JP2006143314A - Transporting container for synthetic resin product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transporting container which inhibits rise in temperature inside the container even if the container is placed for a while at a place exposed to sunlight and prevents a packaging container storing a synthetic resin product inside from being deformed. <P>SOLUTION: A transporting container for transporting is used for transporting a product formed by using a synthetic resin whose glass transition temperature is 50-80°C. The lightness of its surface layer face measured based on JIS Z 8729 is between 80 and 100. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transport container, and more particularly to a transport container used for transporting a product formed of a synthetic resin having a glass transition temperature of 50 ° C. to 80 ° C. as a material.

  As a product made of synthetic resin as a material, it is very hygienic and easy to dispose of, such as trays used in supermarkets, lunch boxes used in convenience stores, etc. There are packaging containers for packaging food, trays for germinated vegetables, etc., and this type of packaging container is mass-produced. Such packaging containers are consumed in large quantities because they are provided at low cost, and the proportion of so-called household waste is increasing. Of course, because of the above-mentioned advantages, “bags” made of synthetic resin have been mass-produced, and the proportion of household bags is also increasing.

  Because packaging containers and bags made of such synthetic resin materials may not be able to catch up with waste if left as they are, biodegradation of synthetic resin materials that can be easily decomposed, such as polylactic acid, etc. It has been studied to produce using a functional resin material. However, a packaging container or bag formed of this type of biodegradable resin is easily deformed or changed depending on the temperature, and the function as the container or bag may be impaired.

  On the other hand, since this type of synthetic resin packaging container or bag has a low unit price, it is stored and transported in large quantities in one transport container. Such a transport container is supposed to be transported while being stored in a cool place, but depending on the temporary storage situation and transport route, it may not be a cool place.

  Even during summer weather, if the container is temporarily stored or transported with the packaging container inside, the temperature inside the container may become very high. The internal temperature exceeded 30 ° C, and after 6 hours, the temperature in the container directly exposed to direct sunlight was found to be as high as 57.5 ° C.

  At this time, if the product stored in the transport container is formed using polylactic acid, which is a biodegradable synthetic resin, the glass transition temperature of this polylactic acid is 55 ° C. As a result, the product is completely deformed and immediately has no commercial value. This is one reason for limiting the use of polylactic acid, which helps solve the waste disposal problem.

Therefore, the present inventors variously examined whether there is any good idea about the transport container, and devised the structure of the transport container, that is, improved air permeability to suppress the rise in internal temperature. The question was made. However, in order to improve the air permeability, a “air hole” is opened in a part of the transport container, and there is a possibility that a foreign substance is mixed from the air hole. If this transport container transports a packaging container for food, this means that the mixed foreign matter may be mixed into the food. The idea of this was postponed, and the transport container described in Patent Document 1 has been studied.
JP 2003-328299 A, Abstract

  The invention described in Patent Document 1 relates to a “corrugated cardboard exterior liner”. “The L * a * b * color system of the surface layer of the exterior liner is controlled to a specific range of tea, By finding that the absolute value of the difference in L * value between the front and bottom surfaces is below a specific value, an exterior liner with excellent white paper appearance, sharpness of printed images and fading resistance can be obtained. " , "To provide an exterior liner excellent in the appearance of white paper on the surface, the sharpness of printed images and the resistance to fading", "A liner for corrugated cardboard comprising two or more paper layers. The surface layer surface brightness (L *) measured in accordance with JIS Z 8729 is 70 to 80, the hue (a *) is 1.6 to 8, the hue (b *) is 10 to 35, and the surface The absolute value (| ΔL * |) of the difference in L * value from the front and lower surfaces is less than the value calculated by [Formula 1] Those having a structure such cardboard exterior liner ", characterized in that.

  However, the technique described in Patent Document 1 is basically a "corrugated cardboard exterior liner whose surface layer is composed of bleached pulp and unbleached pulp" as described in claim 2 thereof. Therefore, it has a “brown color” that easily absorbs sunlight as heat energy. This is because, as described in paragraph 0002 of Patent Document 1, “the liner is mainly used as an exterior for corrugated cardboard. Usually, the pulp constituting the surface layer is unbleached pulp (unbleached pulp). This is because the color tone of tea is a brown color).

  Then, although the technique of this patent document 1 may improve the printing performance with respect to the surface, it basically exhibits a "brown color", so it is easy to absorb sunlight as thermal energy. Therefore, it is not suitable for a container for transporting a product made of biodegradable resin as described above.

  Therefore, the present inventors have conducted various studies on how to make a container for transportation that can suppress an increase in internal temperature even if it is left in a place where it is exposed to sunlight. The invention has been completed.

  That is, the object of the present invention is to suppress the internal temperature rise even when left in a place where it is exposed to sunlight, and to deform the packaging container that is a stored synthetic resin product. An object of the present invention is to provide a container for transportation without any problems.

In order to solve the above problems, first, the means taken by the invention according to claim 1 will be described with reference numerals used in the description of the best mode described below.
“A container for transporting a product formed from a synthetic resin having a glass transition temperature of 50 ° C. to 80 ° C.,
A transportation container characterized by having a surface layer brightness measured in accordance with JIS Z 8729 of 80 or more and less than 100 "
It is.

  That is, the transport container according to the invention of claim 1 may be a so-called “cardboard box” as in Patent Document 1, or may be a box made of synthetic resin, that is, a “container”. Moreover, although it may be in a “bag” shape, the brightness of the surface of the surface layer measured in accordance with JIS Z 8729 is 80 or more and less than 100.

  The “lightness of color” here refers to “object color” instead of “light source color”, and is used in both the “Nippon Color Co., Ltd.” (PCCS) and Munsell color system (Munsell system). The “brightness level” is set and “100” is set as the upper limit. In the present invention, only the lightness of this color is defined, and “hue” and “saturation” are not defined.

  That is, the brightness of the surface of the surface layer measured in accordance with JIS Z 8729 being 80 or more and less than 100 means that a bright color that easily reflects sunlight is adopted, and the brightness described in Patent Document 1 is used. This means that a lighter color having a higher brightness is employed. In other words, the transport container according to the present invention may be pink, light green, or sky blue, but in short, uses a very bright color as its surface color.

  Further, in the transport container according to claim 1, the brightness of the surface layer surface measured in accordance with JIS Z 8729 is set to 80 or more and less than 100, and is not concerned with hue or saturation. By combining pink, light green, and sky blue, it is possible to display various patterns and characters such as contents, manufacturer name or logo mark, and overall design formation.

  In the transport container according to claim 1, the reason why the brightness of the surface layer surface measured in accordance with JIS Z 8729 is 80 or more and less than 100 is the same as general brown corrugated cardboard when the brightness is less than 80. This is because the absorption of solar heat is improved, and there is a possibility that the absorption of heat is partially promoted when patterns and characters are displayed by changing the saturation and hue. The reason why the brightness is less than 100 is that there is no brightness greater than 100.

  The reason why the transport container according to the present invention is specified to transport a product formed from a synthetic resin having a glass transition temperature of 50 ° C. to 80 ° C. is a synthetic resin material used as a packaging container It is because there exists the actual condition which exists in this glass transition temperature range. That is, as a synthetic resin having a glass transition temperature of 50 to 80 ° C., there are A-PET (glass transition temperature 65 ° C.) and polylactic acid (glass transition temperature 55 ° C.), and these synthetic resin materials are used in large quantities. This is because there is a real situation. In particular, since polylactic acid is a biodegradable resin, packaging containers that are mainly molded from it will be used as a material for molding this type of packaging container in the future in order to be able to dispose of waste effectively. This is because an increase is expected.

  Moreover, the reason why the glass transition temperature of the material used as the packaging container needs to be 50 ° C. to 80 ° C. is that the synthetic resin of 50 ° C. or less is suitable as a material for molding the packaging container. This is because a synthetic resin having a temperature of 80 ° C. or higher has no problem even if it is exposed to a hot summer day.

  Therefore, according to the transport container according to the invention of claim 1, a packaging container made of a synthetic resin having a glass transition temperature of 50 ° C. to 80 ° C. is stored and left in a place where it is exposed to sunlight. However, the internal temperature rise can be suppressed to some extent, and the packaging container, which is an internal synthetic resin product, is not deformed. That is, the transport container according to claim 1 can effectively reflect sunlight by increasing the surface brightness, so that the internal temperature can be reduced without forming a “wind hole”. The rise can be suppressed as much as possible, and the deformation of the packaging container as the contents can be prevented.

  Furthermore, the transport container according to claim 1 can be used for temporary storage and transport of packaging containers made of biodegradable resin, which is useful for waste disposal, without deformation, and is useful for waste disposal. This makes it possible to use a large amount of functional resin and take a leap of waste disposal.

In order to solve the above-mentioned problem, the means taken by the invention according to claim 2 is as follows.
“The synthetic resin that constitutes the product is mainly composed of polylactic acid.”
It is.

  In other words, the transport container according to claim 2 limits the object to be stored to a product formed of a synthetic resin material mainly composed of polylactic acid, and is suitable for transporting a biodegradable resin product. It is what.

  Polylactic acid is a representative of the above-described biodegradable resin, which decomposes at an early stage when buried in soil, but is susceptible to thermal deformation. In other words, the transportation container according to claim 2 is most suitable as a dedicated container for transporting a product that is easy to dispose of dust by targeting the product mainly composed of polylactic acid.

  Therefore, the transport container according to the invention of claim 2 is optimal for transporting and storing products that have been treated for dust disposal, in addition to the same effect as that of claim 1 described above. is there.

As described above, in the present invention, as described above,
“A container for transporting a product formed from a synthetic resin having a glass transition temperature of 50 ° C. to 80 ° C.,
The brightness of the surface layer surface measured in accordance with JIS Z 8729 should be 80 or more and less than 100 "
This is a main feature of its structure, so that even if it is left in a place where it is exposed to sunlight, the internal temperature rise can be suppressed, and the packaging is a stored synthetic resin product. It is possible to provide a transport container that does not deform the container.

  In addition, according to the transport container according to the present invention, the temporary storage and transport of packaging containers made of biodegradable resin useful for waste disposal can be performed without deformation, and biodegradability useful for waste disposal. This makes it possible to use a large amount of resin and take a leap of waste disposal.

  Next, the invention according to each claim configured as described above will be described based on the best mode. White paper (lightness of about 95) is pasted on the surface of a brown cardboard box that is generally commercially available, This was the best mode, that is, the transport container of the example. The same corrugated cardboard box used here was adopted as Comparative Example 1.

  Packing containers made of polylactic acid are packed in the entire transport containers according to the above examples and comparative examples, and thermometers are inserted into the upper, middle, and lower sections of the transport containers, respectively. On August 11, 2004 (weather: fine weather, maximum temperature: 42.5 ° C., humidity: 21%), the internal temperature change and the change of the packaging container were examined. The upper stage of each transport container is a position 10 mm below the upper surface, the lower stage part is a position 10 mm above the lower surface, and the middle stage is intermediate between the upper stage and the lower stage, and the upper surface of the transport container. It was the position of 185mm below.

  Under the above conditions, the result of measuring the change in the internal temperature of each transporting container for 6 hours was as shown in Table 1 below. In addition, the comparative example 2 is the same transport container as the comparative example 1, and is installed indoors.

また、このときの各運搬用容器内に収納した包装用容器の形状変化を観察したところ、次の表２の通りであった。なお、この表２中に記載した各符号は、次の意味を有するものである。

Moreover, when the shape change of the packaging container accommodated in each container for transportation at this time was observed, it was as shown in Table 2 below. In addition, each code | symbol described in this Table 2 has the following meaning.

  ○ = No deformation, △ = Slight deformation, × = Large deformation

以上の結果から、最良形態に係る運搬用容器では、夏場の一時保管時間や直射日光に晒しながら運搬する最大時間と考えられる「６時間」を経過しても、内部の温度は、５０℃以上にはならず、中に入れておいたポリ乳酸からなる包装用容器には、何らの変形も生じなかったことが理解できる。

Based on the above results, in the transport container according to the best mode, the internal temperature is 50 ° C. or higher even after passing “6 hours”, which is considered to be the maximum storage time for summer storage and direct sunlight exposure. It can be understood that no deformation occurred in the packaging container made of polylactic acid contained therein.

Claims (2)

A transport container for transporting a product formed from a synthetic resin having a glass transition temperature of 50 ° C to 80 ° C as a material,
A transport container characterized by having a surface layer surface brightness measured in accordance with JIS Z 8729 of 80 or more and less than 100.   The transport container according to claim 1, wherein the synthetic resin constituting the product is mainly composed of polylactic acid.