JPH0431950B2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a method for packaging foods, cosmetics, etc. containing aroma components, by controlling the crystallinity of a film forming an inner layer that contacts the contents. Therefore, it is an attempt to suppress as much as possible the aroma components of the contents from being absorbed into the package and being reduced.

"Conventional technology and its problems" Flavors are added to foods such as chewing gum, ice cream, kutsky, and youth products, as well as cigarettes, and Fragres is added as a fragrance ingredient to cosmetics, soaps, detergents, and air fresheners. It has been widely practiced in the past to increase the commercial value of foods by adding fragrance to them. Aroma components include terpene hydrocarbons (d-limonene, myrcene, etc.), terpene alcohols (α-terpineol, linalool, geraniol, etc.), alcohols (octanol, isoamyl alcohol, etc.), and aldehydes (octanal, citral, etc.). Trans-2-
hexanal, etc.) and esters (ethylcaprate, amylbenzoate, ethylcinnamate, etc.)
etc., or other organic compounds are used.

Products containing these fragrance ingredients are
It is sold packaged in a synthetic resin film or sheet, or a laminate film of these synthetic resin films and a metal thin film.

However, such packaging materials have a problem in that a large amount of the aroma components of the contents are absorbed by the synthetic resin film, which weakens the aroma of the contents and impairs the commercial value of the contents.

This is because many aroma components consist of low-molecular-weight organic compounds with about 3 to 15 carbon atoms, and these organic compounds dissolve in high-molecular-weight synthetic resins.
This is because it diffuses or permeates into the resin.

"Means for Solving the Problems" The present inventor conducted various studies on the sorption phenomenon of aroma components by such synthetic resins, and found that the degree of crystallinity of synthetic resins, especially polyolefin resins, and the sorption of aroma components Recognizing that there is a close relationship between the amount of sorption and the amount of sorption, we have come up with the present invention.

The graphs in FIGS. 1 to 4 show the relationship between the crystallinity of the synthetic resin film and the solubility coefficient S of the aroma component.

Synthetic resin film has crystallinity of 53%, 34%,
A 22% polyethylene film (PE) and an ethylene-vinyl acetate copolymer resin film (EVA; vinyl acetate content: about 0.5 wt%) with a crystallinity of 17% were used. Figure 1 shows ethyl butyrate as a fragrance component, Figure 2 shows ethyl caproate as a fragrance ingredient, Figure 3 shows ethyl caprylate, and Figure 4 shows an aqueous surfactant solution containing ethyl caproate. This is the result.

The solubility coefficient S indicates the solubility of the aroma component per unit volume of the film and per unit partial pressure of the aroma component, and is calculated from the diffusion coefficient D and the permeability coefficient P (1)
Calculated using the formula.

S=P/D [μg/cm ³ ·mmHg] (1) This solubility coefficient S is proportional to the amount of aroma components sorbed onto the film. From the graphs in FIGS. 1 to 4, it can be seen that as the crystallinity of the film increases, the amount of aroma components sorbed decreases.

Here, sorption refers to the phenomenon in which a gaseous aroma component dissolves, diffuses, and permeates into a synthetic resin, or the phenomenon in which an aroma component dissolved in a solution is absorbed into a synthetic resin as a result of competitive sorption with a solvent. This shows the phenomenon of dissolution, diffusion, and permeation.

The present invention was made based on such experimental facts, and by packaging using a polyolefin resin film whose degree of crystallinity is set according to the number of carbon atoms in the main component of the fragrance component, the content can be improved. The amount of sorption of aroma components contained in objects is reduced.

FIG. 5 shows an example of a package produced by the packaging method of the present invention. This package is a pouch-like product made of two laminated films fused together at their peripheral edges, and includes an inner layer 1, an intermediate layer 2, and an outer layer 3.
It has a three-layer laminate structure.

In the present invention, the crystallinity of the polyolefin resin film forming the inner layer 1 in contact with the contents is set in accordance with the aroma components of the contents.

Specifically, when the organic compound forming the main component of the aroma component has 3 to 5 carbon atoms, the crystallinity of the polyolefin resin film forming the inner layer 1 is 40% or more. In addition, when the number of carbon atoms in the organic compound is 6, the crystallinity is 50% or more, and when the number of carbon atoms is 7 or more, the crystallinity is 55% or more, and the number of carbon atoms in the aroma component and the crystallinity of the polyolefin resin. is set almost proportionally.

The degree of crystallinity in the present invention is determined by equation (2) from the density ρ at 23° C. measured by the density gradient method.

X=ρc・(ρ−ρa)/(ρ・(ρc−ρa)…(2) (where ρc is the density of the perfect crystal region at 23℃,
(ρa indicates the density of a completely amorphous region at 23°C) In addition, examples of the polyolefin resin used in the packaging method of the present invention include polyethylene resin, polyethylene copolymer, polypropylene resin, polypropylene copolymer, etc. . Copolymers of these copolymers include ethylene, propylene, butene-1, butene-2, 1-pentene,
-hexane, 4-methyl-1-pentene, etc.

The thickness of the inner layer 1 of the package is preferably as thin as possible to reduce the amount of sorption, and is preferably at most 200 μm, preferably 30 μm or less, and further preferably 10 μm or less to prevent the sorption of subtle aroma components. desirable.

When packaging according to the method of the present invention, it is desirable to provide an intermediate layer 2, an outer layer 3, etc. as necessary to supplement the properties of the inner layer 1 such as strength, air proofness, moisture proofness, and light blocking properties. In that case, it is desirable that the intermediate layer 2 be a layer that exhibits gas barrier properties, and the outer layer 3 be a layer that protects the intermediate layer 2 and the inner layer 1.

Such an intermediate layer 2 may be a metal foil such as aluminum, a polyvinylidene chloride resin film, a film in which a metal such as aluminum is vapor-deposited on a polyvinylidene chloride resin film, a laminate film of a polyvinylidene chloride resin film and a metal foil, etc. It is desirable that the structure be formed in this manner. When using a film in which a metal foil or a metal vapor deposition layer is laminated on a polyvinylidene chloride resin film, it is desirable to provide the polyvinylidene chloride side on the inner layer 1 side.

The outer layer 3 is preferably formed of a polyethylene terephthalate resin film, a polyolefin resin film, a laminate film of polyethylene terephthalate resin and polyolefin resin, or the like.

These layers are integrated by appropriate means such as adhesion, coextrusion, coating, and vapor deposition.

Note that the intermediate layer 2 can also be formed of the following resin. "Polyvinyl alcohol, ethylene vinyl alcohol copolymer, nylon, cellulose, etc." When the intermediate layer 2 is formed of these resins, a layer made of the following materials may be further provided between the intermediate layer 2 and the inner layer 1. can. "Polyvinyl chloride resin, polyvinylidene chloride resin, polyethylene terephthalate resin, polyether resin, polytetrafluoroethylene resin, polyvinylidene fluoride resin, polyolefin resin, blend resin or copolymer of the above resins, ionomer resin, polyimide resin, polyester Resin, metal foil such as aluminum, metal vapor deposited layer" The outer layer 3 can also be formed of the following materials. "Nylon, polyimide resin, polyester resin, paper, metals such as aluminum, natural/synthetic rubber" Furthermore, the packaging body created by the packaging method of the present invention has not only the middle layer 2 and the outer layer 3 but also many more layers. It may be formed by laminating layers, or conversely, it may be formed by only the inner layer 1. In addition, inner layer 1
It may also be a structure in which only a protective layer is laminated on top of the protective layer. In this case, the materials forming the protective layer include polyolefin resin, polyamide resin,
Polyvinylidene resins, copolymers of polyvinylidene resins, polyethylene terephthalate resins, polyimide resins, polyester resins, metal foils such as aluminum, metal vapor deposited layers, cellophane paper, and the like are preferably used.

"Example" Hereinafter, the packaging method of the present invention will be explained in more detail with reference to Examples.

Example 1 High-density polyethylene film with a crystallinity of 53%,
40μm thick (Syuuretsu S6002 manufactured by Showa Denko K.K.), 9μm thick aluminum foil and
A 12 μm polyethylene terephthalate film was laminated. Two of these films were fused together on the polyethylene side to create a package measuring 18 cm x 10 cm.
An aqueous solution containing fragrance ingredients inside this package.
300 ml was sealed and left at 25°C for 10 days. after that,
The amount a of the aroma component sorbed onto the polyethylene film and the amount b of the aroma component remaining in the aqueous solution were measured, and a/b (hereinafter this is defined as the distribution ratio) was determined. The aroma components added to the aqueous solution are as follows. 1) Ethyl butyrate (6 carbon atoms) 2)
Ethyl valerate (7 carbon atoms) 3) Ethyl capreate (8 carbon atoms) 4) Ethyl enanthate (9 carbon atoms) 5) Ethyl caprylate (10 carbon atoms) Also, for comparison, crystals were used instead of PE film. A package was prepared using an ethylene-vinyl acetate copolymer film with a degree of oxidation of 17% and a thickness of 40 μm, and was subjected to the same test.

The relationship between the carbon number of aroma components and the distribution ratio was investigated for each package. The results are shown in Figure 6.

From this result, PE film with high crystallinity is
It was found that the distribution ratio of all aroma components was small, indicating that the sorption of aroma components was low.

Example 2 An aqueous solution in which 2 ppm of α-terpineol was dissolved was sealed in the same package as in Example 1, and the same test as in Example 1 was conducted.

Distribution ratio to PE film is 2.805×10 ^-2 ,
The distribution ratio with respect to the EVA film was 1.355×10 ^-2 , and it was confirmed that the packaging using PE film with a high degree of crystallinity had a small distribution ratio and less adsorption of aroma components.

"Effects of the Invention" As explained above, the packaging method of the present invention sets the crystallinity of the polyolefin resin film in accordance with the number of carbon atoms of the main component of the aroma component, and the organic compound that is the main component of the aroma component. When the number of carbon atoms is 3 to 5, use a polyolefin resin film with a degree of crystallinity of 40% or more, and when the number of carbon atoms of the organic compound that is the main component of the aroma component is 6, use a polyolefin resin film with a degree of crystallinity of 50% or more. This is a method of packaging the contents using a polyolefin resin film with a crystallinity of 55% or more when the organic compound that is the main component of the aroma component has 7 or more carbon atoms. It is possible to provide excellent packaging that reduces the loss of aroma components and maintains the aroma of the contents.

[Brief explanation of drawings]

Figures 1 to 4 are graphs showing the relationship between the crystallinity and solubility coefficient of polyolefin resins, Figure 5 is a cross-sectional view of an example of a package according to the packaging method of the present invention, and Figure 6 is a graph showing the relationship between the crystallinity and solubility coefficient of polyolefin resins. It is a graph showing the relationship between carbon number and distribution ratio.

[Claims]

1. A packaging material made of an electret material, which has planar portions with polarized charges of different polarities on both the front and back surfaces. 2. The packaging material according to claim 1, wherein the surface charge density per one side of the planar portion is 1×10 ⁻¹¹ clones/cm ² or more. 3. The packaging material according to claim 1 or 2, wherein the electret material is a sheet material selected from resin-based films, nonwoven fabrics, paper, and knitted fabrics. 4. The packaging material according to claim 1 or 2, wherein the electret material is a molded structure made of resin. 5. The packaging material according to claim 3 or 4, wherein the resin is selected from polyolefin resins, polyester resins, fluorine-containing resins, polyvinyl chloride resins, polyamide resins, and polyacrylic resins. 6 The electret material is made of a resin film, and the carbon dioxide permeability of the resin film is 500 to 500.
350000c.c./m ²・24hr・atm, oxygen permeability 100~
35000c.c./m ²・24hr・ATM for fresh food packaging