JP2011111437A - Bug repellent, and resin composition and packaging material containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bug repellent excellent in safety and repelling effect against an insect pest, and to provide a resin composition and a packaging material containing the same. <P>SOLUTION: The bug repellent includes a calcium hydroxide powder obtained by grinding seashells. The calcium hydroxide powder preferably has a Ca content of 41 mass% or more and 54 mass% or less. Since the bug repellent is effective against an insect pest belonging to order Coleoptera, it is effective to food applications. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an insect repellent having a repellent effect against pests, a resin composition containing the same, and a packaging material.

  In factories that produce and handle powdered foods such as flour and dried products, food pests are likely to be generated using the powdered food as a bait. Food pests have a high ability to perforate packaging materials from the outside, and normal food packaging easily breaks bags and mixes them inside the food packaging, which is plagued by pest contamination. Such damage is not limited to factories, and pests fly to ordinary households, causing food damage in a wide area.

Examples of food pests that cause such damage include pests belonging to the order Coleoptera. Specifically, they are Kokunosutomodoki, Hiratakokunusutomodoki, Bokuzoeushi, Sawtooth beetle, Rice beetle, Ginseng beetle, Tobacco beetle, Giant cutlet beetle, Himekatsuobushim.
These pests are likely to occur in flour mills and feed mills that handle flour such as wheat flour, confectionery and bakery factories that handle biscuits, chocolate, bread, etc., and general households that handle flour, nuka, powdered milk, boiled food, and the like. It also causes damage to dried fruits and dried vegetables.

Known insect repellents for pest control include organic substances as active ingredients (see, for example, Patent Documents 1 and 2). Patent Document 1 describes a repellent effect on cockroaches, and Patent Document 2 describes that plants, fruits, and the like have effects on various food pests. In patent document 2, it is thought that the organic component contained in the plant and fruit used works effectively.
On the other hand, shell resources such as scallops, which are natural products, are attracting attention from the viewpoint of safety and recycling. There is a technique for obtaining an antibacterial effect by effectively using the calcium component contained in such a shell (see, for example, Patent Documents 3, 4 and 5). Patent Document 3 uses calcium powder obtained by burning shells, Patent Document 4 uses a mixture of calcium carbonate powder and calcium oxide powder obtained by grinding shells, and Patent Document 5 uses calcined calcium powder of shells. It has been.

Japanese Examined Patent Publication No. 61-15041 JP 2006-151896 A JP 2003-26525 A JP 2001-199819 A JP 2009-102277 A

  However, since some organic components contained in the insect repellents described in Patent Documents 1 and 2 have a specific odor, there is a possibility that the odor to the food may be transferred when used as a food packaging material. In addition, organic components cause discoloration and performance degradation due to deterioration due to light and heat, and are highly toxic because they contain highly toxic substances. In particular, they are not suitable for use as food packaging materials. It was.

Moreover, all the calcium powders described in Patent Documents 3 to 5 are calcium carbonate or calcium oxide. Although these powders have a bactericidal and antibacterial action, they do not have a repellent effect that does not attract pests, so it is difficult to completely prevent pest damage to powdered foods. In addition, calcium oxide (CaO) reacts with water (H ₂ O) to produce slaked lime (Ca (OH) ₂ ), and heat is generated due to water leakage during storage and transportation of packaged products. There is a handling problem. Furthermore, when it comes into contact with the skin for a long time, heat may be generated due to sweat or the like, which may cause skin damage.

  An object of the present invention is to provide an insect repellent excellent in safety and a repellent effect against pests, a resin composition containing the same, and a packaging material.

In order to achieve the above object, the insect repellent of the present invention is characterized by comprising calcium hydroxide powder obtained by pulverizing shells.
In the insect repellent of the present invention, the calcium hydroxide powder preferably has a Ca content of 41 mass% or more and 54 mass% or less.
Furthermore, in the insect repellent of the present invention, the calcium hydroxide powder preferably has an average particle size of 2 μm to 12 μm and a maximum particle size of 45 μm or less.
And it is preferable that the insect repellent of this invention further contains at least 1 type of metal selected from Zn, K, Ca, Cr, Se, Fe, Cu, Na, Mg, Mn, I, and P.
Moreover, it is preferable that the insect repellent of this invention is used for the pest use which belongs to Coleoptera.
Furthermore, the insect repellent of the present invention is preferably used for food applications.

The resin composition of the present invention is obtained by kneading the aforementioned insect repellent into a resin.
In the resin composition of the present invention, the calcium hydroxide powder is preferably contained in an amount of 2% by mass or more based on the total amount of the resin composition.
The packaging material of the present invention is characterized by being molded with the above-described resin composition.

According to the present invention, since calcium hydroxide derived from natural products obtained by pulverizing shells is used, safety is excellent. In addition, calcium hydroxide has a higher solubility than calcium carbonate, and when it comes into contact with a pest, it reacts with a bodily fluid of the pest and tends to exhibit strong alkalinity, and thus has an excellent pest repellent effect (invasion prevention effect). Therefore, it is possible to prevent pest contamination. In particular, it can be effectively used as an insect repellent for powdered foods such as flour.
In addition, inorganic calcium hydroxide obtained from shells as a raw material can be maintained semipermanently and maintain a repellent effect against pests.

Hereinafter, the present invention will be specifically described.
The insect repellent of the present invention comprises calcium hydroxide powder obtained by pulverizing shells.
Examples of the shell used as a raw material for the calcium hydroxide powder include scallops, oysters, oysters, clams, clams, idiots, and red shells. Among these, it is preferable to use scallop shells that are subjected to large-scale aquaculture, are easy to obtain shells from processing plants, and have little adhesion of impurities such as seaweed and barnacles to the shell surface. In particular, scallops cultivated in the Sea of Okhotsk are highly safe with little concern about arsenic and cadmium contamination. Since such shells are usually disposed of, waste can be effectively used by using the present invention.

Here, a method for obtaining calcium hydroxide powder from the shell will be described.
First, the shell is washed with water. Cleaning may be performed using a normal method, and impurities attached to the surface of the shell are removed as much as possible.
Next, the shell is heated and fired in a furnace having a temperature of 850 ° C. or higher and 1200 ° C. or lower. Thereby, quick lime (CaO) is obtained from the shell consisting mainly of calcium carbonate (CaCO ₃ ). If the temperature is lower than 850 ° C., the firing is insufficient and unreacted calcium carbonate remains, which is not preferable. On the other hand, if the temperature exceeds 1200 ° C., it is not preferable because it is overfired and uneconomical in terms of thermal energy. As such a furnace, a Beckenbach furnace, a Merz furnace, a rotary kiln, a fluidized firing furnace, or the like can be used.

Next, quick lime (CaO) obtained by firing is sieved to remove impurities such as fine sand. Thereby, the hydration reaction in the next step can be performed uniformly. As the sieve, a vibration sieve or the like equipped with a mesh having an opening size of 5 mm can be used.
Next, 50% water is added to quicklime (CaO) to hydrate. Thereby, calcium hydroxide (Ca (OH) ₂ ) is obtained.
Next, the obtained calcium hydroxide (Ca (OH) ₂ ) is finely pulverized. A normal method may be used for the pulverization, but it is preferable to use a jet mill that has a smaller particle size and can minimize the contamination of the material of the pulverizer due to wear and can be pulverized by the power of jet air.

  The Ca content in the calcium hydroxide powder thus obtained is preferably 41% by mass or more and 54% by mass or less. When Ca content is less than 41 mass%, the repellent effect with respect to a pest may not fully be exhibited. Moreover, when it exceeds 54 mass%, there exists a possibility of producing problems, such as the heat_generation | fever at the time of hydration of calcium oxide, and it is not so preferable. In particular, when used as a food insect repellent, it is more preferably 51% by mass or more and 54% by mass or less.

  The calcium hydroxide powder preferably has an average particle size of 2 to 12 μm and a maximum particle size of 45 μm or less, more preferably an average particle size of 2 to 4 μm and a maximum particle size of 8 μm or less. If the average particle size is less than 2 μm, it tends to aggregate due to moisture in the air, making handling difficult. On the other hand, when the average particle diameter exceeds 12 μm, it is not preferable because, when blended in a film or the like, pinholes are formed to reduce the moisture-proof performance.

Furthermore, the calcium hydroxide powder obtained from the shell by the above method contains a trace amount of metal. The type of metal is at least one selected from Zn, K, Ca, Cr, Se, Fe, Cu, Na, Mg, Mn, I, and P.
The obtained calcium hydroxide powder has an arsenic content of 1% by mass or less and a lead content of 10 ppm or less. If the arsenic content exceeds 1% by mass or the lead content exceeds 10 ppm, the human body is adversely affected. In particular, when used in food applications, it is preferable to obtain food additive approval.

The solubility of calcium hydroxide powder in water is 0.15% by mass at 25 ° C., and the solubility in water is higher than that of calcium carbonate (CaCO ₃ ). The solubility decreases with increasing temperature. The saturated pH of the calcium hydroxide powder is 12.4.
Such calcium hydroxide powder has an excellent repellent effect against pests. In particular, it is highly effective against pests belonging to the order Coleoptera. Examples of the pests belonging to the order of Coleoptera include Physcomitrella serrata, Spiraea serrata, Scarlet weevil, Sawtooth beetle, Rice beetle, Ginseng beetle, Tobacco beetle, Giant beetle weevil, Himekatsu bemushi.

Next, a method for producing a packaging material by forming a film containing the aforementioned calcium hydroxide powder will be described.
First, a resin master batch (resin composition) containing 50% by mass or more of calcium hydroxide powder is prepared. The resin to be used may be appropriately selected according to the use and contents of the packaging material. For example, polyethylene, polypropylene, or the like can be used.

Next, the resin master batch is further diluted with a resin, and a film is produced by a commonly used film forming method such as T-die molding or inflation molding. At this time, the content of the calcium hydroxide powder in the film is preferably 2% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 5% by mass or less. When the content of the calcium hydroxide powder in the film is less than 2% by mass, the repellent effect against pests cannot be sufficiently exhibited. On the other hand, when the content of the calcium hydroxide powder exceeds 10% by mass, it is not preferable because the strength of the film is reduced when blended in the film. In order to prevent the strength of the film from being lowered, the strength can be suppressed by adjusting the particle size to be 1 μm or less, but the kneading work becomes complicated due to powder aggregation or the like, which is not preferable.
The film may be a single layer or multiple layers. Moreover, a laminated body with paper, an aluminum film, etc. may be sufficient. In this case, food pests can be efficiently prevented from entering by blending calcium hydroxide powder into the film layer on the side of the laminated surface with paper or aluminum film.

  Next, using the obtained film, a packaging material is produced by a commonly used method. For example, a laminate film is used for packaging materials for general consumers of wheat flour, the front substrate is a polyester or nylon film, the back substrate (sealant material) is LLDPE (linear low density polyethylene), LDPE (Low density polyethylene) or these multilayer films are used. In addition, a three-layer film may be used for the back substrate. In addition, as a packaging material for rice, a single layer of LLDPE or a two-layer or three-layer film of LLDPE and LDPE is used, and a small hole for venting gas may be provided.

  The packaging material thus obtained becomes a packaging material for foods such as flour such as flour and rice, biscuits, chocolate, bread, nuka, powdered milk, boiled milk, dried fruits, and dried vegetables. In particular, it can be used as a curing film or a stretch film used when storing food in a food factory.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is not restrict | limited at all by the content of description of these Examples.

[Example 1]
After washing the scallop shell with water and baking at 900 ° C. for 4 hours, impurities such as fine sand were removed using a sieve with a mesh opening of 5 mm to obtain 1 kg of baked scallop shell.
Next, 0.5 kg of water was added to the baked scallop shell to hydrate, and jet mill STJ200 (manufactured by Seishin Enterprise Co., Ltd.) was used for the obtained calcium hydroxide, with an average particle size of 10 μm and a maximum particle size of 45 μm. A fine powder was obtained. The calcium content of calcium hydroxide at this time was 51% by mass.
A master batch in which 50% of the obtained fine powder was blended with IDEMITSU LLDPE (linear low density polyethylene manufactured by Idemitsu Kosan Co., Ltd., melt flow rate 1.2 g / 10 min) at 200 ° C. in a 40 mmφ extruder for kneading. The kneading temperature was prepared.
The master batch was diluted 25 times with IDEMITSU SU LLDPE 0134 (linear low density polyethylene manufactured by Idemitsu Kosan Co., Ltd., melt flow rate: 1.2 g / 10 min) (final fine powder content 2%), and molded. A single-layer inflation film having a total thickness of 90 μm was produced at a machine temperature of 200 ° C.
Using the single-layer inflation film, a flour-filled bag having four corners completely sealed with 50 g of flour as a content was prepared as a test sample.

[Example 2]
A test sample was prepared in the same manner as in Example 1 except that the master batch prepared in Example 1 was diluted 10-fold with IDEMITSU LLDPE 0134 (final fine powder content: 5%).

[Example 3]
After washing the scallop shell with water and firing at 1100 ° C. for 4 hours, impurities such as fine sand were removed using a sieve having an opening of 5 mm to obtain 1 kg of fired scallop shell.
Next, 0.5 kg of water was added to the baked scallop shell to hydrate, and the obtained calcium hydroxide was jet milled twice using a jet mill STJ200 (manufactured by Seishin Enterprise Co., Ltd.) A fine powder having a diameter of 2 μm and a maximum particle diameter of 8 μm was obtained. At this time, the calcium content of calcium hydroxide was 53.5% by mass.
A master batch in which 50% of the obtained fine powder was blended with IDEMITSU LLDPE was prepared at a kneading temperature of 200 ° C. in a 40 mmφ extruder for kneading.
The master batch was diluted 5-fold with IDEMITSU LLDPE 0134 (final fine powder content: 10%) to produce a single-layer inflation film having a total thickness of 90 μm at a molding machine temperature of 200 ° C.
Using the single-layer inflation film, a flour-filled bag having four corners completely sealed with 50 g of flour as a content was prepared as a test sample.

[Comparative Example 1]
A single-layer inflation film not containing calcium hydroxide having a total thickness of 90 μm was produced at a molding machine temperature of 200 ° C. using IDEMISU LLDPE 0134.
Using the single-layer inflation film, a flour-filled bag having four corners completely sealed with 50 g of flour as a content was prepared as a test sample.

[Comparative Example 2]
A test sample was prepared in the same manner as in Example 1 except that the master batch prepared in Example 1 was diluted 50-fold with IDEMITSU LLDPE 0134 (final fine powder content 1%).

[Comparative Example 3]
The scallop shell was washed with water and then fired and hydrated, and a fine powder having an average particle size of 11 μm and a maximum particle size of 45 μm was obtained using a jet mill STJ200 (manufactured by Seishin Enterprise Co., Ltd.). The calcium content of the calcium carbonate at this time was 38% by mass.
Thereafter, in the same procedure as in Example 1, a single-layer inflation film containing the obtained fine powder was prepared, and then a bag containing flour was prepared and used as a test sample.

[Comparative Example 4]
After washing the scallop shell with water and firing at 1100 ° C. for 4 hours, impurities such as fine sand were removed using a sieve having an opening of 5 mm to obtain 1 kg of fired scallop shell.
Next, without hydration, a fine powder having an average particle size of 3.5 μm and a maximum particle size of 8 μm was obtained using a jet mill STJ200 (manufactured by Seishin Enterprise Co., Ltd.). The calcium content of calcium oxide at this time was 70% by mass.
Thereafter, in the same procedure as in Example 1, a single-layer inflation film containing the obtained fine powder was prepared, and then a bag containing flour was prepared and used as a test sample.

[Comparative Example 5]
A test sample was prepared in the same manner as in Example 1 except that the master batch prepared in Comparative Example 3 was diluted 10-fold with IDEMITSU LLDPE 0134 (final fine powder content: 5%).

[Comparative Example 6]
A test sample was prepared in the same manner as in Example 1 except that the master batch prepared in Comparative Example 3 was diluted 5-fold with IDEMITSU LLDPE 0134 (final fine powder content: 10%).

[Comparative Example 7]
A test sample was prepared in the same manner as in Example 1 except that the master batch prepared in Comparative Example 4 was diluted 10-fold with IDEMISUSU LLDPE 0134 (final fine powder content: 5%).

[Comparative Example 8]
A test sample was prepared in the same manner as in Example 1 except that the master batch prepared in Comparative Example 4 was diluted 5-fold with IDEMITSU LLDPE 0134 (final fine powder content: 10%).

[Perforation test of flour packaging bags by food pests]
Two sets of test specimens each having the test samples prepared in Examples 1 to 3 and Comparative Examples 1 to 8 placed on a filter paper having a diameter of 6 cm were prepared, and these test specimens were plastic containers (diameter 30 cm × height 15 cm). They were arranged concentrically so as not to overlap.
Next, 100 adult moss were released in the center of the plastic container, and the number of adults collected in each test specimen 24 hours after the release and the number of perforated bags were tested. The contents of evaluation are as follows.

◎: 0 perforations • 0 perforations • 0 adults on sample bag
○: No. of perforations • No. of perforations • One or more adults on sample bag Δ: No. of perforations • One or more perforations • One or more adults on sample bag ×: One or more perforations • One or more perforations • Sample 1 or more adults on the bag

  As shown in Table 1, in Examples 1 to 3, there is no damage due to pests, and the pest repellent effect is excellent. On the other hand, in Comparative Example 1 containing no calcium hydroxide, there were perforations and the insects were damaged. Further, in Comparative Example 2 with a small amount of calcium hydroxide and Comparative Examples 3, 5, 6 containing calcium carbonate instead of calcium hydroxide and Comparative Examples 4, 7, 8 containing calcium oxide instead of calcium hydroxide In the sample bag, the perforation marks and the pests are confirmed, and it can be seen that the pests are not completely repelled.

  In addition to being used as a food insect repellent, such as a packaging bag for storing food or a curing sheet for preventing pest breakage, the present invention is widely used as an insect repellent for clothing and insect repellents for the human body. Can be used.

Claims (9)

  An insect repellent comprising calcium hydroxide powder obtained by pulverizing shells. The insect repellent according to claim 1,
The calcium hydroxide powder has an Ca content of 41% by mass or more and 54% by mass or less. In the insect repellent according to claim 1 or 2,
The calcium hydroxide powder has an average particle size of 2 μm or more and 12 μm or less, and a maximum particle size of 45 μm or less. In the insect repellent according to any one of claims 1 to 3,
An insect repellent, further comprising at least one metal selected from Zn, K, Ca, Cr, Se, Fe, Cu, Na, Mg, Mn, I, and P.   The insect repellent according to any one of claims 1 to 4, which is used for pests belonging to the order Coleoptera.   The insect repellent according to any one of claims 1 to 5, which is used for food applications.   A resin composition obtained by kneading the insect repellent according to any one of claims 1 to 6 into a resin. The resin composition according to claim 7,
The calcium hydroxide powder is contained in an amount of 2% by mass or more based on the total amount of the resin composition.   A packaging material, which is molded from the resin composition according to claim 7 or 8.