JP2019172332A - Water-soluble film and medicine packaging body - Google Patents

Abstract

To provide a water-soluble film for medicine packaging that reduces curling in forming a packaging body with a film having been stored for a long period and thereby hardly causes a position shift to have superior productivity, and that is small in area variation rate with time even in a state in which the package body has a liquid such as a liquid detergent packaged, so that tension of the water-soluble film is not spoiled.SOLUTION: There is provided a water-soluble film for medicine packaging which contains a polyvinyl alcohol-based resin (A) and a plasticizer (B), the water-soluble film for medicine packaging being characterized in that the plasticizer (B) contains a compound expressed by general formula (1), where 1≤a≤4 (a: a positive integer), 1≤b≤4 (b: a positive integer), m≥1, n≥1, and 2≤m+n≤7 (m, n: positive integers).SELECTED DRAWING: None

Description

The present invention relates to a water-soluble film for drug packaging comprising a polyvinyl alcohol resin as a main component, and more specifically, curling is suppressed even after long-term storage, and a liquid such as a liquid detergent is packaged and packaged. The present invention relates to a water-soluble film for drug packaging that can form a good packaging body that does not impair the tension of the water-soluble film over time even in a body state, and a medicine packaging body.
Hereinafter, polyvinyl alcohol may be abbreviated as “PVA”, and a water-soluble film for drug packaging containing a polyvinyl alcohol-based resin as a main component may be simply abbreviated as “water-soluble film”.

  The PVA film is a film made of a PVA resin having water solubility while being a thermoplastic resin, and a hydrophobic film usually used for packaging films such as a polyethylene terephthalate film and a polyolefin film, Various physical properties and feeling of touch are greatly different.

  Conventionally, drug packaging (unit packaging) in which various chemicals such as agricultural chemicals and detergents are put in a bag made of a PVA-based resin film by utilizing the water-solubility of the PVA-based resin has been proposed and used for a wide range of applications. It has been.

  As such a PVA-based water-soluble film, for example, a water-soluble film obtained by blending 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 with respect to 100 parts by weight of PVA. (For example, JP-A-2001-329130) is known.

JP 2001-329130 A

  The water-soluble film disclosed in Patent Document 1 is excellent in water-solubility, blocking resistance, and impact burst strength, but has a problem in the shape stability of the film. For example, the water-soluble film is curled. As a result, when manufacturing the package, it is difficult to handle or misalignment is likely to occur at the time of sealing, so there is a concern that the production efficiency of the package will decrease, and further improvement is desired. there were. In addition, the water-soluble film has a problem in swelling property with respect to a liquid detergent, and when stored as a package, the water-soluble film swells and increases in area over time, so that the tension of the water-soluble film is eliminated. , Appearance and touch may be impaired. Therefore, a water-soluble film that does not impair the tension of the water-soluble film over time has been desired.

  Therefore, in the present invention, under such a background, curling at the time of forming a package with a film stored for a long period of time is reduced, and therefore, misalignment hardly occurs, the productivity is excellent, and the liquid The object of the present invention is to provide a water-soluble film that does not impair the tension of the water-soluble film because the rate of change in area over time is small even in the state of packaging a liquid such as a detergent into a package.

  However, as a result of intensive studies in view of such circumstances, the present inventors have found that a water-soluble film containing a plasticizer (B) having a certain length of an alkyl group and an alkanediol chain as a plasticizer contained in the water-soluble film. The inventors have found that the above object can be achieved and completed the present invention.

［式中、１≦ａ≦４（ａは正の整数）、１≦ｂ≦４（ｂは正の整数）、ｍ≧１、ｎ≧１、かつ２≦ｍ＋ｎ≦７（ｍ，ｎは正の整数）を満足する。］ That is, the gist of the present invention is a water-soluble film comprising a polyvinyl alcohol resin (A) and a plasticizer (B), wherein the plasticizer (B) is a compound represented by the following general formula (1). It is a water-soluble film for medicine packaging characterized by containing.

[Where 1 ≦ a ≦ 4 (a is a positive integer), 1 ≦ b ≦ 4 (b is a positive integer), m ≧ 1, n ≧ 1, and 2 ≦ m + n ≦ 7 (m and n are positive) Integer). ]

  The water-soluble film of the present invention reduces curling when forming a package with a film stored for a long period of time. Therefore, positional displacement is unlikely to occur, the productivity is excellent, and the area changes when immersed in a liquid detergent. Since the rate is small, the tension of the water-soluble film over time is not impaired even when the liquid is packaged to form a package.

  By using the plasticizer having the specific structure used in the present invention, it is presumed that the crystallinity of the water-soluble film can be prevented from being lowered, the swelling can be suppressed, and the area change can be suppressed.

Hereinafter, the present invention will be specifically described.
The water-soluble film of the present invention is a water-soluble film comprising a PVA resin (A) and a specific plasticizer (B).

  In the present invention, it is important that the PVA resin (A) contains a plasticizer (B) having a specific structural formula in order to prevent curling of the water-soluble film and the tension of the drug package over time. It is.

The water-soluble film of the present invention contains a PVA resin as a main component.
The PVA resin (A) used in the present invention may be an unmodified PVA resin or a modified PVA resin, preferably a modified PVA resin.
Moreover, it is also possible to use together 2 or more types of PVA-type resin from which at least 1 differs among a saponification degree, a viscosity, a modified | denatured seed | species, and a modified | denatured amount. Specific examples include using two or more kinds of unmodified PVA resins, using two or more kinds of modified PVA resins, and using two or more kinds of unmodified PVA resins and modified PVA resins. Is mentioned.

  The unmodified PVA resin is a resin mainly composed of a vinyl alcohol structural unit obtained by saponifying a polyvinyl ester resin obtained by polymerizing a vinyl ester compound, and a vinyl alcohol structural unit corresponding to the degree of saponification. And vinyl ester structural units remaining without being saponified.

  Examples of such vinyl ester compounds include vinyl formate, vinyl acetate, vinyl trifluoroacetate, vinyl propionate, vinyl butyrate, vinyl caprate, vinyl laurate, vinyl versatate, vinyl palmitate, and vinyl stearate. Although it is mentioned, it is preferable to use vinyl acetate. The vinyl ester compounds may be used alone or in combination of two or more.

  The copolymerization method of the vinyl ester compound and the unsaturated monomer copolymerizable with the vinyl ester compound may be any known polymerization method such as solution polymerization method, emulsion polymerization method, suspension polymerization method, etc. However, it is usually carried out by a solution polymerization method using an alcohol such as methanol, ethanol or isopropyl alcohol as a solvent.

  The average saponification degree of the PVA resin (A) used in the present invention is preferably 80 mol% or more, more preferably 82 to 99.8 mol%, particularly preferably 85. ˜99.5 mol%. If the average saponification degree is too small, the water solubility tends to decrease. Even if the average saponification degree is too large, the water solubility tends to decrease.

  Moreover, it is preferable that the 4 weight% aqueous solution viscosity in 20 degreeC of PVA-type resin (A) used by this invention is 10-50 mPa * s, More preferably, it is 15-45 mPa * s, Most preferably, it is 20-40 mPa * s. s. If the viscosity is too small, the mechanical strength of the film as a packaging material tends to decrease, and if it is too large, the aqueous solution viscosity during film formation tends to be high and productivity tends to decrease.

  The average degree of saponification is measured according to JIS K 6726 3.5, and the viscosity of a 4% by weight aqueous solution is measured according to JIS K 6726 3.1.2.

  The modified PVA resin is a resin mainly composed of a vinyl alcohol structural unit obtained by saponifying a polyvinyl ester resin obtained by polymerizing a vinyl ester compound. Introduced resin, consisting of vinyl alcohol structural units corresponding to the degree of saponification and vinyl ester structural units remaining without saponification, as well as unsaturated monomer structural units by copolymerization or structural units by post-reaction. The

  As the vinyl ester compound, the same compound as in the case of the PVA resin (A) can be used.

  Examples of unsaturated monomers used for copolymerized modified PVA resins (copolymerized modified PVA resins) to be copolymerized with vinyl ester monomers include ethylene, propylene, isobutylene, α-octene, α -Olefins such as dodecene, α-octadecene, unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid or salts thereof, mono- or dialkyl esters, acrylonitrile, methacrylonitrile, etc. Nitriles, amides such as acrylamide and methacrylamide, olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid and methallyl sulfonic acid or salts thereof, alkyl vinyl ethers, N-acrylamidomethyltrimethylammonium chloride, allyl trimethyl Ammonium chloride, dimethylallyl vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinylidene chloride, polyoxyalkylene (meth) allyl ether such as polyoxyethylene (meth) allyl ether, polyoxypropylene (meth) allyl ether, polyoxyethylene Polyoxyalkylene (meth) acrylates such as (meth) acrylate and polyoxypropylene (meth) acrylate, polyoxyalkylene (meth) acrylamides such as polyoxyethylene (meth) acrylamide and polyoxypropylene (meth) acrylamide, polyoxyethylene (1- (meth) acrylamide-1,1-dimethylpropyl) ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene Hydroxy group-containing α-olefins such as lylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, polyoxypropylene vinylamine, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol And copolymers of derivatives such as acylated products thereof.

  Examples of the modified PVA resin by post reaction (post modified PVA resin) include those having an acetoacetyl group by reaction with diketene, those having a polyalkylene oxide group by reaction with ethylene oxide, epoxy compounds, etc. PVA-based resins obtained by esterification, acetalization, urethanization, etherification, grafting, phosphoric esterification, oxyalkyleneation, etc. of those having a hydroxyalkyl group by reaction with aldehyde compounds having various functional groups The thing obtained by making it react can be mentioned.

  The modified PVA resin has a primary hydroxyl group in the side chain. For example, the number of primary hydroxyl groups in the side chain is usually 1 to 5, preferably 1 to 2, particularly preferably 1. Furthermore, it is preferable to have a secondary hydroxyl group in addition to the primary hydroxyl group. Examples of such modified PVA include a modified PVA resin having a hydroxyalkyl group in the side chain, a modified PVA resin having a 1,2-diol structural unit in the side chain, and the like.

  As the modified PVA resin used in the present invention, an anionic group-modified PVA resin is preferably used from the viewpoint of solubility. Examples of the anionic group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. From the viewpoint of chemical resistance and stability over time, a carboxyl group and a sulfonic acid group are preferable, and a carboxyl group is particularly preferable. .

  The carboxyl group-modified PVA resin can be produced by an arbitrary method. For example, (I) a method in which an unsaturated monomer having a carboxyl group and a vinyl ester compound are copolymerized and then saponified (II ) A method of saponifying after polymerizing a vinyl ester compound in the presence of a carboxyl group-containing alcohol, aldehyde or thiol as a chain transfer agent.

  As the vinyl ester compound in the method (I) or (II), those described above can be used, but vinyl acetate is preferably used.

  Examples of the unsaturated monomer having a carboxyl group in the method (I) include an ethylenically unsaturated dicarboxylic acid (maleic acid, fumaric acid, itaconic acid, etc.), or an ethylenically unsaturated dicarboxylic acid monoester (maleic acid monoester). Alkyl esters, fumaric acid monoalkyl esters, itaconic acid monoalkyl esters, etc.), or ethylenically unsaturated dicarboxylic acid diesters (maleic acid dialkyl esters, fumaric acid dialkyl esters, itaconic acid dialkyl esters, etc.). It is necessary to change to a carboxyl group by hydrolysis during saponification of the polymer], or an ethylenically unsaturated carboxylic acid anhydride (maleic anhydride, itaconic anhydride, etc.), or an ethylenically unsaturated monocarboxylic acid ( (Meth) acrylic acid, crotonic acid, etc. Monomers such as maleic acid, maleic acid monoalkyl ester, maleic acid dialkyl ester, maleate, maleic anhydride, itaconic acid, itaconic acid monoalkyl ester, itaconic acid dialkyl ester, among others , (Meth) acrylic acid, and the like are preferably used, and maleic acid, maleic acid monoalkyl ester, maleic acid dialkyl ester, maleate, and maleic anhydride are preferably used, and maleic acid monoalkyl ester is particularly preferable. Is preferably used.

  In the method (II), a compound derived from a thiol having a large chain transfer effect is particularly effective. Specifically, mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptostearic acid, etc. Is mentioned.

  In addition to the unsaturated monomer having a carboxyl group and the vinyl ester compound, other general monomers may be contained in a range not impairing water solubility, and polymerization may be performed. 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, (meth) acrylamide, (meth) acrylonitrile, styrene, vinyl chloride. Etc. can be used.

  In addition, the method for producing the carboxyl group-modified PVA resin is not limited to the above method. For example, polyvinyl alcohol (partially saponified product or completely saponified product) is reactive with hydroxyl groups such as dicarboxylic acid, aldehyde carboxylic acid, and hydroxycarboxylic acid. A method of post-reacting a carboxyl group-containing compound having a certain functional group can also be carried out.

  The average saponification degree of the modified PVA resin used in the present invention is preferably 80 mol% or more, more preferably 85 to 99.9 mol%, and particularly preferably 90 to 99.8 mol%. If the average degree of saponification is too small, the solubility of the film tends to decrease over time depending on the pH of the drug to be packaged. In addition, when the average saponification degree is too large, the solubility in water tends to be greatly reduced due to the heat history during film formation.

  Further, when an anionic group-modified PVA resin is used as the modified PVA resin, the average saponification degree is preferably 85 mol% or more, more preferably 88 to 99.9 mol%, particularly Preferably it is 90-99.8 mol%, Most preferably, it is 92-99.5 mol%.

  Moreover, it is preferable that the 4 weight% aqueous solution viscosity in 20 degreeC of the modified PVA-type resin used by this invention is 10-50 mPa * s, More preferably, it is 15-45 mPa * s, Most preferably, it is 20-40 mPa * s. is there. If the viscosity is too small, the mechanical strength of the film as a packaging material tends to decrease, and if it is too large, the aqueous solution viscosity during film formation tends to be high and productivity tends to decrease.

  The average degree of saponification is measured according to JIS K 6726 3.5, and the viscosity of a 4% by weight aqueous solution is measured according to JIS K 6726 3.1.2.

  The amount of modification of the modified PVA resin used in the present invention is preferably 1 to 20 mol%, more preferably 1.5 to 15 mol%, and particularly preferably 2 to 12 mol%. If the amount of modification is too small, the solubility in water tends to decrease, and if it is too large, the productivity of PVA resin tends to decrease, biodegradability tends to decrease, and blocking tends to occur. There is.

  In the present invention, when an anionic group-modified PVA resin is used as the modified PVA-based resin, the modified amount of the anionic group-modified PVA-based resin is preferably 1 to 10 mol%, more preferably 1.5 to 9 mol%, particularly preferably 2 to 8 mol%. If the amount of modification is too small, the solubility in water tends to decrease, and if it is too large, the productivity of PVA resin tends to decrease, biodegradability tends to decrease, and blocking tends to occur. There is.

  In the present invention, the PVA resin (A) can be used alone or in combination with an unmodified PVA and a modified PVA resin, and further, the saponification degree, viscosity, modified species, modified amount. Two or more different types may be used in combination. Among these, from the viewpoint of solubility and film strength, it is preferable to contain an unmodified PVA resin and a modified PVA resin, and more preferably an unmodified PVA resin and an anionic group-modified PVA resin. In particular, it is preferable to contain an unmodified PVA resin and a carboxyl group-modified PVA resin.

When the unmodified PVA resin and the modified PVA resin are contained, the content ratio (weight ratio) of the unmodified PVA resin and the modified PVA resin is unmodified PVA resin / modified PVA resin = 1/99. It is preferable that it is -99/1, More preferably, it is 5 / 95-95 / 5, Most preferably, it is 10 / 90-90 / 10.
In particular, from the viewpoint of film properties such as solubility and water-sealability, it is preferably unmodified PVA resin / modified PVA resin = 5/95 to 40/60, more preferably 6/94 to 30/70. Particularly preferred is 7/93 to 20/80. If the content ratio of the unmodified PVA resin is too small, the water-sealing property tends to decrease, and if the content ratio of the modified PVA resin is too small, the solubility tends to decrease.

  In the case where the modified PVA resin and the unmodified PVA resin are contained, the unmodified PVA preferably has a 4% by weight aqueous solution viscosity at 20 ° C. of 5 to 50 mPa · s, more preferably 10 to 10 mPa · s. It is 45 mPa · s, particularly preferably 12 to 40 mPa · s, particularly preferably 15 to 35 mPa · s. If the viscosity is too small, the mechanical strength of the film as a packaging material tends to decrease. On the other hand, if the viscosity is too large, the aqueous solution viscosity during film formation tends to be high and productivity tends to decrease.

The plasticizer (B) used in the present invention will be described.
The plasticizer (B) of the present invention is characterized by containing a compound represented by the following general formula (1).

［式中、１≦ａ≦４（ａは正の整数）、１≦ｂ≦４（ｂは正の整数）、ｍ≧１、ｎ≧１、かつ２≦ｍ＋ｎ≦７（ｍ，ｎは正の整数）を満足する。］

[Where 1 ≦ a ≦ 4 (a is a positive integer), 1 ≦ b ≦ 4 (b is a positive integer), m ≧ 1, n ≧ 1, and 2 ≦ m + n ≦ 7 (m and n are positive) Integer). ]

  The compound represented by the general formula (1) has a molecular structure having an alkanediol chain in the molecule and containing a quaternary carbon in a part of the alkanediol chain. By having an alkanediol chain in the molecule, it is excellent in water-solubility of the plasticizer and compatibility with the PVA resin, and includes a quaternary carbon in a part of the alkanediol chain, and two alkyl groups in the quaternary carbon. , The swelling balance in the thickness direction of the PVA-based resin film is stabilized and exhibits an effective action for curling suppression of the film.

  In the present invention, a, b, m, and n shown in the general formula (1) are 1 ≦ a ≦ 4 (a is a positive integer), 1 ≦ b ≦ 4 (b is positive) Integer), m ≧ 1, n ≧ 1, and 2 ≦ m + n ≦ 7 (m and n are positive integers).

  A and b shown in the formula of the general formula (1) represent the chain length of the alkyl group bonded to the quaternary carbon in the alkanediol chain. a and b are characterized by satisfying 1 ≦ a ≦ 4 and 1 ≦ b ≦ 4, respectively, more preferably 1 ≦ a ≦ 2, and 1 ≦ b ≦ 2, particularly a = 1, It is preferable that b = 1. If either one of a and b is too longer than the chain length, the water-solubility of the plasticizer is lowered and the PVA resin and the plasticizer may be phase separated, which is not preferable. Moreover, when an alkyl group is not contained in any one of them, the swelling balance in the thickness direction of the PVA-based resin film is deteriorated, and the curling of the film is likely to occur.

  M and n shown in the general formula (1) represent the chain length of the alkane alcohol group bonded to the quaternary carbon in the alkanediol chain. m and n are each characterized by m ≧ 1, n ≧ 1, and 2 ≦ m + n ≦ 7, and more preferably m ≧ 1, n ≧ 1, and 2 ≦ m + n ≦ 4, Is preferably m = 1 and n = 1. When the chain length represented by m + n is too larger than the chain length, the water solubility of the plasticizer is lowered and the PVA resin and the plasticizer may be phase separated, which is not preferable. Similarly, when either one of them does not contain an alkanediol chain, the water-solubility of the plasticizer is lowered and the PVA resin and the plasticizer may be phase-separated.

  Specific examples of the compound of m + n = 2 shown in the general formula (1) include 2,2-dimethyl-1,3-propanediol and 2-methyl-2-ethyl-1,3-propane. Diol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-2-butyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2 -Propyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2,2-dipropyl-1,3-propanediol, 2-propyl-2-butyl-1,3- Examples thereof include propanediol and 2,2-dibutyl-1,3-propanediol.

  Specific examples of the compound of m + n = 3 shown in the general formula (1) include 2,2-dimethyl-1,4-butanediol, 2-methyl-2-ethyl-1,4-butane. Diol, 2-methyl-2-propyl-1,4-butanediol, 2-methyl-2-butyl-1,4-butanediol, 2,2-diethyl-1,4-butanediol, 2-ethyl-2 -Propyl-1,4-butanediol, 2-ethyl-2-butyl-1,4-butanediol, 2,2-dipropyl-1,4-butanediol, 2-propyl-2-butyl-1,4- Examples include butanediol and 2,2-dibutyl-1,4-butanediol.

  Specific examples of the compound of m + n = 4 shown in the general formula (1) include 2,2-dimethyl-1,5-pentanediol and 2-methyl-2-ethyl-1,5-pentane. Diol, 2-methyl-2-propyl-1,5-pentanediol, 2-methyl-2-butyl-1,5-pentanediol, 2,2-diethyl-1,5-pentanediol, 2-ethyl-2 -Propyl-1,5-pentanediol, 2-ethyl-2-butyl-1,5-pentanediol, 2,2-dipropyl-1,5-pentanediol, 2-propyl-2-butyl-1,5- Pentanediol, 2,2-dibutyl-1,5-pentanediol, 3,3-dimethyl-1,5-pentanediol, 3-methyl-3-ethyl-1,5-pentanediol, 3-methyl-3- Professional 1,5-pentanediol, 3-methyl-3-butyl-1,5-pentanediol, 3,3-diethyl-1,5-pentanediol, 3-ethyl-3-propyl-1,5-pentane Diol, 3-ethyl-3-butyl-1,5-pentanediol, 3,3-dipropyl-1,5-pentanediol, 3-propyl-3-butyl-1,5-pentanediol, 3,3-dibutyl -1,5-pentanediol and the like.

  Specific examples of the compound of m + n = 5 shown in the general formula (1) include 2,2-dimethyl-1,6-hexanediol and 2-methyl-2-ethyl-1,6-hexane. Diol, 2-methyl-2-propyl-1,6-hexanediol, 2-methyl-2-butyl-1,6-hexanediol, 2,2-diethyl-1,6-hexanediol, 2-ethyl-2 -Propyl-1,6-hexanediol, 2-ethyl-2-butyl-1,6-hexanediol, 2,2-dipropyl-1,6-hexanediol, 2-propyl-2-butyl-1,6- Hexanediol, 2,2-dibutyl-1,6-hexanediol, 3,3-dimethyl-1,6-hexanediol, 3-methyl-3-ethyl-1,6-hexanediol, 3-methyl-3- Professional 1,6-hexanediol, 3-methyl-3-butyl-1,6-hexanediol, 3,3-diethyl-1,6-hexanediol, 3-ethyl-3-propyl-1,6-hexane Diol, 3-ethyl-3-butyl-1,6-hexanediol, 3,3-dipropyl-1,6-hexanediol, 3-propyl-3-butyl-1,6-hexanediol, 3,3-dibutyl -1,6-hexanediol and the like.

  Specific examples of the compound of m + n = 6 shown in the general formula (1) include 2,2-dimethyl-1,7-heptanediol and 2-methyl-2-ethyl-1,7-heptane. Diol, 2-methyl-2-propyl-1,7-heptanediol, 2-methyl-2-butyl-1,7-heptanediol, 2,2-diethyl-1,7-heptanediol, 2-ethyl-2 -Propyl-1,7-heptanediol, 2-ethyl-2-butyl-1,7-heptanediol, 2,2-dipropyl-1,7-heptanediol, 2-propyl-2-butyl-1,7- Heptanediol, 2,2-dibutyl-1,7-heptanediol, 3,3-dimethyl-1,7-heptanediol, 3-methyl-3-ethyl-1,7-heptanediol, 3-methyl-3- Professional 1,7-heptanediol, 3-methyl-3-butyl-1,7-heptanediol, 3,3-diethyl-1,7-heptanediol, 3-ethyl-3-propyl-1,7-heptane Diol, 3-ethyl-3-butyl-1,7-heptanediol, 3,3-dipropyl-1,7-heptanediol, 3-propyl-3-butyl-1,7-heptanediol, 3,3-dibutyl -1,7-heptanediol, 4,4-dimethyl-1,7-heptanediol, 4-methyl-4-ethyl-1,7-heptanediol, 4-methyl-4-propyl-1,7-heptanediol 4-methyl-4-butyl-1,7-heptanediol, 4,4-diethyl-1,7-heptanediol, 4-ethyl-4-propyl-1,7-heptanediol, 4- Tyl-4-butyl-1,7-heptanediol, 4,4-dipropyl-1,7-heptanediol, 4-propyl-4-butyl-1,7-heptanediol, 4,4-dibutyl-1,7 -Heptanediol and the like.

  Specific examples of the compound of m + n = 7 shown in the general formula (1) include 2,2-dimethyl-1,8-octanediol and 2-methyl-2-ethyl-1,8-octane. Diol, 2-methyl-2-propyl-1,8-octanediol, 2-methyl-2-butyl-1,8-octanediol, 2,2-diethyl-1,8-octanediol, 2-ethyl-2 -Propyl-1,8-octanediol, 2-ethyl-2-butyl-1,8-octanediol, 2,2-dipropyl-1,8-octanediol, 2-propyl-2-butyl-1,8- Octanediol, 2,2-dibutyl-1,8-octanediol, 3,3-dimethyl-1,8-octanediol, 3-methyl-3-ethyl-1,8-octanediol, 3-methyl-3- Professional 1,8-octanediol, 3-methyl-3-butyl-1,8-octanediol, 3,3-diethyl-1,8-octanediol, 3-ethyl-3-propyl-1,8-octane Diol, 3-ethyl-3-butyl-1,8-octanediol, 3,3-dipropyl-1,8-octanediol, 3-propyl-3-butyl-1,8-octanediol, 3,3-dibutyl -1,8-octanediol, 4,4-dimethyl-1,8-octanediol, 4-methyl-4-ethyl-1,8-octanediol, 4-methyl-4-propyl-1,8-octanediol 4-methyl-4-butyl-1,8-octanediol, 4,4-diethyl-1,8-octanediol, 4-ethyl-4-propyl-1,8-octanediol, 4- Tyl-4-butyl-1,8-octanediol, 4,4-dipropyl-1,8-octanediol, 4-propyl-4-butyl-1,8-octanediol, 4,4-dibutyl-1,8 -Octanediol and the like.

  Among them, for the purpose of stabilizing the swelling balance in the thickness direction of the PVA-based resin film and suppressing curling of the film, a, b, m, and n shown in the formula of the general formula (1) are a = a compound having a symmetric structure satisfying b and m = n, specifically, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol 2,2-dipropyl-1,3-propanediol, 2,2-dibutyl-1,3-propanediol, 3,3-dimethyl-1,5-pentanediol, 3,3-diethyl-1,5- Pentanediol, 3,3-dipropyl-1,5-pentanediol, 3,3-dibutyl-1,5-pentanediol, 4,4-dimethyl-1,7-heptanediol, 4,4-diethyl-1 7-heptane-diol, 4,4-dipropyl-1,7-heptane diol, such as 4,4-dibutyl-1,7-heptane diol. Furthermore, for the purpose of improving the water solubility of the plasticizer and the compatibility with the PVA resin, a, b, m, and n shown in the formula (1) are 1 ≦ a ≦ 2, 1 ≦. A compound having a symmetric structure satisfying b ≦ 2, a = b, 2 ≦ m + n ≦ 4, and m = n is preferable. Specifically, 2,2-dimethyl-1,3- Examples include propanediol, 2,2-diethyl-1,3-propanediol, 3,3-dimethyl-1,5-pentanediol, and 3,3-diethyl-1,5-pentanediol.

  Among these, for the purpose of maximizing the curl suppressing effect, a, b, m, n shown in the general formula (1) are a = 1, b = 1, m = 1, n. It is most preferable to use 2,2-dimethyl-1,3-propanediol where = 1.

  In this invention, a filler (C), surfactant (D), etc. can be further contained as needed.

  The filler (C) is contained for the purpose of blocking resistance, and examples thereof include organic fillers and inorganic fillers. Among them, organic fillers are preferably used. Moreover, it is preferable to use both an organic filler and an inorganic filler in combination from the viewpoint of improving the water-sealability when creating a package.

The organic filler of the present invention is a particulate substance (primary particle) composed of an organic compound and having an arbitrary shape such as a needle shape / bar shape, a layer shape, a scale shape, a spherical shape, or an aggregate of the particulate matter ( Secondary particles).
Such organic fillers are mainly selected from polymer compounds such as melamine resins, polymethyl (meth) acrylate resins, polystyrene resins, and biodegradable resins such as starch and polylactic acid. It is done. Among these, biodegradable resins such as polymethyl (meth) acrylate resins, polystyrene resins, and starch are preferable, and starch is particularly preferable from the viewpoint of dispersibility with respect to the PVA resin (A).

  Examples of the starch include raw starch (corn starch, potato starch, sweet potato starch, wheat starch, kissava starch, sago starch, tapioca starch, sorghum starch, rice starch, bean starch, kudzu starch, bracken starch, lotus starch, Castor starch, etc.), physically modified starch (α-starch, fractionated amylose, wet heat-treated starch, etc.), enzyme-modified starch (hydrolyzed dextrin, enzyme-degraded dextrin, amylose, etc.), chemically modified starch (acid-treated starch, hypochlorous starch) Chloric acid oxidized starch, dialdehyde starch, etc.), chemically modified starch derivatives (esterified starch, etherified starch, cationized starch, crosslinked starch, etc.) and the like. Of these, raw starch, especially corn starch and rice starch are preferably used from the viewpoint of availability and economy.

  The average particle diameter of the organic filler is preferably 5 to 50 μm, more preferably 10 to 40 μm, and particularly preferably 15 to 35 μm. If the average particle size is too small, the blocking property of the film tends to be high. If the average particle size is too large, fillers tend to aggregate together, resulting in a decrease in dispersibility, or a tendency to become a pinhole when the film is stretched during molding. There is.

  The average particle size of the organic filler is a value measured with a laser diffraction particle size distribution measuring device, and is calculated from the D50 value (50% cumulative particle size) of the obtained cumulative volume distribution.

The inorganic filler of the present invention is a particulate substance (primary particle) composed of an inorganic compound and having an arbitrary shape such as a needle shape / bar shape, a layer shape, a scale shape, a spherical shape, or an aggregate of the particulate matter ( Secondary particles).
Examples of the inorganic filler include silica (silicon dioxide), diatomaceous earth, titanium oxide, calcium oxide, magnesium oxide, aluminum oxide, barium oxide, germanium oxide, tin oxide, zinc oxide, and other oxide-based inorganic compounds, talc and clay. , 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 titanate, 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 Beam, aluminum sulfate, potassium aluminum sulfate, ammonium nitrate, sodium nitrate, potassium nitrate, aluminum nitrate, ammonium chloride, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium phosphate, potassium chromate, and the like. These may be used alone or in combination of two or more.

  Among them, it is preferable to use an oxide-based inorganic compound and talc, more preferably titanium oxide, talc, from the point that the hydrogen bonding action with the PVA resin (A) is excellent and the effect of improving water sealability is increased. Silica is preferably used, and silica is particularly preferably used.

  The average particle size of the inorganic filler is preferably 1 to 20 μm, more preferably 2 to 15 μm, and particularly preferably 3 to 10 μm. If the average particle size is too small, the blocking property of the film tends to be high, and the flexibility and toughness of the film tend to be lowered. If it is too large, the effect of improving the water sealing property tends to be difficult to obtain.

  The average particle size of the inorganic filler is a value measured with a laser diffraction particle size distribution measuring device, and is calculated from the D50 value (50% cumulative particle size) of the obtained cumulative volume distribution.

  It is preferable that content of the said filler (C) is 1-30 weight part with respect to 100 weight part of PVA-type resin (A), Most preferably, it is 2-25 weight part, More preferably, it is 2.5-20. Parts by weight. When the content is too small, the blocking property tends to be high, and when it is too large, the flexibility and toughness of the film tend to be lowered.

  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 the PVA film, and is usually a nonionic surfactant, a cationic surfactant, an anion. Surfactant is mentioned. For example, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl nonyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan Polyoxyethylene alkylamino ethers such as monostearate, polyoxyethylene sorbitan monooleate, polyoxyalkylene alkyl ether phosphate monoethanolamine salt, polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether These can be used alone or in combination of two or more. Of these, polyoxyalkylene alkyl ether phosphate monoethanolamine salt and polyoxyethylene lauryl amino ether are preferable in terms of production stability.

  About content of this surfactant (D), it is preferable that it is 0.01-3 weight part with respect to 100 weight part of PVA-type resin (A), More preferably, it is 0.05-2.5 weight part. Particularly preferred is 0.1 to 2 parts by weight. When the content is too small, the peelability between the cast surface of the film forming apparatus and the formed PVA-based film tends to decrease, and the productivity tends to decrease. When the content is too large, the water-soluble film is used as a package. There is a tendency to cause inconvenience such as a decrease in adhesive strength at the time of sealing.

  Further, other water-soluble polymers (for example, sodium polyacrylate, polyethylene oxide, polyvinyl pyrrolidone, dextrin, chitosan, chitin, methylcellulose, hydroxyethylcellulose, etc.), perfumes, rust prevention, etc. within the range that does not hinder the object of the invention An agent, a coloring agent, a bulking agent, an antifoaming agent, an ultraviolet absorber, liquid paraffins, a fluorescent brightening agent, a bitter component (for example, denatonium benzoate, etc.) and the like can also be contained. These may be used alone or in combination of two or more.

  Moreover, in this invention, it is preferable to mix | blend antioxidant from the point of yellowing suppression. Examples of such antioxidants include sulfites such as sodium sulfite, potassium sulfite, calcium sulfite, and ammonium sulfite, tartaric acid, ascorbic acid, sodium thiosulfate, tecol, longalite, and the like. Among these, sulfites, particularly sodium sulfite 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 resin (A). It is.

<Production of PVA film>
The PVA-based film before the surface coating and heat treatment of water described above can be produced by the following method.
(I) PVA-based resin (A), preferably a plasticizer (B), and if necessary, a PVA-based resin composition further containing a filler (C), a surfactant (D) and the like in water A step of producing a film-forming raw material by dissolving, (II) a step of casting the film-forming raw material obtained in the step (I), and (III) a step of drying the cast film-forming raw material. is there.
Hereinafter, each step will be specifically described.

[[I] dissolution step]
In the dissolution step, the PVA-based resin composition is dissolved or dispersed with water to prepare an aqueous solution or aqueous dispersion that serves as a film forming raw material.
In addition, a melt | dissolution process shows the process until a PVA-type resin composition melt | dissolves or disperse | distributes to water and obtains the film forming raw material without an undissolved substance.
As a method for dissolving the PVA-based resin composition in water, normal temperature dissolution, high temperature dissolution, pressure dissolution, etc. are usually employed. Among them, there are few undissolved materials, and high temperature dissolution from the viewpoint of excellent productivity. Pressure dissolution is preferred.
The dissolution temperature is usually 80 to 100 ° C., preferably 90 to 100 ° C. in the case of high-temperature dissolution, and is usually 80 to 130 ° C., preferably 90 to 120 ° C. in the case of pressure dissolution. The dissolution time may be appropriately adjusted depending on the dissolution temperature and the pressure during dissolution, but 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 products tend to remain, and if the dissolution time is too long, productivity tends to decrease.

In the melting step, examples of the stirring blade include paddle, full zone, max blend, twister, anchor, ribbon, and propeller.
Further, after the dissolution, defoaming treatment is performed on the obtained PVA resin aqueous solution. Examples of the defoaming method include stationary defoaming, vacuum defoaming, and biaxial extrusion defoaming. It is done. Of these, stationary defoaming and biaxial extrusion defoaming are preferable. The temperature for stationary 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 solid concentration of the film forming raw material is preferably 10 to 50% by weight, more preferably 15 to 40% by weight, and particularly preferably 20 to 35% by weight. If the concentration is too low, the productivity of the film tends to decrease. If the concentration is too high, the viscosity becomes too high, and it takes time to defoam the film forming raw material, or a die line tends to occur during film formation. There is.

[[II] casting process]
In the film forming step, the film forming raw material prepared in the dissolving step and the monohydric alcohol compounding step having 1 to 3 carbon atoms is formed into a film shape and subjected to a drying treatment as necessary, so that the moisture content is 15% by weight. It adjusts to the PVA-type film made into the following.
In film formation, for example, methods such as a melt extrusion method and a casting method can be adopted, and the casting method is preferable in terms of film thickness accuracy.
When performing the casting method, for example, (ii) a method of casting the film forming raw material on a cast surface such as a metal surface by passing it between gaps using an applicator, a bar coater, etc. (ii) T type The PVA-based film of the present invention is produced by discharging from a slit such as a slit die and casting the film-forming raw material by a method such as casting on a cast surface such as an endless belt or a metal surface of a drum roll, and the like. be able to.

  The temperature of the film-forming raw material immediately before casting is preferably 60 to 98 ° C, particularly preferably 70 to 95 ° C. If the temperature is too low, the viscosity of the film forming raw material tends to increase and the productivity of the PVA-based film tends to decrease, and if it is too high, foaming or the like tends to occur.

[[III] Drying step]
After casting, the film-forming raw material is dried on the cast surface. The surface temperature of the cast surface is preferably 50 to 110 ° C, particularly preferably 70 to 100 ° C. If the surface temperature is too low, the moisture content of the film increases due to insufficient drying and tends to be blocked, and if it is too high, the film-forming raw material tends to foam and the film formation tends to be poor.
In drying during film formation, drying by a hot roll, drying by blowing hot air on a film using a floating dryer, drying by a far infrared device, a dielectric heating device, or the like can be used in combination.

  The film-forming raw material is dried until the moisture content is 15% by weight or less by the above drying treatment, and then peeled off from the cast surface. (If further drying is performed using a hot roll after peeling from the cast surface, peeling is performed from the dry hot roll. To obtain a PVA film. The PVA-type film peeled from the cast surface (or the dry heat roll) is cooled in an environment of 10 to 35 ° C.

In addition, the surface of the PVA film of the present invention may be a plane, but on one side or both sides of the PVA film in terms of blocking resistance, slipperiness during processing, reduction in adhesion between products, and appearance. It is also preferable to perform uneven processing such as an embossed pattern, a fine uneven pattern, and a 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 is usually 0.01 to 5 seconds, preferably 0.1 to 3 seconds, although it depends on the processing pressure and the film forming speed.
Moreover, you may perform a cooling process after an uneven | corrugated processing in order to prevent unintentional extending | stretching of the film by a heat | fever as needed.
The water-soluble film of the present invention thus obtained is used for unit packaging of chemicals such as agricultural chemicals and detergents, (hydraulic pressure) transfer films, sanitary products such as napkins and paper diapers, filth treatment products such as ostomy bags, blood-absorbing sheets, etc. It is useful for various packaging applications such as medical supplies, temporary substrates such as seedling sheets, seed tapes, and embroidery base fabrics.

<Water-soluble film for drug packaging>
The water-soluble film of the present invention can be suitably used particularly as a water-soluble film for drug packaging. The water-soluble film for drug packaging is preferably a water-soluble film for detergent packaging or a water-soluble film for agricultural chemical packaging, and particularly preferably a water-soluble film for liquid detergent packaging.

Examples of the drug include agricultural chemicals such as insecticides, fungicides, and herbicides, fertilizers, detergents, and the like, and detergents are particularly preferable.
The shape of the drug may be liquid or solid, and in the case of liquid, it is liquid, and in the case of solid, it may be granular, tablet, powder or the like.
The drug is preferably a drug used by dissolving or dispersing in water. Further, the pH of the drug may be alkaline, neutral or acidic.

<Drug package>
As a medicine package of the present invention, the above-mentioned medicine is included in a package made of a water-soluble film. Since it is packaged with a water-soluble film, it is used for applications in which the entire package is put into water and the drug is dissolved or dispersed in water after the water-soluble film is dissolved, so that the effect of the drug can be expressed. Therefore, it is suitable for a unit drug package in which a relatively small amount of drug such as one dose is packaged.

    The drug package of the present invention is manufactured, for example, by bonding the ends of two water-soluble films cut into a square shape and putting the drug therein. The length of one side of such a cut water-soluble film is usually 10 to 50 mm, preferably 20 to 40 mm. Moreover, the thickness of this water-soluble film is 10-120 micrometers normally, Preferably it is 15-110 micrometers, More preferably, it is 20-100 micrometers. The amount of the drug to be encapsulated, for example, the liquid detergent is usually 5 to 50 mL, preferably 10 to 40 mL.

  The drug package of the present invention usually has a smooth surface. However, embossed patterns, fine uneven patterns, special engraving patterns on the outer surface of the package (water-soluble film) in terms of blocking resistance, slipperiness during processing, reduced adhesion between products (package), and appearance , Etc. may have been subjected to uneven processing. In addition, the medicine package of the present invention in which a liquid detergent is packaged retains the shape containing the liquid detergent during storage. At the time of use (during washing), the package (water-soluble film) comes into contact with water, so that the liquid detergent contained in the package is dissolved and flows out of the package.

  When a liquid detergent is packaged to form a package using the water-soluble film of the present invention, a known method can be employed. For example, (1) a method for heat sealing, (2) a method for water sealing, (3) a method for sealing with glue, and the like (2) a method for water sealing is versatile and advantageous.

As the liquid detergent, the pH value when dissolved or dispersed in water is preferably 6 to 12, particularly preferably 7 to 11, and the water content is preferably 15% by weight or less, particularly 0. 0.1 to 10% by weight, more preferably 0.1 to 7% by weight, and the film is excellent in water solubility without gelation or insolubilization.
The liquid drug is fluid and has a viscosity that is not particularly limited as long as it is a liquid drug that changes its shape according to the container, but it is preferably 10 to 200 mPa · s. In addition, the viscosity of this liquid chemical | medical agent is measured with the B-type rotational viscometer under normal temperature.
The pH value is measured according to JIS K 3362 8.3. The water content is measured according to JIS K 3362 7.21.3.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the examples, “parts” and “%” mean weight basis.

<Example 1>
As the PVA resin (A), 100 parts of a carboxyl group-modified PVA (A) having a 4% aqueous solution viscosity at 20 ° C. of 22 mPa · s, an average saponification degree of 94 mol% and a modification amount of 2.0 mol% with maleic acid monomethyl ester 20 parts of 2,2-dimethyl-1,3-propanediol (a = 1, b = 1, m = 1, n = 1 in the general formula (1)) as a plasticizer (B), filler (C) 8 parts of starch (average particle size 20 μm), 0.2 parts of polyoxyalkylene alkyl ether phosphate monoethanolamine salt and 455 parts of water as surfactant (D) were mixed at a temperature of 90 ° C. A dissolution treatment for 90 minutes was performed to obtain a PVA-based resin aqueous solution (solid content concentration 22%) in which starch was dispersed.
The obtained PVA aqueous solution was degassed at 80 ° C. and cooled to 40 ° C., and then the PVA aqueous solution was cast on a polyethylene terephthalate film, and 0.350 m / min in a 3 m drying chamber (105 ° C.). The dried film was peeled from the polyethylene terephthalate film to obtain a water-soluble film having a thickness of 80 μm and a moisture content of 7% by weight.

[Curl properties]
(Evaluation methods)
The obtained water-soluble film was cut out in the flow direction (MD) 160 mm and the width direction (TD) 120 mm, and one side of the TD of the film was fixed as shown below (FIG. 1), and the film was 23 ° C., 50% RH. The length (R) of the curl diameter of the film when viewed from the bottom when it was suspended for 10 days in the environment was evaluated. In addition, when the curl diameters differed at both ends, the smaller value was adopted as the length (R) of the curl diameter.
When the curl shape is a perfect circle, the diameter length of the perfect circle is the length of the curl diameter (R). When the curl shape is an ellipse, the major axis length and minor axis length of the ellipse are averaged. The numerical value (calculated by (major axis length + minor axis length) / 2) was defined as the curl diameter length (R).

[Figure 1]

Evaluation criteria 3 points: No curling, 2 points where no curl diameter exists ... 1 point where the curl diameter length (R) is 15 mm or more and film curve deformation due to curling is loose ... The curl length (R) is less than 15 mm and the film curve deformation due to curl is strong.

[Area swelling for liquid detergents]
(Evaluation methods)
The obtained PVA-based water-soluble film was cut into a square shape with a flow direction (MD) of 100 mm and a width direction (TD) of 100 mm, and placed on a flat glass plate, and the MD and TD dimensions were measured with calipers. Next, using the liquid detergent solution in “Arière Power Gel Ball S (manufactured by P & G)”, the film was immersed in 4 mL of liquid detergent solution maintained at 40 ° C. for 24 hours, and then the film was taken out immediately. Then, it was placed on a flat glass plate, the dimensions of MD and TD were each measured with calipers, and the area change rate (%) was determined by the following equation. In addition, said measurement operation was performed in the environment of 23 degreeC and 50% RH. The results are shown in Table 1.
〔formula〕
Area change rate (%) = {(area after immersion−area before immersion) / area before immersion} × 100

Comparative Example 1
In Example 1, except that the plasticizer (B) was changed to 20 parts of trimellirol propane (a = 2, b: not applicable, m = 1, n = 1 of the general formula (1)), A PVA-based water-soluble film having a thickness of 80 μm and a moisture content of 7% by weight was obtained. The results are shown in Table 1.

Comparative Example 2
In Example 1, the thickness of the plasticizer (B) was changed in the same manner except that glycerin (a = 0 in general formula (1), b: excluded, m = 1, n = 1) was changed to 20 parts. A PVA water-soluble film having a thickness of 80 μm and a moisture content of 7% by weight was obtained. The results are shown in Table 1.

  In Example 1 using the water-soluble film of the present invention, the curl of the water-soluble film is small even after storage for a long period of time, the curl suppressing effect is excellent, and the area change rate with respect to the liquid detergent is small. A film which did not lose its tension over time when used in the above was obtained. On the other hand, Comparative Example 1 using trimethylolpropane as the plasticizer had a large area change rate, although the curl suppressing effect was obtained. In Comparative Example 2 containing glycerin, curl was greatly generated after long-term storage, and the area change rate was large, so that the tension when used in a package was inferior.

  The water-soluble film of the present invention has curling suppressed even after long-term storage, and further, even if a liquid is packaged, it does not lose its tension over time, so it can be used for drug-packaging water-soluble films (unit packaging of drugs such as agricultural chemicals and liquid detergents) Useful for applications.

Claims (10)

A water-soluble film for drug packaging comprising a polyvinyl alcohol resin (A) and a plasticizer (B), wherein the plasticizer (B) contains a compound represented by the following general formula (1) Water-soluble film for drug packaging.

[Where 1 ≦ a ≦ 4 (a is a positive integer), 1 ≦ b ≦ 4 (b is a positive integer), m ≧ 1, n ≧ 1, and 2 ≦ m + n ≦ 7 (m and n are positive) Integer). ]   The water-soluble film for drug packaging according to claim 1, wherein the content of the plasticizer (B) is 5 parts by weight or more with respect to 100 parts by weight of the polyvinyl alcohol resin (A).   In the said Formula (1), it is a = b and m = n, The water-soluble film for medicine packaging of Claim 1 or 2 characterized by the above-mentioned.   The water-soluble film for medicine packaging according to any one of claims 1 to 3, wherein the plasticizer (B) is 2,2-dimethyl-1,3-propanediol.   The water-soluble film for drug packaging according to any one of claims 1 to 4, further comprising a filler (C).   The water-soluble film for drug packaging according to claim 5, wherein the content of the filler (C) is 1 to 30 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin (A).   The water-soluble film for drug packaging according to any one of claims 1 to 6, wherein the polyvinyl alcohol-based resin (A) contains an anionic group-modified polyvinyl alcohol-based resin (a1).   The water-soluble film for packaging medicine according to any one of claims 1 to 7, wherein the medicine is a detergent.   The drug-soluble water-soluble film according to any one of claims 1 to 7, wherein the drug is a liquid detergent.   A drug packaging body in which a drug is packaged by the water-soluble film for drug packaging according to claim 1.