JPS6033470B2 - Synthetic resin film for tobacco drying - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin film for drying tobacco, and more specifically, it is used when naturally drying tobacco, and is used for "quick drying".
The present invention also relates to a synthetic resin film for house coating that prevents the occurrence of "white blurred leaves".

Conventionally, when harvested tobacco leaves are naturally dried, the method is to hang the harvested tobacco leaves inside a so-called "Tobacco Pipe House J" in which a steel pipe frame assembled outdoors is coated with a synthetic resin film, and then air-dried. However, the drying of tobacco leaves depends on the temperature and humidity inside the greenhouse as well as the light quality, which affects the external appearance of the dried leaves, the physical properties of the dried leaves, and the aroma and taste, and various types of abnormal leaves can occur. occurs, affecting the quality of leaf tobacco.

Abnormally dry leaves include ``rapidly drying leaves'' (leaves that should be brown in color, but leaves that partially or entirely turn yellowish-brown or yellow) and ``whitish leaves'' (leafs with brown leaf petioles). Leaves that are thin, whitish, or light brown, with a large difference in color tone between the tip of the hollyhock and the base of the leaf), ``Moure leaf'' (leaf with dark brown color and extremely brittle millet), and `` There are various types of leaves, such as "Red-brown leaves" (with leaves that are reddish-brown in color), and all of these have drawbacks in the physical properties of the dried leaves and the flavor.
Among these abnormal leaves, a concrete method to prevent "rapidly drying leaves" and "white blurred leaves" is to remove the synthetic resin film that is used when the sun's rays are strong or when the temperature is high. Alternatively, there is a known method of preventing drying by placing a colored or colorless cheesecloth-like curtain with a light transmittance of about 60 to 40% underneath to limit the amount of light that enters the "tobacco pipe house". (Leaf Tobacco Research No. 72, July 1975).

Another method is to install curtains made of a material that does not transmit UV rays on the side walls of the tobacco pipe house in order to prevent the tobacco from being directly irradiated with the UV rays that enter the pipe house. There are methods to prevent bleaching (whitening leaves) (see Japanese Patent Publication No. 51-1796), but these methods are used in conjunction with conventionally used synthetic resin films for tobacco pipe houses. Not only does it require a lot of material cost, but it also requires a lot of labor for installation, removal, etc. In addition, if a curtain that does not transmit ultraviolet rays is hung on the side wall, ventilation cannot be achieved, so there is a drawback that it cannot be used in a pipe house that does not have a normal ventilation fan. The present invention
"White poke leaves" and "quick drying leaves" during tobacco drying
As a result of research on a synthetic resin film that has optical properties effective in preventing the occurrence of abnormal leaves, it has been found that it almost completely blocks wavelengths of 38 m or less, and has an average transmittance of 40% for all light rays with wavelengths of 380 to 500 nm. By drying using a film that has the following properties and has a total light transmittance of 30 to 70% for wavelengths of 50 m or more, it is possible to prevent the occurrence of "white blurred leaves" and especially "quick drying leaves". They discovered that it is effective and completed the present invention.

The present invention will be explained in detail below. Examples of synthetic resins that can be used to produce the synthetic resin film of the present invention include polyvinyl chloride, polyvinylidene chloride, ethylene-vinycetate copolymer, polyethylene, polypropylene, polyester, polyamide, polymethyl methacrylate, and polycarbonate. Examples include homopolymers such as these, and copolymers containing monomers constituting these polymers.One or more of these synthetic resins can be used as a film forming material to form single or composite films. It can be done.

In order to give specific light transmittance by kneading or coating the synthetic resin film of the present invention, for example, in order to almost completely block the transmission of ultraviolet rays with wavelengths shorter than 38 mm, salicylic acid esters, benzophenone, etc. ultraviolet absorbers such as benzotriazole-based, nickel rust salt-based, cyanoacrylate-based, or pigments with an absorption band in the ultraviolet region,
Fifteen types or two or more types of dyes can be used.

In order to reduce the average transmittance of all light rays that pass through the wavelength range of 38 m to 50 m to 40% or less, dyes with light, yellow, and green colors that have characteristic absorption in the wavelength range shorter than 50 m should be used. Alternatively, one or more pigments are used.

Furthermore, the transmittance of all light rays with wavelengths longer than 50 m is 30 ~
In order to achieve a range of 70%, materials such as carbon black, titanium white, and aluminum foil powder, which have characteristic absorption of light, and titanium, yellow, and yellow lead whose characteristic absorption band is in a wavelength region shorter than 50 mm are required. One or more types of light-shielding colorants such as the following are used. The film of the present invention contains an ultraviolet absorber, a light-shielding colorant, and a dye or pigment having characteristic absorption in a wavelength region shorter than 50 m as described above in order to impart specific light transmittance and adjust optical properties. I use it, but
When tobacco is dried under the synthetic resin film coating of the present invention, the working environment (visual problems caused to workers' eyes)
From the viewpoint of practicality (can the drying progress of tobacco hung to dry in a pipe house be recognized from outside the house?), it is recommended to select and use light-shielding colorants, dyes, or pigments that are less irritating to the eyes. preferable. When using light-shielding colorants, dyes, or pigments that are highly irritating to the visual sense, they may be used as colorants to reduce the irritating visual sensation, as long as the light wavelength and light energy transmission characteristics do not exceed the scope of the present invention. For example, it is preferable to further use a coloring agent such as black, white, gray, or green. The film of the present invention includes the above-mentioned film forming material,
In addition to ultraviolet absorbers, light-shielding colorants, and dyes or pigments that have absorption properties in the wavelength region shorter than 50 m, other additives may be added as necessary, such as plasticizers, antioxidants, and light stabilizers. It goes without saying that a thickening agent, an antifogging agent, etc. may be used.

The film of the present invention can be produced by various known processing methods such as calendering, extrusion, and solution casting, which are suitable for film forming materials.

The thickness of the film is practically preferably in the range of about 50 mm to 200 mm, because if it is thin, it will have poor mechanical strength and will be easily torn, while if it is thick, it will be heavy and inconvenient to handle. If one or both sides of the film of the present invention is provided with satin-like or silk-like irregularities (grains), it is possible to suppress the transmission of straight rays among the rays that pass through the film and increase the transmission of scattered rays. It is possible to prevent deterioration in the quality of dried leaves caused by uneven drying, such as hollyhock competition and rapid drying, which tend to occur when tobacco is dried under light beams with a large amount of straight light components, and to achieve the object of the present invention. It is particularly preferable as a film for.
The reason why the film of the present invention further restricts the transmission of light rays between 38 m and 50 m is that in order to prevent the occurrence of "white blurred leaves", it is not enough to simply block ultraviolet rays as described in Japanese Patent Publication No. 51-1796. The effect is insufficient, and furthermore, from 380 nm to 50 nm
This is based on the knowledge that it is necessary to limit the transmission of light rays between 38 Mm and 50 m to prevent the occurrence of "white blur". Although it is preferable to completely prevent its transmission,
Light rays between Mm and 37 m are not as strong in causing "white blurred leaves" as light rays below 37 m, so some transmission is allowed, but it is better to have as little as possible, and the transmittance should be 40% or less.

If too many rays with wavelengths of 500 nm or more are allowed to pass through,
The temperature inside the pipe house rises rapidly, causing "rapid drying of leaves", especially when there is a lot of direct light passing through.
This is not desirable as the incidence of

On the other hand, if all of this light is not allowed to pass through, the temperature inside the drying chamber will drop, resulting in drying conditions that are likely to cause abnormal leaves such as "red leaves" and "stuffy leaves," and the number of tobacco leaves stored in the pipe house must also be reduced. Therefore, the total light transmittance suitable for drying is preferably within the range of 30 to 70%.
As mentioned above, the film of the present invention can appropriately suppress and adjust the ultraviolet rays and visible rays that pass through the film by using an ultraviolet absorber, a light-shielding colorant, and a dye or pigment that has absorption characteristics in a wavelength region shorter than 500 nm. Not only does the inside of the pipe house where the film of the present invention is spread not reach extremely high temperatures, but it also transmits a sufficient amount of light necessary for drying, making it extremely effective in preventing the occurrence of "white blurred leaves" and "rapidly drying leaves." It is also effective in preventing the occurrence of another type of abnormal leaf, ``red leaf''.

When tobacco is dried under the coating of the film of the present invention, the film exhibits the effect of absorbing and blocking heat rays, and even when the sun rays hit in the morning, the temperature inside the pipe house does not rise sharply, and the temperature rises in the pipe house in the evening. On the contrary, after death, it is possible to prevent the temperature inside the greenhouse from dropping rapidly, and therefore the temperature change inside the greenhouse becomes slow, which has a favorable effect on the tobacco leaves and creates the optimal temperature, humidity, light quality, and light intensity conditions for tobacco drying. Therefore, it is possible to obtain Aoi tobacco of excellent quality and high commercial value, and its utility value is great. The present invention will be described below based on Examples, but it should be understood that the present invention is not limited to the following Examples unless it departs from the gist of the invention.

Films (thickness 150 mm) having the compositions described in the following Examples and Reference Examples were prepared by a conventional calendering method.

Note that parts are by weight.

Example 1 A film having a specific light transmittance defined by the present invention (hereinafter referred to as No. 1 film) was prepared from a composition having the following formulation.

)It was created. No. The light transmittance of one film is shown in FIGS. 1 and 2.

Polyvinyl chloride *1 100 parts Plasticizer *2 5 Anchor stabilizer *3 4 parts Anti-fog agent *4
1 part UV absorber *5
1.5 parts light-shielding colorant *6
0.3 parts colorant *7
1 part Note) *1: Straight polymer manufactured by Mitsubishi Monsanto Chemical ■ Average degree of polymerization 1050 *2: Phthalate ester plasticizer *3; Barium liquid stabilizer *4; Sorbitan ester surfactant *5; Penzophenol UV absorber *6: 1:1 mixed toner of aluminum foil powder and titanium oxide
*7; Fast Yellow 1 (pigment: CI number 11710) Example 2 A film having a specific light transmittance defined in the present invention (hereinafter referred to as No. 2 film) was made from the composition of the following formulation.

)It was created. No. The light transmittance of the two films is shown in FIGS. 1 and 2.

Polyvinyl chloride 10 Ikarito plasticizer 5 parts Stabilizer
4 parts antifogging agent
1 part UV absorber *8
2-part light-shielding colorant *9
0.2 parts coloring agent *lo
2 parts Note) *8; Penzotriazole ultraviolet absorber *9; Titanium yellow and carbon black 2:1
Mixed toner *10: Fast Yellow HR (pigment: C.I. No. 77002) Example 3 No. 3 obtained in Example 2 above. A film (hereinafter referred to as No. 3 film) was prepared by applying satin-like texture to both sides of the No. 2 film.

No. The light transmittance of the three films is shown in FIGS. 1 and 2.

Reference Example 1 For comparison, a film (hereinafter referred to as No. 4 film) having a light transmittance other than that specified in the present invention was prepared from a composition with the following formulation.

)It was created. No. The light transmittance of the 4 films is shown in FIGS. 1 and 2.

Polyvinyl chloride 10 Base plasticizer 5 Base stabilizer
4 parts antifogging agent
1 part UV absorber *11
1 part colorant *12
1 part Note) *11; Cyanoacrylate ultraviolet absorber *12: Oil Red B (pigment: CIA Nanno-26105 Reference Example 2 For comparison, a film with a specific light transmittance from the composition of the following formulation ( Hereinafter, it will be referred to as No. 5 film.

)It was created. No. The light transmittance of the 5 film is shown in FIGS. 1 and 2.

Polyvinyl chloride 10 parts Plasticizer (dioctyl phthalate) 45 parts Heat stabilizer (dibutyltin malate) 1.5 parts (calcium stearate) 0.5 parts (zinc stearate) 0.7 parts Lubricant (stearic acid)
0.1 part antifogging agent (sorbitan monolaurate)
1. Ikari UV absorber (2-hydroquine-4-methoxybenzophenone) 1. Sparse area light-shielding colorant (1:1 mixed toner of aluminum foil powder and titanium oxide) ○ - Band area A pipe house was coated with each of the films prepared as described above, and a drying test was conducted.

The drying test results are shown in Table 1 below. For comparison, the drying test was conducted using the conventional method (commercially available anti-fog agricultural satin vinyl film, the light transmittance of which is shown as 6 in Figures 1 and 2) and the conventional method (wooden greenhouse). ) and drying was carried out at the same time.

The results are also listed in Table 1.

Table 1 ◎ Hardly occurs ○ Slightly occurs △ Slightly occurs × Very often occurs As shown in Table 1 above, No. 1 with specific light transmittance of the present invention. 2 film and No. When tobacco is dried by covering the pipe house with 3 film, the yield of normal leaves is almost the same as with the conventional method, and it is also effective in preventing the occurrence of abnormal leaves such as "white blurred leaves" and "quick drying leaves". It turns out to be effective.

No. 1 film is no. 38 compared to 2 films.
This indicates that it is difficult to completely prevent the occurrence of "white blurred leaves" when some light rays between the width of 1.5 m and 50 m are transmitted. 5 film is No. This can also be seen from the fact that "white blurred leaves" occur more often than with 1 film. about 6
No. 1, which blocks the transmission of light rays with wavelengths shorter than 0 mm and relatively well transmits light rays with wavelengths longer than 60 mm. Film No. 4 is effective in preventing the occurrence of "white blurred leaves", but it has been shown that it produces undesirable abnormal leaves such as a large number of "quick drying leaves", and in the end it is the No. 4 film for drying tobacco leaves. 2, No
．． 3 films are passed through, especially No. 3 film is optimal.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the total light transmission characteristics of each film described in Examples and Reference Examples, and FIG. 2 is a diagram showing straight light transmission characteristics. 1...No. 1. Light transmission curve of film, 2...
...No. 2 Light transmission curve of film, 3...
・No. 3. Light transmission curve of film, 4...N
o. 4 Light transmission curve of film, 5...No. 5 Light transmission curve of film, 6... Light transmission curve of commercially available antifogging agricultural satin vinyl film. Figure 2

Claims (1)

[Claims] 1 Almost completely blocks the transmission of light rays with wavelengths shorter than 380 nm, and has an average transmittance of 40% or less for all light rays with wavelengths between 380 nm and 500 nm, and 500 nm
A synthetic resin film for tobacco drying, characterized in that the transmittance of total light rays at longer wavelengths is in the range of 30 to 70%.