JP6866638B2 - Water-soluble film and drug packaging - Google Patents

Description

The present invention may be described as a water-soluble film (hereinafter, "PVA-based film") mainly containing a polyvinyl alcohol-based resin (hereinafter, polyvinyl alcohol may be abbreviated as "PVA"). ). More specifically, the peeling strength of the sealed portion when water-sealed is high and the sealing property is excellent. Therefore, even if a liquid such as a liquid chemical is packaged into a package, the package does not leak. It relates to a water-soluble film useful for use and a drug package using the same.

The PVA-based film is a film made of a PVA-based resin that is a thermoplastic resin but has water solubility, and a hydrophobic film that is usually often used for packaging films such as polyethylene terephthalate films and polyolefin films is a film. The physical properties and the feel of the film are significantly different.

Conventionally, it has been proposed to take advantage of the water solubility of PVA-based resin to package chemicals (unit packaging) in which various chemicals such as pesticides and detergents are put in a bag made of a film of PVA-based resin, and it is used for a wide range of applications. ing.

As a water-soluble unit packaging bag used for such applications, for example, 5 to 30 parts by weight of a plasticizer, 1 to 10 parts by weight of starch, and 0.01 to 2 parts by weight of a surfactant are blended with 100 parts by weight of PVA. A water-soluble film (see, for example, Patent Document 1), a 4 wt% aqueous solution viscosity at 20 ° C. is 10 to 35 mPs · s, an average saponification degree of 80.0 to 99.9 mol%, and an anionic group modification amount of 1 to 1. With respect to 100 parts by weight of 10 mol% anionic group-modified PVA resin (A), 20 to 50 parts by weight of the plasticizer (B), 2 to 30 parts by weight of the filler (C), and 0. A water-soluble film (see, for example, Patent Document 2) made of a resin composition containing 01 to 2.5 parts by weight is known.

Japanese Unexamined Patent Publication No. 2001-329130 Japanese Unexamined Patent Publication No. 2004-161823

However, the water-soluble film disclosed in Patent Documents 1 and 2 does not have sufficient peeling strength of the water-sealed portion when a liquid such as a liquid detergent is packaged to form a package, and there is a concern about liquid leakage. It was a thing, and further improvement was required.

Therefore, in the present invention, under such a background, even in a state in which a liquid such as a liquid chemical is packaged into a package, the peeling strength of the water-sealed portion is high and the sealing property is excellent, and therefore the liquid leaks. Provided are a water-soluble film useful for a package without water, and a drug package in which various drugs are packaged with the water-soluble film.

However, as a result of diligent research in view of such circumstances, the present inventor has found that the PVA-based resin has an anionic group-modified PVA-based resin and a 4 wt% aqueous solution viscosity at 20 ° C. in a water-soluble film mainly composed of a PVA-based resin. The present invention has been completed by finding that it is excellent in water-sealing property when packaging a liquid such as a liquid drug to prepare a drug package by containing two different types of unmodified PVA resins.

That is, the present invention is a water-soluble film containing a PVA-based resin (A), wherein the PVA-based resin (A) is an anionic group-modified PVA-based resin (A1), a 4 wt% aqueous solution at 20 ° C. viscosity (alpha) is contained unmodified PVA (A2) 4 wt% aqueous solution viscosity at and 20 ° C. (beta) unmodified PVA of 1~20mPa · s (A3) of 21~80mPa · s, the anionic group The content of the unmodified polyvinyl alcohol (A2) is 1 to 20 parts by weight with respect to 100 parts by weight of the modified polyvinyl alcohol-based resin (A1), and the content of the unmodified polyvinyl alcohol (A3) is 0.5 to 10 parts by weight. the parts der Ru soluble film to the first aspect.
Further, in the present invention, the second gist is a drug package made of the water-soluble film.

The water-soluble film of the present invention is a water-soluble film containing a PVA-based resin (A), wherein the PVA-based resin (A) is an anionic group-modified PVA-based resin (A1) by 4 weight at 20 ° C. % aqueous solution viscosity (alpha) is unmodified PVA (A2) and 4 wt% aqueous solution viscosity at 20 ° C. of 21~80mPa · s (β) is contained unmodified PVA (A3) of 1 to 20 mPa · s, the anion The content of the unmodified polyvinyl alcohol (A2) is 1 to 20 parts by weight, and the content of the unmodified polyvinyl alcohol (A3) is 0.5 with respect to 100 parts by weight of the sex group-modified polyvinyl alcohol-based resin (A1). it can be 10 parts by weight der because, the water-soluble film having excellent water-sealing properties when packaged liquids, such as liquid medicament to prepare a medicine package is.

The difference (α-β) between the 4% by weight aqueous solution viscosity (α) of the unmodified PVA (A2) at 20 ° C. and the 4% by weight aqueous solution viscosity (β) of the unmodified PVA (A3) at 20 ° C. is 10 to 50 mPa. -If s, a water-soluble film having more excellent water-sealing property can be obtained.

Further, when the content ratio (A2 / A3) of the unmodified PVA (A2) and the unmodified PVA (A3) is 1/9 to 9/1 (weight ratio), the water-soluble film having further excellent water-sealing property is obtained. be able to.

Further, when the plasticizer (B) is contained, the water-soluble film can be made flexible when it is used as a drug package.

Further, when the content of the plasticizer (B) is 20 parts by weight or more with respect to 100 parts by weight of the PVA-based resin (A), even in a state where a liquid such as a liquid chemical is packaged into a package. The toughness of the water-soluble film over time is not impaired, and the mechanical strength becomes excellent.

When the water content of the water-soluble film is 3 to 15% by weight, the mechanical strength and the sealing property become more excellent.

Further, in the case of the drug packaging body characterized in that the liquid drug is packaged in the water-soluble film, the drug packaging body has a high peeling strength of the water-sealed portion and does not leak the liquid. ..

Further, when the pH value of the liquid drug when dissolved or dispersed in water is 6 to 12 and the water content is 15% by weight or less, the water-soluble film becomes water-soluble without gelling or insolubilizing. Excellent.

Hereinafter, the configuration of the present invention will be described in detail, but these are examples of desirable embodiments and are not specified in these contents.
In the present invention, (meth) acrylic means acrylic or methacrylic.

<PVA resin (A)>
The water-soluble film of the present invention is usually made of a PVA-based resin (A). The PVA-based resin composition (A) contains an anionic group-modified PVA-based resin (A1) as a main component, and is blended with two types of unmodified PVA having a specific aqueous solution viscosity. Hereinafter, the anionic group-modified PVA-based resin (A1), the unmodified PVA (A2), and the unmodified PVA (A3) contained in the PVA-based resin (A) will be described.

[Anionic group-modified PVA resin (A1)]
Examples of the type of anionic group of the anionic group-modified PVA-based resin (A1) include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. In terms of chemical resistance and stability over time, the carboxyl group , A sulfonic acid group is preferable, and a carboxyl group is particularly preferable.

The amount of modification of the anionic group-modified PVA resin (A1) is usually 1 to 10 mol%, preferably 2 to 9 mol%, particularly preferably 2 to 8 mol%, and particularly preferably 3 to 7 mol%. is there. If the amount of such modification is too small, the solubility in water tends to decrease, and if it is too large, the productivity of the PVA-based resin tends to decrease, the biodegradability tends to decrease, and blocking is caused. It tends to be easier.

The average saponification degree of the anionic group-modified PVA resin (A1) is usually 85 mol% or more, preferably 88 to 99 mol%, and particularly preferably 90 to 97 mol%. If the average degree of saponification is too small, the solubility of the water-soluble film in water tends to decrease over time depending on the pH of the drug to be packaged, and if the average degree of saponification is too large, the film is formed. The thermal history tends to significantly reduce the solubility in water. In the present invention, the average saponification degree is a value measured in accordance with JIS K 6726 3.5.

The degree of polymerization of the PVA-based resin can generally be indicated by the water-soluble viscosity, and the viscosity of the anionic group-modified PVA-based resin (A1) at 20 ° C. is usually 5 to 50 mPa. s, preferably 13 to 40 mPa · s, particularly preferably 17 to 30 mPa · s. If the viscosity is too small, the mechanical strength of the water-soluble film as a packaging material tends to decrease, and if it is too large, the viscosity of the aqueous solution during film formation tends to be high and the productivity tends to decrease. In the present invention, the viscosity of the 4 wt% aqueous solution is a value measured according to JIS K 6726 3.11.2.

The anionic group-modified PVA resin (A1) is obtained by copolymerizing, for example, a vinyl ester compound with an unsaturated monomer having an anionic group copolymerizable with the vinyl ester compound, and then saponifying the vinyl ester compound. It can be manufactured by doing so. Hereinafter, the carboxy group-modified PVA-based resin, which is a preferable modified species, will be described.

The above-mentioned carboxyl group-modified PVA resin can be produced by any method. For example, (i) a method of copolymerizing an unsaturated monomer having a carboxyl group with a vinyl ester compound and then saponifying the compound (ii). ) Examples thereof include a method in which an alcohol, an aldehyde, a thiol or the like having a carboxyl group is allowed to coexist as a chain transfer agent to polymerize a vinyl ester compound and then saponified.

Examples of the vinyl ester compound in the method (i) or (ii) above include vinyl formate, vinyl acetate, trifluorovinyl acetate, vinyl propionate, vinyl butyrate, vinyl caprate, vinyl laurate, vinyl versatic acid. , Vinyl palmitate, vinyl stearate and the like, but vinyl acetate is preferably used. The vinyl ester compound may be used alone or in combination of two or more.

Examples of the unsaturated monomer having a carboxyl group in the method (i) above include ethylenically unsaturated dicarboxylic acid (maleic acid, fumaric acid, itaconic acid, etc.) or ethylenically unsaturated dicarboxylic acid monoester (malein). Acid monoalkyl ester, fumaric acid monoalkyl ester, itaconic acid monoalkyl ester, etc.) or ethylenically unsaturated dicarboxylic acid diester (maleic acid dialkyl ester, fumaric acid dialkyl ester, itaconic acid dialkyl ester, etc.) [However, these diesters Needs to be converted to a carboxyl group by hydrolysis during the saponification of the copolymer. ], Or monomers such as ethylenically unsaturated carboxylic acid anhydrides (maleic anhydride, itaconic anhydride, etc.), or ethylenically unsaturated monocarboxylic acids ((meth) acrylic acid, crotonic acid, etc.), and theirs. Examples include salts, among which maleic acid, maleic acid monoalkyl ester, maleic acid dialkyl ester, maleate, maleic anhydride, itaconic acid, itaconic acid monoalkyl ester, itaconic acid dialkyl ester, (meth) acrylic acid, etc. It is preferable to use maleic acid, maleic acid monoalkyl ester, maleic acid dialkyl ester, maleate, maleic anhydride, and particularly maleic acid monoalkyl ester. These can be used alone or in combination of two or more.

In the above method (ii), a compound derived from a thiol having a particularly large chain transfer effect is effective, and examples thereof include the following compounds.

In addition, salts of the compounds represented by the above general formulas (1) to (3) can also be mentioned. Specific examples thereof include mercaptoacetate, 2-mercaptopropionate, 3-mercaptopropionate, 2-mercaptostearate and the like. These compounds can be used alone or in combination of two or more.

As the above-mentioned polymerization method, for example, a known polymerization method such as a solution polymerization method, an emulsion polymerization method, or a suspension polymerization method can be arbitrarily used, but usually a lower alcohol such as methanol, ethanol or isopropyl alcohol is used as a solvent. It is carried out by the solution polymerization method. In such solution polymerization, as a method for charging a monomer, first, the entire amount of the vinyl ester compound and, for example, a part of the unsaturated monomer having a carboxyl group described above are charged, polymerization is started, and the remaining unsaturated compound is charged. Any method can be used, such as a method in which the monomer is continuously or dividedly added during the polymerization period, a method in which the unsaturated monomer having a carboxyl group described above is collectively charged, and the like.

As the polymerization catalyst, a known polymerization catalyst such as an azo catalyst such as azobisisobutyronitrile, a peroxide catalyst such as acetyl peroxide, benzoyl peroxide, or lauroyl peroxide is appropriately selected depending on the polymerization method. be able to. The reaction temperature of the polymerization is selected from the range of 50 ° C. to the boiling point of the polymerization catalyst.

The saponification is carried out in the presence of a saponification catalyst by dissolving the obtained copolymer in alcohol. Examples of the alcohol include alcohols having 1 to 5 carbon atoms such as methanol, ethanol and butanol. These can be used alone or in combination of two or more. The concentration of the copolymer in alcohol is selected from the range of 20 to 50% by weight.

As the saponification catalyst, for example, an alkali metal hydroxide such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium methylate, or an alkali catalyst such as alcoholate can be used, and an acid can be used. It is also possible to use a catalyst. The amount of the saponification catalyst used is preferably 1 to 100 mmol equivalent with respect to the vinyl ester compound. These saponification catalysts can be used alone or in combination of two or more.

The method for producing the above-mentioned carboxyl group-modified PVA-based resin is not limited to the above-mentioned method, and for example, the PVA-based resin (partially saponified or completely saponified) is reactive with hydroxyl groups such as dicarboxylic acid, aldehyde carboxylic acid, and hydroxycarboxylic acid. It is also possible to carry out a method of post-reacting a carboxyl group-containing compound having a certain functional group.

When a sulfonic acid-modified PVA-based resin modified with a sulfonic acid group is used, for example, vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, metaallyl sulfonic acid, 2-acrylamide-2-methylpropane sulfonic acid, etc. A method of copolymerizing a copolymerized component of sulfonic acid or a salt thereof with a vinyl ester compound and then saponifying the sulfonic acid, vinyl sulfonic acid or a salt thereof, 2-acrylamide-2-methylpropanesulfonic acid or a salt thereof, and the like with PVA. It can be manufactured by a method of adding Michael to a based resin or the like.

In addition to the unsaturated monomer having a carboxyl group and the vinyl ester compound, other general monomers may be contained within a range that does not impair the water solubility, and the polymerization may be carried out. Examples of the body include alkyl esters of ethylenically unsaturated carboxylic acids, allyl esters of saturated carboxylic acids, α-olefins, alkyl vinyl ethers, alkyl allyl ethers, and (meth) acrylamide, (meth) acrylonitrile, styrene, and vinyl chloride. Etc. can be used. These can be used alone or in combination of two or more.

[Unmodified PVA (A2) and Unmodified PVA (A3)]
Unmodified PVA can be produced by saponifying a vinyl ester-based polymer usually obtained by polymerizing a vinyl ester-based compound. The unmodified PVA (A2) and the unmodified PVA (A3) used in the present invention can also be produced in the same manner. As the vinyl ester compound, the same compound as the anionic group-modified PVA resin (A1) can be used, and the polymerization method and saponification are the same as those of the anionic group-modified PVA resin (A1). Can be done in a way.

In the present invention, the unmodified PVA (A2) and the unmodified PVA (A3) are unmodified PVA having different viscosities from each other.

The viscosity (α) of the unmodified PVA (A2) at 20 ° C. is 21 to 80 mPa · s, preferably 25 to 70 mPa · s, particularly preferably 30 to 60 mPa · s, and even more preferably 35. ~ 50 mPa · s. If the viscosity is too small, the sealing strength at the time of water sealing tends to decrease or the mechanical strength of the film tends to decrease, and if it is too large, the viscosity of the aqueous solution at the time of film formation tends to be high and the productivity tends to decrease. ..

The viscosity (β) of the unmodified PVA (A3) at 20 ° C. is 1 to 20 mPa · s, preferably 2 to 18 mPa · s, particularly preferably 3 to 15 mPa · s, and even more preferably. It is 4 to 13 mPa · s. If the viscosity is too small, the sealing strength at the time of water sealing tends to decrease or the mechanical strength of the film tends to decrease, and if it is too large, the viscosity of the aqueous solution at the time of film formation tends to be high and the productivity tends to decrease. ..

Further, the difference (α-β) between the 4% by weight aqueous solution viscosity (α) of the unmodified PVA (A2) at 20 ° C. and the 4% by weight aqueous solution viscosity (β) of the unmodified PVA (A3) at 20 ° C. is 10 to 10. It is preferably 50 mPa · s, more preferably 15 to 45 mPa · s, and particularly preferably 20 to 40 mPa · s. If the difference in viscosity of the 4% by weight aqueous solution is too small, the water seal strength tends to decrease, and if it is too large, the water solubility tends to decrease.

The average saponification degree of the unmodified PVA (A2) and the unmodified PVA (A3) is usually 80 mol% or more, preferably 82 to 99 mol%, and particularly preferably 85 to 90 mol%. If the average degree of saponification is too small, the solubility of the water-soluble film in water tends to decrease over time depending on the pH of the drug to be packaged, and if the average degree of saponification is too large, the film is formed. The thermal history tends to significantly reduce the solubility in water.

Further, it is preferable to use the unmodified PVA (A2) and the unmodified PVA (A3) having the same average saponification degree. The difference in the average saponification degree between the unmodified PVA (A2) and the unmodified PVA (A3) is preferably within 5 mol%, particularly preferably within 3 mol%. If the difference in the average saponification degree is too large, the solubility in water tends to decrease.

The PVA-based resin (A) of the present invention contains the unmodified PVA (A2) and the unmodified PVA (A3) with the above-mentioned anionic group-modified PVA-based resin (A1) as a main component. Here, the main component means a component that occupies the majority of the whole, and the content of the anionic group-modified PVA-based resin (A1) is preferably 70% by weight or more, preferably 80% by weight or more of the PVA-based resin (A). It is more preferable to contain the above.

The content of unmodified PVA (A2) in the PVA-based resin (A), to the anionic group-modified PVA-based resin (A1) 100 parts by weight, Ri 20 parts by der, more preferably 3 to 15 It is by weight, particularly preferably 5 to 13 parts by weight, particularly preferably 6 to 10 parts by weight. The content of unmodified PVA (A3) in the PVA-based resin (A), to the anionic group-modified PVA-based resin (A1) 100 parts by weight, Ri 0.5-10 parts by weight der, more preferably Is 1 to 7 parts by weight, particularly preferably 1.5 to 5 parts by weight, and particularly preferably 2 to 4 parts by weight. If the content is too small, the water seal strength tends to decrease, and if the content is too large, the water solubility tends to decrease.

The content ratio (A2 / A3) of the unmodified PVA (A2) and the unmodified PVA (A3) is usually 1/9 to 9/1, preferably 5/5 to 9/1, particularly preferably in terms of weight ratio. Is 6/4 to 8/2. If the content ratio of the unmodified PVA (A2) to the unmodified PVA (A3) is too small, the water seal strength tends to decrease or the mechanical strength tends to decrease, and if it is too large, the water solubility tends to decrease. There is.

The viscosity of the 4 wt% aqueous solution of the PVA-based resin (A) at 20 ° C. is usually 5 to 50 mPa · s, preferably 13 to 45 mPa · s, and particularly preferably 17 to 40 mPa · s. If the viscosity is too small, the sealing strength at the time of water sealing tends to decrease, and if it is too large, the viscosity of the aqueous solution at the time of film formation tends to be high and the productivity tends to decrease.
In the present invention, the viscosity of the 4 wt% aqueous solution is a value measured according to JIS K 6726 3.11.2.

In the present invention, resins other than the anionic group-modified PVA-based resin (A1), unmodified PVA (A2) and unmodified PVA (A3), for example, the degree of saponification, viscosity, modified species, modified amount and the like are different. The PVA-based resin may be contained in the PVA-based resin (A) within a range that does not impair the effects of the present invention.

[Plasticizer (B)]
In the present invention, it is preferable to include the plasticizer (B) in the water-soluble film from the viewpoint of giving flexibility to the water-soluble film, and it is more preferable to use the following two types of plasticizer (B) in combination.

One of the plasticizers (B) is a polyhydric alcohol (b1) having a melting point of 80 ° C. or higher (hereinafter, may be abbreviated as a plasticizer (b1)), and the other has a melting point of 80 ° C. or higher. A polyhydric alcohol (b2) having a temperature of 50 ° C. or lower (hereinafter, may be abbreviated as a plasticizer (b2)) is tough during the production of water-soluble films and packaging, and packaging for liquid chemicals. It is preferable in terms of shape stability over time when it is made into a body.

As the polyhydric alcohol (b1) having a melting point of 80 ° C. or higher, most of sugar alcohols, monosaccharides and polysaccharides can be applied. Among them, for example, salicyl alcohol (83 ° C.) and catechol (105 ° C.). ° C.), resorcinol (110 ° C.), hydroquinone (172 ° C.), bisphenol A (158 ° C.), bisphenol F (162 ° C.), dihydric alcohols such as neopentylglycol (127 ° C.), fluorochlorsinol (218 ° C.), etc. Trihydric alcohols, erythritol (121 ° C), traytoll (88 ° C), pentahydric alcohols such as pentaerythritol (260 ° C), xylitol (92 ° C), arabitol (103 ° C), fusitol (153 ° C), glucose ( 146 ° C.), pentahydric alcohols such as fructose (104 ° C.), hexahydric alcohols such as mannitol (166 ° C.), sorbitol (95 ° C.), inositol (225 ° C.), lactitol (146 ° C.), sucrose (186 ° C.), Examples thereof include octahydric alcohols such as trehalose (97 ° C.) and 9-valent or higher alcohols such as martitol (145 ° C.). These can be used alone or in combination of two or more. The numbers in parentheses above indicate the melting points of each compound.
Among the above, those having a melting point of 85 ° C. or higher, particularly preferably 90 ° C. or higher, are preferable in terms of the tensile strength of the water-soluble film. The upper limit of the melting point is preferably 300 ° C., particularly preferably 200 ° C.

Further, in the present invention, it is preferable that the number of hydroxyl groups in one molecule of the plasticizer (b1) is 4 or more in terms of compatibility with the PVA-based resin, and more preferably 5 to 10, in particular. The number is preferably 6 to 8, and specific examples thereof include sorbitol, sucrose, and trehalose.

Further, in the present invention, the plasticizer (b1) preferably has a molecular weight of 150 or more, more preferably 160 to 500, and particularly preferably 180 to 400, in terms of the toughness of the water-soluble film. Specifically, for example, sorbitol, sucrose and the like can be mentioned as suitable ones.

On the other hand, as the polyhydric alcohol (b2) having a melting point of 50 ° C. or lower, most aliphatic alcohols can be applied, and for example, ethylene glycol (-13 ° C.), diethylene glycol (-11 ° C.), and the like are preferable. Triethylene glycol (-7 ° C), propylene glycol (-59 ° C), tetraethylene glycol (-5.6 ° C), 1,3-propanediol (-27 ° C), 1,4-butanediol (20 ° C) , 1,6-hexanediol (40 ° C), tripropylene glycol, dihydric alcohols such as polyethylene glycol with a molecular weight of 2000 or less, trihydric or higher such as glycerin (18 ° C), diglycerin, triethanolamine (21 ° C). Alcohol can be mentioned. From the viewpoint of flexibility of the water-soluble film, a film having a melting point of 30 ° C. or lower, particularly preferably 20 ° C. or lower is preferable. The lower limit of the melting point is usually −80 ° C., preferably −10 ° C., and particularly preferably 0 ° C. These can be used alone or in combination of two or more. The numbers in parentheses above indicate the melting points of each compound.

Further, in the present invention, it is easy to control the flexibility near room temperature (25 ° C.) when the number of hydroxyl groups in one molecule of the plasticizer (b2) is 4 or less, particularly 3 or less. Specifically, for example, glycerin and the like are preferable.

Further, in the present invention, the plasticizer (b2) preferably has a molecular weight of 100 or less, more preferably 50 to 100, and particularly preferably 60 to 95, from the viewpoint of easy control of flexibility. Specifically, for example, glycerin and the like can be mentioned.

In the present invention, a plasticizer (b3) other than the above-mentioned plasticizers (b1) and (b2) can be used in combination, and examples of the plasticizer (b3) include trimetylolpropane (58 ° C.) and diethylene glycol. Alcohols such as monomethyl ether, cyclohexanol, carbitol, polypropylene glycol, ethers such as dibutyl ether, carboxylic acids such as stearic acid, oleic acid, linoleic acid, linolenic acid, sorbic acid, citric acid, adipic acid, cyclohexanone, etc. Examples thereof include ketones, monoethanolamine, triethanolamine, ethylenediamine, amines such as imidazole compounds, and amino acids such as alanine, glycine, aspartic acid, glutamic acid, histidine, lysine, and cysteine. These can be used alone or in combination of two or more.

In the present invention, the content of the plasticizer (B) is preferably 20 parts by weight or more, particularly 25 to 70 parts by weight, and further 30 to 60 parts by weight with respect to 100 parts by weight of the PVA-based resin (A). It is preferably parts by weight, particularly 35 to 50 parts by weight. If the content of the plasticizer (B) is too small, the toughness of the water-soluble film tends to be impaired over time when a liquid such as a liquid chemical is packaged into a package. If it is too much, the mechanical strength tends to decrease.

The content weight ratio (b1 / b2) of the plasticizer (b1) and the plasticizer (b2) is preferably 0.1 to 5, more preferably 0.35 to 4.5, and particularly preferably 0.35 to 4.5. It is 0.4 to 4, more preferably 0.5 to 3.5, and particularly preferably 0.7 to 3. If the content weight ratio is too small, the water-soluble film tends to be too soft, the sealing strength at low temperature tends to decrease, blocking tends to occur easily, and if it is too large, the water-soluble film tends to be hard. It tends to be too brittle and brittle even in low humidity environments.

The contents of the plasticizer (b1) and the plasticizer (b2) are 5 to 40 parts by weight, and further 8 to 40 parts by weight, based on 100 parts by weight of the PVA-based resin (A). It is preferably 30 parts by weight, particularly preferably 10 to 25 parts by weight, and the plasticizer (b2) is preferably 5 to 40 parts by weight, more preferably 10 to 35 parts by weight, and particularly preferably 15 to 30 parts by weight.
If the amount of the plasticizer (b1) is too small, the water-soluble film tends to be too soft and blocking tends to occur, and if it is too large, the water-soluble film tends to be too hard and tends to become brittle even in a low humidity environment. is there. Further, if the amount of the plasticizer (b2) is too small, the water-soluble film tends to be too hard and tends to be brittle even in a low humidity environment, and if it is too large, the water-soluble film tends to be too soft and blocking is likely to occur. There is.

Further, the total amount of the plasticizer (b1) and the plasticizer (b2) is preferably 70% by weight or more, more preferably 80% by weight or more, and particularly 87% by weight or more, based on the entire plasticizer (B). In particular, it is preferably 90% by weight or more, more preferably 95% by weight or more. Particularly preferably, the entire plasticizer (B) is composed of only the plasticizer (b1) and the plasticizer (b2). If the total amount of the plasticizers (b1) and (b2) is too small, the mechanical strength tends to decrease.

Further, in the present invention, it is usually preferable to further contain a filler (C), a surfactant (D) and the like.

[Filler (C)]
The filler (C) used in the present invention is contained for the purpose of blocking resistance, and specific examples thereof include inorganic fillers and organic fillers, with which organic fillers are preferable. The average particle size is preferably 0.1 to 50 μm, more preferably 0.5 to 40 μm. The average particle size can be measured by, for example, a laser diffraction type particle size distribution measuring device or the like.

The average particle size of the inorganic filler is preferably 1 to 10 μm, and if the average particle size is too small, the effect of dispersing the water-soluble film in water tends to be small, and if it is too large. When the water-soluble film is molded, it tends to have pinholes or its appearance deteriorates when it is stretched.

Specific examples of the inorganic filler include talc, clay, silicon dioxide, diatomaceous soil, kaolin, mica, asbestos, gypsum, graphite, glass balloon, glass beads, calcium sulfate, barium sulfate, ammonium sulfate, calcium sulfite, calcium carbonate. , Whisker-like calcium carbonate, magnesium carbonate, dosonite, dolomite, potassium nitrate, carbon black, glass fiber, alumina fiber, boron fiber, processed mineral fiber, carbon fiber, carbon hollow sphere, bentonite, montmorillonite, copper powder, sodium sulfate, Potassium Sulfate, Zinc Sulfate, Copper Sulfate, Iron Sulfate, Magnesium Sulfate, Aluminum Sulfate, Aluminum Potassium Sulfate, Ammonium Nitrate, Sodium Nitrate, Potassium Nitrate, Aluminum Nitrate, Ammonium Chloride, Sodium Chloride, Potassium Chloride, Magnesium Chloride, Calcium Chloride, Sodium Phosphate , Potassium nitrate, calcium citrate and the like. These can be used alone or in combination of two or more.

The organic filler preferably has an average particle size of 0.5 to 50 μm, more preferably 1 to 40 μm, particularly preferably 2 to 30 μm, and further preferably 3 to 25 μm. If the average particle size is too small, the cost tends to be high, and if it is too large, the water-soluble film tends to become pinholes when stretched by the molding process.

Examples of such an organic filler include starch, melamine-based resin, polymethyl (meth) acrylate-based resin, polystyrene-based resin, and biodegradable resin such as polylactic acid. As the organic filler, a biodegradable resin such as a polymethyl (meth) acrylate resin, a polystyrene resin, or a starch is preferably used. These can be used alone or in combination of two or more.

Examples of the above-mentioned starch include raw starch (corn starch, horse bell starch, sweet potato starch, wheat starch, kissaba starch, sago starch, tapioca starch, morokoshi starch, rice starch, bean starch, kudzu starch, warabi starch, hass starch, etc. Hishi starch, etc.), physically modified starch (α-starch, fractionated amylose, moist heat-treated starch, etc.), enzyme-modified starch (hydrolyzed dextrin, enzymatically degraded dextrin, amylose, etc.), chemically degraded modified starch (acid-treated starch, hypoa) Chloric acid oxidized starch, dialdehyde starch, etc.), chemically modified starch derivatives (esterified starch, etherified starch, cationized starch, crosslinked starch, etc.) and the like can be mentioned. Among them, it is preferable to use raw starch, especially corn starch and rice starch, from the viewpoint of easy availability and economy. These can be used alone or in combination of two or more.

The content of the filler (C) is preferably 1 to 30 parts by weight, more preferably 2 to 25 parts by weight, particularly 2.5 to 20 parts by weight, based on 100 parts by weight of the PVA-based resin (A). It is preferably a part. If the content is too small, the blocking resistance tends to decrease, and if it is too large, the water-soluble film tends to become pinholes when stretched by the molding process.

[Surfactant (D)]
The surfactant (D) used in the present invention is contained for the purpose of improving the peelability from the cast surface during the production of a water-soluble film, and is usually a nonionic surfactant, a cationic surfactant, or an anion. Surfactants can be mentioned. Examples of the nonionic surfactant include polyoxyethylene nonylphenyl ether, polyoxyethylene octyl nonyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene sorbitan monolaurate, and polyoxyethylene sorbitan mono. Polyoxyethylene such as palmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyalkylene alkyl ether phosphate monoethanolamine salt, polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, etc. Examples thereof include alkyl amino ethers, which are used alone or in combination of two or more. Of these, polyoxyalkylene alkyl ether phosphoric acid ester monoethanolamine salt and polyoxyethylene lauryl amino ether are preferable from the viewpoint of production stability. These can be used alone or in combination of two or more.

The content of the surfactant (D) is preferably 0.01 to 3 parts by weight, more preferably 0.1 to 2.5 parts by weight, based on 100 parts by weight of the PVA-based resin (A). In particular, it is preferably 0.5 to 2 parts by weight. If the content is too small, the peelability between the cast surface of the film-forming device and the water-soluble film formed tends to decrease, and the productivity tends to decrease. If the content is too large, the water-soluble film is used as a packaging material. There is a tendency to cause inconveniences such as a decrease in adhesive strength at the time of sealing.

In the present invention, other water-soluble polymers (for example, sodium polyacrylate, polyethylene oxide, polyvinylpyrrolidone, dextrin, chitosan, chitin, methylcellulose, hydroxyethylcellulose, etc.) and other water-soluble polymers are used as long as the object of the invention is not impaired. , Fragrance, rust preventive, colorant, bulking agent, defoamer, ultraviolet absorber, liquid paraffin, fluorescent whitening agent, bitterness component (for example, denatonium benzoate, etc.) and the like can be contained. These can be used alone or in combination of two or more.

Further, in the present invention, it is preferable to add an antioxidant from the viewpoint of suppressing yellowing. Examples of such antioxidants include sulfites such as sodium sulfite, potassium sulfite, calcium sulfite, and ammonium sulfite, tartrate acid, ascorbic acid, sodium thiosulfate, catechol, and longalit, among which sulfites, particularly sulfites. Sodium is preferred. The blending amount is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, and particularly preferably 0.3 to 3 parts by weight with respect to 100 parts by weight of the PVA-based resin (A).

<Water-soluble film>
The thickness of the water-soluble film of the present invention is appropriately selected depending on the intended use and the like, but is preferably 10 to 120 μm, more preferably 30 to 110 μm, and particularly preferably 45 to 100 μm. If the thickness is too thin, the mechanical strength of the PVA-based film tends to decrease, and if it is too thick, the dissolution rate in water tends to be slow, and the film forming efficiency also tends to decrease.

Further, in the present invention, the water content of the obtained PVA-based film (water-soluble film) is preferably 3 to 15% by weight, particularly 5 to 14% by weight, in terms of mechanical strength and sealing property. Further, it is preferably 6 to 13% by weight. If the water content is too low, the film tends to be too hard, and if it is too high, blocking tends to occur. The adjustment to such a water content can be achieved by appropriately setting drying conditions and humidity control conditions.
The water content is measured in accordance with JIS K 6726 3.4, and the obtained volatile matter value is used as the water content.

The water-soluble film of the present invention is mainly composed of a PVA-based resin (A), preferably a plasticizer (B), and if necessary, a filler (C), a surfactant (D), and the like, and water is used. It is obtained by dissolving or dispersing the film, preparing a film-forming raw material, and forming the film. For such film formation, for example, a melt extrusion method or a casting method can be adopted, and the casting method is preferable in terms of film thickness accuracy. Here, the main body means a component that has a great influence on the characteristics of the water-soluble film of the present invention, and the content of the component is usually 30% by weight or more, preferably 30% by weight or more of the whole film-forming raw material excluding water. Is 50% by weight or more.

In the casting method, for example, the above water is added to the PVA-based resin (A) (powder) to dissolve the PVA-based resin to obtain a PVA-based resin aqueous solution, preferably a plasticizer (B) and other formulations. Add the material to obtain a film-forming raw material. Alternatively, water is added to and dissolved in a resin composition containing a PVA-based resin (A), preferably a plasticizer (B) and various formulations to obtain a film-forming raw material. The solid content concentration of the film-forming raw material is preferably 10 to 50% by weight, particularly preferably 15 to 40% by weight, and further preferably 20 to 35% by weight. If the concentration is too low, the productivity of the water-soluble film tends to decrease, and if it is too high, the viscosity becomes too high, it takes time to defoam the dope, and die lines are generated during the formation of the water-soluble film. Tend to do.

As the dissolution method, normal temperature dissolution, high temperature dissolution, pressure dissolution and the like are usually adopted, and among them, high temperature dissolution and pressure dissolution are preferable because there are few undissolved substances and the productivity is excellent.
The melting temperature is usually 80 to 100 ° C., preferably 90 to 100 ° C. in the case of high temperature melting, and usually 80 to 130 ° C., preferably 90 to 120 ° C. in the case of pressure melting.
The dissolution time is usually 1 to 20 hours, preferably 2 to 15 hours, and more preferably 3 to 10 hours. If the dissolution time is too short, undissolved substances tend to remain, and if the dissolution time is too long, productivity tends to decrease.

Further, in the melting step, examples of the stirring blade include a paddle, a full zone, a max blend, a twister, an anchor, a ribbon, a propeller, and the like.
Further, after dissolution, the obtained film-forming raw material is subjected to a defoaming treatment, and examples of such defoaming methods include static defoaming, vacuum defoaming, biaxial extrusion defoaming and the like. .. Of these, static defoaming and biaxial extrusion defoaming are preferable.
The temperature for static defoaming is usually 50 to 100 ° C., preferably 70 to 95 ° C., and the defoaming time is usually 2 to 30 hours, preferably 5 to 20 hours.

The film-forming raw material is passed through a slit such as a T-die, poured onto a cast surface such as a metal surface of an endless belt or a drum roll or a surface of a plastic base material such as a polyethylene terephthalate film, dried, and further if necessary. The PVA-based film of the present invention can be obtained by heat treatment.
For example, it can be carried out under the following film forming conditions.

The temperature of the discharge portion of the film-forming raw material at the time of film-forming is preferably 60 to 98 ° C, particularly 70 to 95 ° C. If the temperature is too low, the drying time tends to be long and the productivity tends to decrease, and if it is too high, foaming or the like tends to occur.

At the time of film formation, the film formation speed is preferably 3 to 80 m / min, particularly preferably 5 to 60 m / min, and further preferably 8 to 50 m / min.
Further, the heat treatment can be performed by a thermal roll, but other examples include floating and far-infrared treatment. In particular, it is preferable to use a heat roll in terms of productivity. The heat treatment temperature is preferably 50 to 150 ° C., particularly preferably 70 to 130 ° C., and the heat treatment time is preferably 1 to 60 seconds, particularly 3 to 50 seconds, and further. Is preferably 5 to 40 seconds.

Further, a PVA-based film can also be obtained by casting a film-forming raw material on a plastic base material such as a polyethylene terephthalate film or a polyethylene film or a metal base material using an applicator and drying it.

In the present invention, the film formation is preferably carried out in an environment of, for example, 10 to 35 ° C, particularly 15 to 30 ° C. The humidity is usually 70% RH or less.

The surface of the PVA-based film may be plain, but from the viewpoints of blocking resistance, slipperiness during processing, reduction of adhesion between products, and appearance, an embossed pattern is formed on one or both sides of the PVA-based film. It is also preferable to perform uneven processing such as fine uneven pattern and special engraving pattern.
In such uneven processing, the processing temperature is usually 60 to 150 ° C., preferably 80 to 140 ° C. The processing pressure is usually 2 to 8 MPa, preferably 3 to 7 MPa. The processing time depends on the processing pressure and the film forming speed, but is usually 0.01 to 5 seconds, preferably 0.1 to 3 seconds.
Further, if necessary, a cooling treatment may be performed after the uneven processing treatment in order to prevent unintended stretching of the film due to heat.

In the present invention, the obtained PVA-based film can be wound into a core tube (S1) to form a film roll. The obtained film roll can be supplied as a product as it is, but preferably, it is wound around a core tube (S2) having a length corresponding to a film width of a desired size and supplied as a film roll.

The core tube (S1) for winding the film has a cylindrical shape, and the material thereof can be appropriately selected from metal, plastic and the like, but metal is preferable in terms of robustness and strength.
The inner diameter of the core tube (S1) is preferably 3 to 30 cm, more preferably 10 to 20 cm.
The wall thickness of the core tube (S1) is preferably 1 to 30 mm, more preferably 2 to 25 mm.
The length of the core tube (S1) needs to be longer than the width of the film, and it is preferable that the length of the core tube (S1) protrudes from the end of the film roll by 1 to 50 cm.

The core tube (S2) has a cylindrical shape, and the material thereof can be appropriately selected from paper, metal, plastic, etc., but paper is preferable in terms of weight reduction and handling.
The inner diameter of the core tube (S2) is preferably 3 to 30 cm, more preferably 10 to 20 cm.
The wall thickness of the core tube (S2) is preferably 1 to 30 mm, more preferably 3 to 25 mm.
The length of the core tube (S2) may be as long as or longer than the width of the PVA-based film of the product, and is preferably the same to 50 cm longer.

When wound around the core tube (S2), the PVA-based film is slit to a desired width.
Such a slit is slit by using a shear blade, a leather blade, or the like, but it is preferable to slit by a shear blade from the viewpoint of smoothness of the slit cross section.

In the present invention, the obtained film roll is wrapped with a packaging film made of a water vapor barrier resin, and the film is not particularly limited, but has a moisture permeability of 10 g / m ² / day (according to JIS Z 0208). Measurement) The following can be used. Specific examples include, for example, a single-layer film such as high-density polyethylene, low-density polyethylene, polypropylene, polyester, polyvinylidene chloride-coated polybropyrene, glass-deposited polyester, or a laminated film thereof, or a split cloth, paper, or non-woven fabric. And the laminated film with. Examples of the laminated film include a laminated film of glass-deposited polyester and polyethylene, a laminated film of polyvinylidene chloride-coated polybropyrene and polyethylene, and the like.

It is preferable that such a film is subjected to antistatic treatment from the viewpoint of preventing foreign matter from being mixed in, and the antistatic agent may be kneaded into the film or coated on the surface. In the case of kneading, an antistatic agent of about 0.01 to 5% by weight is used with respect to the resin, and in the case of surface coating, ^{an antistatic agent of about 0.01 to 1 g / m 2 is used.}
As the antistatic agent, for example, alkyldiethanolamine, polyoxyethylenealkylamine, higher fatty acid alkanolamide, sorbitan fatty acid ester and the like are used.

Next, the film roll is wrapped with a wrapping film of a steam barrier resin, and then a wrapping film made of an aluminum material is further wrapped. As such a film, an aluminum foil, an aluminum foil and a moisture-resistant plastic film are laminated. Film (for example, laminated film of aluminum foil and polyethylene film), laminated film of aluminum vapor-deposited film and moisture-resistant plastic film (for example, laminated film of aluminum-deposited polyester film and polyethylene film), laminated film of alumina-deposited film and moisture-resistant plastic film (For example, a laminated film of an alumina vapor-deposited polyester film and a polyethylene film) and the like. In the present invention, a laminated film of an aluminum foil and a polyolefin film and a laminated film of an aluminum vapor-deposited film and a polyolefin film are particularly useful, and particularly stretched polypropylene. A laminated film composed of a film / polyethylene film / aluminum foil / polyethylene film, a laminated film composed of a stretched polypropylene film / low density polyethylene film / aluminum foil, and the like are useful.

For packaging, the inner wrapping film made of water vapor barrier resin and the outer wrapping film made of aluminum material may be sequentially wrapped, and the excess portion in the width direction may be pushed into the core tube.

The film roll of the present invention is provided with protective pads having core tube through holes at both ends of the film roll, either directly or after packaging, in order to prevent scratches on the edges and adhesion of foreign substances such as dust. Can be done.
As for the shape of the protective pad, a disk-shaped sheet or film is practical according to the film roll. In order to make the protective effect remarkable, it is preferable to add a buffer function such as a foam, a woven fabric, or a non-woven fabric. Further, a desiccant may be separately enclosed in order to protect the film roll from humidity, or may be laminated or mixed in the protective pad.
Plastic is advantageous as the material of the protective pad, and specific examples thereof include polystyrene, polyethylene, polypropylene, polyester, and polyvinyl chloride.

Further, as the protective pad containing the desiccant, for example, calcium chloride, silica gel, molecular sieves, saccharides, particularly saccharides having high osmotic pressure, desiccants such as water-absorbent resins, or water-absorbing agents are used as natural celluloses, synthetic celluloses, etc. A moisture-absorbing layer that is dispersed, impregnated, coated and dried in a moldable material such as glass cloth or non-woven fabric, and these hygroscopic agents or water-absorbing agents are applied to the above-mentioned moldable material, polyester film, polyethylene film, polypropylene film, Teflon ( Registered trademark) Examples thereof include those sandwiched between thermoplastic resin films such as films.
Examples of commercially available sheet desiccants are "ID Sheet" manufactured by ID Co., Ltd., "Arrow Sheet" and "Zeo Sheet" manufactured by Shinagawa Kasei Co., Ltd., and "High Sheet Dry" manufactured by High Sheet Industry Co., Ltd. And so on.

The film roll packaged by such means is supported by providing brackets (support plates) on the projecting portions at both ends of the core tube or placing the projecting portions at both ends on a pedestal, and is supported in the so-called air without touching the ground. It is preferable that the product is stored and transported in a floating state. Brackets are used when the film width is relatively small, and mounts are used when the film width is relatively large.
The bracket is made of plywood or a plastic plate, and its size may be such that the four sides of the bracket are larger than the diameter of the film roll.

Then, a pair of brackets are arranged and fitted upright on the core tube protrusions at both ends of the film roll so as to face each other, and are provided on the film roll. The fitting may be provided with a hollow hole slightly larger than the diameter of the core tube in the central portion of the bracket, or may be hollowed out in a U shape from the upper portion to the central portion of the bracket so that the core tube can be easily inserted.

Film rolls supported by brackets are stored and transported in cartons such as cardboard boxes, but when using rectangular brackets, the four corners should be cut off to facilitate storage work. preferable.
Further, it is advantageous to fix the pair of brackets with a binding tape so that they do not wobble, and the side surface (thickness portion) of the brackets has the same width as the tape so that the tape does not move or loosen at that time. It is also practical to provide a tape misalignment prevention groove to some extent.

When storing or transporting the packaged film roll, it is desirable to avoid extremely high and low temperature, low humidity and high humidity conditions, specifically, the temperature is 10 to 30 ° C and the humidity is 40 to 75% RH. ..

The water-soluble film of the present invention thus obtained is useful for various packaging applications, and above all, it is useful for unit packaging applications such as chemicals. The drug is not particularly limited and may be alkaline, neutral or acidic, and the shape of the drug may be any of granules, tablets, powders, powders, liquids and the like, but particularly in water. Drugs that are dissolved or dispersed are preferred, and are particularly useful for packaging liquid drugs.

<Drug packaging>
The drug package of the present invention comprises a liquid drug encapsulated in a package made of a water-soluble film. The size of the drug package is usually 10 to 50 mm in length, preferably 20 to 40 mm. The thickness of the film of the package made of the water-soluble film is usually 10 to 120 μm, preferably 15 to 110 μm, and more preferably 20 to 100 μm. The amount of the liquid drug contained is usually 5 to 50 mL, preferably 10 to 40 mL.

The liquid drug preferably has a pH value of 6 to 12, particularly preferably 7 to 11, and a water content of 15% by weight or less, particularly preferably 15% by weight or less, when dissolved or dispersed in water. It is preferably 0.1 to 10% by weight, more preferably 0.1 to 7% by weight, and the film is not gelled or insolubilized and has excellent water solubility.
The pH value is measured in accordance with JIS K 3362 8.3. The water content is measured according to JIS K 3362 7.21.3.

In addition, examples of liquid chemicals include liquid chemicals used for various washings, sterilization, surface finishing, etc., such as washing clothes and detergents for dishes and the like. Specific examples thereof include liquid detergents, softening agents, fragrance finishing agents, bleaching / sterilizing agents, and the like, and among them, liquid detergents are preferable.

The surface of the drug package of the present invention is on the outer surface of the package (water-soluble film) from the viewpoints of blocking resistance, slipperiness during processing, reduction of adhesion between products (packages), and appearance. It is preferable that the embossed pattern, the fine uneven pattern, the special engraved pattern, or the like is subjected to uneven processing, but it may be smooth.

Further, the drug package of the present invention in which a liquid drug is packaged retains a shape containing the liquid drug during storage. Then, during use (during washing), the package (water-soluble film) comes into contact with water, so that the package dissolves and the contained liquid drug flows out of the package.

A known method can be adopted when packaging a liquid drug into a package using the water-soluble film of the present invention. For example, (1) a method of heat-sealing, (2) a method of water-sealing, (3) a method of glue-sealing, and the like can be mentioned. Among them, the (2) water-sealing method is versatile and useful.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
In the example, "part" and "%" mean the weight standard.

Prior to the examples, the following carboxyl group-modified PVA and two types of unmodified PVA having different viscosities of 4% aqueous solution at 20 ° C. were prepared.
Carboxylic acid modified PVA (A1-1):
Viscosity of 4% aqueous solution at 20 ° C. 22 mPa · s, average saponification degree 94 mol%,
Modification amount by maleic acid monomethyl ester 2.0 mol%
-Unmodified PVA (A2-1):
Viscosity of 4% aqueous solution at 20 ° C. 40 mPa · s, average saponification degree 88 mol%
Unmodified PVA (A3-1):
4% aqueous solution viscosity at 20 ° C. 5 mPa · s, average saponification degree 88 mol%

<Example 1>
As the PVA-based resin (A), 90 parts of carboxyl group-modified PVA (A1-1), 8 parts of unmodified PVA (A2-1), 2 parts of unmodified PVA (A3-1), and a plasticizer (B). 20 parts of sorbitol, 20 parts of glycerin, 8 parts of starch (average particle size 20 μm) as filler (C), and 1 part of polyoxyalkylene alkyl ether phosphate monoethanolamine salt as surfactant (D). .4 parts and water were mixed and subjected to a dissolution treatment to obtain a film-forming raw material (solid content concentration 25%) in which starch was dispersed.
The obtained film-forming raw material was defoamed at 80 ° C. and cooled to 40 ° C. The PVA aqueous solution was cast on a polyethylene terephthalate film, passed through a 3 m drying chamber (105 ° C.) at a speed of 0.350 m / min, and dried to obtain a PVA-based film (water-soluble film) having a thickness of 89 μm. Obtained.
The obtained PVA-based film (water-soluble film) was measured as follows.

[Peeling strength of water seal part]
(Preparation of measurement test piece)
After adjusting the humidity of the PVA-based film at 23 ° C. and 40% RH for 24 hours, the PVA-based film is arranged so that one side is parallel to the MD direction (flow direction) from the central portion in the width direction of the PVA-based film. A film was cut out into a 50 mm × 50 mm square shape to obtain a PVA-based film (1). Further, a PVA-based film is cut out from the central portion in the width direction of the PVA-based film so that one side parallel to the MD direction (flow direction) is 70 mm and one side parallel to the TD direction (width direction) is 15 mm. It was made into a film (2).

(Measurement of peel strength)
The above PVA-based film (1) cut out to a size of 50 mm × 50 mm is placed on a 30 cm square glass plate with the cast surface facing up, and a cotton swab (manufactured by Just Neo: antibacterial cotton swab) sufficiently moistened with water is used for PVA-based film. Water was applied to the film (1) in a circle having a diameter of 1 cm. After that, the cast surface side of the PVA-based film (2) cut out to another 15 mm × 70 mm was placed on the PVA-based film (1) 5 seconds after wetting it with water, and a weight of 85 g was slowly applied. Two PVA-based films were adhered to each other.
After leaving this for 10 seconds, the lower PVA-based film (1) is fixed to the substrate glass, a spring scale is attached to the end face of the upper PVA-based film (2), and the film is pulled upward at a speed of 2 mm / sec. Therefore, the peel strength (g / 15 mm) was measured. The measurement was carried out in an environment of 23 ° C. and 40% RH.

The peel strength of the water-sealed portion of the obtained PVA-based film of Example 1 was 130 g / 15 mm, and it had good sealing properties.

<Example 2, Comparative Examples 1 and 2>
In Example 1, a PVA-based film (water-soluble film) was obtained in the same manner except that the changes were made as shown in Table 1.
The obtained PVA-based film (water-soluble film) was evaluated in the same manner as in Example 1.

The evaluation results of Examples and Comparative Examples are shown in Table 1 below.

In the above embodiment, the film has a high peeling strength of the water-sealed portion and excellent sealing property. Therefore, even in a state where a liquid such as a liquid drug is packaged to form a drug agent package, the liquid liquid is used. There was no worry of leakage. On the other hand, in the comparative example, the peel strength of the water-sealed portion was low and the sealing property was inferior, so that there was a concern about liquid leakage.

[Preparation of drug packaging]
For the PVA-based film of Example 1 obtained above, a drug package was prepared by the following procedure using a package manufacturing machine manufactured by Angel.
That is, a PVA-based film (bottom film) is fixed on a mold (molded package: length 45 mm, width 42 mm, height 30 mm) at the bottom of the device, and a PVA-based film (bottom film) is also fixed at the top of the device. Top film) was fixed. The bottom film was heated for 10 seconds with a dryer that generates hot air at 90 ° C., and the bottom film was vacuum formed into a mold. After that, 20 mL of the liquid detergent (containing 5.4% glycerin, 22.6% propylene glycol, 10.4% water) used in "Ariel Power Gel Ball" manufactured by P & G was molded into a PVA-based film. I put it in. 1.5 g of water was applied to the top film, and the top film and the bottom film were pressure-bonded. After crimping for 30 seconds, the vacuum was released to obtain a drug package. The appearance of the obtained package was not a problem.

The water-soluble film of the present invention has high peeling strength at the sealed portion when water-sealed and is excellent in sealing property. Therefore, even when a liquid such as a liquid chemical is packaged into a package, the liquid leaks. It is a water-soluble film that is useful for packaging, and is particularly useful for unit packaging of chemicals, especially liquid chemicals.

Claims (9)

A water-soluble film containing a polyvinyl alcohol-based resin (A), wherein the polyvinyl alcohol-based resin (A) has an anionic group-modified polyvinyl alcohol-based resin (A1) and a 4% by weight aqueous solution viscosity (α) at 20 ° C. The anionic group-modified polyvinyl alcohol containing 21 to 80 mPa · s unmodified polyvinyl alcohol (A2) and a 4 wt% aqueous solution viscosity (β) at 20 ° C. of 1 to 20 mPa · s unmodified polyvinyl alcohol (A3). The content of the unmodified polyvinyl alcohol (A2) is 1 to 20 parts by weight, and the content of the unmodified polyvinyl alcohol (A3) is 0.5 to 10 parts by weight with respect to 100 parts by weight of the based resin (A1). water-soluble film characterized by Rukoto Oh. The difference (α-β) between the viscosity (α) of the unmodified polyvinyl alcohol (A2) at 20 ° C. and the viscosity (β) of the unmodified polyvinyl alcohol (A3) at 20 ° C. is 10 to 50 mPa. The water-soluble film according to claim 1, wherein the film is s. The water-soluble according to claim 1 or 2, wherein the content ratio (A2 / A3) of the unmodified polyvinyl alcohol (A2) and the unmodified polyvinyl alcohol (A3) is 1/9 to 9/1 (weight ratio). Sex film. The water-soluble film according to any one of claims 1 to 3 , further comprising a plasticizer (B). The water-soluble film according to claim 4 , wherein the content of the plasticizer (B) is 20 parts by weight or more with respect to 100 parts by weight of the polyvinyl alcohol-based resin (A). The water-soluble film according to any one of claims 1 to 5 , wherein the water-soluble film has a water content of 3 to 15% by weight. The water-soluble film according to any one of claims 1 to 6 , which is used for drug packaging. A drug package comprising the liquid drug packaged in the water-soluble film according to any one of claims 1 to 7. The drug package according to claim 8 , wherein the liquid drug has a pH value of 6 to 12 and a water content of 15% by weight or less when dissolved or dispersed in water.