JP2012034623A - Hydro colloid film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydro colloid film having sufficient water repellency and softness.SOLUTION: The hydro colloid film includes: a main layer containing the hydro colloid film as a main component used as food or food additive; and a hydrophobic layer formed on at least one surface of the main layer by a spin coat, covering more than 50 area% of one surface of the main layer, and having a thickness of 0.1-20 μm.

Description

  The present invention relates to a hydrocolloid film having sufficient water repellency and flexibility.

  Conventionally, as a use of a hydrocolloid film, a film-like food such as an oral refreshing agent is known in the food field. In the cosmetics field, it is used for film-like soaps, and in the pharmaceutical field, it is used for wafers. In recent years, food packaging applications have been developed. Unlike the case where a plastic film is used as a packaging material, the hydrocolloid film has the advantage that it is not necessary to remove the packaging during cooking or eating because it can be eaten as it is. As such a hydrocolloid film, there is a film having water solubility, and a film mainly composed of gelatin, pullulan or the like is known (Patent Document 1).

  Such water-soluble hydrocolloid films are used as, for example, food packaging materials such as instant noodles, instant soups, seasoning oils, and dried vegetables, and binding bands that bind dry noodles such as somen and udon. However, such a hydrocolloid film having water solubility is insufficient in water repellency and has a problem that it cannot be used for packaging materials for foods containing a lot of moisture.

  As a method for forming a hydrophobic layer on a hydrocolloid film, a method of impregnating or coating a polyhydric alcohol, wax, or natural resin (Patent Document 2), a method of uniformly dispersing an aliphatic higher alcohol ester in a film ( Patent Document 3) proposes a method (Patent Document 4) in which a hydrophobic layer is formed and then the surface of the film is covered with an intermediate layer (adhesive layer).

JP-A-6-105660 JP-A 63-240752 JP-A-1-228444 JP-A-5-132570

  However, in the method of forming a hydrophobic layer by impregnating, since the film containing hydrocolloid is hydrophilic, wax or resin does not form a uniform layer, resulting in unevenness on the film surface and the entire film surface. However, it is difficult to form a hydrophobic layer and water repellency is poor. Further, in the method of imparting hydrophobicity by uniformly dispersing the aliphatic higher alcohol ester in the film, there is a problem that uniform dispersion itself is difficult. Furthermore, in the method of covering the hydrophobic layer via the intermediate layer, the film thickness is increased by providing the intermediate layer, and as a result, the film properties are adversely affected, such as poor flexibility and poor transparency. There is a problem of giving.

  Then, an object of this invention is to provide the hydrocolloid film provided with sufficient water repellency and a softness | flexibility.

  In order to achieve the above object, the present inventors have conducted extensive research and found that a hydrocolloid film in which a thin hydrophobic layer is uniformly formed on the entire surface of the film can be provided. That is, the present invention includes a main layer containing a hydrocolloid used as a food or food additive as a main component, and at least one surface of the main layer formed by spin coating, and 50 on one surface of the main layer. A hydrocolloid film that covers an area% or more and has a hydrophobic layer having a thickness of 0.1 to 20 μm.

  As described above, according to the present invention, a hydrocolloid film having high water repellency and flexibility can be provided.

  In the hydrocolloid film according to the present invention, the hydrocolloid used in the main layer includes alginic acid, alginate, carrageenan, agar, fur celerane, pectin, gelatin, tamarind seed gum, xanthan gum, guar gum, tara gum, locust bean gum, cassia gum, arabian Examples thereof include gum, arabinogalactan, curdlan, pullulan, glucomannan, acyl gellan gum, deacylated gellan gum, starch, modified starch, dextrin, chitosan, carboxymethylcellulose (CMC), CMC salt, and other cellulose derivatives. These hydrocolloids may be used alone or in combination of two or more. The hydrocolloid can be appropriately selected as in the following example in consideration of the dissolution temperature of the hydrocolloid film. For example, when producing a cold water soluble film, alginic acid, alginate, tamarind seed gum, xanthan gum, carrageenan, guar gum, tara gum, locust bean gum, cassia gum, gum arabic, arabinogalactan, pullulan, starch, modified starch, dextrin, CMC, CMC salt, cellulose derivative or the like is preferably used as the main component of the main layer. In the case of producing a hot water-dissolved film, it is preferable that agar, fur celerane, acyl gellan gum, deacylated gellan gum, curdlan or the like is a main component of the main layer.

  Agar includes low-intensity agar and instantly soluble agar. As the low-intensity agar, for example, the one described in Japanese Patent No. 3023244 can be used. As the rapidly soluble agar, for example, those described in Japanese Patent Publication No. 63-005053 can be used. The processed starch is a cross-linked starch, a substituted starch, an oxidized starch, an acid-treated starch or the like, and a commercially available product can be used.

  By combining two or more of the above hydrocolloids, physical properties such as improvement in film strength, heat sealability and stretchability, and hue can be changed. For example, carrageenan and locust bean gum are known to increase in strength due to a synergistic effect in a water gel state, but an improvement in strength can be confirmed even in a film. In addition, the water absorption of the main layer can be greatly increased by blending and blending one or more materials having high water absorption such as carrageenan, xanthan gum, glucomannan, or psyllium seed gum. Furthermore, the main layer insoluble in hot water can be obtained by dealkalization after adding glucomannan to high alkali. Furthermore, since low melting point agar has a lower melting point than that of a polymer, the heat sealability can be improved by blending into the main layer. Thus, materials can be appropriately selected according to the physical properties of the target hydrocolloid film.

  The main layer preferably further contains a polyhydric alcohol or a saccharide as a plasticizer in order to impart flexibility to the film. Examples of the polyhydric alcohol include those having water retention characteristics when blended in a hydrocolloid, specifically, dihydric alcohols such as ethylene glycol and propylene glycol; trihydric alcohols such as glycerin; sorbitol and mannitol. Sugar alcohols such as saccharose, maltose, xylitol, and reduced starch saccharified products; monosaccharides such as glucose, galactose, fructose, and xylose; disaccharides such as saccharose, trehalose, maltose, and lactose; and oligos such as degradation products of starch Examples of the sugar include galactooligosaccharide, isomaltoligosaccharide, xylo-oligosaccharide, soybean oligosaccharide, nigero-oligosaccharide, emulsifying oligosaccharide, and fructo-oligosaccharide.

  The main layer may contain additives such as inorganic and organic powders, fibers, coloring agents, and fragrances. Examples of inorganic and organic powders include starch, silica, titanium dioxide, and poorly soluble salts. By adding starch, silica, titanium dioxide, etc., the color of the film can be made white and the texture is also improved. Examples of the fibers include cellulose fibers, hemicellulose fibers, chitin, and chitosan. A paper-like film can be obtained by adding cellulose fibers. Examples of the colorant include natural dyes, synthetic colorants, and pigments. Furthermore, functional materials such as antibacterial components such as hinokitiol, wasabiol and glycine may be added.

  The main layer preferably contains 10 to 96% by weight of hydrocolloid, more preferably 20 to 90% by weight. The polyhydric alcohol is preferably contained in the main layer in an amount of 2 to 40% by weight.

  The thickness of the main layer is not particularly limited, but is preferably about 10 to 100 μm for packaging purposes.

  In the hydrocolloid film according to the present invention, the hydrophobic layer preferably contains at least one selected from waxes, waxes, hardened oils, low HLB emulsifiers, and natural resins. Examples of waxes and waxes include carbana wax, candelilla wax, beeswax, paraffin wax, microcrystalline wax, rice wax, cocoa butter, and cholesterol ester. Examples of the hardened oil include hardened castor oil and rapeseed hardened oil. Examples of low HLB emulsifiers include HLB 5 or lower emulsifiers such as sucrose fatty acid esters and tristearic acid glycerides. Examples of natural resins include rosin, dammar, mastic, shellac, and the like.

  The thickness of the hydrophobic layer is 0.1 to 20 μm, and more preferably 1 to 10 μm. If it is thinner than 0.1 μm, the water repellency is not sufficient, and if it is thicker than 20 μm, the flexibility is impaired, the flexibility of the hydrocolloid film is inferior, and the hydrophobic layer is cracked. The film thickness of the hydrophobic layer can be adjusted by a usual method using a spin coating method. The thickness of the hydrophobic layer is preferably uniform. The thickness of the hydrophobic layer can be determined using a general film thickness meter, SEM, or the like.

  In the hydrocolloid film according to the present invention, a hydrophobic layer is formed on at least one surface of the main layer. When the hydrophobic layer is formed on only one surface of the main layer, the hydrophobic layer covers 50 area% or more of one surface, and preferably covers 70 area% or more. When it is less than 50 area%, the water repellency is inferior. The area% can be adjusted by a usual method using a spin coating method. The area% can be obtained by processing an image taken using a general optical microscope.

  The hydrocolloid film can be manufactured by the following manufacturing method. First, the raw material is dissolved in water and the defoamed dope is coated on a support such as a stainless steel belt, glass fiber, drum, various plastic films, or sheets, and various coatings such as spray, roll coater, comma coater, or die coater. Using an apparatus, casting is performed using a pump, an extrusion molding machine, or the like so that the thickness is constant. Next, the support is heated using hot water or oil, heat transfer from an electric heater, hot air, infrared rays, or the like to evaporate moisture in the cast dope. The main layer can be obtained by drying the water content from about 2% to about 25%, preferably from 4% to 20% by weight.

  After the main layer is obtained by the above production method, a hydrophobic layer is formed. The hydrophobic layer is prepared by, for example, first dissolving wax, waxes, or natural resins in a good solvent or melting them by heating to prepare a solution, coating the solution on the surface of the main layer by spin coating, and then drying the solution. Alternatively, a hydrocolloid film can be obtained by forming a hydrophobic layer by solidification by cooling.

  The formation of the hydrophobic layer by the spin coating method can be easily produced by using a solvent generally used for foods. That is, since the hydrocolloid film is hydrophilic, the solvent used in food can be applied without repelling, and the target product can be uniformly coated. Examples of the solvent include ethanol and isopropyl alcohol.

  The hydrocolloid film according to the present invention can be used in various applications and is not particularly limited. For example, in food applications, food packaging materials such as instant noodles, instant soup, seasoning oil, and dried vegetables, somen noodles It can be used as a binding band for binding dry noodles such as udon, as a packaging for pasty foods such as jams and cream sauces, as a container for foods containing moisture, and as a partition for lunch boxes. As cosmetics and daily necessities, it can be used as packaging for soaps, pesticides, fertilizers, etc.

In the examples and comparative examples according to the present invention, each physical property was measured as follows.
Hydrophobic layer thickness: Using a film thickness meter, the thicknesses of the uncoated film and the coated film were measured at five locations, respectively, and the thickness of the hydrophobic layer was calculated from the difference between the average values.
Proportion (area%) of the hydrophobic layer on the main layer: The surface of the hydrophobic layer was photographed using an optical microscope. 100 locations were selected at random from the captured images, and it was determined from the difference in brightness between the images that the bright portions were covered with a hydrophobic layer, and the coverage was determined by image processing.

Water repellency: Water droplets were dropped on the surface of the hydrocolloid film, and water repelling was visually confirmed. The water repellency was evaluated as follows.
○: After dropping the water droplets, the film did not absorb the water droplets and the water repellent effect was confirmed.
Δ: Water droplets were not absorbed immediately after dropping, but the film absorbed water droplets over time.
X: Immediately after dropping the water droplet, the film absorbed the water droplet.
Flexibility: The hydrocolloid film was bent and it was confirmed whether the hydrophobic layer was peeled off. The flexibility was evaluated as follows.
○: The hydrophobic layer did not peel off.
Δ: Partially peeled off the hydrophobic layer when bent considerably.
X: The hydrophobic layer peeled easily.
Solubility: The hydrocolloid film was immersed in hot water at 80 ° C., and a difference in solubility from the film having only the main layer was confirmed.
○: Dissolved in the same manner as the film having only the main layer.
X: It does not dissolve as compared with the film having only the main layer.

Example 1
8 parts by weight of agar (S-6; manufactured by Ina Food Industry Co., Ltd.) and 2 parts by weight of glycerin were dispersed in water (total 100 parts by weight), heated at 90 ° C. or more for 3 minutes or more and dissolved in water. Next, the solution was degassed and cast onto the support at a predetermined thickness. Thereafter, the atmosphere including the support is set to 50 ° C. to 95 ° C. to evaporate the water in the solution and dried until the water content becomes about 5 to 15%. The main layer (film according to Reference Example 1) Got. Next, a natural resin Mastic gum (manufactured by Ichimaru Falcos) 1.0 wt% ethanol solution was applied to one surface of this main layer by spin coating (2 mL, rotation speed 1500 rpm) to Example 1. Such a hydrocolloid film was obtained. Table 1 shows the thickness and ratio of the hydrophobic layer, and the water repellency, flexibility and solubility of the resulting hydrocolloid film.

Example 2
7 parts by weight of κ-carrageenan and 3 parts by weight of glycerin were dispersed in water (total 100 parts by weight), heated at 90 ° C. or higher for 3 minutes or more, and dissolved in water. Thereafter, a hydrocolloid film according to Example 2 was obtained in the same manner as Example 1. The results are shown in Table 1.

Example 3
7 parts by weight of sodium alginate and 3 parts by weight of glycerin were dispersed in water (total 100 parts by weight), heated at 90 ° C. or more for 3 minutes or more and dissolved in water. Thereafter, a hydrocolloid film according to Example 3 was obtained in the same manner as Example 1. The results are shown in Table 1.

Example 4
40 parts by weight of gelatin and 4 parts by weight of glycerin were dispersed in water (total 100 parts by weight), heated at 90 ° C. or more for 3 minutes or more, and dissolved in water. Thereafter, a hydrocolloid film according to Example 4 was obtained in the same manner as Example 1. The results are shown in Table 1.

Example 5
A main layer was produced in the same manner as in Example 1. Then, a hydrocolloid film according to Example 3 was applied to one surface of this main layer by applying a 1.0% by weight ethanol solution of mastic gum, which is a natural resin, by spin coating (1.5 mL, rotation speed 1500 rpm). Obtained. Table 1 shows the thickness of the hydrophobic layer, the proportion to be squeezed, and the water repellency, flexibility and solubility of the resulting hydrocolloid film.

Example 6
After producing the main layer in the same manner as in Example 1, the formation of the hydrophobic layer by spin coating in Example 1 was repeated 5 times to obtain the hydrocolloid film according to Example 4. Table 1 shows the thickness of the hydrophobic layer, the proportion to be squeezed, and the water repellency, flexibility and solubility of the resulting hydrocolloid film.

Example 7
A main layer was obtained in the same manner as in Example 1. Thereafter, a carbana wax melted by heating on the surface of the main layer was applied by spin coating (2 mL, 1500 rpm) to obtain a hydrocolloid film according to Example 7. The results are shown in Table 1.

Comparative Example 1
8 parts by weight of agar (S-6; manufactured by Ina Food Industry Co., Ltd.) and 2 parts by weight of glycerin were dispersed in water (total 100 parts by weight), heated at 90 ° C. or more for 3 minutes or more and dissolved in water. Next, 2 parts by weight of a 1.0% by weight ethanol solution of mastic gum, which is a natural resin, was added to this solution and dispersed and mixed to obtain a hydrocolloid film according to Comparative Example 1. The results of water repellency and flexibility of the obtained hydrocolloid film are shown in Table 1.

Comparative Example 2
A hydrocolloid film according to Comparative Example 2 was obtained in the same manner as in Example 1 except that the comma method was used instead of the spin coating method. Table 1 shows the thickness and ratio of the hydrophobic layer, and the water repellency, flexibility and solubility of the resulting hydrocolloid film.

Comparative Example 3
A main layer was produced in the same manner as in Example 1. Next, a hydrocolloid film according to Comparative Example 3 was applied to one surface of this main layer by applying a 1.0% by weight ethanol solution of mastic gum, which is a natural resin, by spin coating (1.0 mL, rotation speed 1500 rpm). Obtained. Table 1 shows the thickness of the hydrophobic layer, the proportion to be squeezed, and the water repellency, flexibility and solubility of the resulting hydrocolloid film.

Comparative Example 4
After producing the main layer in the same manner as in Example 1, the formation of the hydrophobic layer by spin coating in Example 1 was repeated 10 times to obtain a hydrocolloid film according to Comparative Example 4. Table 1 shows the thickness of the hydrophobic layer, the proportion to be squeezed, and the water repellency, flexibility and solubility of the resulting hydrocolloid film.

Claims (1)

A main layer containing a hydrocolloid used as a food or food additive as a main component;
A hydrocolloid film having a hydrophobic layer formed on at least one surface of the main layer by spin coating, covering 50% by area or more of the one surface of the main layer, and having a thickness of 0.1 to 20 μm.