JP3609894B2 - Boric acid-based material packaging film - Google Patents

Description

【００２８】
【発明の効果】
本発明の水溶性フィルムは、ホウ酸系物質を包装して放置した場合であっても、フィルム中のＰＶＡとホウ酸が反応してＰＶＡをゲル化させることがなく、フィルムの水溶性の経時的低下が少ない。また、本発明の化合物（Ｂ）は、優れたホウ酸キャッチャー剤として作用するとともに、フィルム表面への移行性が小さい優れた可塑剤として機能し、ブリードアウトやブロッキングが少ない水溶性フィルムが提供される。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polyvinyl alcohol (hereinafter abbreviated as PVA) water-soluble film for packaging a boric acid material. More specifically, the present invention relates to a water-soluble film that does not cause gelation of PVA in the film even when a boric acid-based substance is packaged, and has little deterioration in water solubility with time.
[0002]
[Prior art]
In recent years, water-soluble film is a method in which a fixed amount of various drugs such as detergents are sealed and packaged, put into water in its packaging form at the time of use, and the content is dissolved or dispersed together with the packaging film. A lot has been done. The advantages of this unit packaging are that it can be used without directly touching dangerous chemicals during use, and that a certain amount is packaged, so that weighing during use is unnecessary. Of these chemicals, boric acid is often added in order to impart bactericidal properties, prevent spoilage, and further provide insecticidal performance and slaughtering performance. If a drug containing boric acid is packaged with a water-soluble film based on PVA, the PVA and boric acid react, the film becomes insoluble in water, and the function as a water-soluble film is lost. The property changes to hard and brittle properties at low temperatures, the impact strength at low temperatures is greatly reduced, and there are problems such as film tearing during transportation and work.
[0003]
In order to prevent the insolubilization reaction due to the presence of boric acid, a film containing a compound having many 1,2-glycol bonds in the molecule, particularly sorbitol, is used as a boric acid catcher agent. However, since sorbitol has poor compatibility with PVA and is a powder at room temperature, it needs to be added in a large amount in order to sufficiently function as a boric acid catcher agent, and the film properties are greatly reduced. A phenomenon occurs in which white powder is deposited on the film surface. In addition, since sorbitol has almost no plasticizing performance of PVA, it is necessary to add a plasticizer of PVA separately. This is also not preferable because the mechanical properties of the film are lowered. Glycerin, which is generally used as a plasticizer for PVA, has a drawback that it has no ability as a boric acid catcher and has a very high migration property in a film. Therefore, at present, unit packaging of drugs such as detergents containing boric acid has not been put into practical use.
[0004]
[Problems to be solved by the invention]
The present invention solves the above problems, and is a case where a drug is packaged over a long period of time as a water-soluble film for packaging pharmaceuticals such as agricultural chemicals and detergents containing boric acid, which has a high dissolution rate in water. Another object of the present invention is to provide a water-soluble film that retains water solubility and has very little plasticizer migration.
[0005]
[Means for Solving the Problems]
As a result of intensive studies in view of the present situation, the present inventors have added 1 to 4 moles of alkylene oxide to 1 part of a 4 to 6-valent polyhydric alcohol to 100 parts by weight of the polyvinyl alcohol resin (A). The present inventors have found a water-soluble film for packaging boric acid substances comprising a composition obtained by blending 2 to 100 parts by weight of the obtained compound (B), and have completed the present invention.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The PVA resin (A) used in the present invention is a saponified product of polyvinyl ester. Examples of the vinyl ester include vinyl acetate, vinyl propionate, vinyl formate, vinyl versatate, vinyl pivalate and the like, and industrially produced and cost-effective vinyl acetate is usually used. PVA-based resins are produced by polymerizing vinyl esters in the presence of radical initiators in a bulk or alcohol solvent, and then partially or highly saponified with the action of an alkali or acid catalyst.
[0007]
The degree of polymerization of the PVA-based resin is not particularly limited, but in the case of a water-soluble film, the mechanical properties of the film are also important, and strong strength and flexibility are required even in the case of a thin thickness of 10 to 100 μm. In view of the strength and toughness of the film, the viscosity average polymerization degree (hereinafter abbreviated as polymerization degree) is 200 to 10,000, preferably 500 to 4000. If the degree of polymerization is less than 200, the film strength tends to be weak, and if the degree of polymerization is more than 10,000, the viscosity of the solution when preparing the film increases and there is a problem in workability.
[0008]
The degree of saponification of the PVA-based resin is usually 40 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 98 mol% in consideration of film strength, film stiffness and bag-making property.
[0009]
The PVA resin of the present invention is a saponified product of the above-mentioned polyvinyl ester. However, in order to further improve the water solubility, a single amount having a vinyl ester and a sulfonic acid group, a carboxyl group, an amino group, a quaternary ammonium base and the like. PVA modified with an ionic group can also be used by copolymerizing and saponifying the body. Among these, PVA having a sulfonic acid group or a carboxyl group is particularly preferable. The content rate of the monomer unit which has these functional groups is 0.1-10 mol%, Preferably it is 1-5 mol%.
[0010]
Examples of the monomer having a sulfonic acid group include 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof, 2-acrylamido-1-methylpropanesulfonic acid or a salt thereof, and 2-methacrylamide-2-methylpropanesulfonic acid. Or the salt, olefin sulfonic acids, such as ethylene sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid, or its salt is mentioned. Among these, 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof is preferable from the viewpoint of copolymerization reactivity with vinyl ester and stability during saponification.
[0011]
Monomers having a carboxyl group include maleic anhydride, mono- or dialkyl maleic acid esters, itaconic acid or alkyl esters thereof, acrylic acid, allyl carboxylic acid, saponified carboxylic acid or a salt thereof. Acid esters are also included. Among these, maleic anhydride, itaconic acid or derivatives thereof are preferable.
[0012]
The compound (B) used for this invention is obtained by addition-reacting 1-4 mol of alkylene oxide with respect to 1 mol of 3-6 valent polyhydric alcohol. Compound (B) obtained by addition reaction of 1 to 4 moles of alkylene oxide to 1 mole of 3 to 6-valent polyhydric alcohol is liquid at room temperature and is an excellent phase for PVA resin (A). It has solubility and plasticizing performance, has little transferability to the outside of the film, and has low bleed out and blocking properties.
[0013]
Examples of the trivalent to hexavalent polyhydric alcohol that is a raw material of the compound (B) include glycerin, trimethylolpropane, diglycerin, pentaerythritol, xylose, arabinose, ribulose, and sorbitol. Glycerin, pentaerythritol, and sorbitol are preferable. Furthermore, among these, sorbitol which has the very outstanding plasticization performance with respect to PVA-type resin (A) whose saponification degree is 99 mol% or more is the most preferable.
[0014]
Examples of the alkylene oxide which is another raw material of the compound (B) include ethylene oxide and propylene oxide, preferably ethylene oxide. In some cases, ethylene oxide and propylene oxide may be mixed and added. The preferred added mole number of alkylene oxide is 2 to 3. When the average number of added moles of alkylene oxide is less than 1 mole, a problem arises in the plasticizer migration. Moreover, when average addition mole number exceeds 4 mol, compatibility with PVA-type resin (A) will fall, and the plasticization effect will also fall. In addition, the added mole number here is an average added mole number, and distribution may exist in the added mole number. However, it is not preferred that 5 mol or more of adduct compound is mixed in at least 50% by weight.
[0015]
The compounding quantity of the compound (B) with respect to PVA-type resin (A) is 2-100 weight part with respect to 100 weight part of PVA-type resin (A), Preferably it is 5-30 weight part. When the compounding amount of the compound (B) is less than 2 parts by weight, the performance as a boric acid catcher agent is insufficient, and when a medicine containing boric acid is packaged, the deterioration of water solubility with time cannot be suppressed, Insufficient flexibility of the film and low impact strength at low temperatures. When the compounding amount of the compound (B) exceeds 100 parts by weight, problems occur in film strength reduction, blocking property and bag-making property.
[0016]
Moreover, what is generally used as a plasticizer of PVA-type resin can also be used together with the water-soluble film of this invention depending on the case other than a compound (B). Examples of these plasticizers include polyhydric alcohols such as glycerin, diglycerin, triglycerin and diethylene glycol, polyethers such as polyethylene glycol and polypropylene glycol, phenol derivatives such as bisphenol A and bisphenol S, and N-methylpyrrolidone. Examples include amide compounds and water.
[0017]
The boric acid substance used in the present invention may be any agent containing boric acid, and refers to a boron compound that reacts with PVA to form a gel-like substance. Boric acid, boric acid ester, borax Etc. Specific examples thereof include detergents containing boric acid, anti-corrosion agents used in kitchens, disinfectants, toilet deodorants, and the like. These substances may be in the form of powder, granules, solids such as spheres and tablets, or in some cases liquid.
[0018]
In forming a composition comprising the PVA-based resin (A) and the compound (B) of the present invention, the aqueous solution is cast or melted and extruded from a T-die or an inflation molding machine. The method is used. At that time, usual additives such as a colorant, a fragrance, an extender, an antifoaming agent, a release agent, an ultraviolet absorber, and an inorganic powder may be appropriately blended as necessary. Moreover, you may add water-soluble polymers, such as starch, carboxymethylcellulose, methylcellulose, and hydroxymethylcellulose within the range which does not impair the characteristic of this invention as needed.
[0019]
【Example】
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. In the examples, “%” and “parts” are based on weight unless otherwise specified.
[0020]
[Method of measuring water solubility of film]
A film sample was cut into a 40 × 40 mm square, squeezed with a slide mount, immersed in water stirred at 20 ° C. and 10 ° C., and the time (seconds) until the film was completely dissolved was measured. .
[0021]
[Measurement method of plasticizer migration]
A 10 × 10 cm bag was made from the film using a heat sealer, and 15 g of a substance containing boric acid was packaged and heat sealed. Double packaging was performed on the packaged bag with an aluminum / polyethylene laminate film bag so that moisture and plasticizer would not scatter to the outside, and the product was left in a constant temperature bath at 40 ° C. for a predetermined time. The amount of plasticizer in the film before and after standing was measured. The amount of plasticizer in the film is measured by drying the film sample for 5 hours in a vacuum dryer at 50 ° C., removing moisture, and performing Soxhlet extraction with methanol. The amount of plasticizer was determined. The “plasticizer residual ratio” after standing was expressed as “%” by dividing “the amount of plasticizer after being left” by “the amount of plasticizer before being left”.
[0022]
Example 1
An aqueous solution of a composition in which 15 parts of a compound obtained by adding 2 moles of ethylene oxide to 1 mole of sorbitol was added to 100 parts of PVA having a polymerization degree of 1750 and a saponification degree of 88 mole%, was transferred to a heat roll at 70 ° C. The film was cast to obtain a film having a thickness of 40 μm. As a boric acid substance, a powder obtained by blending 10 parts of boric acid and 90 parts of diatomaceous earth was used as a model substance. After this medicine was packaged with a film, it was left in a thermostat at 40 ° C. for 1 month. The water solubility of the film before and after standing and the amount of the remaining plasticizer were measured. The results are shown in Table 1. The film of the present invention has excellent water-solubility, very little plasticizer migration, and is flexible and tough even after a boric acid-containing substance is packaged and left at 40 ° C. for 1 month. Was holding. Moreover, there was no bleed-out of the plasticizer to the film surface, and the film was transparent.
[0023]
Comparative Example 1
Using 100 parts of PVA used in Example 1 and 15 parts of glycerin as a plasticizer, a 40 μm film was prepared. After packaging a boric acid model material in the same manner as in Example 1, it was left at 40 ° C. for 1 month. did. The water solubility and plasticizer amount of the film before and after standing were measured. The results are shown in Table 1. After standing, the film did not dissolve in water at all, and gelation had progressed. Moreover, the plasticizer transferability was changed to a very large, hard and brittle film.
[0024]
Comparative Example 2
A film of 40 μm was prepared using 100 parts of PVA used in Example 1 with 15 parts of glycerin and 10 parts of sorbitol as a plasticizer. Compared with the film of Example 1, this film was not stiff and had a low strength. In the same manner as in Example 1, after packaging the boric acid model material, it was allowed to stand at 40 ° C. for 1 month, and the water solubility and the amount of plasticizer of the film were measured. The results are shown in Table 1. The film after being allowed to dissolve was dissolved in water, but the dissolution rate was considerably reduced, and the film after being allowed to stand was a white turbid film as a result of sorbitol moving to the surface of the film and crystallizing. Further, as in Comparative Example 1, the amount of plasticizer remaining in the film was small, and the film was hard and brittle.
[0025]
Example 2
Vinyl acetate and maleic anhydride are copolymerized in a methanol solvent and subjected to a saponification reaction by a conventional method. A carboxylic acid having a polymerization degree of 1200, a saponification degree of 96 mol%, and a copolymer unit content of maleic acid groups of 4 mol% is obtained. Sodium acid base-modified PVA was obtained. An aqueous solution of a composition in which 25 parts of a compound obtained by adding 3 moles of ethylene oxide to 1 mole of sorbitol was added to 100 parts of this modified PVA was cast into a hot roll at 70 ° C., and the thickness was 40 μm. A film was obtained. A dishwashing detergent composed of surfactant, sodium silicate, sodium hydroxide, sodium tripolyphosphate and boric acid was used as a model substance for boric acid substances. After packaging the drug according to the above test method, It was left in a thermostat for 1 month. The water solubility of the film before and after standing and the amount of the remaining plasticizer were measured. The results are shown in Table 1. Even after the drug was packaged and allowed to stand, the water solubility of the film did not drop at all.
[0026]
Comparative Example 3
A 40 μm film was prepared using 100 parts of PVA used in Example 2 with 25 parts of glycerin and 8 parts of sorbitol as a plasticizer. This film was less strong than the film of Example 2. In the same manner as in Example 2, after packaging the boric acid model material, it was allowed to stand at 40 ° C. for 1 month, and the water solubility of the film before and after being left and the amount of the remaining plasticizer were measured. The results are shown in Table 1. Although the film after standing was dissolved in water, the dissolution rate was considerably reduced, and the film after standing was a white turbid film as a result of sorbitol moving to the surface of the film and crystallizing.
[0027]
[Table 1]

[0028]
【The invention's effect】
The water-soluble film of the present invention does not cause the PVA and boric acid in the film to react with each other and gel the PVA even when the boric acid-based material is packaged and allowed to stand. There is little degradation. In addition, the compound (B) of the present invention functions as an excellent boric acid catcher agent, functions as an excellent plasticizer with low migration to the film surface, and provides a water-soluble film with little bleeding out and blocking. The

Claims (1)

2 to 100 parts by weight of a compound (B) obtained by addition reaction of 1 to 4 moles of alkylene oxide to 1 mole of a 4 to 6 valent polyhydric alcohol is blended with 100 parts by weight of a polyvinyl alcohol resin (A). A water-soluble film for boric acid material packaging for packaging at least one boric acid material selected from the group consisting of detergents, antiseptics, bactericides, and deodorants .