] The average primary particle size of the water-insoluble inorganic component is preferably 0.1 μm or more, more preferably 1 μm or more, and preferably 10 μm or less, and more preferably 5 μm or less. The average primary particle size of the water-insoluble inorganic component is the D50 (median diameter) of the volume-based cumulative particle size distribution, measured by the same method as the average particle size of water-insoluble inorganic powder A.

[0100] In the water-soluble unit-dose article W, the water-insoluble inorganic component may be contained in either the water-soluble resin substrate X or the granular material Y, or in both, but from the viewpoint of ease of manufacture, it is preferably contained in the granular material Y.

[0101] (Anionic polymer) Examples of anionic polymers include polymers having a carboxylic acid group or a salt thereof and having a weight-average molecular weight of 3,000 or more. Examples of anionic polymers include one or more polymers selected from polyacrylic acid and its salts, copolymers of acrylic acid and maleic acid and their salts, and polymaleic acid and its salts.

[0102] Examples of polyacrylic acid and its salts include one or more selected from polyacrylic acid, sodium polyacrylate, and potassium polyacrylate, and preferably one or more selected from sodium polyacrylate and potassium polyacrylate.

[0103] Examples of acrylic acid-maleic acid copolymers and their salts include one or more selected from acrylic acid-maleic acid copolymers, sodium salts of acrylic acid-maleic acid copolymers, and potassium salts of acrylic acid-maleic acid copolymers, and preferably one or more selected from sodium salts of acrylic acid-maleic acid copolymers and potassium salts of acrylic acid-maleic acid copolymers. The molar ratio of the acrylic acid-maleic acid copolymer is preferably 1 / 99 or more, more preferably 10 / 90 or more, and preferably 99 / 1 or less, and more preferably 90 / 10 or less, as the number of moles of acrylic acid / the number of moles of maleic acid.

[0104] Examples of polymaleic acid and its salts include one or more selected from polymaleic acid, sodium polymaleate, and potassium polymaleate, and preferably one or more selected from sodium polymaleate and potassium polymaleate.

[0105] The anionic polymer may be a copolymer containing monomers other than acrylic acid and maleic acid that are copolymerizable with acrylic acid and / or maleic acid, as long as this does not hinder the expression of the effects of the present invention. Examples of monomers other than acrylic acid and maleic acid that are copolymerizable with acrylic acid and / or maleic acid include one or more selected from vinyl monomers, acrylic monomers, and styrene monomers, and more specifically, one or more selected from methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, and styrene. The molar ratio of monomers other than acrylic acid and maleic acid that are copolymerizable with acrylic acid and / or maleic acid in the anionic polymer is preferably 0 mol% or more, preferably 5 mol% or less, more preferably 3 mol% or less, and even more preferably 0 mol% in the anionic polymer. Accordingly, the polyacrylic acid and its salts, the copolymer of acrylic acid and maleic acid and its salts, and the polymaleic acid and its salts of the present invention may be polymers or copolymers that, in the total constituent monomers, contain monomers other than acrylic acid and maleic acid that are copolymerizable with acrylic acid and / or maleic acid in an amount of 0 mol% to 5 mol%.

[0106] The weight-average molecular weight of the anionic polymer is preferably 3,000 or more, more preferably 3,500 or more, even more preferably 4,000 or more, even more preferably 5,000 or more, even more preferably 6,000 or more, even more preferably 7,000 or more, even more preferably 8,000 or more, even more preferably 9,000 or more, even more preferably 10,000 or more, and preferably 100,000 or less, more preferably 50,000 or less, even more preferably 25,000 or less, and even more preferably 15,000 or less. This weight-average molecular weight can be measured according to the weight-average molecular weight measurement method described below.

[0107] The weight-average molecular weight of anionic polymers can be measured by GPC (gel permeation chromatography), and the weight-average molecular weight (Mw) can be determined using a conversion standard. The GPC measurement conditions are shown below. ·column: Manufactured by Tosoh Corporation, Product name: TSK-GEL guard PWXL Manufactured by Tosoh Corporation, Product name: TSK-GEL G4000 PWXL Manufactured by Tosoh Corporation, Product name: TSK-GEL G2500 PWXL Mobile phase: 0.1 mol / L potassium dihydrogen phosphate and 0.1 mol / L sodium dihydrogen phosphate aqueous solutions / acetonitrile = 90 / 10 (volume ratio) • Detector: Differential refractive index detector Column temperature: 40°C ·Flow rate: 1.0mL / min • Conversion reference material: Polyacrylic acid (manufactured by American Standard Corporation) • Sample: An aqueous polymer solution containing 0.8 g of solids is mixed with deionized water to prepare a total volume of 200 mL. 10 μL of this prepared solution is then taken and injected into the column.

[0108] In addition, in the water-soluble unit-dose article W, the anionic polymer may be contained in either the water-soluble resin substrate X or the granular material Y, or it may be contained in both.

[0109] (water) Water may be added to the water-soluble unit-dose article W. Examples of water include ion-exchanged water, purified water, and distilled water. The water also includes water used to add the components of the water-soluble unit-dose article W. In the water-soluble unit-dose article W, water may be contained in either the water-soluble resin substrate X or the granular material Y, or in both.

[0110] [Examples and Comparative Examples] Examples and comparative examples of the present invention will be described below, but the present invention is not intended to be limited to these examples.

[0111] In the examples and comparative examples, samples of water-soluble unit-dose articles were first prepared. For the water-soluble unit-dose article samples, a 7.5 cm x 7.5 cm rectangular flat bag made of polyvinyl alcohol (PVA) nonwoven fabric (manufactured by WBLLGG) was used as the water-soluble resin substrate. In addition, the following materials were used as granular material for the water-soluble unit-dose article W sample. • LAS: Sodium laurylbenzenesulfonate "Neoperex G-65" (manufactured by Kao Corporation) AES: Sodium polyoxyethylene (2) lauryl ether sulfate (average number of moles of oxyethylene groups is 2, containing 30% by mass of sodium lauryl sulfate) • AS: Sodium lauryl sulfate "Emal 10G" (manufactured by Kao Corporation) AEO(10): Polyoxyethylene(10) lauryl ether (average number of moles of oxyethylene groups: 10) • Sodium carbonate: Light ash (bulk density 600 g / L, average particle size 100 μm, manufactured by Central Glass Co., Ltd.) • Sodium bicarbonate: Sodium bicarbonate (manufactured by AGC Inc.) • Sodium citrate: Trisodium citrate (crystalline, manufactured by Showa Chemical Co., Ltd.) • PEI-EO: Ethoxylated polyethyleneimine "Sokalan HP 20" (manufactured by BASF) • Silica: "Toxeal NR" (average particle size 181 μm, manufactured by Oriental Silicas Corporation) • Zeolite: "Zeobuilder" (Type 4A, average particle size 3.5 μm, manufactured by ZEOBUILDER)

[0112] In Examples 1-4 and Comparative Examples 2 and 3, zeolite powder was sprinkled on both outer surfaces of the water-soluble resin substrate, and the zeolite particles were evenly distributed between and on the surfaces of the water-soluble fibers by rubbing. In Example 1, the ratio of the mass of zeolite powder held on the surface of the water-soluble resin substrate to the surface area of ​​the water-soluble resin substrate was 1.60 × 10⁻⁶. -4 g / cm 2was used. In Example 2, the mass ratio of the zeolite powder held on the surface of the water-soluble resin substrate to the surface area of the water-soluble resin substrate was 2.67×10 -4 g / cm 2 was used. In Example 3, the mass ratio of the zeolite powder held on the surface of the water-soluble resin substrate to the surface area of the water-soluble resin substrate was 5.33×10 -4 g / cm 2 was used. In Example 4, the mass ratio of the zeolite powder held on the surface of the water-soluble resin substrate to the surface area of the water-soluble resin substrate was 8.00×10 -4 g / cm 2 was used. In Comparative Example 2, the mass ratio of the zeolite powder held on the surface of the water-soluble resin substrate to the surface area of the water-soluble resin substrate was 0.533×10 -4 g / cm 2 was used. In Comparative Example 3, the mass ratio of the zeolite powder held on the surface of the water-soluble resin substrate to the surface area of the water-soluble resin substrate was 10.67×10 -4 g / cm 2 was used. In Comparative Example 1, no zeolite powder was held on the water-soluble resin substrate.

[0113] In Examples 1 to 4 and Comparative Examples 1 to 3, samples of water-soluble unit-dose articles were prepared by holding granular materials having a common configuration on the water-soluble resin substrates. Specifically, in Examples 1 to 4 and Comparative Examples 1 to 3, samples of water-soluble unit-dose articles were prepared by accommodating granular materials in the water-soluble resin substrates prepared as described above. Table 1 shows the contents (the compounding amounts of the active ingredients of each material) (mass %) of each component other than the zeolite powder held on both surfaces outside the water-soluble resin substrates in the samples of water-soluble unit-dose articles prepared in the examples and comparative examples.

[0114]

Table 1

[0115] Samples of water-soluble unit-dose articles according to Examples 1 to 4 and Comparative Examples 1 to 3 were subjected to a storage test. In the storage test, each sample was kept in a thermostatic chamber at 30°C and 70% RH, and the mass increase rate, feel, and appearance of the sample were evaluated at each time point from the start of the retention for 1 to 14 days.

[0116] The mass increase rate was determined as the ratio of the increase in mass after the storage test to the mass at the start of the test for each sample.

[0117] Regarding the feel, the evaluator touched the sample of the water-soluble unit-dose article by hand and evaluated it according to the following criteria. A: Crispy B: Somewhat crispy C: Sticky D: Extremely sticky

[0118] Regarding powder adhesion, the evaluator touched the sample of the water-soluble unit-dose article by hand and evaluated it according to the following criteria. A: No powder adheres to the hand B: Some powder adheres to the hand C: Powder adheres to the hand

[0119] Table 2 shows the ratio of the mass of zeolite powder retained on the surface of the water-soluble resin substrate to the surface area of the water-soluble resin substrate, as well as the evaluation results of the mass increase rate, feel, and powder adhesion in the storage test, for samples of unit-dose articles according to Examples 1 to 4 and Comparative Examples 1 to 3.

[0120]

Table 2

[0121] For samples according to Examples 1 to 4 and Comparative Example 3 in which the ratio of the content (mass) of zeolite powder to the surface area of the water-soluble resin substrate is 1.0×10 -4 g / cm 2 or more, the ratio of the content (mass) of zeolite powder to the surface area of the water-soluble resin substrate is 1.0×10 -4 g / cm 2The sample obtained in terms of tactile evaluation was better than that of the samples in Comparative Examples 1 and 2, which were less than 8.5 × 10⁻⁶. -4 g / cm 2 In the samples related to Examples 1-4 and Comparative Examples 1 and 2 below, the ratio of zeolite powder content (mass) to the surface area of ​​the water-soluble resin substrate was 8.5 × 10⁻⁶. -4 g / cm 2 Better evaluation results were obtained in terms of powder adhesion compared to the sample related to Comparative Example 3.

[0122] Figure 3 is a graph showing the change in the rate of mass increase for each sample over time. The water-soluble unit-dose samples from Examples 1-4 and Comparative Examples 1-3 all show similar changes in the rate of mass increase. In other words, although the water-soluble resin constituting the water-soluble resin substrate is of a similar degree in all samples from Examples 1-4 and Comparative Examples 1 and 2, it was found that stickiness was sufficiently suppressed in the samples from Examples 1-4 due to the action of the zeolite powder. [Explanation of symbols]

[0123] W...Water-soluble unit dose article X…Water-soluble resin base Y...granular

Claims

1. A water-soluble unit-dose article in which granular material is held in a water-soluble resin substrate, It contains water-insoluble inorganic powder A held on the surface of the water-soluble resin substrate, The ratio of the mass of the water-insoluble inorganic powder A held on the surface of the water-soluble resin substrate to the surface area of ​​the water-soluble resin substrate is 1.0 × 10 －４ g / cm ２ The above 8.5 x 10 －４ g / cm ２ The following is Water-soluble unit dose product.

2. The average particle size of the water-insoluble inorganic powder A is 3 μm or more and 4 μm or less. The water-soluble unit dose article according to claim 1.

3. The water-insoluble inorganic powder A is zeolite powder. The water-soluble unit dose article according to claim 1.

4. It further contains one or more selected from surfactant B and water-soluble inorganic salt C. The water-soluble unit dose article according to claim 1.

5. The water-soluble resin substrate is composed of one or more selected from water-soluble fiber structures and water-soluble films. The water-soluble unit dose article according to claim 1.

6. This is a unit-dose product of laundry detergent. A water-soluble unit-dose article according to any one of claims 1 to 5.

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