WO2017043506A1 - Water-soluble film, and chemical package - Google Patents

Abstract

Provided is a water-soluble film with which it is possible to form a good package that, after serving as a package, is tough and tear-resistant and that, even when serving as a package by packaging a liquid such as a liquid detergent, has good workability when serving as a package due to having excellent flexibility before the packaging. Further provided, as a drug package formed by packaging various chemicals using said water-soluble film, is a water-soluble film comprising a polyvinyl alcohol resin (A). Given the tensile storage elastic modulus (X₂₀) at 20°C, and the tensile storage elastic modulus (Y₂₀) at 20°C after the film is left to stand immersed for 48 hours in a 10wt%-glycerol ethanol solution at 40°C, the difference (X₂₀-Y₂₀) does not exceed 0 GPa.

Description

Water-soluble film and drug package

The present invention includes a water-soluble film (hereinafter sometimes referred to as a PVA-based film) mainly composed of a polyvinyl alcohol-based resin (hereinafter, polyvinyl alcohol may be abbreviated as PVA) and a liquid detergent. The present invention relates to a package body in which liquid is packaged. More specifically, the water-soluble film before forming the package has excellent flexibility, so that the processability when forming the package is good, and after forming the package, the water-soluble film is strong and the water-soluble film is not easily broken. The present invention relates to a water-soluble film and a medicine package that can form a 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 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. Water-soluble film (see, for example, Patent Document 1), 4 wt% aqueous solution viscosity at 20 ° C. is 10 to 35 mPa · s, average saponification degree 80.0 to 99.9 mol%, anionic group modification amount 1 to The plasticizer (B) is 20 to 50 parts by weight, the filler (C) is 2 to 30 parts by weight, and the surfactant (D) is 0.1 parts by weight per 100 parts by weight of the anionic group-modified PVA resin (A). A water-soluble film made of a resin composition containing 01 to 2.5 parts by weight (see, for example, Patent Document 2) is known.

JP 2001-329130 A JP 2004-161823 A

The water-soluble films disclosed in Patent Documents 1 and 2 are excellent in water-solubility and can be used as a medicine package in which a liquid detergent or the like is packaged. However, the film becomes softer after the packaging body than before the packaging body. Therefore, for the water-soluble film before packaging, the water-soluble film itself is relatively hard, and it is necessary to strictly control the temperature conditions during packaging. Further, after packaging, since it becomes soft, the appearance deteriorates, and there is a concern of bag breaking, so that further improvement as a water-soluble film has been demanded.

Therefore, in the present invention, in such a background, even when a liquid such as a liquid detergent is packaged to form a package, the water-soluble film before packaging is excellent in flexibility, so that it can be processed into a package. A water-soluble film capable of forming a good package that is tough and resistant to tearing after being made into a package, and a good appearance, and a drug package in which various drugs are packaged with the water-soluble film provide.

However, as a result of intensive studies in view of such circumstances, the present inventors usually found that liquid detergents often contain glycerin, and therefore, by observing the elastic behavior of the film with respect to the glycerin-containing alcohol solution, We considered that the applicability of the adhesive film to the package could be verified.

Therefore, in the water-soluble film mainly composed of PVA-based resin, the hardness of the water-soluble film before and after immersion in a predetermined solution is observed, and the tensile storage elastic modulus before film immersion is the tensile storage elastic modulus after film immersion. Before packaging a liquid detergent or other liquid by making it the same or smaller, it has excellent flexibility in order to facilitate processing when it is made into a packaging body. Then, it discovered that the water-soluble film which can form the tough and durable packaging body which has the favorable external appearance which does not break a bag can be obtained.

That is, the gist of the present invention is a water-soluble film containing a PVA resin (A), which has a tensile storage elastic modulus (X ₂₀ ) at ₂₀ ° C. and 10 weight by weight of glycerin at 40 ° C. Or a water-soluble film having a difference (X ₂₀ -Y ₂₀ ) from a tensile storage modulus (Y ₂₀ ) at 20 ° C. after standing immersed for 48 hours in a% ethanol solution of 0 GPa or less, or A water-soluble film comprising a PVA-based resin (A), which has a tensile storage modulus (X ₅ ) at 5 ° C., and the water-soluble film is allowed to stand still in a 40% glycerol 10 wt% ethanol solution for 48 hours. tensile storage modulus at 5 ° C. after location immersed (Y ₅₎ the difference between (X ₅ -Y ₅₎ is related to the water-soluble film is less than 0 GPa.

Furthermore, the present invention also provides a medicine package using the water-soluble film.

Even when the water-soluble film of the present invention is used to wrap a liquid such as a liquid detergent into a package, the water-soluble film before packaging is excellent in workability when used as a package due to its excellent flexibility, It is a water-soluble film that can form a tough, water-soluble film that does not easily break and has a good appearance after packaging, and can be used for various packaging applications, especially for unit packaging applications such as drugs. Useful.

Also, when the water-soluble film contains a plasticizer (B), it becomes more flexible when used as a medicine package.

And when content of a plasticizer (B) is 20 weight part or more with respect to 100 weight part of PVA-type resin (A), when liquid, such as a liquid detergent, is packaged and it is set as a package body, it is water-soluble with time. The strength of the adhesive film is not impaired, and the mechanical strength is also improved.

Furthermore, when the PVA-based resin (A) is an anionic group-modified PVA-based resin, the solubility in water becomes excellent.

In addition, when the water content of the water-soluble film is 3 to 15% by weight, the mechanical strength and the sealing property are improved.

Hereinafter, the present invention will be specifically described.
The water-soluble film of the present invention is a water-soluble film containing a PVA resin (A).

And the water-soluble film of this invention is a water-soluble film containing PVA-type resin (A), Comprising: Tensile storage elastic modulus (X20) in ₂₀ degreeC, and a water-soluble film are 40 degreeC glycerin. It is important that the difference (X ₂₀ -Y ₂₀ ) with respect to the tensile storage modulus (Y ₂₀ ) at 20 ° C. after standing still in a 10 wt% ethanol solution for 48 hours is 0 GPa or less, preferably It is −10 to 0 GPa, particularly preferably −3 to −0.05 GPa, and further preferably −2 to −0.1 GPa.

In the present invention, if the difference in tensile storage elastic modulus (X ₂₀ -Y ₂₀ ) is too large, the processability when making a package is deteriorated, the appearance of the package is also deteriorated, and it is easily broken. End up. In addition, when too small, there exists a tendency for a package to become hard too much and to break a bag easily.

In the present invention, the tensile storage elastic modulus (X ₂₀ ) is preferably 0.5 to 5 GPa, particularly 0.8 to 4.5 GPa, more preferably 1 to 4 GPa. If the tensile storage modulus (X ₂₀ ) is too small, the strength of the water-soluble film tends to decrease and tends to break during production, and if it is too large, the water-soluble film tends to be too hard to be easily embossed on the surface. There is.

Further, the tensile storage modulus (Y ₂₀ ) is preferably 1 to 6 GPa, particularly 1.3 to 4.5 GPa, more preferably 1.5 to 4 GPa. When the tensile storage modulus (Y ₂₀ ) is too small, the strength of the water-soluble film is lowered, and when it is used as a package for liquid detergent, it tends to break the bag. In this case, the water-soluble film tends to be too hard to feel.

The water-soluble film of the present invention is a water-soluble film containing a PVA resin (A), and has a tensile storage elastic modulus (X ₅ ) at ₅ ° C. and glycerin at 40 ° C. 10 wt% ethanol solution for 48 hours to stand soaked tensile storage modulus at 20 ° C. after (Y ₅₎ the difference between (X ₅ -Y ₅₎ it is important that at most 0 GPa, preferably It is −10 to 0 GPa, particularly preferably −3 to −0.05 GPa, and further preferably −2 to −0.1 GPa.

In the present invention, if the difference in tensile storage elastic modulus (X ₅ -Y ₅ ) is too large, the processability when forming a package is deteriorated, the appearance of the package is also deteriorated, and it is easily broken. End up. In addition, when too small, there exists a tendency for a package to become hard too much and to break a bag easily.

In the present invention, the tensile storage modulus (X ₅ ) is preferably 1 to 5 GPa, particularly 1.5 to 4.5 GPa, more preferably 2 to 4 GPa. If the tensile storage modulus (X ₅ ) is too small, the strength of the water-soluble film tends to decrease and tends to break during production. If it is too large, the water-soluble film tends to be too hard to be easily embossed on the surface. There is.

Further, the tensile storage elastic modulus (Y ₅ ) is preferably 2 to 7 GPa, particularly 2.5 to 6.5 GPa, more preferably 3 to 6 GPa. When the tensile storage modulus (Y ₅ ) is too small, the strength of the water-soluble film is lowered, and when it is used as a package for a liquid detergent, it tends to break the bag. In this case, the water-soluble film tends to be too hard to feel.

Here, each tensile storage elastic modulus is measured as follows.
That is, the tensile storage modulus at ₅ ℃ (X 5) and the tensile storage modulus at ₂₀ ℃ (X 20), a water-soluble film from the central portion in the width direction of the water-soluble film vertical 2 cm, in the transverse 5mm Cut out, vacuum dried at 80 ° C., and further dried with phosphorous pentoxide to prepare a measurement test sample. The obtained measurement test sample was measured using a dynamic viscoelasticity measuring device “DVA-225”. The storage elastic modulus was continuously measured while raising the temperature of the water-soluble film at a frequency of 10 Hz and a temperature increase rate of 5 ° C./min from −70 ° C. to 180 ° C., and the tensile storage elastic modulus (X ₅ ) The tensile storage modulus (X ₂₀ ) at 20 ° C. is measured.

The tensile storage modulus at ₅ ℃ (Y 5) and tensile storage modulus at 20 ° C. for (Y ₂₀₎ is a water-soluble film from the central portion in the width direction of the water-soluble film longitudinal 10cm, laterally 10cm After being cut out, it was left to stand for 48 hours in 4 mL of a 10% by weight ethanol solution of glycerin maintained at 40 ° C., then taken out from the solution, wiped off, further cut into 2 cm in length and 5 mm in width, and 80 ° C. And vacuum drying, and further drying with diphosphorus pentoxide to prepare a measurement test sample. The obtained measurement test sample was performed in the same manner as the measurement of the tensile storage elastic modulus (X ₅ ) and (X ₂₀ ), and the tensile storage elastic modulus (Y ₅ ) at ₅ ° C. and the tensile storage elastic modulus at 20 ° C. ( Y ₂₀ ) is measured.

Note that the above-described tensile storage elastic modulus at 20 ° C. and tensile storage elastic modulus at 5 ° C. are as follows. In the case of 20 ° C., for example, the temperature in a state where the package is left under normal conditions is used. This is because, in the case of 5 ° C., for example, the temperature in the situation where the package is left at the air temperature in winter is assumed.

Next, the PVA resin (A) used in the present invention will be described.
Examples of the PVA resin (A) used in the present invention include unmodified PVA and modified PVA resin.

The average saponification degree of the PVA resin (A) used in the present invention is preferably 80 mol% or more, particularly 82 to 99.9 mol%, more preferably 85 to 98.5 mol%, particularly It is preferably 90 to 97 mol%. Further, when unmodified PVA is used as the PVA resin (A), the average saponification degree is preferably 80 mol% or more, particularly 82 to 99 mol%, more preferably 85 to 90 mol. % Is preferred. When a modified PVA resin is used as the PVA resin (A), the average saponification degree is preferably 80 mol% or more, particularly 85 to 99.9 mol%, more preferably 90 mol%. It is preferably ˜98 mol%. Further, when an anionic group-modified PVA resin is used as the PVA resin (A), the average saponification degree is preferably 85 mol% or more, particularly 88 to 99 mol%, It is 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. 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.

The polymerization degree of the PVA-based resin (A) can be generally represented by an aqueous solution viscosity, and a 4 wt% aqueous solution viscosity at 20 ° C. is preferably 5 to 50 mPa · s, more preferably 10 to 45 mPa · s. In particular, it is preferably 15 to 40 mPa · s. When unmodified PVA is used as the PVA resin (A), the viscosity of the 4% by weight aqueous solution of unmodified PVA at 20 ° C. is preferably 5 to 50 mPa · s, more preferably 10 to 45 mPa · s. It is preferably s, particularly 15 to 40 mPa · s. When a modified PVA resin is used as the PVA resin (A), the viscosity of the 4% by weight aqueous solution at 20 ° C. of the modified PVA resin is preferably 5 to 50 mPa · s, more preferably 10 to It is preferably 45 mPa · s, particularly 15 to 40 mPa · s. If the viscosity is too small, the mechanical strength of the water-soluble 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.

In addition, said average saponification degree is measured based on JIS K 6726 3.5, and 4 weight% aqueous solution viscosity is measured according to JIS K 6726 311.2.

Examples of the modified PVA resin used in the present invention include an anionic group-modified PVA resin, a cationic group-modified PVA, and a nonionic group-modified PVA resin. Among these, it is preferable to use an anionic group-modified PVA resin from the viewpoint of solubility in water. 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, particularly a carboxyl group is preferable. .

The modification amount of the anionic group-modified PVA resin is preferably 1 to 10 mol%, more preferably 2 to 9 mol%, particularly preferably 2 to 8 mol%, particularly preferably 3 to 7 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 the PVA-based resin tends to decrease or the biodegradability tends to decrease, and also causes blocking. There is a tendency to become easy, and the practicality decreases.

In the present invention, each of the above PVA resins (A) can be used alone, or a combination of unmodified PVA and modified PVA resin, and further, saponification degree, viscosity, modified species, modified amount. Two or more different types may be used in combination. Especially, in this invention, it is preferable that PVA-type resin (A) contains modified PVA-type resin. In particular, it preferably contains an anionic group-modified PVA resin, or preferably contains an anionic group-modified PVA resin and an unmodified PVA, and particularly contains an anionic group-modified PVA resin and an unmodified PVA. It is preferable.

The content ratio (weight ratio) between the modified PVA resin and the unmodified PVA is preferably 95/5 to 60/40, particularly 94/6 to 70/30, more preferably 93/7 to 80/20. It is preferable that If the content is too small, the plasticizer tends to bleed out, and if it is too large, blocking tends to occur.

When the modified PVA resin and the unmodified PVA are used in combination, the unmodified PVA preferably has a 4% by weight aqueous solution viscosity at 20 ° C. of 5 to 50 mPa · s, more preferably 8 to 45 mPa · s. In particular, it is preferably 12 to 40 mPa · s, more preferably 15 to 35 mPa · s. If the viscosity is too small, the mechanical strength of the water-soluble 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.

Next, the water-soluble film of the present invention is produced, for example, as follows.

Unmodified PVA can be produced by saponifying a vinyl ester polymer obtained by polymerizing a vinyl ester compound.

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. Can be mentioned. Of these, vinyl acetate is preferably used as the vinyl ester compound. The vinyl ester compounds may be used alone or in combination of two or more.

The modified PVA resin is a method of copolymerizing the vinyl ester compound and an unsaturated monomer copolymerizable with the vinyl ester compound and then saponifying, or a method of post-modifying unmodified PVA. Etc. can be manufactured.

In the present invention, the following unsaturated monomer copolymerizable with the vinyl ester compound may be copolymerized. However, when a modified PVA resin is obtained, a modified group is used as the following monomer. It is necessary to copolymerize the unsaturated monomer having. Examples of unsaturated monomers include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, α-octadecene, 3-buten-1-ol, 4-penten-1-ol, 5- Derivatives such as hydroxy group-containing α-olefins such as hexen-1-ol and acylated products thereof, unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, undecylenic acid, Examples thereof include salts, monoesters, dialkyl esters, amides such as diacetone acrylamide, acrylamide and methacrylamide, olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid and methallyl sulfonic acid, and salts thereof. These may be used alone or in combination of two or more. In addition, the content rate of the said copolymerizable monomer is 10 mol% or less normally.

Examples of the modified PVA resin include those having a primary hydroxyl group in the side chain. For example, the number of primary hydroxyl groups is usually 1 to 5, preferably 1 to 2, and particularly preferably 1. It is done. In particular, it is preferable to have a secondary hydroxyl group in addition to the primary hydroxyl group. Examples thereof include a PVA resin having a 1,2-diol structural unit in the side chain and a PVA resin having a hydroxyalkyl group in the side chain. Such a PVA resin having a 1,2-diol structural unit in the side chain includes, for example, (i) a method of saponifying a copolymer of vinyl acetate and 3,4-diacetoxy-1-butene, and (ii) acetic acid. A method of saponifying and decarboxylating a copolymer of vinyl and vinyl ethylene carbonate; and (iii) saponifying and decarboxylating a copolymer of vinyl acetate and 2,2-dialkyl-4-vinyl-1,3-dioxolane. It can be produced by a method of ketalization, (iv) a method of saponifying a copolymer of vinyl acetate and glyceryl monoallyl ether, or the like.

As a polymerization method in the preparation of the PVA resin (A), for example, a known polymerization method such as a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method can be arbitrarily used. Usually, methanol, ethanol or isopropyl is used. It is carried out by a solution polymerization method using a lower alcohol such as alcohol as a solvent. In this solution polymerization, the monomer is charged in the case of a modified PVA resin. First, the whole amount of the vinyl ester compound and a part of the unsaturated monomer having a carboxyl group, for example, are charged, and polymerization is performed. Any method may be used such as a method of starting and adding the remaining unsaturated monomers continuously or in portions during the polymerization period, or a method of batch-feeding the unsaturated monomers having a carboxyl group. it can.

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

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

Examples of the saponification catalyst include alkali catalysts such as alkali metal hydroxides and alcoholates such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium methylate, and the like. It is also possible to use a catalyst. The saponification catalyst is preferably used in an amount of 1 to 100 mmol equivalents relative to the vinyl ester compound. These saponification catalysts can be used alone or in combination of two or more.

The carboxyl group-modified PVA resin in the modified PVA resin can be produced by any method, for example, (I) saponification after copolymerization of an unsaturated monomer having a carboxyl group and a vinyl ester compound. And (II) a saponification method 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), the above-mentioned compounds can be used, but vinyl acetate is preferably used.

Examples of the unsaturated monomer having a carboxyl group in the method (I) include ethylenically unsaturated dicarboxylic acid (maleic acid, fumaric acid, itaconic acid, etc.), or ethylenically unsaturated dicarboxylic acid monoester (maleic acid). Acid monoalkyl 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.) (however, these diesters) It is necessary to change to a carboxyl group by hydrolysis during 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 Salt. Among them, it is preferable to use 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, especially maleic acid monoalkyl ester. These may be used alone or in combination of two or more.

In the method (II), a compound derived from a thiol having a particularly large chain transfer effect is effective, and examples thereof include compounds represented by the following general formulas (1) to (3).

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

The method for producing the carboxyl group-modified PVA resin is not limited to the above method. For example, the PVA resin (partially saponified product or fully 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.

When a sulfonic acid-modified PVA resin modified with a sulfonic acid group is used, for example, vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, etc. A method of saponification after copolymerizing the above copolymerization component with a vinyl ester compound, Michael addition of vinylsulfonic acid or a salt thereof, 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof, etc. to a PVA resin It can be manufactured by a method or the like.

On the other hand, examples of a method for post-modifying the above-mentioned unmodified PVA include a method of converting the unmodified PVA into acetoacetate ester, acetalization, urethanization, etherification, grafting, phosphoric esterification, and oxyalkylene.

In addition to the unsaturated monomer having a carboxyl group and the vinyl ester compound, other general monomers may be contained in a range that does not impair water solubility. For example, 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. These may be used alone or in combination of two or more.

In the present invention, it is preferable that a plasticizer (B) is contained in the PVA resin (A) from the viewpoint of imparting flexibility to the water-soluble film when the medicine package is used. Only one type of plasticizer (B) can be used, or at least two types can be used in combination. In particular, the toughness of the water-soluble film itself when using at least two types as a package is used. This is preferable.

One type of the plasticizer (B) is a polyhydric alcohol (b1) having a melting point of 80 ° C. or higher (hereinafter sometimes abbreviated as plasticizer (b1)), and the other type has a melting point. A toughness at the time of manufacturing a film or a package and a package for a liquid detergent, being a polyhydric alcohol (b2) (hereinafter sometimes abbreviated as a plasticizer (b2)) of 50 ° C. or less; This is preferable in terms of shape stability over time.

As the polyhydric alcohol (b1) having a melting point of 80 ° C. or higher, many of sugar alcohols, monosaccharides and polysaccharides can be applied. Among them, for example, salicyl alcohol (83 ° C.), catechol (105 ° C.) ), Resorcinol (110 ° C.), hydroquinone (172 ° C.), bisphenol A (158 ° C.), bisphenol F (162 ° C.), dipentyl glycol (127 ° C.) and the like, phloroglucinol (218 ° C.), etc. Trihydric alcohols, tetrahydric alcohols such as erythritol (121 ° C), threitol (88 ° C), pentaerythritol (260 ° C), xylitol (92 ° C), arabitol (103 ° C), fucitol (153 ° C), glucose (146 ), Pentahydric alcohols such as fructose (104 ° C.), mannitol (16 ° C), hexahydric alcohols such as sorbitol (95 ° C), inositol (225 ° C), octahydric alcohols such as lactitol (146 ° C), sucrose (186 ° C), trehalose (97 ° C), maltitol (145 ° C), etc. Of 9 or more alcohols. These may be used alone or in combination of two or more. In addition, the inside of said () shows melting | fusing point of each compound.
Among them, those having a melting point of 85 ° C. or higher, particularly 90 ° C. or higher are preferable from the viewpoint of the tensile strength of the water-soluble film. The upper limit of the melting point is preferably 300 ° C., particularly 200 ° C.

Furthermore, in the present invention, among the plasticizers (b1), the number of hydroxyl groups in one molecule is preferably 4 or more from the viewpoint of compatibility with the PVA resin, more preferably 5 to 10, and particularly preferably. 6 to 8, specifically, for example, sorbitol, sucrose, trehalose and the like are preferable.

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 toughness of the water-soluble film. Specific examples include sorbitol, sucrose, and the like.

On the other hand, as the polyhydric alcohol (b2) having a melting point of 50 ° C. or lower, many of aliphatic alcohols are applicable. For example, ethylene glycol (−13 ° C.), diethylene glycol (−11 ° C.), 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, trivalent or higher valents such as glycerin (18 ° C), diglycerin, triethanolamine (21 ° C) Examples include alcohol. And the thing whose melting | fusing point is 30 degrees C or less, especially 20 degrees C or less is preferable at the point of the softness | flexibility of a water-soluble film. The lower limit of the melting point is usually −80 ° C., preferably −10 ° C., particularly preferably 0 ° C. These may be used alone or in combination of two or more. In the above (), the melting point of each compound is shown.

Furthermore, in the present invention, among the plasticizers (b2), the number of hydroxyl groups in one molecule is 4 or less, particularly 3 or less because flexibility at room temperature (25 ° C.) can be easily controlled. Specifically, for example, glycerin and the like are preferable.

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, in terms of easy control of flexibility. Specifically, glycerol etc. are suitable, for example.

In the present invention, a plasticizer (b3) other than the plasticizers (b1) and (b2) may be used in combination. Examples of the plasticizer (b3) include trimethylolpropane (58 ° C.), diethylene glycol. Alcohols such as monomethyl ether, cyclohexanol, carbitol, and polypropylene glycol, ethers such as dibutyl ether, carboxylic acids such as stearic acid, oleic acid, linoleic acid, linolenic acid, sorbic acid, citric acid, and adipic acid, cyclohexanone, etc. Ketones, amines such as monoethanolamine, triethanolamine, ethylenediamine and imidazole compounds, and amino acids such as alanine, glycine, aspartic acid, glutamic acid, histidine, lysine and cysteine. These may 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 with respect to 100 parts by weight of the PVA resin (A), particularly 25 to 70 parts by weight, more preferably 30 to 60 parts by weight. Part by weight, in particular 35 to 50 parts by weight is preferred. If the content of the plasticizer (B) is too small, the toughness of the water-soluble film tends to be deteriorated over time when a liquid such as a liquid detergent is packaged to form a package. In addition, when there is too much, it exists in the tendency for mechanical strength to fall.

Further, regarding the plasticizer (b1) and the plasticizer (b2), the content weight ratio (b1 / b2) is preferably 0.1 to 5, particularly 0.2 to 4.5, more preferably It is preferably 0.5 to 4, particularly 0.7 to 3. If the content ratio is too small, the water-soluble film tends to be too soft and tends to be blocked, and if it is too large, the water-soluble film tends to be too hard and tends to be brittle even in a low-humidity environment. is there.

The content of the plasticizer (b1) and the plasticizer (b2) is 5 to 40 parts by weight of the plasticizer (b1), more preferably 8 to 100 parts by weight of the PVA resin (A). The amount is preferably 30 parts by weight, particularly 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. If the amount is too large, the water-soluble film tends to be too hard and tends to be brittle even in a low humidity environment. is there. Moreover, when there is too little plasticizer (b2), there exists a tendency for a water-soluble film to become hard too much, and there exists a tendency for it to become brittle also in a low-humidity environment, and when too much, a water-soluble film becomes too soft and tends to produce blocking. There is.

Furthermore, 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 with respect to the entire plasticizer (B). In particular, it is preferably 90% by weight or more, more preferably 95% by weight or more. Particularly preferred is the case where the entire plasticizer (B) consists solely of 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.

In the present invention, a filler (C), a surfactant (D) and the like can be further contained as necessary.

The filler (C) used in the present invention is contained for the purpose of blocking resistance, and specific examples include inorganic fillers and organic fillers. Among them, organic fillers are preferable. The average particle diameter is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm. In addition, the said average particle diameter can be measured with a laser diffraction type particle size distribution measuring apparatus etc., for example.

Such an inorganic filler preferably has an average particle size of 1 to 10 μm. If the average particle size is too small, the effect of dispersibility of the water-soluble film in water tends to be small. When the water-soluble film is formed and processed, it tends to become a pinhole when it is stretched, or the appearance tends to deteriorate.

Specific examples of the inorganic filler include, for example, talc, clay, silicon dioxide, diatomaceous earth, kaolin, mica, asbestos, gypsum, graphite, glass balloon, glass beads, calcium sulfate, barium sulfate, ammonium sulfate, calcium sulfite, and 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, aluminum sulfate, potassium aluminum sulfate, ammonium nitrate, sodium nitrate, potassium nitrate, aluminum nitrate, ammonium chloride, chloride Thorium, potassium chloride, magnesium chloride, calcium chloride, sodium phosphate, potassium chromate, calcium citrate. These may be used alone or in combination of two or more.

The organic filler preferably has an average particle size of 0.5 to 20 μm, more preferably 0.5 to 10 μm, particularly preferably 0.5 to 7 μm, still more preferably 0.5 to 5 μm. is there. If the average particle size is too small, the cost tends to be high, and if it is too large, a pinhole tends to be formed when the water-soluble film is stretched.

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

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 acid) 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. These may 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 resin (A). Part. When the content is too small, the blocking resistance tends to decrease, and when the content is too large, a pinhole tends to be formed when the water-soluble film is stretched.

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, an anion. Surfactant is mentioned. Nonionic surfactants include, for example, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl nonyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene sorbitan monolaurate, 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 An alkylamino ether etc. are mentioned, It uses 1 type or in combination of 2 or more types. Of these, polyoxyalkylene alkyl ether phosphate monoethanolamine salt and polyoxyethylene lauryl amino ether are preferable in terms of production stability. These may 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 resin (A). In particular, the amount is preferably 0.5 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 water-soluble 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.

In the present invention, other water-soluble polymers (for example, sodium polyacrylate, polyethylene oxide, polyvinylpyrrolidone, dextrin, chitosan, chitin, methylcellulose, hydroxyethylcellulose, etc.) , Fragrances, rust inhibitors, colorants, extenders, antifoaming agents, ultraviolet absorbers, liquid paraffins, fluorescent brighteners, bitterness components (for example, denatonium benzoate, etc.), and the like can also be included. These may be used alone or in combination of two or more.

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, tartaric acid, ascorbic acid, sodium thiosulfate, catechol, Rongalite, etc. Among them, 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).

In the present invention, as described above, a resin composition comprising a PVA resin (A), preferably further a plasticizer (B), and further contains a filler (C) and a surfactant (D) as necessary. And this is formed into a PVA film. In forming the film, for example, a method such as a melt extrusion method or a casting method can be employed, and the casting method is preferable in terms of film thickness accuracy.

In the present invention, the casting method is performed, for example, as follows.
As the dissolution method, normal temperature dissolution, high temperature dissolution, pressure dissolution, etc. are usually employed. Among them, high temperature dissolution and pressure dissolution are preferred because there are few undissolved materials and excellent productivity.
The dissolution temperature is usually 80 to 100 ° C., preferably 90 to 100 ° C. when dissolving at high temperature, and usually 80 to 130 ° C., preferably 90 to 120 ° C. when dissolving under pressure.
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 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.

In the casting method, for example, water is added to the PVA resin (A) (powder) to form a PVA resin aqueous solution, preferably a plasticizer (B) and other blends are added, and the resin composition is dispersed in water. A liquid or aqueous solution is obtained. Alternatively, water is added to a resin composition containing a PVA resin (A), preferably a plasticizer (B) and various blends, to obtain an aqueous dispersion or aqueous solution of the resin composition. The solid concentration of the aqueous dispersion or aqueous solution of such a resin composition is preferably 10 to 50% by weight, particularly 15 to 40% by weight, more preferably 20 to 35% by weight. If the concentration is too low, the productivity of the water-soluble film tends to decrease. If the concentration is too high, the viscosity becomes too high, and it takes time to defoam the dope. Tend to. Furthermore, if the temperature of the metal surface of the endless belt or drum roll is too low, drying tends to take time, and if it is too high, foaming tends to occur during film formation.

The aqueous dispersion or aqueous solution is passed through a slit such as a T-die, cast onto a cast surface such as a metal surface of an endless belt or drum roll, or a plastic substrate surface such as a polyethylene terephthalate film, dried, and dried as necessary. The PVA film of the present invention can be obtained by further heat treatment.
For example, it can be performed under the following film forming conditions.

The temperature of the discharge part in the aqueous dispersion or aqueous solution of the PVA-based resin composition 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. If the temperature is too high, foaming or the like tends to occur.

In film formation, the film formation speed is preferably 3 to 80 m / min, particularly 5 to 60 m / min, more preferably 8 to 50 m / min.
Moreover, in heat processing, although it can also carry out with a hot roll, a floating, a far-infrared process, etc. are mentioned other than that. In particular, it is preferable in terms of productivity to carry out with a hot roll. 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, Is preferably 5 to 40 seconds.

Alternatively, an aqueous dispersion or aqueous solution of the resin composition can be cast on a plastic substrate or a metal substrate such as a polyethylene terephthalate film or a polyethylene film using an applicator, and dried to obtain a PVA film.

The thickness of the PVA film is appropriately selected depending on the application and the like, but is preferably 10 to 120 μm, more preferably 15 to 110 μm, and particularly preferably 20 to 100 μm. If the thickness is too thin, the mechanical strength of the PVA-based film tends to decrease. If the thickness is too thick, the dissolution rate in water tends to be slow, and the film forming efficiency tends to decrease.

The width of the PVA film is appropriately selected depending on the application and the like, but is preferably 300 to 5000 mm, more preferably 500 to 4000 mm, and particularly preferably 800 to 3000 mm. If the width is too narrow, the production efficiency tends to decrease, and if it is too wide, it tends to be difficult to control slackness or film thickness.

The length of the PVA-based film is appropriately selected depending on the application and the like, but is preferably 500 to 20000 m, more preferably 800 to 15000 m, and particularly preferably 1000 to 10,000 m. If this length is too short, there is a tendency that it takes time to switch the PVA film, and if it is too long, there is a tendency that the appearance defect and weight due to winding tightening become too heavy.

The surface of the PVA-based film may be a plane, but an embossed pattern or fine pattern is formed on one or both sides of the film from the viewpoints of blocking resistance, slipperiness during processing, reduced adhesion between products, and appearance. It is also preferable to perform uneven processing such as an uneven pattern, a special engraving pattern, or the like.
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.

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 properties. Further, it is preferably 6 to 13% by weight. If the moisture content is too low, the film tends to be too hard, and if it is too high, blocking tends to occur. Adjustment to such a moisture content can be achieved by appropriately setting drying conditions and humidity control conditions.
In addition, the said moisture content is measured based on JISK67263.4, and let the value of the obtained volatile matter be a moisture content.

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

The PVA-based film (water-soluble film) thus obtained has a difference (X ₂₀ -Y ₂₀ ) between the tensile storage elastic modulus (X ₂₀ ) and the tensile storage elastic modulus (Y ₂₀ ) at 20 ° C. It is important to satisfy at least one of the difference (X ₅ -Y ₅ ) between the tensile storage modulus (X ₅ ) and the tensile storage modulus (Y ₅ ) at 0 ° C., and the difference (X ₂₀ -Y ₂₀ ) Or the difference (X ₅ -Y ₅ ) is controlled within the above range, for example, (1) a method in which two or more polyhydric alcohols used as plasticizers are used in combination, in particular, a polyhydric alcohol having a large difference in melting points. (2) A method of blending more plasticizer than usual, (3) A combination of these methods, and the like. Among these, the method (1) is preferable in that the above physical properties can be controlled while maintaining various physical properties of the water-soluble film.

In this invention, the obtained PVA-type film can be made into a film roll by winding up to a core pipe (S1). Although the obtained film roll can be supplied as a product as it is, it is preferably wound around a core tube (S2) having a length corresponding to the film width of a desired size and supplied as a film roll.

The core tube (S1) for winding the film is cylindrical, and the material can be appropriately selected from metals, plastics, etc., but metal is preferred from the standpoint 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 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 preferably protrudes from 1 to 50 cm from the end of the film roll.

The core tube (S2) has a cylindrical shape, and the material thereof can be appropriately selected from paper, metal, plastic and the like, but is preferably paper 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 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 any length that is equal to or longer than the PVA film width of the product, and preferably is equal to or longer than 50 cm.

When winding on the core tube (S2), the PVA film is slit to a desired width.
Such a slit is slit using a shear blade or a leather blade, but it is preferable to slit with a shear blade in terms of the smoothness of the slit cross section.

In the present invention, the obtained film roll is packaged with a packaging film of a water vapor barrier resin, but such a film is not particularly limited, but the moisture permeability is 10 g / m ² · 24 hr (according to JIS Z 0208). Measurement) The following can be used. Specific examples include, for example, single-layer films such as high-density polyethylene, low-density polyethylene, polypropylene, polyester, polyvinylidene chloride-coated polypropylene, and glass-deposited polyester, or laminated films thereof, or split cloth, paper, and non-woven fabric. A laminated film etc. are mentioned. Examples of the laminated film include a laminated film of glass-deposited polyester and polyethylene, a laminated film of polyvinylidene chloride-coated polypropylene and polyethylene, and the like.

Such a film is preferably subjected to an antistatic treatment from the viewpoint of preventing the introduction of foreign substances, 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 relative to the resin is used, 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, polyoxyethylene alkylamine, higher fatty acid alkanolamide, sorbitan fatty acid ester and the like are used.

Next, it is preferable to wrap a packaging film made of an aluminum material after the film roll is packaged with a packaging film of a water vapor barrier resin, and as such a film, an aluminum foil, an aluminum foil and a moisture-resistant plastic film can be used. Laminated film (for example, laminated film of aluminum foil and polyethylene film), laminated film of aluminum vapor deposited film and moisture resistant plastic film (eg laminated film of aluminum vapor deposited polyester film and polyethylene film), laminated film of alumina vapor deposited film and moisture resistant plastic film (For example, a laminated film of an alumina-deposited polyester film and a polyethylene film). Lum, laminated film of aluminum vapor-deposited film and polyolefin film are useful, especially laminated film composed of stretched polypropylene film / polyethylene film / aluminum foil / polyethylene film, stretched polypropylene film / low density polyethylene film / aluminum foil A laminated film or the like is useful.
For packaging, the inner steam-barrier resin packaging film and the outer aluminum material are used for packaging, and the remaining portion in the width direction is pushed into the core tube.

In the film roll of the present invention, core tube through holes are formed at both ends of the film roll directly from the film roll or after being wrapped with a packaging film in order to prevent scratches at the end and adhesion of foreign matters such as dust. A protective pad can be attached.
As the shape of the protective pad, a disc-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 foam, woven fabric, and non-woven fabric. Moreover, in order to protect a film roll from moisture, a desiccant can be enclosed separately, or it can be laminated or mixed in the protective pad.
The protective pad material is advantageously plastic, and specific examples thereof include polystyrene, polyethylene, polypropylene, polyester, polyvinyl chloride, and the like.

Examples of the protective pad containing the desiccant include, for example, calcium chloride, silica gel, molecular sieves, saccharides, particularly saccharides with high osmotic pressure, desiccants or water absorbents such as water absorbent resins, natural celluloses, synthetic celluloses, A moisture absorbent layer dispersed, impregnated, coated and dried in a moldable material such as glass cloth or non-woven fabric, and these desiccant or water absorbing agent can be used for the above moldable material, polyester film, polyethylene film, polypropylene film, Teflon ( And those sandwiched between thermoplastic resin films such as (registered trademark) film.
Examples of commercially available sheet-like desiccants include “Idie Sheet” manufactured by IDY, “Arrow Sheet” and “Zeo Sheet” manufactured by Shinagawa Kasei Co., Ltd., and “High Sheet Dry” manufactured by High Sheet Industrial Co., Ltd. .

The film roll wrapped by such means is supported by providing brackets (support plates) at both end projections of the core tube or by placing the both end projections on a gantry, and without being grounded, so-called air Storage and transportation are preferably performed in a floating state. A bracket is used when the film width is relatively small, and a gantry is used when the film width is relatively large.
The bracket is made of a veneer plate or a plastic plate, and the size of the bracket is sufficient if the four sides of the bracket are larger than the diameter of the film roll.

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

The film roll supported by the bracket is stored and transported in a carton such as a cardboard box, but when using a rectangular bracket, the four corners should be cut off to facilitate the work during storage. preferable.
In addition, it is advantageous to fix the pair of brackets with a binding tape so that the pair of brackets do not wobble. At that time, the side of the bracket (thickness portion) is the same as the tape width so that the tape does not move or loosen. It is also practical to provide a tape misalignment prevention groove.

When storing or transporting packaged film rolls, it is desirable to avoid extreme high and low temperatures, low humidity, and high humidity conditions. Specifically, the temperature should be 10-30 ° C. and humidity 40-75% RH. .

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

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. It is preferably 1 to 10% by weight, more preferably 0.1 to 7% by weight, and the film does not gel or insolubilize and has excellent water solubility.
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.

<Drug package>
As a medicine package of the present invention, a liquid detergent is included in a package made of a water-soluble film. The size of the medicine package is usually 10 to 50 mm in length, preferably 20 to 40 mm. In addition, the thickness of the package of the water-soluble film is usually 10 to 120 μm, preferably 15 to 110 μm, more preferably 20 to 100 μm. The amount of the liquid detergent to be included is usually 5 to 50 mL, preferably 10 to 40 mL.

The surface of the drug package of the present invention is usually smooth. 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 using the water-soluble film of the present invention to package a liquid detergent into a package, 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.

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.

The following were prepared as PVA-type resin.
Carboxyl group-modified PVA (A1): 4% aqueous solution viscosity at 20 ° C. 22 mPa · s, average saponification degree 94 mol%, modified amount with maleic acid monomethyl ester 2.0 mol%
Carboxyl group-modified PVA (A2): 4% aqueous solution viscosity at 20 ° C. 22 mPa · s, average saponification degree 96 mol%, modified amount by maleic acid monomethyl ester 4.0 mol%
Unmodified PVA (A3): 4% aqueous solution viscosity at 20 ° C. 18 mPa · s, average saponification degree 88 mol%
Unmodified PVA (A4): 4% aqueous solution viscosity at 20 ° C. 22 mPa · s, average saponification degree 88 mol%
Unmodified PVA (A5): 4% aqueous solution viscosity at 20 ° C. 5 mPa · s, average saponification degree 88 mol%

<Example 1>
As PVA resin (A), 90 parts of carboxyl group-modified PVA (A1), 10 parts of unmodified PVA (A3), 20 parts of sorbitol (b1) and 20 parts of glycerin (b2) as plasticizer (B) 8 parts starch (average particle size 20 μm) as filler (C), 2 parts polyoxyalkylene alkyl ether phosphate monoethanolamine salt as surfactant (D), and water are mixed and dissolved. The PVA aqueous solution (solid content concentration 25%) in which starch was dispersed was obtained.
The obtained PVA aqueous solution was degassed 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 film (water-soluble film) having a thickness of 80 μm. Obtained.

The following measurements were performed on the PVA film obtained above.
[Tensile storage modulus (X ₅ ) and (X ₂₀ )]
From the central part in the width direction of the PVA-based film obtained above, the film was cut into 2 cm length and 5 mm width, vacuum-dried at 80 ° C., and further dried with diphosphorus pentoxide to prepare a measurement test sample. . Using the dynamic viscoelasticity measuring device “DVA-225”, the obtained measurement test sample was continuously measured while raising the film at a measurement frequency of 10 Hz and a temperature increase rate of 5 ° C./min from −70 ° C. to 180 ° C. The storage elastic modulus was measured, and the tensile storage elastic modulus (X ₅ ) at ₅ ° C. and the tensile storage elastic modulus (X ₂₀ ) at 20 ° C. were measured.

[Tensile storage modulus (Y ₅ ) and (Y ₂₀ )]
The film was cut into a length of 10 cm and a width of 10 cm from the center in the width direction of the PVA-based film obtained above, and then immersed in 4 mL of a 10 wt% ethanol solution of glycerin maintained at 40 ° C. for 48 hours. Then, after taking out from the solution and wiping off the solution, it was further cut into 2 cm length and 5 mm width, vacuum-dried at 80 ° C., and further dried with diphosphorus pentoxide to prepare a measurement test sample. The obtained measurement test sample was carried out in the same manner as the measurement of the tensile storage elastic modulus (X ₅ ) and (X ₂₀ ), and the tensile storage elastic modulus (Y ₅ ) at ₅ ° C. and the tensile storage elastic modulus at 20 ° C. (Y ₂₀ ) was measured.

<Examples 2-7, Comparative Examples 1-2>
In Example 1, it carried out similarly except having changed as shown in Table 1, and obtained the PVA-type film (water-soluble film).
About the obtained PVA-type film (water-soluble film), evaluation similar to Example 1 was performed.

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

From the results of Table 1 above, the water-soluble film of the example in which the tensile storage elastic modulus before the film immersion of the water-soluble film is smaller than the tensile storage elastic modulus after the film immersion is such that the film before the packaging is flexible. The film is excellent in processability when used as a package, and is a water-soluble film that can form a good package that is tough and the film is not easily torn after the package. In the water-soluble film of the comparative example in which the tensile storage elastic modulus before immersion is larger than the tensile storage elastic modulus after film immersion, the water-soluble film is a water-soluble film that can be easily broken after the packaging. I can guess.

[Production of drug packaging]
About the PVA-type film of Example 1 obtained above, the medicine packaging body was produced in the following procedures using the packaging body manufacturing machine made from Engel.
That is, a PVA film (bottom film) is fixed on a mold (package to be molded: length 45 mm, width 42 mm, height 30 mm) at the bottom of the apparatus, and PVA film ( Top film) was fixed. The bottom film was heated for 10 seconds with a dryer generating hot air at 90 ° C., and the bottom film was vacuum-formed into a mold. After that, 20 mL of liquid detergent (containing 5.4% glycerin, 22.6% propylene glycol, and 10.4% moisture) packaged in P &G's “Arière Power Gel Ball” was added to 20 mL of PVA film. did. 1.5 g of water was applied to the top film, and the top film and the bottom film were pressure bonded. After pressure bonding for 30 seconds, the vacuum was released to obtain a drug package. The appearance of the obtained package was satisfactory.

In the above embodiments, specific forms in the present invention have been described. However, the above embodiments are merely examples and are not construed as limiting. Various modifications apparent to those skilled in the art are contemplated to be within the scope of this invention.

The water-soluble film of the present invention has excellent water solubility, and even when a liquid such as a liquid detergent is packaged to form a package, the water-soluble film before packaging is made into a package by being excellent in flexibility. It is very useful as a water-soluble film that can form a good package that is tough and resistant to tearing the water-soluble film, and can be used for various packaging applications. It is particularly useful for unit packaging applications such as drugs.

Claims (11)

1. A water-soluble film containing a polyvinyl alcohol-based resin (A), which has a tensile storage modulus (X ₂₀ ) at 20 ° C. and the water-soluble film in a 10% by weight ethanol solution of glycerin at 40 ° C. for 48 hours. A water-soluble film, wherein a difference (X ₂₀ -Y ₂₀ ) from a tensile storage modulus (Y ₂₀ ) at 20 ° C. after immersion by standing is 0 GPa or less.
2. The water-soluble film according to claim 1, wherein the tensile storage modulus (X ₂₀ ) is 0.5 to 5 GPa and the tensile storage modulus (Y ₂₀ ) is 1 to 6 GPa.
3. A water-soluble film comprising a polyvinyl alcohol-based resin (A), which has a tensile storage modulus (X ₅ ) at 5 ° C. and the water-soluble film in a 10 wt% ethanol solution of glycerin at 40 ° C. for 48 hours. A water-soluble film characterized in that a difference (X ₅ -Y ₅ ) from a tensile storage modulus (Y ₅ ) at 5 ° C. after soaking is 0 GPa or less.
4. The water-soluble film according to claim 3, wherein the tensile storage elastic modulus (X ₅ ) is 1 to 5 GPa and the tensile storage elastic modulus (Y ₅ ) is 2 to 7 GPa.
5. The water-soluble film according to any one of claims 1 to 4, further comprising a plasticizer (B).
6. The water-soluble film according to claim 5, 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 resin (A).
7. The water-soluble film according to any one of claims 1 to 6, wherein the polyvinyl alcohol resin (A) is an anionic group-modified polyvinyl alcohol resin.
8. The water-soluble film according to any one of claims 1 to 7, wherein the water content of the water-soluble film is 3 to 15% by weight.
9. The water-soluble film according to any one of claims 1 to 8, which is used for drug packaging.
10. A drug package comprising the water-soluble film according to any one of claims 1 to 9 and a liquid detergent packaged therein.
11. 11. The pharmaceutical package according to claim 10, wherein the liquid detergent has a pH value of 6 to 12 when dissolved or dispersed in water and a water content of 15% by weight or less.