JP2012034624A - Hydrocolloid film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrocolloid film with a high heat-sealing strength.SOLUTION: The film contains hydrocolloid which is used in a food or as a food additive. The heat-sealing strength of the film is at least 1.2 N, and the hydrocolloid contains at least 5 wt.% of at least one of agar, gelatin, pullulan, modified starch and starch. The surface of the film is subjected to at least one of a corona discharge treatment, matting and embossing.

Description

  The present invention relates to a hydrocolloid film having high heat seal strength.

As the hydrocolloid film, cellophane mainly composed of cellulose, wafers mainly composed of starch, and films mainly composed of pullulan and starch are known. In recent years, hydrocolloid films have also been used for food applications. For example, edible packaging applications for packaging food materials and applications for eating films such as oral fresheners are known. Among hydrocolloid films, an edible film produced from a food material has an advantage that it can be eaten as it is, unlike the case where a plastic film is used as a packaging material, so that it is not necessary to remove the packaging during cooking or eating. Such edible films include those having hydrocolloid properties and water solubility, and those having gelatin, pullulan and the like as main components are known (Patent Document 1).

  Such water-soluble edible films are used as, for example, wrapping seasonings such as instant noodles and instant soups, and as a binding band for binding dry noodles such as somen and udon. The requirements for an edible film when used in such applications include high heat seal strength and the ability to completely package seasonings and the like without breakage during production or distribution.

  Examples of a method for increasing the heat seal strength include a method for coating a film surface with a component for improving the sealing property, a method for performing a printing process, and a method for performing a lamination process by laminating.

JP-A-6-105660

  However, in the method of coating on the film surface, it is difficult to uniformly apply the coating liquid or powder on the film surface, so the film surface may be uneven and the appearance may be impaired, or the heat seal strength may not be sufficient Therefore, there is a problem that a hydrocolloid film having high heat seal strength cannot be obtained. Even in the printing method, it is difficult to adjust the printing solution, which causes problems such as uneven printing, and greatly reduced productivity for uniform printing. In the method of laminating, since it is difficult to firmly bond the layers, there is a problem that the heat seal strength is lowered and a hydrocolloid film having a high heat seal strength cannot be obtained. Accordingly, an object of the present invention is to provide a hydrocolloid film having high heat seal strength.

  In order to achieve the above object, the present inventors have made extensive studies and found that a hydrocolloid film having high heat seal strength can be provided. That is, the present invention is a hydrocolloid film comprising a hydrocolloid, wherein the heat seal strength of the film is 1.2 N or more.

  As described above, according to the present invention, a hydrocolloid film having high heat seal strength can be provided.

  Examples of the hydrocolloid used in the hydrocolloid film according to the present invention include alginic acid, alginate, carrageenan, agar, fur celerane, pectin, gelatin, tamarind seed gum, xanthan gum, guar gum, tara gum, locust bean gum, cassia gum, gum arabic, arabinogalactan , Curdlan, pullulan, glucomannan, acyl gellan gum, deacylated gellan gum, starch, modified starch, dextrin, chitosan, hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), carboxymethylcellulose (CMC), and CMC salt Etc. The hydrocolloid may be used alone or in combination of two or more, and at least one of agar, gelatin, pullulan, processed starch and starch is preferably contained in the hydrocolloid, and agar is contained in the hydrocolloid. More preferably. 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, It is preferable that HPMC, HPC, CMC, CMC salt or the like is a main component. In the case of producing a hot water-dissolved film, it is preferable that alginic acid, alginate, carrageenan, agar, fur celerane, acyl gellan gum, deacylated gellan gum, or curdlan be the main component. Moreover, you may improve the intensity | strength and solubility of a film by combining two or more said hydrocolloids.

  Agar includes low-intensity agar and low-melting-point agar. As the low-intensity agar, for example, the one described in Japanese Patent No. 3023244 can be used. The low melting point agar can be obtained by selecting a raw material seaweed to obtain a physical property having a low melting point or by performing hydroxyethylation. The melting point of the low melting point agar is, for example, 86 ° C. or lower. 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.

  The hydrocolloid film according to the present invention may contain a plasticizer such as a polyhydric alcohol in addition to the hydrocolloid. Further, for the purpose of improving productivity, an emulsifier such as sucrose fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, and lecithin may be included.

  The hydrocolloid film according to the present invention preferably contains 10 to 96% by weight of hydrocolloid, and more preferably 20 to 90% by weight. When one or more of agar, gelatin, pullulan, modified starch and starch are contained in the hydrocolloid, it is preferably contained in the hydrocolloid in an amount of 5% by weight or more, and more preferably 10% by weight or more. preferable. It is preferable that a predetermined amount of these hydrocolloids is contained because the heat seal strength is particularly high.

  The hydrocolloid film according to the present invention preferably has a heat seal strength of 1.2 N or more, and more preferably 2.0 N or more. The heat seal strength can be increased by the type of hydrocolloid and the surface treatment of an edible film described later. The heat seal strength can be measured with reference to JIS Z1707. For example, the sealing surfaces of the film sample pieces (width is 15 mm) are bonded to each other using a heat sealer. The sealing time can be 0.5 seconds and the sealing temperature can be 140 ° C. A heat seal strength (N / 15 mm) measurement of the bonded sample is performed using a tensile strength measuring machine. The tensile speed can be 50 mm / min.

  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 edible film can be obtained by drying the moisture content from about 2% to about 25%, preferably from 4% to 20% by weight. Although the thickness of a hydrocolloid film is not specifically limited, In order to maintain solubility and a softness | flexibility, it is preferable that it is 10-250 micrometers, and it is more preferable that it is 20-100 micrometers.

  After the hydrocolloid film according to the present invention is obtained by the above production method, it is necessary to further treat the film surface. As the surface treatment, physical treatment may be applied for the purpose of improving the heat seal strength of the hydrocolloid film by increasing the hydrophilic group on the film surface or increasing the surface area, and among them, corona discharge treatment, mat processing, and Embossing is preferred, and among these, corona discharge treatment is more preferred. Two or more surface treatments may be combined. By the surface treatment, the heat seal strength can be increased.

  In order to obtain a heat seal strength of 1.2 N or more, preferably 2.0 N or more, it is necessary to perform a surface treatment on the hydrocolloid film as described above. Performing surface treatment on a film has also been performed on plastic films such as petroleum. Petroleum-based plastic films have hydrophobic base material properties, and in the case of heat sealing, the film is heated and bonded by utilizing the thermal melting of the film base itself. In the case of a plastic film, depending on the substrate characteristics of the film, the melting point may be high or the heat seal may not be melted and the heat seal may be weak. Films are laminated to improve heat seal strength. The purpose of performing corona discharge treatment, mat processing, and embossing on a plastic film is to improve the wettability of the film. By improving the wettability of the plastic film surface, the substrate can be uniformly applied to the film surface during lamination or vapor deposition. However, the corona discharge treatment, mat processing, and embossing treatment are performed on the plastic film, and the hydrophilic group increases on the film surface, so that the plastic film is a hydrophobic substrate as described above for the heat seal strength. Hydrophobic groups and hydrophilic groups cancel each other, and the heat seal strength tends to decrease without improving. Moreover, the effect of improving the heat seal strength is not seen due to the influence that the contact point of the film decreases and the adhesiveness decreases due to the increase in the surface area. On the other hand, since hydrocolloid film is mainly composed of a hydrophilic base material, applying a corona discharge treatment, mat processing or embossing processing increases the hydrophilic group or surface area of the film surface, which is unimaginable. It was found that it worked more effectively and the heat seal strength improved dramatically. This is thought to be due to the increase in hydrophilic groups on the film surface, so that the hydrophilic base material is easily dissolved by heating at the time of sealing, and the sealing strength is improved more than expected. In addition, by increasing the surface area of the film surface, when heated during heat sealing, the area to evaporate water increases proportionally, making it easier for the hydrophilic base material to dissolve than before processing, and sealing properties Is thought to improve.

  In the corona discharge treatment, a corona discharge is generated by applying a high frequency / high voltage output supplied by a high frequency power source between the discharge electrode and the treatment roll, and the hydrocolloid film is passed under the corona discharge. The conditions for performing the corona discharge treatment are not particularly limited, but in order to obtain the hydrocolloid film according to the present invention, the corona discharge treatment is preferably performed at 10 to 500 W for 0.01 to 10 seconds, and 20 to 300 W. It is more preferable to carry out for 0.1 to 1.0 second, and it is particularly preferable to carry out at 20 to 80 W for 0.1 to 0.5 second. Corona discharge treatment is also performed on plastic films. However, it is known that when a plastic film is subjected to corona discharge treatment, the heat seal strength is not improved or decreased. Nevertheless, corona discharge treatment on hydrocolloid film is thought to be due to the synergistic effect of physical surface modification of the discharge itself and chemical surface modification by the generation of polar functional groups, but high heat seal strength is obtained. It is done.

  Matting is also called sand blasting, and the film is made by spraying pulverized materials such as glass powder, silica sand, gold-copper sand, walnuts, etc. with air flow on at least one side of the hydrocolloid film or by using centrifugal force to collide. By the processing method of making the surface uneven, the surface area of the film is roughened and becomes larger due to fine bumps and grooves of impact marks, and the heat seal strength of the hydrocolloid film is improved. The groove formed on the film surface is preferably processed to a depth of 0.1 μm to 20 μm, and more preferably 1 μm to 10 μm. Even if the treatment is performed at 0.1 μm or less, the increase in the surface area of the film is small and the effect on the heat seal strength is also small. Even if it processes at 20 micrometers or more, the intensity | strength of a film may be reduced and it may have a bad influence at the time of use.

  Embossing is a processing method in which unevenness of a specific pattern is formed on a film by pressing it using a lithographic plate or roll. Generally, it is processed in the above mat processing by hot-pressing with a roll embossing machine. Make the film surface uneven as in. By performing the treatment, the film surface area is increased, and the heat seal strength of the hydrocolloid film is improved. The embossed pattern can be selected from various patterns such as silk, cloth, and satin. The depth of the unevenness is preferably processed to a depth of 0.1 μm to 20 μm, and processed to be 1 μm to 10 μm. More preferably. Even if the treatment is performed at 0.1 μm or less, the increase in the surface area of the film is small and the effect on the heat seal strength is also small. Even if it processes at 20 micrometers or more, the intensity | strength of a film may be reduced and it may have a bad influence at the time of use.

  The hydrocolloid film according to the present invention can be used for various applications in various fields, and is not particularly limited, but is limited by the type of hydrocolloid that can be used for the application. For example, in an edible hydrocolloid film used for foods and food additives, it can be used as a wrapping for seasonings such as instant noodles and instant soups, and as a binding band for binding dry noodles such as somen and udon. In the cosmetics and daily necessities fields, it can be used as packaging materials, soaps, pesticides and fertilizers.

In the examples and comparative examples according to the present invention, the following commercial products were used.
Agar: Ina Agar S-7, Low Intensity Agar manufactured by Ina Food Industry Co., Ltd .: Ultra Agar AX-200, Low melting point agar manufactured by Ina Food Industry Co., Ltd .: Ina Agar UP-60, Gelatin manufactured by Ina Food Industrial Co., Ltd. 250 Bloom processed starch: hydroxypropylated tapioca starch

  In the examples and comparative examples according to the present invention, each physical property was measured as follows.

Heat seal strength (N):
Using a heat sealer, the sealing surfaces of the obtained hydrocolloid film film sample pieces (with a width of 15 mm) were adhered to each other. The sealing time was 0.5 seconds and the sealing temperature was 140 ° C. Measurement of heat seal strength (N / 15 mm) of the bonded sample was performed using a tensile strength measuring machine. The tensile speed was 50 mm / min.

Experimental example 1
(Examples 1-1 to 1-7)
Hydrocolloid films according to Examples 1-1 to 1-7 were prepared using the formulations shown in Table 1 (100 parts by weight in total). Specifically, first, a raw material containing a hydrocolloid was heated for 3 minutes or more above the melting point of the hydrocolloid and dissolved in water. Next, the solution was degassed and cast onto the support at a predetermined thickness. Thereafter, the atmosphere including the support was heated to 50 ° C. to 95 ° C. to evaporate the water in the solution and dried until the water content was about 5% to 15%. The dried film surface is subjected to (a) corona discharge treatment at 40 W for 0.2 seconds using a corona discharge treatment apparatus, and (b) glass powder is projected using a sandblast treatment apparatus to produce a 5 μm groove on the surface. Or (c) An embossed pattern having a depth of 5 μm was produced on the surface using a roll embossing machine to obtain an edible film according to Examples 1-1 to 1-7. Table 1 shows the heat seal strength of the hydrocolloid film. The processing depth of the films according to (b) and (c) was measured using a displacement measuring instrument (manufactured by Keyence Corporation).

(Comparative Examples 1-1 to 1-7)
Hydrocolloid films according to Comparative Examples 1-1 to 1-7 were prepared using the formulations shown in Table 2 (total 100 parts by weight). Specifically, hydrocolloid films according to Comparative Examples 1-1 to 1-7 were obtained in the same manner as in Examples 1-1 to 1-7 except that the surface treatment was not performed. Table 2 shows the heat seal strength of the hydrocolloid film.

Experimental example 2
(Examples 2-1 to 2-3)
Hydrocolloid films according to Examples 2-1 to 2-3 were prepared using the formulations shown in Table 3 (total 100 parts by weight). Specifically, hydrocolloid films according to Examples 2-1 to 2-3 were obtained in the same manner as in Examples 1-1 to 1-7. Table 3 shows the heat seal strength of the hydrocolloid film.

(Comparative Examples 2-1 to 2-3)
Hydrocolloid films according to Comparative Examples 2-1 to 2-3 were prepared with the formulations shown in Table 3 (total 100 parts by weight). Specifically, hydrocolloid films according to Comparative Examples 2-1 to 2-3 were obtained in the same manner as in Examples 1-1 to 1-7 except that the surface treatment was not performed. Table 3 shows the heat seal strength of the hydrocolloid film.

Experimental example 3
(Comparative Example 3-1)
A hydrocolloid film according to Comparative Example 3-1 was prepared with the formulation shown in Table 4 (total 100 parts by weight). Specifically, first, a raw material containing a hydrocolloid was heated for 3 minutes or more above the melting point of the hydrocolloid and dissolved in water. Next, the solution was degassed and cast onto the support at a predetermined thickness. Thereafter, the atmosphere including the support was heated to 50 ° C. to 95 ° C. to evaporate the water in the solution and dried until the water content was about 5% to 15%. A solution of casein was uniformly applied to the dried film surface and then dried to obtain a hydrocolloid film according to Comparative Example 3-1. Table 4 shows the heat seal strength of the hydrocolloid film.

Experimental Example 4
(Examples 4-1 to 4-8)
Hydrocolloid films according to Examples 4-1 to 4-8 were prepared using the formulations shown in Table 5 (total 100 parts by weight). Specifically, hydrocolloid films according to Examples 4-1 to 4-8 were obtained in the same manner as Examples 1-1 to 1-7. Table 5 shows the heat seal strength of the hydrocolloid film.

(Comparative Examples 4-1 to 4-8)
Hydrocolloid films according to Comparative Examples 4-1 to 4-8 were prepared using the formulations shown in Table 6 (total 100 parts by weight). Specifically, hydrocolloid films according to Comparative Examples 4-1 to 4-8 were obtained in the same manner as in Examples 1-1 to 1-7 except that the surface treatment was not performed. Table 6 shows the heat seal strength of the hydrocolloid film.

Experimental Example 5
(Examples 5-1 to 5-8)
Hydrocolloid films according to Examples 5-1 to 5-8 were prepared with the formulations shown in Table 7 (total 100 parts by weight). Specifically, first, a raw material containing a hydrocolloid was heated for 3 minutes or more above the melting point of the hydrocolloid and dissolved in water. Next, the solution was degassed and cast onto the support at a predetermined thickness. Thereafter, the atmosphere including the support was heated to 80 ° C. to evaporate the water in the solution and dried until the water content was about 5% to 15%. The dried film surface is subjected to (a) corona discharge treatment at 40 W for 0.2 seconds using a corona discharge treatment apparatus, and (b) glass powder is projected using a sandblast treatment apparatus to produce a 5 μm groove on the surface. Or (c) An emboss pattern having a depth of 5 μm was produced on the surface using a roll embossing machine, and hydrocolloid films according to Examples 5-1 to 5-8 were obtained. Table 6 shows the heat seal strength of the hydrocolloid film.

(Comparative Examples 5-1 to 5-8)
Hydrocolloid films according to Comparative Examples 5-1 to 5-8 were prepared using the formulations shown in Table 8 (total 100 parts by weight). Specifically, hydrocolloid films according to Comparative Examples 5-1 to 5-8 were obtained in the same manner as in Examples 5-1 to 5-8 except that the surface treatment was not performed. Table 8 shows the heat seal strength of the hydrocolloid film.

Experimental Example 6
(Comparative Example 6-1)
The film surface of a PET film (thickness 25 μm, manufactured by Toyobo Co., Ltd.) was subjected to a corona discharge treatment at 40 W for 0.2 seconds using a corona discharge treatment apparatus, and Comparative Example 6-1 (b) a sandblast treatment apparatus Is used to project a glass powder, and a groove of 5 μm is formed on the surface, and (c) an emboss pattern having a depth of 5 μm is formed on the surface using a roll embossing machine. Such a film was obtained. As a result of measuring the heat seal strength in the same manner as in the hydrocolloid film, the comparative example 6-1 was 1.8 N, the comparative example 6-2 was 1.9 N, and the comparative example 6-3 was 1.8 N. The heat seal strength of the PET film not subjected to corona discharge treatment was 1.9N.

Claims (3)

A film containing hydrocolloid,
A hydrocolloid film, wherein the heat seal strength of the film is 1.2 N or more.   2. The hydrocolloid film according to claim 1, wherein at least 5 wt% of the hydrocolloid is contained in the hydrocolloid among agar, gelatin, pullulan, processed starch, and starch.   The hydrocolloid film according to claim 1 or 2, wherein the film surface is subjected to at least one of corona discharge treatment, mat processing and embossing.