JPH0717765B2 - Polyvinyl alcohol film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is that one side of a film is water-impermeable, and the other side of the film is water-soluble or water-dispersible in water at about 40 ° C. or lower. The present invention relates to a film having a function of dissolving or dispersing the whole film in water.

(Prior Art) Conventionally, materials having both water-soluble and water-impermeable properties have been proposed.

Japanese Unexamined Patent Publication (Kokai) No. 50-113556 discloses a partially hydrolyzed polyvinyl alcohol, a plasticizer and a metal borate.
A composition that is insoluble in a small amount of water and soluble in a large amount of water is described. That is, it is very difficult to store a large amount of water or body fluid.

Japanese Patent Publication No. 56-500037 discloses a toilet bag using a modified hydroxypropyl cellulose that is soluble in water at about 16 ° C or lower but is insoluble in water at 16 ° C or higher. However, the water temperature in the toilet fluctuates depending on the season, and especially in summer, it rises above 16 ° C, so it has the drawback that it cannot be flushed into the toilet.

Japanese Unexamined Patent Publication No. 63-181758 discloses a pouch for an artificial anus capable of being dumped in running water, in which one layer of the laminate is composed of hot water-soluble and water-resistant tissue paper, and can be dissolved in toilet water or It is possible that it does not disperse and adversely affects the function of the toilet.

(Problems to be Solved by the Invention) In the conventional techniques described above, one side is impermeable to a large amount of water, and when one side contacts water, it is easily decomposed or dissolved in water. There is no material that does this, and it has not been commercialized.

The present invention provides a basic material in which one side of a film is water-insoluble for a long time, and when the other side of the film is infiltrated with water, the entire film is easily dissolved or dispersed in water in a short time. The purpose is to

(Means for Solving the Problems) The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and found that the mechanism for forming a gel of polyvinyl alcohol and the water repellent function of the water repellent are combined. Thus, the inventors have found that the water impermeability of one side of the film is dramatically increased, and that when the film is thrown into water, it dissolves or disperses in water in a short time, and has reached the present invention.

That is, the present invention is directed to a film comprising a polyvinyl alcohol having a saponification degree of 70 to 98% and a gelling promoter of polyvinyl alcohol, and a water repellent agent coated on one surface of the film.

Hereinafter, the present invention will be described in detail.

Generally, polyvinyl alcohol means polyvinyl alcohol or its derivative. Polyvinyl alcohol is
There is a known method such as hydrolysis by producing polyvinyl acetate obtained by polymerizing vinyl acetate, that is, deacetic acid production. In this process, the degree of hydrolysis is called saponification degree, and it is an amount showing the proportion of deacetic acid in the monomer unit of polyvinyl alcohol. A saponification degree of 100% means that all the acetic acid ester residues of polyvinyl acetate are hydrolyzed to hydroxyl groups, and a polyvinyl alcohol with a saponification degree of 95% means that the monomer unit of polyvinyl acetate is 95% hydroxyl groups. Is replaced with.

The polyvinyl alcohol used in the present invention is not particularly limited as long as it has a saponification degree of 70 to 98% and is soluble, swelled or dispersed in water at about 40 ° C or lower. Further, the molecular weight of polyvinyl alcohol, that is, the degree of polymerization is not limited, and, for example, it is possible to use polyvinyl alcohol having a low degree of polymerization and a high degree of polymerization as a blend. Furthermore, if it dissolves, swells, or disperses in water at approximately 40 ° C or lower, it is a binary, ternary, or quaternary copolymer containing as a monomer of polyvinyl alcohol a monomer that can be copolymerized with vinyl acetate. It doesn't matter. Examples of the copolymerizable monomer component include monomers having a double bond in the molecule. As an example, methyl vinyl ether, styrene, vinyl chloride, allyl alcohol, acrylic acid and its ester, methacrylic acid and its ester, acrylonitrile, vinylpyrrolidone, chloroprene, butadiene, isoprene, ethylene, propylene and the like can be mentioned.

The polyvinyl alcohol gelation accelerator used in the present invention refers to salts having a coagulating effect on polyvinyl alcohol, substances capable of chemically binding polyvinyl alcohol and diol type, and the like. Salts preferably used in the present invention include sulfates such as sodium sulfate, magnesium sulfate, aluminum sulfate, ammonium sulfate and potassium sulfate, nitrates such as sodium nitrate, ammonium nitrate and aluminum nitrate, phosphates such as sodium phosphate, and chromic acid. Chromates such as potassium are included. Examples of the substance capable of chemically bonding with polyvinyl alcohol include compounds such as boric acid, borate, borax, copper, aluminum, titanium, zirconium, tin and vanadium.

The ratio of these gelling promoters to polyvinyl alcohol depends on the gelling ability of each gelling promoter, but it depends on the monomer unit of polyvinyl alcohol.
It is preferable to contain 0.1 to 30 mol%, preferably 0.1 to 20 mol%. When the concentration of the gelling agent is lower than 0.1 mol%, the water impermeability required for the film is deteriorated, and when it exceeds 30 mol%, the water solubility of the film is not sufficiently obtained, which is the purpose. The film performance cannot be obtained.

The film containing the gelling agent and polyvinyl alcohol in the present invention as constituent elements can be produced by various methods. Preferably, the polyvinyl alcohol is
After being dissolved, swelled or dispersed in water at an appropriate temperature by a known method, an aqueous solution or dispersion of a gelation accelerator is added, mixed under stirring, and cast and dried to produce the composition. A heat treatment step may be added to increase the film strength.

The film of the present invention can be obtained by coating a polyvinyl alcohol film containing a gelling agent obtained under the above conditions with a water repellent agent by a known method such as a coating method or a spraying method. To be

Generally, a water-repellent agent is called a water-repellent treatment that imparts a property of resisting wetting (wetting) with water to the surface of a film or the like, and refers to a chemical agent used for this. Water repellents are commonly used for surface treatment of textiles, especially textiles.
A substance that repels water is required to impart water repellency to the surface, and compounds with lower surface energy tend to repel water. If Shimese in chemical structure, -CF _3> -CF _2> -CH
₃ > Repel water well in the order of CH ₂ . That is, compounds with saturated hydrocarbon moieties such as paraffin and stearic acid, and compounds with multiple methyl groups such as silicone resins are
It is generally known as a portion that imparts water repellency. In addition, fluorine compounds with perfluoroalkyl groups have both water repellency and oil repellency, which repels oily substances.

Typical examples of the water repellent used in the present invention include paraffin, aluminum stearate, zirconium stearate, a silicone resin or methylhydropolysiloxane as a main component, and a reactive silicone compound or pyridinium which is reticulated by a catalyst. Reactive long-chain saturated hydrocarbon compounds such as salt-type cationic surfactants, methylol stearamide, octadecyl ethylene urea, etc., and acrylic acid polyfluoroalkyl esters having perfluoroalkyl groups as side chains And compounds containing fluorine in the main chain. A water repellent comprising a compound having a perfluoroalkyl group having a property of repelling water and oil is preferably used, but another water repellent may be selected depending on the application. Further, there is no limitation on the heat treatment method for improving the coating amount and the strength and durability after coating.

The water-repellent agent as described above is a known method such as a coating method in which a compound having water repellency is emulsified in water using a small amount of a surfactant or dispersed and dissolved in a solvent on the film surface. It can be coated with and can be dried and heat treated depending on the application.

The thickness of the film of the present invention is not particularly limited, but is usually 25-
A thickness of 250 μm is preferably used.

Further, in order to improve the flexibility of the film, a plasticizer may be added to the extent that the performance of the film is not impaired. Glycols are generally used as the plasticizer. For example, ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol,
Hexamethylene glycol, propylene glycol, glycerin, 2,3-butanediol, 1,3-butanediol,
Examples include diethylene glycol and triethylene glycol.

Further, since the film layer containing polyvinyl alcohol as a main component is colored, a coloring agent or dye may be added to the extent that the performance and strength of the film are not impaired. For example, Benzopurpurine4BX
KX), Nippon Orange GC, Chrysophenine NS, Direct Sky Blue 5B, NipponFast Vio-letBB, Direct Brown M ), Nippon Deep Black extra, Sulfur Indigo R, Sulfur Black BC, Mikelen Blue RS
(Mikethrene Blue RS), Naphtol A
S), Farst Scarlet G base (Fast ScarletG
Base), Roselin NS (Rocceline NS), Acid Brilliant Scarlet 3R
R), Chrome Green F (Chrome Green F), Chrome Black AC (ChromeBlack AC), Rhodamine B (Rhodamine
B), Ceriton Fast Piston F3B (Celliton Fast Pi
nkF3B), Seriton Fast Blue FFR (Celliton Fas
t Blue FFR) and the like.

Although the principle of the water impermeability of one side of the film of the present invention and the dispersibility or solubility of the entire film in water is unknown, it is possible to obtain a film containing a gelling agent by treating the surface with a water repellent agent. The synergistic effect of is obtained.

The ostomy bag, wound dressing, bandage, diaper, sanitary napkin, with the film of the present invention as a basic component,
It can be applied to products in various fields such as tampons, garbage disposal bags, body waste bags, urine collection bags, portable urine collection bags, laundry bags, containers or bags for medical waste.

(Example) Hereinafter, the present invention will be described in detail based on examples.

Example 1 Polyvinyl alcohol (hereinafter abbreviated as PVA) (UF-170)
M, manufactured by Unitika Ltd., saponification degree 95.5-97.5 mol%) 15
It was taken in a g beaker, and 90 g of distilled water was added to swell it sufficiently, and then PVA was dissolved in a 90 ° C water bath under strong stirring. A solution prepared by dissolving 1.17 g of aluminum sulfate in 10 g of distilled water was added to this solution with stirring and mixed. After defoaming the bubbles in the solution,
The mixed solution was cast on a polyethylene terephthalate film and air dried at room temperature overnight. The obtained film was designated as A film.

Next, about 2 ml of AG-650 (manufactured by Asahi Glass Co., Ltd.) consisting of a solution of a polymer having a linear acrylic main chain with a side chain of a perfluoroalkyl group as a water repellent agent on a 20 cm square A film is used.
After applying evenly, dry at room temperature for about 1 hour, and then 100
Heat treatment was performed at about 10 minutes.

Comparative Example 1 The same operation as in Example 1 was performed except that the heat treatment was performed at 100 ° C. for about 10 minutes without applying the water repellent.

Example 2 In Example 1, 1.17 g of aluminum sulfate was added to 0.21 g of boric acid.
The same operation was performed except that it was replaced with.

Comparative Example 2 The same operation as in Example 2 was performed except that the heat treatment was performed at 100 ° C. for about 10 minutes without applying the water repellent.

Example 3 The same operation as in Example 1 was performed except that PVA (UF-170M) was replaced with PVA (UP-180, manufactured by Unitika Ltd., saponification degree: 87 to 89 mol%).

Comparative Example 3 The same operation as in Example 3 was performed except that the heat treatment was performed at 100 ° C. for about 10 minutes without applying the water repellent.

Example 4 In Example 3, 1.17 g of aluminum sulfate was added to 0.21 g of boric acid.
The same operation was performed except that it was replaced with.

Comparative Example 4 The same operation as in Example 4 was performed, except that the water repellent was not applied and the heat treatment was performed at 100 ° C. for about 10 minutes.

Example 5 The same operation as in Example 1 was performed except that PVA (UF-170M) was replaced with PVA (E-180, manufactured by Unitika Ltd., saponification degree: 87 to 89 mol%).

Comparative Example 5 The same operation as in Example 5 was performed, except that the water repellent was not applied and the heat treatment was performed at 100 ° C. for about 10 minutes.

Test Example A 10 cm square bag was prepared by heat sealing with the surface of the film obtained in Examples 1 to 5 that was treated with the water repellent agent being the inside. Similarly, similar bags were prepared from the films of Comparative Examples 1 to 5.

30 ml of distilled water was added to each bag and it was observed how it changed. The results are shown in Table-1.

Moreover, 10 cm square of each film was added to 50 ml of distilled water, and the change in the situation was observed under stirring. The results are shown in Table-2.

As is clear from Table-1, the bag made from the film of the present invention has a water retention property for 1 hour or more, and as is clear from Table-2, the film of the present invention is within several tens of minutes. It has the property of being dissolved or dispersed in water.

(Effect of the Invention) The polyvinyl alcohol film of the present invention is water-insoluble on one side for a long time, and when water is infiltrated from the other side of the film, the entire film is easily dissolved in water in a short time or It can be dispersed and is very useful in various fields.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-31535 (JP, A) JP-A-49-120494 (JP, A) JP-B-42-7957 (JP, B1)

Claims (1)

[Claims] 1. A film comprising a polyvinyl alcohol having a saponification degree of 70 to 98% and a gelling accelerator for polyvinyl alcohol, and a water repellent agent coated on one surface of the film.