阅读说明：本技术 水溶性薄膜和药剂包装体、以及水溶性薄膜的制造方法 (Water-soluble film, drug package, and method for producing water-soluble film ) 是由 日里贵裕 于 2018-06-12 设计创作，主要内容包括：为了得到卷曲被抑制、成形为包装体时不易引起错位、体现良好的密封性、且制成包装体时的外观特性也优异的水溶性薄膜,提供一种水溶性薄膜,其为含有聚乙烯醇系树脂(A)作为主成分的水溶性薄膜,在20℃的水的水面上漂浮60秒时的前述水溶性薄膜的宽度方向(TD)的延展率(X<Sub>TD</Sub>)相对于流动方向(MD)的延展率(X<Sub>MD</Sub>)之比(X<Sub>TD</Sub>/X<Sub>MD</Sub>)为1.05～1.5。(To obtain a water-soluble film which is suppressed in curling, hardly causes displacement when formed into a package, exhibits good sealability, and has excellent appearance characteristics when formed into a package, a water-soluble film is providedA water-soluble film containing a polyvinyl alcohol resin (A) as a main component, wherein the water-soluble film has an elongation (X) in the width direction (TD) when floating on a water surface of water at 20 ℃ for 60 seconds TD ) Elongation (X) relative to the flow direction (MD) MD ) Ratio of (X) TD /X MD ) 1.05 to 1.5.)

1. A water-soluble film comprising a polyvinyl alcohol resin A as a main component, characterized in that the water-soluble film has an elongation X in the width direction TD when floating on a water surface of water at 20 ℃ for 60 seconds_TDElongation X relative to flow direction MD_MDRatio of X_TD/X_MD1.05 to 1.5.

2. The water-soluble film according to claim 1, wherein the water content is 3 to 15% by weight.

3. The water-soluble film according to claim 1 or 2, wherein the polyvinyl alcohol resin a is an anionic group-modified polyvinyl alcohol resin.

4. The water-soluble film according to any one of claims 1 to 3, which is used for pharmaceutical packaging.

5. A drug package comprising a package formed from the water-soluble film according to any one of claims 1 to 4 and a drug packaged in the package.

6. The pharmaceutical package of claim 5, wherein the pharmaceutical is a detergent.

7. The pharmaceutical package of claim 6, wherein the detergent is a liquid detergent.

8. A method for producing a water-soluble film according to any one of claims 1 to 4, comprising: a step of casting, drying and film-forming a film-forming material containing the polyvinyl alcohol resin A; a step of performing heat treatment so that the temperature of the film obtained by the film formation is 50 to 95 ℃; and a step of winding the heat-treated film with a draw ratio of 1.05 to 1.5.

Technical Field

The present invention relates to a water-soluble film containing a polyvinyl alcohol resin as a main component, and more particularly to: a water-soluble film which is suppressed in curling and can be formed into a package having excellent appearance characteristics without causing any strain when a drug such as a liquid detergent is packaged.

Hereinafter, polyvinyl alcohol is abbreviated as "PVA" and a water-soluble film containing a polyvinyl alcohol resin as a main component is abbreviated as "PVA-based water-soluble film" in some cases.

Background

Packaging of a drug in which various drugs such as agricultural chemicals and detergents are put into a bag formed of a film of a PVA-based resin, which has been proposed to cause water solubility of PVA, has been used in a wide range of fields.

In addition to excellent solubility, water-soluble films used for the above-mentioned pharmaceutical packaging applications are required to satisfy various properties such as good sealability, no occurrence of bag breakage, no occurrence of strain, no occurrence of reduction in stretching, and other mechanical properties and appearance properties when formed into a package.

As the water-soluble film used in the above-mentioned applications, for example, there are known water-soluble films: by containing a PVA-based resin and 2 types of plasticizers having a specific melting point in specific amounts relative to the PVA-based resin, a package having high tensile strength and tensile elongation and excellent mechanical properties and having good appearance properties can be formed without being damaged by stretching of the water-soluble film even in a liquid-packed state (see, for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

However, although the water-soluble film disclosed in patent document 1 can provide a package excellent in mechanical properties and appearance properties without causing a reduction in stretching with time, on the other hand, the film may curl depending on the production conditions, and if a curl is generated in the water-soluble film, for example, in the production of a water-soluble film package, handling is difficult or displacement is easily caused at the time of sealing, and therefore, there is a concern that the production efficiency of the package may be reduced, and further improvement is desired.

Accordingly, in the present invention, in such a context, there is provided: a water-soluble film which is suppressed in curling, hardly causes displacement when formed into a package, exhibits good sealability, and has excellent appearance characteristics when formed into a package, a drug package using the water-soluble film, and a method for producing a water-soluble film.

Means for solving the problems

Accordingly, the present inventors have conducted intensive studies in view of the above circumstances and, as a result, have found that: in the PVA-based water-soluble film, focusing on the anisotropy of the film, the following effects are obtained by imparting anisotropy that is not possessed by the conventional water-soluble film, that is, by increasing the elongation in the width direction relative to the elongation in the flow direction with respect to the elongation in the width direction and the flow direction of the film: the curl is suppressed, and when a package is formed using a water-soluble film, the package is less likely to cause displacement of a seal portion, exhibits good sealability, and is particularly suitable for water-tightness.

In detail, although there is usually no difference in the elongation ratio between the width direction and the flow direction of the film, it is considered that the film is less likely to curl without causing a difference in tension, and as a result, the present invention unexpectedly found that: the ratio of the elongation in the width direction to the elongation in the flow direction is adjusted to a specific range, whereby a water-soluble film having reduced curling and suitable for packaging applications can be obtained.

Namely, the gist of the present invention relates to a water-soluble agentAn aqueous film comprising a PVA-based resin (A) as a main component, characterized in that the film has an elongation (X) in the width direction (TD) of the aqueous film when the film floats on a water surface of water at 20 ℃ for 60 seconds_TD) Elongation (X) relative to the flow direction (MD)_MD) Ratio of (X)_TD/X_MD) 1.05 to 1.5.

Further, the present invention provides: a drug package using the water-soluble film, and a method for producing the water-soluble film.

ADVANTAGEOUS EFFECTS OF INVENTION

The water-soluble film of the present invention is suppressed in curling, and therefore, when formed into a package, the film hardly causes displacement, exhibits good sealability, and further, is suppressed in deformation of the package, and therefore, a package having excellent appearance characteristics can be obtained.

Further, when the water content of the water-soluble film of the present invention is 3 to 15% by weight, the film is excellent in mechanical strength and heat sealability.

Further, if the PVA-based resin (a) is an anionic group-modified PVA-based resin, the solubility of the water-soluble film is excellent.

Further, if the water-soluble film of the present invention is used for packaging a medicine, the medicine can be used without breaking the package.

A drug package comprising a package formed of the water-soluble film and a drug packaged in the package can be used easily without breaking the bag.

Further, in the case of a drug package in which the drug is a detergent, the labor for measuring when the detergent is used can be omitted, and the drug package can be used more easily.

Further, in the case of a medicine package in which the detergent is a liquid detergent, the package can be used more easily without contaminating the surroundings with the liquid detergent.

The method for producing the water-soluble film comprises the following steps: a step of casting, drying and film-forming a film-forming material containing the PVA based resin (A); a step of performing heat treatment so that the temperature of the film obtained by the film formation is 50 to 95 ℃; and a step of winding the film after the heat treatment so that the draw ratio is 1.05 to 1.5, the curl of the obtained water-soluble film is suppressed, and therefore, displacement is less likely to occur when the film is formed into a package, and good sealing properties can be obtained.

Drawings

Fig. 1 is a diagram for explaining measurement conditions of the length (a) of the curl diameter of the film used for evaluating the curl property of the water-soluble film.

Detailed Description

The present invention will be specifically described below.

The water-soluble film of the present invention is a water-soluble film containing a PVA-based resin (A) as a main component, and is characterized in that the film has an elongation (X) in the width direction (TD) when the film floats on a water surface of water at 20 ℃ for 60 seconds_TD) Elongation (X) relative to the flow direction (MD)_MD) Ratio of (X)_TD/X_MD) 1.05 to 1.5.

In the present invention, the "width direction of the film" generally means a direction substantially perpendicular to the longitudinal direction of the film. In particular, in a water-soluble film which is discharged to a casting die such as a casting drum (a drum roll) or an endless belt and cast to form a film, a direction which is substantially orthogonal to a flow direction of the film at the time of film formation, typically, a direction in which a distance between both edges of the film becomes the shortest. In the present invention, the width direction of the film is referred to as "TD" and the flow direction of the film is referred to as "MD".

An elongation (X) in the width direction (TD)_TD) Elongation (X) relative to the flow direction (MD)_MD) Ratio of (X)_TD/X_MD) The measurement and calculation were carried out as follows.

First, the PVA-based water-soluble film was left to stand under the conditions of 23 ℃ and 50% RH humidity for 24 hours, then cut into 150 mm. times.150 mm dimensions under the circumstances, and a circle having a diameter of 75mm was drawn with a water pen at the center of the opposite surface side to the water surface side when floating on the water surface.

Further, inside the circle, the same diameter is drawn in parallel with TD and MD of the film, respectivelyLength of 75mm of wire (S)_TD0) And (S)_MD0)。

Then, the surface with the circle drawn thereon was faced upward, and the PVA based water-soluble film was floated on the center of a water tank filled with 20 ℃ water and having a length of 350mm and a width of 250 mm. Upon and after the water absorption, the film swells and slowly expands, and the circle drawn on the film deforms together with the expansion of the film.

2 lines (S) drawn parallel to TD and MD respectively after floating on the water surface for 60 seconds were measured_TD60) And (S)_MD60) The elongation (X) of TD is calculated from the ratio of the length after stretching to the length before stretching_TD) And the elongation (X) of MD_MD) To find the ratio (X)_TD/X_MD)。

Elongation (X) of TD_TD) And the elongation (X) of MD_MD) Calculated according to the following equation.

X_TD(％)＝S_TD60/S_TD0×100

X_MD(％)＝S_MD60/S_MD0×100

TD extensibility (X) of the water-soluble film_TD) Elongation (X) relative to MD_MD) Ratio of (X)_TD/X_MD) 1.05 to 1.5, preferably 1.07 to 1.40, and particularly preferably 1.10 to 1.30. Ratio of elongation (X)_TD/X_MD) If it is too large, strain is generated when the packaging body is formed, and the appearance and mechanical properties are degraded, and if it is too small, the effect of suppressing curling is degraded.

The water-soluble film of the present invention is produced, for example, as described below.

The water-soluble film of the present invention contains the PVA-based resin (a) as a main component, and the content of the PVA-based resin (a) as a main component herein means that the PVA-based resin (a) is contained usually in an amount of 50 wt% or more, preferably 55 wt% or more, based on the total amount of the water-soluble film.

First, the PVA-based resin (a) used in the present invention will be described.

Examples of the PVA resin (a) used in the present invention include an unmodified PVA resin and a modified PVA resin.

The unmodified PVA-based resin can be produced as follows: the vinyl ester polymer can be produced by polymerizing a vinyl ester compound to obtain a vinyl ester polymer and saponifying the obtained vinyl ester polymer.

Examples of the vinyl ester compound include vinyl formate, vinyl acetate, vinyl trifluoroacetate, vinyl propionate, vinyl butyrate, vinyl decanoate, vinyl laurate, vinyl neodecanoate, vinyl palmitate, and vinyl stearate, and vinyl acetate is preferably used. The vinyl ester compounds can be used alone, also can be combined with 2 or more.

The modified PVA-based resin can be produced as follows: the vinyl ester compound is copolymerized with an unsaturated monomer copolymerizable with the vinyl ester compound, and then saponified.

Examples of the unsaturated monomer copolymerizable with the vinyl ester compound include olefins such as ethylene, propylene, isobutylene, α -octene, α -dodecene, and α -octadecene, hydroxyl group-containing α -olefins such as 3-buten-1-ol, 4-penten-1-ol, and 5-hexen-1-ol, and derivatives such as acylates thereof; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic anhydride, itaconic acid, and undecylenic acid, salts thereof, monoesters thereof, or dialkyl esters thereof; amides such as diacetone acrylamide, and methacrylamide; olefin sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid, and salts thereof. These can be used alone or in combination of 2 or more.

Examples of the modified PVA resin include those having a primary hydroxyl group in a side chain, and for example, the modified PVA resin has a secondary hydroxyl group in addition to the primary hydroxyl group, and the number of primary hydroxyl groups in the side chain is usually 1 to 5, preferably 1 to 2, and particularly preferably 1. Examples of the modified PVA resin include a PVA resin having a hydroxyalkyl group in a side chain thereof, a PVA resin having a1, 2-diol structural unit in a side chain thereof, and the like. The PVA-based resin having a1, 2-diol structural unit in a side chain can be produced, for example, by the following method: method (1) of saponifying a copolymer of vinyl acetate and 3, 4-diacetoxy-1-butene; a method (2) in which a copolymer of vinyl acetate and vinyl ethylene carbonate is subjected to saponification and decarboxylation; method (3) of saponifying and deketalizing a copolymer of vinyl acetate and 2, 2-dialkyl-4-vinyl-1, 3-dioxolane; method (4) of saponifying a copolymer of vinyl acetate and glycerol monoallyl ether; and the like.

As a method for copolymerizing the vinyl ester compound with an unsaturated monomer copolymerizable with the vinyl ester compound, for example, a known polymerization method such as a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, or the like can be arbitrarily used, and the copolymerization is generally carried out by a solution polymerization method using an alcohol such as methanol, ethanol, or isopropanol as a solvent.

The polymerization catalyst may be any known polymerization catalyst such as an azo catalyst such as azobisisobutyronitrile, a peroxide catalyst such as acetyl peroxide, benzoyl peroxide, lauroyl peroxide, or the like, and the like, depending on the polymerization method. These can be used alone or in combination of 2 or more. The reaction temperature of the polymerization is selected from the range of about 50 ℃ to the boiling point.

The saponification can be carried out by a known method, and usually, the resulting copolymer is dissolved in an alcohol and is carried out in the presence of a saponification catalyst. Examples of the alcohol include methanol, ethanol, and butanol. These can be used alone or in combination of 2 or more. From the viewpoint of the dissolution rate, the concentration of the copolymer in the alcohol is selected from the range of 20 to 50% by weight.

As the saponification catalyst, for example, an alkali catalyst such as hydroxide or alcoholate of an alkali metal such as sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, or potassium methoxide may be used, or an acid catalyst may be used. These can be used alone or in combination of 2 or more. The amount of the saponification catalyst used is preferably 1 to 100 millimolar equivalents based on the vinyl ester compound.

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

The carboxyl group-modified PVA resin may be produced by any method, and examples thereof include the following methods: a method (i) in which an unsaturated monomer having a carboxyl group is copolymerized with a vinyl ester compound and then saponified; a method (ii) in which a vinyl ester compound is polymerized in the presence of an alcohol, an aldehyde, a thiol or the like having a carboxyl group as a chain transfer agent and then saponified; and the like.

As the vinyl ester compound in the above-mentioned method (i) or (ii), those mentioned above can be used, and vinyl acetate is preferably used.

Examples of the unsaturated monomer having a carboxyl group in the method (i) include ethylenically unsaturated dicarboxylic acids (e.g., maleic acid, fumaric acid, and itaconic acid), ethylenically unsaturated dicarboxylic monoesters (e.g., monoalkyl maleate, monoalkyl fumarate, and monoalkyl itaconate), ethylenically unsaturated dicarboxylic diesters (e.g., dialkyl maleate, dialkyl fumarate, and dialkyl itaconate) (these diesters need to be hydrolyzed to become a carboxyl group at the time of saponification of the copolymer), ethylenically unsaturated carboxylic anhydrides (e.g., maleic anhydride and itaconic anhydride), ethylenically unsaturated monocarboxylic acids ((meth) acrylic acid, crotonic acid), and other monomers, and salts thereof, and among them, maleic acid, monoalkyl maleate, dialkyl maleate, maleic anhydride, itaconic acid, and monoalkyl itaconate are preferably used, Dialkyl itaconate, (meth) acrylic acid, etc., maleic acid, monoalkyl maleate, dialkyl maleate, maleate salt, maleic anhydride are particularly preferably used, and monoalkyl maleate is more preferably used. These can be used alone or in combination of 2 or more.

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

[ wherein, in the general formulas (1) and (2), n is an integer of 0 to 5, R₁、R₂、R₃Each represents a hydrogen atom or a lower alkyl group (optionally containing a substituent).]

[ wherein, in the general formula (3), n is an integer of 0 to 20. ]

Specific examples thereof include thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, and 2-mercaptostearic acid. These can be used alone or in combination of 2 or more.

In addition to the above-mentioned unsaturated monomer having a carboxyl group and vinyl ester compound, other general monomers may be contained and polymerized in a range not impairing water solubility, and examples of the monomers include alkyl esters of ethylenically unsaturated carboxylic acids, allyl esters of saturated carboxylic acids, α -olefins, alkyl vinyl ethers, alkyl allyl ethers, (meth) acrylamides, (meth) acrylonitriles, styrenes, and vinyl chlorides.

The method for producing the carboxyl group-modified PVA-based resin is not limited to the above-described method, and for example, the following method may be performed: post-reacting polyvinyl alcohol (partially or completely saponified) with a carboxyl group-containing compound having a functional group reactive with a hydroxyl group, such as dicarboxylic acid, aldehyde carboxylic acid, or hydroxycarboxylic acid; and the like.

In the case of using a sulfonic acid group-modified PVA-based resin, for example, a method of copolymerizing a copolymerizable component such as vinylsulfonic acid, styrenesulfonic acid, allylsulfonic acid, methallylsulfonic acid, or 2-acrylamido-2-methylpropanesulfonic acid with a vinyl ester-based compound and then saponifying the copolymer; a method of adding Michael addition of vinyl sulfonic acid or a salt thereof, 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof, or the like to PVA, and the like.

On the other hand, examples of the method for post-modifying the unmodified PVA-based resin include methods in which the unmodified PVA-based resin is acetoacetylated, acetalized, carbamated, etherified, grafted, phosphated, and oxyalkylated.

The average saponification degree of the PVA-based resin (a) of the present invention is preferably 80 mol% or more, particularly preferably 82 to 99.9 mol%, further preferably 85 to 99.5 mol%, and particularly preferably 90 to 99.0 mol%. If the average saponification degree is too low, the solubility of the film tends to decrease with time depending on the pH of the drug to be packaged.

In particular, in the case of using an unmodified PVA-based resin as the PVA-based resin (a) in the present invention, the average saponification degree is preferably 80 mol% or more, particularly preferably 82 to 99 mol%, and further preferably 85 to 90 mol%. If the average saponification degree is too small, the water solubility tends to decrease. The average saponification degree tends to be too high, and the water solubility tends to be lowered.

On the other hand, when the modified PVA-based resin is used as the PVA-based resin (a), the average saponification degree thereof is preferably 80 mol% or more, particularly preferably 85 to 99.9 mol%, and further preferably 90 to 99.0 mol%. If the average saponification degree is too low, the solubility of the film tends to decrease with time depending on the pH of the drug to be packaged. If the average saponification degree is too high, the solubility to water tends to be greatly reduced by the thermal history at the time of film formation.

Further, when the PVA-based resin (a) is an anionic group-modified PVA-based resin, the average saponification degree thereof is preferably 85 mol% or more, particularly preferably 88 to 99.9 mol%, further preferably 90 to 99.5 mol%, and particularly preferably 90 to 99.0 mol%.

The PVA-based resin (A) of the present invention has a 4 wt% aqueous solution viscosity at 20 ℃ of preferably 10 to 50 mPas, particularly preferably 15 to 45 mPas, and further preferably 20 to 40 mPas. If the viscosity is too low, the mechanical strength of the film as a packaging material tends to be low, and if it is too high, the viscosity of the aqueous solution at the time of film formation tends to be high, and the productivity tends to be low.

In the present invention, the amount of modification of the anionic group-modified PVA-based resin is preferably 1 to 10 mol%, particularly preferably 2 to 9 mol%, and further preferably 2 to 8 mol%. If the amount of modification is too small, the solubility in water tends to be low, and if it is too large, the productivity of the PVA-based resin tends to be low, the biodegradability tends to be low, and blocking tends to be easily caused.

In the present invention, the PVA-based resins (a) may be used alone, or 2 or more kinds of resins different in saponification degree, viscosity, kind of modification, amount of modification, and the like may be used in combination, or combinations of unmodified PVA-based resins and modified PVA-based resins may be used.

In the present invention, the PVA-based resin (a) is preferably a modified PVA-based resin, particularly preferably an anionic group-modified PVA-based resin, and more preferably a carboxyl group-modified PVA-based resin, in view of maintaining solubility for a long period of time. In addition, from the viewpoint of film strength, the anionic group-modified PVA-based resin and the unmodified PVA-based resin are preferably contained, and particularly, the carboxyl group-modified PVA-based resin and the unmodified PVA-based resin are preferably contained.

The content ratio (weight ratio) of the modified PVA resin to the unmodified PVA resin when used in combination is preferably 95/5 to 60/40, particularly preferably 94/6 to 70/30, and further preferably 93/7 to 80/20. If the content ratio is too small, the water solubility tends to decrease, and if it is too large, the water solubility of the packaged acidic substance tends to decrease.

When the modified PVA based resin and the unmodified PVA based resin are used in combination, the viscosity of a 4 wt% aqueous solution of the unmodified PVA based resin at 20 ℃ is preferably 5 to 50 mPas, particularly preferably 10 to 45 mPas, further preferably 12 to 40 mPas, and particularly preferably 15 to 35 mPas. If the viscosity is too low, the mechanical strength of the film as a packaging material tends to be low, while if it is too high, the viscosity of the aqueous solution at the time of film formation tends to be high, and the productivity tends to be low.

The average degree of saponification described above was measured in accordance with JIS K67263.5, and the viscosity of a 4 wt% aqueous solution was measured in accordance with JIS K67263.11.2.

In the present invention, it is preferable that the PVA-based resin (a) contains a plasticizer (B) in order to impart flexibility to the film when the PVA-based resin (a) is formed into a package. The plasticizer (B) may be used alone in 1 kind, or may be used in combination of 2 or more kinds, and in the case of producing a package, at least 2 kinds are preferably used in combination in view of toughness of the film itself, capability of sealing at low temperature, and high strength of the sealed portion.

In the production of a water-soluble film, toughness in the production of a package, and shape stability over time and sealing properties at low temperatures in the production of a package for a liquid detergent, it is preferable that 1 of the plasticizers (B) is a polyol (B1) (hereinafter, sometimes referred to simply as "plasticizer (B1)") having a melting point of 80 ℃ or higher, and the other 1 is a polyol (B2) (hereinafter, sometimes referred to simply as "plasticizer (B2)") having a melting point of 50 ℃ or lower.

As the above-mentioned polyhydric alcohol (b1) having a melting point of 80 ℃ or higher, sugar alcohols, monosaccharides, and polysaccharides can be mostly used, examples thereof include diols such as salicyl alcohol (83 ℃ C.), catechol (105 ℃ C.), resorcinol (110 ℃ C.), hydroquinone (172 ℃ C.), bisphenol A (158 ℃ C.), bisphenol F (162 ℃ C.), neopentyl glycol (127 ℃ C.), triols such as phloroglucinol (218 ℃ C.), tetrol (121 ℃ C.), threitol (88 ℃ C.), tetrahydric alcohols such as pentaerythritol (260 ℃ C.), xylitol (92 ℃ C.), arabitol (103 ℃ C.), fucitol (153 ℃ C.), glucose (146 ℃ C.), pentahydric alcohols such as fructose (104 ℃ C.), mannitol (166 ℃ C.), sorbitol (95 ℃ C.), hexahydric alcohols such as inositol (225 ℃ C.), lactitol (146 ℃ C.), sucrose (186 ℃ C.), octahydric alcohols such as trehalose (97 ℃ C.), and nine-or more alcohols such as maltitol (145 ℃ C.). These can be used alone or in combination of 2 or more. Incidentally, () represents a melting point.

Among the above, the water-soluble film preferably has a melting point of 85 ℃ or higher, particularly preferably 90 ℃ or higher, in view of the tensile strength. The upper limit of the melting point is preferably 300 ℃ and particularly preferably 200 ℃.

In the present invention, the plasticizer (b1) preferably has 4 or more, particularly preferably 5 to 10, and further preferably 6 to 8 hydroxyl groups in 1 molecule in terms of compatibility with the PVA-based resin (a), and specifically, for example, sorbitol, sucrose, trehalose and the like are suitable examples.

In the present invention, the plasticizer (b1) has a molecular weight of preferably 150 or more, particularly preferably 160 to 500, and further preferably 180 to 400, in view of the toughness of the water-soluble film, and specifically, for example, sorbitol, sucrose and the like are suitable examples.

On the other hand, examples of the polyhydric alcohol (b2) having a melting point of 50 ℃ or lower include aliphatic alcohols, preferably glycols such as ethylene glycol (-13 ℃), diethylene glycol (-11 ℃), triethylene glycol (-7 ℃), propylene glycol (-59 ℃), tetraethylene glycol (-5.6 ℃), 1, 3-propanediol (-27 ℃), 1, 4-butanediol (20 ℃), 1, 6-hexanediol (40 ℃), tripropylene glycol, polyethylene glycol having a molecular weight of 2000 or lower, and trihydric or higher alcohols such as glycerol (18 ℃), diglycerol, and triethanolamine (21 ℃). These can be used alone or in combination of 2 or more. Incidentally, () represents a melting point. Among the above, in terms of flexibility of the water-soluble film, the melting point is particularly preferably 30 ℃ or lower, and more preferably 20 ℃ or lower. The lower limit of the melting point is usually-80 ℃, preferably-10 ℃, particularly preferably 0 ℃.

Further, in the present invention, the number of hydroxyl groups in 1 molecule of the plasticizer (b2) is preferably 4 or less, and particularly preferably 3 or less, and specifically, glycerin or the like is suitable, in terms of easily controlling flexibility at around room temperature (25 ℃).

In the present invention, the plasticizer (b2) is preferably 100 or less in molecular weight, particularly preferably 50 to 100, further preferably 60 to 95, and specifically, glycerin or the like is suitable, because flexibility can be easily controlled.

In the present invention, a plasticizer (b3) other than the plasticizers (b1) and (b2) may be used in combination, and examples of the plasticizer (b3) include trimethylolpropane (58 ℃), diethylene glycol monomethyl ether, cyclohexanol, carbitol, polypropylene glycol, and other alcohols, dibutyl ether, and other ethers, stearic acid, oleic acid, linoleic acid, linolenic acid, sorbic acid, citric acid, adipic acid, and other carboxylic acids, cyclohexanone, and other ketones, monoethanolamine, triethanolamine, ethylenediamine, imidazole compounds, and other amines, and alanine, glycine, aspartic acid, glutamic acid, histidine, lysine, cysteine, and other amino acids. These can be used alone or in combination of 2 or more.

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

The weight ratio (b1/b2) of the plasticizer (b1) to the plasticizer (b2) is preferably 0.1 to 5, more preferably 0.2 to 4, still more preferably 0.5 to 3, and particularly preferably 0.7 to 2. If the content ratio is too small, the water-soluble film tends to be too soft and blocking tends to occur easily, and if it is too large, the water-soluble film tends to be too hard and tends to become brittle in a low-humidity environment.

The content of the plasticizer (b1) and the plasticizer (b2) is preferably 5 to 40 parts by weight, particularly preferably 8 to 30 parts by weight, and further preferably 10 to 25 parts by weight of the plasticizer (b1), and the plasticizer (b2) is preferably 5 to 40 parts by weight, particularly preferably 10 to 35 parts by weight, and further preferably 15 to 30 parts by weight, based on 100 parts by weight of the PVA-based resin (a).

If the amount of the plasticizer (b1) is too small, the water-soluble film tends to be too hard, and if it is too large, the water-soluble film tends to be too soft. If the amount of the plasticizer (b2) is too small, the water-soluble film tends to be too hard and brittle under a low humidity environment, and if it is too large, the water-soluble film tends to be too soft and blocking tends to occur easily.

Further, the total amount of the plasticizer (B1) and the plasticizer (B2) is preferably 70% by weight or more, more preferably 80% by weight or more, particularly preferably 87% by weight or more, further preferably 90% by weight or more, particularly preferably 95% by weight or more, based on the entire plasticizer (B), and most preferably the entire plasticizer (B) is composed of only the plasticizer (B1) and the plasticizer (B2). When the total amount of the plasticizer (b1) and the plasticizer (b2) is too small, the mechanical strength tends to decrease.

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

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

The inorganic filler preferably has an average particle diameter of 1 to 10 μm, and if the average particle diameter is too small, the effect of dispersibility of the water-soluble film in water tends to be small, and if the average particle diameter is too large, pinholes tend to be formed during stretching when the water-soluble film is molded, or the appearance tends to be lowered.

Specific examples of the inorganic filler include talc, clay, silica, diatomaceous earth, kaolin, mica, asbestos, gypsum, graphite, glass spheres, glass beads, calcium sulfate, barium sulfate, ammonium sulfate, calcium sulfite, calcium carbonate, whisker-like calcium carbonate, magnesium carbonate, dawsonite, dolomite, potassium titanate, carbon black, glass fiber, alumina fiber, boron fiber, processed mineral fiber, carbon hollow spheres, bentonite, montmorillonite, copper powder, sodium sulfate, potassium sulfate, zinc sulfate, copper sulfate, iron sulfate, magnesium sulfate, aluminum potassium sulfate, ammonium nitrate, sodium nitrate, potassium nitrate, aluminum nitrate, ammonium chloride, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium phosphate, and potassium chromate. These can be used alone or in combination of 2 or more.

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

Examples of the organic filler include starch, melamine resins, polymethyl (meth) acrylate resins, polystyrene resins, and biodegradable resins such as polylactic acid. Among them, biodegradable resins such as polymethyl (meth) acrylate resins, polystyrene resins, and starches are preferably used. These can be used alone or in combination of 2 or more.

Examples of the starch include native starch (corn starch, potato starch, sweet potato starch, wheat starch, tapioca starch (cassava starch), sago starch, tapioca starch (tapioca starch), sorghum starch, rice starch, bean starch, arrowroot starch, fern starch, lotus starch, water caltrop starch, etc.), physically modified starch (α -starch, fractionated amylose (fractionated amylose), heat-treated starch, etc.), enzymatically modified starch (hydrolyzed dextrin, amylose, etc.), chemically decomposed modified starch (acid-treated starch, hypochlorous oxidized starch, dialdehyde starch, etc.), chemically modified starch derivatives (esterified starch, etherified starch, cationized starch, crosslinked starch, etc.), and the like. These can be used alone or in combination of 2 or more. Among them, raw starch, particularly corn starch and rice starch are preferably used from the viewpoint of availability and economy.

The content of the filler (C) is preferably 1 to 30 parts by weight, particularly preferably 2 to 25 parts by weight, and further preferably 2.5 to 20 parts by weight, based on 100 parts by weight of the PVA based resin (A). If the content is too small, the blocking resistance tends to be low, and if it is too large, pinholes tend to be formed when the water-soluble film is stretched during molding.

The surfactant (D) used in the present invention is contained for the purpose of improving the releasability from the casting surface in the production of a water-soluble film, and examples thereof include a nonionic surfactant, a cationic surfactant, and an anionic surfactant. Examples thereof include polyoxyethylene alkyl amino ethers such as polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl nonyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene alkyl ether phosphate monoethanol amine salt, polyoxyethylene lauryl amino ether, and polyoxyethylene stearyl amino ether, and 1 kind or a combination of 2 or more kinds thereof may be used. Among them, polyoxyalkylene alkyl ether phosphate monoethanolamine salt, polyoxyethylene lauryl amino ether are suitable in terms of production stability.

The content of the surfactant (D) is preferably 0.01 to 4 parts by weight, particularly preferably 0.1 to 3 parts by weight, and further preferably 0.5 to 2.5 parts by weight, based on 100 parts by weight of the PVA based resin (A). If the content is too small, the releasability between the casting surface of the film forming apparatus and the water-soluble film after film formation tends to be low, and the productivity tends to be low, and if too large, there is a tendency that defects such as a decrease in the adhesive strength at the time of sealing performed when the water-soluble film is formed into a package are caused.

In the present invention, other water-soluble polymers (for example, sodium polyacrylate, polyethylene oxide, polyvinyl pyrrolidone, dextrin, chitosan, chitin, methyl cellulose, hydroxyethyl cellulose, and the like), perfumes, rust inhibitors, colorants, extenders, antifoaming agents, ultraviolet absorbers, fluorescent whitening agents, liquid paraffins, bitter components (for example, benzalkonium) and the like may be further contained within a range not to impair the object of the present invention. These can be used alone or in combination of 2 or more.

In the present invention, it is preferable to add an antioxidant in order to suppress yellowing. Examples of the antioxidant include sulfites such as sodium sulfite, potassium sulfite, calcium sulfite and ammonium sulfite, tartaric acid, ascorbic acid, sodium thiosulfate, catechol and rongalite, among which sulfites are preferable and sodium sulfite is particularly preferable. The amount of the above-mentioned component is preferably 0.1 to 10 parts by weight, particularly preferably 0.2 to 5 parts by weight, and further preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the PVA based resin (A).

< production of PVA-based Water-soluble film >

In the present invention, a PVA-based resin composition containing a PVA-based resin (a), preferably further a plasticizer (B), and if necessary, a filler (C) and a surfactant (D) is obtained as described above, and the PVA-based resin composition is produced in the order of [ I ] dissolution step, [ II ] film formation step, and [ III ] winding step to form a PVA-based water-soluble film.

[ (I ] dissolution procedure ]

In the dissolving step, the PVA-based resin composition is dissolved or dispersed with water to prepare an aqueous solution or an aqueous dispersion as a film-forming raw material.

As a method for dissolving the PVA resin composition in water, ordinary temperature dissolution, high temperature dissolution, pressurized dissolution, and the like are generally employed, and among them, high temperature dissolution and pressurized dissolution are preferred from the viewpoint of a small amount of undissolved matter and excellent productivity.

The dissolution temperature is usually 80 to 100 ℃ and preferably 90 to 95 ℃ in the case of high-temperature dissolution, and 80 to 130 ℃ and preferably 90 to 120 ℃ in the case of pressurized dissolution.

The dissolution time may be suitably adjusted depending on the dissolution temperature and the pressure at the time of dissolution, and is usually 1 to 20 hours, preferably 2 to 15 hours, and particularly preferably 3 to 10 hours. If the dissolution time is too short, undissolved matter tends to remain, and if it is too long, productivity tends to decrease.

In the dissolving step, examples of the stirring blade include a paddle, FULLZONE, MAXBLEND, TWINSTAR, anchor, screw, and propeller.

Further, after the dissolution, the obtained PVA-based resin aqueous solution is subjected to a defoaming treatment, and examples of the defoaming method include standing defoaming, vacuum defoaming, twin-screw extrusion defoaming, and the like. Among them, standing defoaming and twin-screw extrusion defoaming are preferable.

The temperature for the standing deaeration is usually 50 to 100 ℃, preferably 70 to 95 ℃, and the deaeration time is usually 2 to 30 hours, preferably 5 to 20 hours.

The solid content concentration of the film-forming raw material is preferably 10 to 50 wt%, particularly preferably 15 to 40 wt%, and further preferably 20 to 35 wt%. If the concentration is too low, the film productivity tends to be low, and if it is too high, the viscosity becomes too high, and it takes time to defoam the film-forming raw material, or a die mark tends to be generated during film formation.

[ (II ] film-Forming Process)

In the film-forming step, the film-forming raw material prepared in the dissolving step is formed into a film shape, and is dried as necessary, thereby adjusting the film to a PVA-based water-soluble film having a water content of less than 15 wt%.

In the case of film formation, for example, a melt extrusion method, a casting method, or the like can be used, and a casting method is preferable in terms of accuracy of film thickness.

In the case of casting, for example, the PVA-based water-soluble film of the present invention can be produced by discharging the film-forming material from a slit such as a T-slot die, casting the film onto a casting surface such as an endless belt or a metal surface of a drum roll, and drying the film.

The temperature of the film-forming material in the film-forming material discharge portion of the T-shaped slit die or the like is preferably 60 to 98 ℃, and particularly preferably 70 to 95 ℃. If the temperature is too low, the viscosity of the film-forming raw material increases, and the productivity of the PVA-based water-soluble film tends to decrease, and if it is too high, foaming tends to occur.

After casting, the film-forming material is dried on the casting surface, and in the drying, the casting surface such as the metal surface of the endless belt or the drum roll is generally heated. The surface temperature of the casting surface is preferably 50 to 150 ℃, and particularly preferably 60 to 140 ℃. If the surface temperature is too low, drying is insufficient, and the water content of the film becomes high, so that blocking tends to occur easily, and if it is too high, the film-forming raw material foams, and film-forming defects tend to occur.

In the drying during film formation, drying by a hot roll, drying by blowing hot air to a film by a floating dryer, drying by a far infrared device, a medium heating device, and the like may be used in combination.

In the above-mentioned drying treatment, the film-forming raw material is dried until the water content becomes less than 15% by weight, and then peeled from the casting surface (in the case where the film is peeled from the casting surface and then dried by a heat roll, peeled from the drying heat roll), whereby a PVA-based water-soluble film can be obtained. The PVA water-soluble film peeled from the casting surface (or the drying heat roller) is conveyed while being cooled in an environment of 10 to 35 ℃.

[ (III ] winding Process)

In the winding step, the PVA-based water-soluble film peeled from the casting surface or the like in the film forming step is conveyed and wound up and wound around a core tube (S1) to prepare a film roll.

The obtained film roll may be directly supplied as a product, and preferably, the film roll may be rewound on a core tube having a length corresponding to the width of the PVA-based water-soluble film of a desired size (S2), or may be supplied as a film roll of a desired size.

The core tube (S1) around which the PVA water-soluble film is wound is cylindrical, and the material thereof may be selected from metal, plastic, and the like as appropriate, and metal is preferable in terms of firmness and strength.

The inner diameter of the core tube (S1) is preferably 3 to 30cm, more preferably 10 to 20 cm.

The wall thickness of the core tube (S1) is preferably 1 to 30mm, more preferably 2 to 25 mm.

The length of the core tube (S1) must be longer than the width of the PVA water-soluble film, and preferably 1 to 50cm protrudes from the end of the film roll.

The core pipe (S2) is cylindrical, and the material thereof may be paper, metal, plastic, or the like as appropriate, and paper is preferable in terms of weight reduction and handling properties.

The inner diameter of the core tube (S2) is preferably 3 to 30cm, more preferably 10 to 20 cm.

The wall thickness of the core tube (S2) is preferably 1 to 30mm, more preferably 3 to 25 mm.

The length of the core tube (S2) is equal to or longer than the width of the PVA water-soluble film of the product, and preferably equal to 50 cm.

When wound on the core tube (S2), the PVA-based water-soluble film is cut into a desired width.

In the above-mentioned slitting, slitting is performed with a cutter, a leather cutter, or the like, and in terms of smoothness of the slit cross section, slitting is preferably performed with a cutter.

In order to adjust the stretching ratio of the PVA-based water-soluble film of the present invention, it is important to perform heat treatment so that the film becomes a specific temperature range and the stretching ratio is adjusted to a specific range after the film forming step in the film production step [ II ].

The heat treatment method and the method of adjusting the draw ratio will be described below.

The heat treatment in the present invention is performed after the film forming step separately from the drying at the time of film formation, and is performed for the purpose of relaxing the residual stress of the film generated when the stretching ratio is adjusted, and adjusting the elongation in the width direction.

In the heat treatment, the heat treatment is performed so that the temperature of the film is preferably 50 to 95 ℃, particularly preferably 55 to 90 ℃, further preferably 60 to 85 ℃, and particularly preferably 65 to 80 ℃. If the temperature is too low, the curl improvement effect tends to be difficult to obtain, and if it is too high, the solubility tends to decrease, or the sealing property (particularly, water sealing property) tends to decrease during the formation of the package.

The "temperature of the film" is a value obtained by measuring the temperature of the surface of the film immediately after the heat treatment by an infrared temperature recorder, specifically, the temperature of the film at a position 5cm from the outlet of the heat treatment apparatus, and can be measured by a commercially available infrared temperature recorder (for example, "FLIR C2" manufactured by FLIR SYSTEMS Co.).

Specifically, in the heat treatment, the temperature (temperature of the heat treatment apparatus) at which the thin film is heat-treated is preferably 50 to 120 ℃, particularly preferably 60 to 115 ℃, and further preferably 70 to 110 ℃. If the temperature is too low, the curl improvement effect tends to be difficult to obtain, and if it is too high, the solubility tends to decrease, or the sealing property (particularly, water sealing property) tends to decrease at the time of forming the package.

The heat treatment time may be suitably adjusted depending on the heat treatment temperature, and is preferably 0.01 to 30 seconds, particularly preferably 0.05 to 25 seconds, and further preferably 0.1 to 20 seconds. If it is too short, the curl suppression effect tends to be low, and if it is too long, the curl is suppressed, but the solubility of the film tends to be low.

The heat treatment temperature and time are preferably high temperature heat treatment for a short time, more preferably 90 to 120 ℃ for 0.01 to 5 seconds, and still more preferably 100 to 115 ℃ for 0.05 to 3 seconds, from the viewpoint of suppressing the decrease in film solubility and improving productivity.

The heat treatment can be carried out usually by a heat roll, and in addition, there can be mentioned: heat treatment by blowing hot air to the film with a floating dryer, heat treatment with a far infrared device, a dielectric heating device, or the like. In the present invention, the stretching ratio is preferably adjusted by a heat roll in terms of ease and excellent productivity. In addition, a plurality of heat rollers may be used.

In the present invention, in the heat treatment, among the film surfaces having 2 surfaces, the film surface side (α surface side) opposite to the film surface side (β surface side) in contact with the casting surface (endless belt, metal surface of drum roll, etc.) is preferably subjected to heat treatment, and in particular, the α surface of the film is preferably in contact with a heat roll (heat treatment apparatus portion) in terms of suppressing curling of the film.

The film after the heat treatment thus obtained was subjected to a stretching ratio adjustment in the following winding step, whereby a PVA-based water-soluble film in which the elongation in the width direction and the flow direction were controlled to a specific ratio could be obtained.

The draw ratio is the winding speed of the film (peripheral speed of the winding roll) (v) in the winding process₁) The moving speed of the film (the belt conveying speed in the case of a belt, and the peripheral speed of a drum in the case of a drum) (v) in the film forming step₀) Ratio of (v)₁/v₀)。

The draw ratio can be adjusted by appropriately controlling the belt conveying speed, the peripheral speed of the take-up roll, the peripheral speed of the heat roll (when the heat roll is used in the heat treatment step), and other speeds.

Specifically, the draw ratio is preferably 1.05 to 1.5, particularly preferably 1.1 to 1.4, and further preferably 1.2 to 1.3.

If the draw ratio is less than 1.05, the effect of suppressing curling tends to be reduced, and if it is more than 1.5, strain is generated when the package is formed, and mechanical properties such as strength of the package are reduced.

In the present invention, the film winding speed (v) is preferably set so that the curl suppression effect is easily obtained₁) The moving speed of the film relative to the heat treatment step (the peripheral speed of the heat roll in the case of using the heat roll in the heat treatment step) (v)₂) Ratio of (v)₁/v₂) At least 1.0 or more, particularly preferably 1.05 to 1.4, and more preferably 1.1 to 1.3.

In the present invention, it is preferable that the film having a temperature within a specific range by the heat treatment is wound at a speed higher than the moving speed of the heat treatment step, and it is particularly preferable that the film is wound at a speed higher than the winding speed of the film from a position close to the heat treatment apparatus.

Winding speed (v) of film₁) The change start position of (b) is preferably within 5m, particularly preferably within 3m, of the rear of the heat treatment apparatus. When the change start position is excessively displaced, the effect of relaxing the residual stress generated by the heat treatment is weakened, and the effect of the present invention may not be obtained.

In the present invention, the belt conveying speed (peripheral speed of the drum when the drum is used) is preferably 6 to 25 m/min, and particularly preferably 10 to 20 m/min.

The peripheral speed of the heat roll is preferably 6 to 25 m/min, particularly preferably 8 to 20 m/min.

The peripheral speed of the winding roll for winding the film is preferably 8 to 40 m/min, and particularly preferably 10 to 30 m/min.

Thus, the PVA water-soluble film of the present invention can be produced.

The thickness of the PVA-based water-soluble film may be suitably selected depending on the application, etc., and is preferably 10 to 120. mu.m, particularly preferably 15 to 110 μm, and further preferably 20 to 100. mu.m. If the thickness is too small, the mechanical strength of the film tends to decrease, and if it is too large, the dissolution rate of the film into water tends to be slow, and the film forming efficiency also tends to decrease.

The width of the PVA-based water-soluble film may be suitably selected depending on the application, etc., and is preferably 300 to 5000mm, particularly preferably 500 to 4000mm, and further preferably 600 to 3000 mm. If the width is too small, the production efficiency tends to be low, and if the width is too large, the film tends to be loose and the control of the film thickness tends to be difficult.

The length of the PVA-based water-soluble film may be suitably selected depending on the application, and is preferably 100 to 20000m, particularly preferably 800 to 15000m, and further preferably 1000 to 10000 m. If the length is too short, the replacement of the film tends to require time and effort, and if the length is too long, the appearance tends to be poor due to windup, and the weight tends to be excessively heavy.

The surface of the PVA-based water-soluble film may be flat, and it is also preferable to previously subject one or both surfaces of the film to an embossing pattern, a fine uneven pattern, a special engraved pattern, or the like, from the viewpoints of blocking resistance, slidability during processing, reduced adhesion between products, and appearance.

The processing temperature in the above-mentioned embossing is usually 60 to 150 ℃, preferably 80 to 140 ℃. The working pressure is usually 2 to 8MPa, preferably 3 to 7 MPa. The processing time depends on the processing pressure and the film forming speed, and is usually 0.01 to 5 seconds, preferably 0.1 to 3 seconds.

If necessary, after the embossing treatment, に, a cooling treatment may be performed to prevent unwanted stretching of the film due to heat.

In the present invention, the water content of the PVA-based water-soluble film to be obtained is preferably 3 to 15% by weight, particularly preferably 5 to 9% by weight, and more preferably 6 to 8% by weight, in terms of mechanical strength and heat sealability. If the water content is too low, the film becomes too hard, and the moldability in the case of forming a package and the impact resistance of the package tend to be lowered, while if it is too high, blocking tends to be easily generated. The adjustment to the water content can be achieved by appropriately setting the drying conditions and the humidity adjustment conditions.

The water content was measured according to JIS K67263.4, and the obtained value of the volatile component was defined as the water content.

In the present invention, the step of producing the PVA water-soluble film is preferably carried out, for example, at 10 to 35 ℃ and particularly preferably at 15 to 30 ℃. Humidity is usually 70% RH or less.

The film roll obtained in the present invention is packaged in a packaging film of a water vapor barrier resin, and then stored and transported for various uses, and the packaging film is not particularly limited, and may have a moisture permeability of 10g/m²24hr (measured according to JIS Z0208) or less. Specific examples thereof include single layer films such as high density polyethylene, low density polyethylene, polypropylene, polyester, polyvinylidene chloride-coated polypropylene, glass-deposited polyester, laminated films thereof, and laminated films of slit cloth (slit cloth), paper, and nonwoven fabric. Examples of the laminate film include a laminate film of glass-deposited polyester and polyethylene, and a laminate film of polyvinylidene chloride-coated polypropylene and polyethylene.

The film is preferably further subjected to antistatic treatment in advance in order to prevent the incorporation of foreign matter, and the antistatic agent may be kneaded into the film or may be coated on the surface. When the mixture is kneaded, the antistatic agent is used in an amount of about 0.01 to 5 wt% based on the resin, and when the mixture is surface-coated, the antistatic agent is used in an amount of 0.01 to 1g/m²And (4) antistatic agents.

Examples of the antistatic agent include alkyldiethanolamines, polyoxyethylenealkylamines, higher fatty acid alkanolamides, sorbitan fatty acid esters, and the like.

Next, the film roll is preferably wrapped with a wrapping film of a water vapor barrier resin, and then further wrapped with a wrapping film made of an aluminum material. Examples of the film include an aluminum foil, a laminated film of an aluminum foil and a moisture-resistant plastic film (for example, a laminated film of an aluminum foil and a polyethylene film), a laminated film of an aluminum vapor-deposited film and a moisture-resistant plastic film (for example, a laminated film of an aluminum vapor-deposited polyester film and a polyethylene film), a laminated film of an aluminum oxide vapor-deposited film and a moisture-resistant plastic film (for example, a laminated film of an aluminum oxide vapor-deposited polyester film and a polyethylene film), and the like, and a laminated film of an aluminum foil and a polyolefin film, a laminated film of an aluminum vapor-deposited film and a polyolefin film, particularly useful are a laminated film formed of a composition of a stretched polypropylene film/polyethylene film/aluminum foil/polyethylene film, a laminated film formed of a composition of a stretched polypropylene film/low-density polyethylene film/aluminum foil, and the like.

In the case of packaging, the packaging film is formed of an inner water vapor barrier resin and an outer aluminum material, and the excess portion can be pushed into the core tube in the width direction.

In the film roll of the present invention, in order to prevent the adhesion of foreign matter such as scratches and dust at the end portions, protective pads having core tube through holes are attached to the film roll either directly or after the film roll is wrapped with a wrapping film.

The shape of the protection pad is practically a disk-shaped sheet or film depending on the film roll. In order to make the protective effect remarkable, a cushioning function such as a foam, a woven fabric, or a nonwoven fabric may be added. In order to protect the film roll from moisture, a desiccant may be separately sealed in advance, or the film roll may be laminated or mixed in the protective pad.

Plastic is advantageous as a material for the protective pad, and specific examples thereof include polystyrene, polyethylene, polypropylene, polyester, polyvinyl chloride, and the like.

Examples of the protective pad containing a desiccant include: forming a moisture-absorbing layer by dispersing, impregnating, and drying a drying agent or a water-absorbing agent such as calcium chloride, silica gel, a molecular sieve, a saccharide, particularly a saccharide having a high osmotic pressure, a water-absorbent resin, or the like in a moldable material such as natural cellulose, synthetic cellulose, glass cloth, nonwoven fabric, or the like; the desiccant or water absorbent is sandwiched between the above moldable materials, and thermoplastic resin films such as polyester film, polyethylene film, polypropylene film, and Teflon (registered trademark) film.

Examples of commercially available sheet-like desiccants include: "I.D. Sheet" manufactured by ID Corporation, "Shinagawa Chemical Industry Co., Ltd," ALLOSHEET "," ZEOSHEET ", and" Hi-Sheet Dry "manufactured by Hi-Sheet Industries.

The film roll packaged by the above-described means is preferably stored and transported in a state of floating in the sky, without being grounded, by providing brackets (support plates) on the protruding portions at both ends of the core tube, or by placing and supporting the protruding portions at both ends on a stand. When the width of the film is small, a bracket is used, and when the width of the film is large, a mount is used.

The bracket is formed by plywood and plastic plates, and the size of the bracket is only required to be larger than the diameter of the film roll on 4 sides.

The core tube protruding portions at both ends of the film roll are arranged upright so as to face each other, and a pair of brackets are fitted to the core tube protruding portions, and are provided on the film roll. The chimeric reaction can be carried out as follows: the bracket is provided at its central portion with a hollow hole slightly larger than the diameter of the core tube, or is hollow in a U-shape from the upper portion to the central portion of the bracket in such a manner that the core tube can be easily inserted.

In order to store and transport the film roll supported by the bracket in a cardboard box such as a corrugated cardboard box, it is preferable to use a rectangular bracket by cutting four corners thereof and placing the bracket thereon in order to facilitate the operation during storage.

In addition, it is also practical to provide a belt displacement preventing groove on the side surface (thickness portion) of the bracket in advance to the same extent as the belt width so as not to cause movement or loosening of the belt.

During storage or transportation of the packaged film roll, it is desirable to avoid extreme conditions of high temperature, low humidity, and high humidity, and specifically, the temperature is preferably 10 to 30 ℃ and the humidity is preferably 40 to 75% RH.

The water-soluble film of the present invention thus obtained is excellent in shape stability during long-term storage and impact resistance at low temperatures, and therefore is useful for various packaging applications such as unit packaging of chemicals such as agricultural chemicals and detergents, films for (hydraulic) transfer, sanitary goods such as napkins and diapers, dirt treatment goods such as fistulization bags, medical goods such as blood-sucking sheets, and temporary substrates such as nursery sheets, seed tapes, and embroidery bases.

The water-soluble film of the present invention may be particularly suitable for unit packaging applications for pharmaceutical agents.

< medicinal preparation Package >

The drug package of the present invention is a package in which a drug is encapsulated in the PVA-based water-soluble film of the present invention. Since the drug is packaged in a water-soluble film, the drug is dissolved or dispersed in water when the water-soluble film is dissolved after the drug is put into water together with the package, and a drug package in which a relatively small amount of drug such as 1 dose is packaged is suitable for exhibiting the effect of the drug.

Examples of the encapsulated chemical include pesticides such as insecticides, fungicides, and herbicides, fertilizers, and detergents are particularly preferred. The shape of the drug may be liquid or solid, and in the case of liquid, the drug is liquid, and in the case of solid, the drug is in the form of granules, tablets, or powders. The drug is preferably used by dissolving or dispersing in water, and in the present invention, it is particularly preferable to encapsulate a liquid detergent. The pH of the agent may be any of alkaline, neutral, and acidic.

The surface of the above-mentioned medicine package is generally smooth, and the outer surface of the package (PVA-based water-soluble film) may be subjected to embossing, fine uneven pattern, special engraved pattern or other uneven processing from the viewpoints of blocking resistance, slidability during processing, reduced adhesion between products (packages), and appearance.

Hereinafter, a liquid detergent package as an example of the medicine package of the present invention will be described.

The liquid detergent package retains the shape of the liquid detergent packed therein during storage. In addition, when the liquid detergent is used (washed), the package (water-soluble film) is dissolved by contacting water, and the liquid detergent contained therein flows out of the package.

The size of the liquid detergent package is usually 10 to 50mm, preferably 20 to 40mm in length.

The thickness of the film of the packaging body made of the PVA water-soluble film is usually 10 to 120 μm, preferably 15 to 110 μm, and more preferably 20 to 100 μm.

The amount of the liquid detergent to be contained is usually 5 to 50mL, preferably 10 to 40 mL.

When a liquid detergent is packaged in the PVA water-soluble film of the present invention to form a drug package, a known method can be used.

For example, the film (bottom film) is fixed to a mold located at the lower part of the molding apparatus and the film (top film) is fixed to the upper part of the apparatus by sticking 2 sheets of the PVA-based water-soluble film. The bottom film is heated in a dryer, vacuum-molded in a mold, and then a liquid detergent is put into the molded film, and then the top film and the bottom film are pressure-bonded. After the pressure bonding, the vacuum was applied to obtain a package.

Examples of the method for pressure-bonding the film include (1) a method of heat-sealing, (2) a method of water-sealing, and (3) a method of paste-sealing, and among them, the method of (2) water-sealing is general and advantageous.

In general, the film tends to curl easily when water is applied, but the PVA-based water-soluble film of the present invention is suppressed in curling, hardly causes displacement of a sealed portion due to curling, and has good water sealing strength, and therefore, it can be suitably used for a method for performing water sealing.

The liquid detergent preferably has a pH value of 6 to 12, particularly preferably 7 to 11 when dissolved or dispersed in water. The liquid detergent has a water content of preferably 15% by weight or less, particularly preferably 0.1 to 10% by weight, and more preferably 0.1 to 7% by weight, and the water-soluble film is not gelled or insolubilized and has excellent water solubility.

The pH value is measured according to JIS K33628.3. The water content was measured according to JIS K33627.21.3.