JP3457544B2 - Adsorption plastic sheet and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cupboard, a refrigerator,
Adhesive plastic that is placed on the back and inside of tatami mats, inside car interiors, in desk drawers, push-in doors, in kennels, etc. to adsorb moisture, odor substances, ethylene gas emitted from fruits and vegetables such as fruits and vegetables It is about the seat.

[0002]

2. Description of the Related Art Conventionally, activated carbon and charcoal have been known as dehumidifying / deodorizing materials. Among them, as the one using activated carbon, for example, one in which a container is filled with activated carbon or one in which activated carbon is contained in foamed plastic (Japanese Patent Laid-Open No. 54-54-
41968). This activated carbon is
It excels in the ability to adsorb moisture and odorous substances, but hardly releases the moisture and odorous substances once adsorbed. Therefore, the adsorption performance deteriorates with use, and the dehumidifying / deodorizing material must be frequently replaced.

On the other hand, charcoal has excellent adsorbability and has a property of releasing water and odorous substances. Therefore, the dehumidifying and deodorizing material using charcoal has a long lifespan, and can be used in cupboards, refrigerators,
It is widely used as a dehumidifying material and deodorant material for desk drawers, push-in doors, kennels, etc. However, for example, if charcoal is used as it is in a cupboard, it may stain the tableware black, which is not practical. The problem of contamination can be solved by packing charcoal in a breathable container, but the space for storing tableware will be reduced by the amount of the container.

In order to solve this problem, a sheet-shaped dehumidifying / deodorizing material has been proposed so that it can be easily applied to a cupboard or the like. This dehumidifying / deodorizing material is produced by dispersing finely ground powdered charcoal in water to form an ink, applying the ink to a fiber base cloth, or dyeing the fiber base cloth with the ink. . Since the dehumidifying / deodorizing material is in the form of a sheet, it can be laid on a cupboard or the like without being bulky, and tableware can be arranged on it. Then, the powdered charcoal introduced by coating or dyeing can adsorb moisture and odorous substances and prevent the generation of moisture and odor.

However, even with this moisture-proof / deodorant material, since the charcoal powder in the ink used separates from the fiber base cloth to some extent, the disadvantage that this charcoal powder contaminates tableware and the like still remains. It will be. Also, it takes a lot of time to disperse powdered charcoal in water, apply ink, and dye with ink.
The deodorant material is not suitable for mass production, and there is a problem that the manufacturing cost becomes high. In addition, a surfactant may be used when dispersing the powdered charcoal in water, but this surfactant remains in the dehumidifying / deodorizing material obtained, and there is a problem that it adheres to tableware and the like. . In addition, since the fiber base cloth is used, there is a problem that it is easily soiled with a liquid seasoning such as soy sauce, which tends to be unsanitary.

On the other hand, a freshness-preserving film in which a powdered charcoal is contained in a plastic sheet has also been proposed (Japanese Patent Laid-Open No. Hei 9)
-29853). Since this freshness-keeping film can be manufactured by extrusion molding, it is easy to manufacture, and it is sanitary because it does not impregnate a liquid seasoning. However, since the powdered charcoal is almost buried in the plastic matrix, there is a problem that the adsorption performance becomes insufficient.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and provides a plastic sheet for adsorption which has no problem of contamination, is easy to manufacture, is hygienic, and has excellent adsorption performance. Its purpose is to provide.

[0008]

DISCLOSURE OF THE INVENTION The present invention, which was made to solve the above-mentioned problems, contains normal polyethylene and metallocene polyethylene (that is, polyethylene polymerized by a metallocene catalyst) and powder charcoal is blended. Further, it is a plastic sheet for adsorption composed of plastic containing bubbles (claim 1).

According to the present invention, since powdered charcoal is blended, it is possible to adsorb moisture and odorous substances and prevent the generation of moisture and odor. Further, since the charcoal powder is carried by the plastic, it does not come off and does not contaminate tableware or the like. In addition, since the plastic does not soak into the liquid seasoning and the like, it is hygienic unlike the case where a fiber base cloth or the like is used. The plastic of this adsorption plastic sheet has excellent impact absorption performance because it contains air bubbles, and since it has a large surface area, it can provide many places for contact between the atmosphere air and powdered charcoal, and dehumidify and deodorize. The effect can be enhanced. A plastic sheet having excellent strength can be obtained by using a plastic in which ordinary polyethylene and metallocene polyethylene are mixed.

In the present invention, ordinary polyethylene and metallocene polyethylene are used in a total plastic weight of 100.
5 parts by weight or more of metallocene polyethylene to 60 parts by weight
By admixing so as to be less than or equal to parts by weight, it is possible to obtain an adsorption plastic sheet having excellent strength, cushioning properties (shock absorption performance), and manufacturability (claim 2).

In the present invention, if the bubbles are continuous bubbles, the air, which is the atmosphere, can penetrate into the inside of the adsorbing plastic sheet, and more places for contact between the air and the powdered charcoal can be provided. Therefore, the dehumidifying / deodorizing effect can be further enhanced (Claim 3).

In the present invention, when the expansion ratio of the plastic containing bubbles is set to 10 times or more and 40 times or less, a suitable place for the contact between air and the powdered charcoal is maintained while maintaining a proper shock absorbing performance and flexibility. We can provide more and dehumidify
The deodorizing effect can be further enhanced (Claim 4).

In the present invention, the powdered charcoal used is preferably white charcoal powder having excellent adsorptivity (claim 5), and particularly preferably white charcoal powder made from Ubamegashi as a raw material (claim 6).

This adsorption plastic sheet is produced by continuously extruding a plastic compound obtained by mixing powdered charcoal and a foaming agent into a molten plastic obtained by mixing ordinary polyethylene and metallocene polyethylene through a mouthpiece to foam. It is produced by exposing a part of the powdered charcoal on the inner wall of the bubbles (claim 7). This makes it possible to provide many places for contact between air and powdered charcoal. Further, it can be produced more easily than a dehumidifying / deodorizing agent obtained by dispersing charcoal powder in water, and it is not necessary to use a surfactant.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view of a suction plastic sheet 1 according to an embodiment of the present invention. The adsorption plastic sheet 1 is made of plastic containing air bubbles, and powdered charcoal is dispersed in the plastic.

As the powdered charcoal, powdered charcoal is used in the form of powder. The pulverization can be performed by using a known means such as a pulverizer. The particle size of the powdered charcoal is not particularly limited, but an average particle size of 10 micrometers or more and 100 micrometers or less is preferably used. If the particle size is less than the above range, the particles may become bulky and may be difficult to knead into the plastic.
On the other hand, if the particle size exceeds the above range, the dispersion efficiency may decrease and the adsorption performance may be impaired.

Here, the charcoal is a solid residue after pyrolysis of wood, and is a type of amorphous carbon. For charcoal,
It includes black and white charcoal made by charcoal kiln, carbonized carbon made by carbonization, and extinguished carbon made by incomplete combustion of wood. Since charcoal has excellent adsorptivity, it adsorbs moisture, odorous substances, ethylene gas, etc. in the atmosphere. On the contrary, when the concentration of moisture or odorous substance in the atmosphere decreases, the adsorbed moisture, odorous substance or ethylene gas is released. In this way, charcoal repeats adsorption and release, so unlike activated carbon, which is simply superior in adsorption,
Maintains dehumidifying and deodorizing effects over a long period of time. As described above, since the powdered charcoal is mixed in the adsorbing plastic sheet 1, it is possible to adsorb moisture and odorous substances, prevent the generation of moisture and odors, and maintain the effect for a long time. be able to.

In this adsorption plastic sheet 1, bincho charcoal powder is used as the powder charcoal. Binchotan charcoal is a high-quality charcoal produced in the southern part (Wakayama prefecture) etc. made from Ubamegashi (Umeme oak) as a raw material, and it is a kind of white charcoal. In general, white charcoal has a higher carbon content and a lower oxygen and hydrogen content than black charcoal and the like, and therefore has a higher adsorptivity than black charcoal and the like. In particular, white charcoal made from Ubamegashi has excellent adsorptivity. Since this adsorption plastic sheet uses Bincho charcoal, which is a kind of white charcoal made from Ubamegashi, the dehumidifying and deodorizing effects are further enhanced.

In the adsorbing plastic sheet 1, the amount of powdered charcoal is preferably 1 part by weight or more and 40 parts by weight or less, particularly preferably 5 parts by weight or more and 30 parts by weight or less, relative to 100 parts by weight of the plastic. If the amount of powdered charcoal is less than the above range, the dehumidifying / deodorizing effect may not be sufficient. On the contrary, when the amount of powdered charcoal exceeds the above range, the moldability of the adsorption plastic sheet 1 may be deteriorated.

The plastic used for the adsorption plastic sheet 1 is preferable because polyethylene can be incinerated without generating toxic gas.

[0022] As the polyethylene, (hereinafter also referred to as "metallocene polyethylene") polyethylene polymerized by a metallocene catalyst to the usual polyethylene may be used as a blend. Thereby, the strength of the adsorption plastic sheet 1 can be increased. The metallocene polyethylene content is preferably 5 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the total plastic. If the amount of the metallocene polyethylene compounded is less than the above range, the effect of improving strength may be insufficient. On the contrary, when the amount of the metallocene polyethylene exceeds the above range,
Foaming may be difficult.

The adsorbing plastic sheet 1 contains air bubbles. The inclusion of air bubbles enhances the impact absorption performance, and also increases the surface area to provide more fields for contact between air and powdered charcoal. The cells may be open cells or closed cells, but open cells are preferred. By forming continuous bubbles,
Air, which is the atmosphere, can penetrate into the inside of the adsorption plastic sheet 1, so that more places for contact between the air and the powdered charcoal can be provided, and the dehumidifying / deodorizing effect can be further enhanced.

The expansion ratio (ratio of the density in the absence of bubbles to the density in the presence of bubbles) of the plastic sheet for adsorption 1 is preferably 10 times or more and 40 times or less, and particularly preferably 10 times or more and 30 times or less. preferable. If the expansion ratio is less than the above range, the impact absorption performance and dehumidifying / deodorizing effect of the adsorption plastic sheet 1 may be insufficient. On the contrary, if the expansion ratio exceeds the above range, the strength of the adsorption plastic sheet 1 may be weakened.

The bubbles are generally formed by foaming a foaming agent. The foaming agent used may be a low boiling type foaming agent or a thermal decomposition type foaming agent. In particular, it is preferable to use a low-boiling type foaming agent because foaming is completed instantly and suitable for mass production. Examples of the low boiling point foaming agent include aliphatic hydrocarbons such as propane, butane and pentane,
Examples thereof include chlorinated aliphatic hydrocarbons such as methylene chloride and methyl chloride, freon, inorganic gases such as nitrogen and carbon dioxide, and the like.

The plastic used for the adsorbing plastic sheet 1 includes a coloring agent in addition to the foaming agent described above.
An appropriate amount of a foaming aid, a stabilizer, a plasticizer, a weathering agent, a deterioration inhibitor, a processing aid and the like are added.

The size of the adsorbing plastic sheet 1 is appropriately determined according to the intended use. The adsorption plastic sheet 1 shown in FIG. 1 is used as an underlay of dishes in a cupboard, and has a length of 4 meters, a width of 30 cm, and a thickness of 1 to 2 mm.
If the adsorbing plastic sheet 1 is too large to be used in a cupboard or the like, it may be cut into an appropriate size before use. In this case, since the main plastic sheet for adsorption 1 is made of plastic containing bubbles, it can be easily cut with a cutter knife, scissors or the like.

Next, an example of a method of manufacturing the adsorption plastic sheet 1 will be described. First, a plastic compound containing powdered charcoal is heated and melted, a low-boiling type foaming agent is injected by a pump from a foaming agent injection port provided near the center of the extruder, well kneaded, and cooled to an appropriate temperature. Then extrude it from the die into a sheet. Almost at the same time as the extrusion, the low-boiling type foaming agent is vaporized to form bubbles and become a foam (so-called foam extrusion). At this time, by adjusting the type and amount of the nucleating agent to be blended, the bubbles can be made continuous cells,
It can be a closed bubble. As described above, the plastic sheet for adsorption 1 can be mass-produced easily and at low cost simply by blending powdered charcoal into the plastic compound in the usual plastic extrusion molding. Moreover, by exposing the powdered charcoal on the inner wall thereof, it becomes possible to provide many places for contact between air and the powdered charcoal.

The powdered charcoal may be directly blended into the plastic compound, but it is preferable to blend the powdered charcoal into the plastic compound by using master pellets prepared by forcibly kneading the powdered charcoal into the plastic and processing it into pellets. preferable. As a result, the dispersibility of the charcoal powder, which is fine particles and is likely to cause poor dispersion, can be improved, and contamination of the environment of the extruder and the workplace can be prevented.

Next, an example of use of the adsorption plastic sheet 1 will be described. First, by laying the adsorption plastic sheet 1 in the cupboard as described above, it is possible to adsorb the moisture generated from the wet tableware and suppress the generation of mold. Moreover, since it is made of plastic, water and liquid seasonings do not soak in, which is hygienic. Further, by placing the adsorption plastic sheet 1 in the refrigerator, the offensive odor in the refrigerator can be removed. Further, by wrapping the fruits and vegetables in the adsorption plastic sheet 1, it is possible to adsorb ethylene gas and the like generated from the fruits and vegetables while preventing the evaporation of water, and the freshness of the fruits and vegetables can be maintained by their synergistic effect. . Further, the plastic sheet 1 for adsorption is pushed in, and laid in a closet or the like, so that the futon or clothes can be dried and the occurrence of mites can be suppressed. Also, by placing the pet in a pet house for dogs, cats, small birds, etc., the body odor of the pet can be absorbed. Also, by laying the plastic sheet for adsorption 1 under the tatami of a wooden house, or by using it as an inner material of the tatami, a wallpaper, etc., it is possible to suppress the aldehyde's filling in the room, which is a problem especially in a new house, to prevent allergies and the like. Can be prevented. Further, by laying this adsorption plastic sheet 1 under the floor of a wooden house, it is possible to prevent moisture and prevent wood from decaying. Furthermore, by using the plastic sheet for adsorption 1 as a backing material for the interior of an automobile, it is possible to eliminate odors such as cigarette odors in the interior of the automobile.

[0031] below, detailing adsorption plastic sheet of the present invention by way of Reference Examples.

[ Reference Example] A plastic compound containing 100 parts by weight of polyethylene and Bincho charcoal powder (having an average particle diameter of about 10 μm) was charged into an extruder, heated and melted, and then butane was injected as a foaming agent. Then, the mixture was kneaded and extruded into a sheet form from a die (diameter 55 mm, clearance 0.5 mm). Almost at the same time as the extrusion, the foaming agent vaporized to form an open-cell foam, and an adsorbed plastic sheet of Reference Example was obtained. The thickness of this adsorption plastic sheet was about 1.5 mm , and the expansion ratio was about 24 times.

Comparative Example A charcoal ink was prepared by dispersing Bincho charcoal powder equivalent to that in Reference Example in water. This charcoal ink was applied to a base cloth made of cotton non-woven fabric and dried so that the coating amount was about 27 g / m ^{2 in} terms of Bincho charcoal powder, and an adsorption sheet of a comparative example was obtained.

[Evaluation of Fastness to Rubbing] The adsorption plastic sheet of the reference example and the adsorption sheet of the comparative example were subjected to a fastness test in accordance with "JIS L0849 (1996)". There were two types of tests, a dry test and a wet test. The results of the tests are shown in Table 1 below.

[0035]

[Table 1]

In Table 1, the adsorption plastic sheet of the reference example is superior to the adsorption sheet of the comparative example in the fastness in both the dry test and the wet test. From this, it is understood that the adsorption sheet of the present invention is unlikely to contaminate tableware or the like.

[0037]

As described above, according to the present invention,
It is possible to obtain a hygienic plastic sheet for adsorption, which has no problem of contamination, is excellent in dehumidifying and deodorizing effects, has shock absorbing performance, is easy to manufacture, and is hygienic.

[Brief description of drawings]

FIG. 1 is a perspective view showing a suction plastic sheet according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Adsorption plastic sheet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C08K 3/04 C08K 3/04 C08L 23/04 C08L 23/04 (72) Inventor Susumu Taguchi Suoka City, Okayama Prefecture Matsuo Ryu 1170 Address 2 West Japan Novaform Co., Ltd. (56) Reference JP 54-41968 (JP, A) JP 11-43611 (JP, A) JP 11-100455 (JP, A) 61-111538 (JP, U) Special table 56-501839 (JP, A)

Claims (7)

(57) [Claims] 1. An adsorbent plastic sheet comprising ordinary polyethylene and metallocene polyethylene and containing powdered charcoal and made of plastic containing air bubbles. 2. The adsorption plastic sheet according to claim 1, wherein ordinary polyethylene and metallocene polyethylene are blended in an amount of 5 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the total weight of the plastic. 3. The adsorption plastic sheet according to claim 1, wherein the bubbles are continuous bubbles. 4. The plastic sheet for adsorption according to claim 1, wherein the expansion ratio of the plastic containing bubbles is 10 times or more and 40 times or less. 5. The adsorption plastic sheet according to claim 1, wherein the powdered charcoal is white charcoal powder. 6. The adsorption plastic sheet according to claim 5, wherein the white charcoal is white charcoal made from Ubamegashi. 7. A molten plastic obtained by mixing ordinary polyethylene and metallocene polyethylene with powdered charcoal and foamed charcoal.
A method for producing a plastic sheet for adsorption, characterized in that a plastic compound containing a foaming agent is continuously extruded from a die to foam, and a part of the powdered charcoal is exposed at the inner wall of the bubble.