KR20020002646A - A Producing Method of Mothproof Film - Google Patents

Abstract

The present invention relates to a method for producing a insect repellent film by melting and mixing a polyolefin resin, an inorganic filler and an encapsulated insect repellent. More specifically, a capsule containing an insect repellent based on 20 to 80 parts by weight of a polyolefin resin and 20 to 80 parts by weight of an inorganic filler. It is manufactured by inflation or tee-die casting method after melt mixing 0.01 to 10 parts by weight, and uniaxially or biaxially stretches the film to a total area stretching ratio of 1.5 to 36 times according to the required moisture permeability after fabrication of the original sheet. It relates to a manufacturing method of the insect repellent film. The film produced by this method is able to keep the insect repellent from quickly moving to the film surface, thereby maintaining the insect repellent effect for a long time, and it is particularly suitable for application for fruit bags because of its moisture permeability.

Description

Insect repellent film manufacturing method {A Producing Method of Mothproof Film}

The present invention relates to a method for producing a polyolefin-based insect repellent film having an effect on the control of pests, such as superspidities, diopterans, stamens or flies, mosquitoes that live in the ground. More specifically, the present invention relates to a method of manufacturing a insect repellent film by melt-mixing an encapsulated insect repellent into a polyolefin resin and an inorganic filler. The film thus prepared has excellent persistence and moisture permeability, and is particularly suitable for fruit bag encapsulation. The feature is that

When insect repellents that are effective in controlling insects such as superspecies, diopterans, stamens, flies, and mosquitoes in the ground are used in the polyolefin-based film, the chemicals are sprayed only where necessary. It is known as one of the effective pest control methods due to the effect and the slow release of the insect repellent in the film. However, in general, the insect repellent is incompatible with the polyolefin resin, so it is very difficult to disperse the insect repellent in the film, and the insect repellent effect is short-lived as the insect repellent transfers to the surface immediately after film forming. Of course, among the known techniques for proper dispersion of the insect repellent is a method of forming a insect repellent masterbatch using a porous plastic pellets, and dry mixed with a resin to form a film.

However, in this case, there is no problem in the dispersion of the insect repellent, but since the base of the master batch is plastic, it is melted during film forming and the mold disappears, so there is no effect of suppressing the transition of the insect repellent to the film surface.

In US Pat. No. 4,666,706, an insect repellent film was prepared using an adhesive polyoxazoline to secure the persistence of the insect repellent effect. However, when the insect repellent film thus prepared was used for the fruit bag, the insect repellent effect has a long-term retention property, but there is little moisture permeability, so that the fruit becomes soggy and rot due to moisture.

An object of the present invention is to improve the above problems, it is possible to maintain the insect repellent effect for a long time by inhibiting the film surface migration speed of the insect repellent and also to ensure the moisture permeability of the film is particularly suitable for application for fruit bag It is to provide a method for producing a film.

Insect repellent film manufacturing method of the present invention relates to a method for producing a repellent film by melt-mixing the encapsulated insect repellent in a polyolefin resin and an inorganic filler after the production of the original resin and stretched to the original resin, particularly the fruit bag Suitable for use for

The composition of the present invention is prepared by inflation or tee-die casting method after melting and mixing 0.01 to 10 parts by weight of the capsule containing the insect repellent against 20 to 80 parts by weight of polyolefin resin, 20 to 80 parts by weight of inorganic filler, and manufacturing the original sheet It is the same as the production method of the insect repellent film, characterized in that the uniaxial or biaxial stretching of the film in the range of 1.5 to 36 times the total area stretching magnification according to the required water vapor transmission rate.

Insect repellent capsules used in the present invention are used to ensure the persistence of the insect repellent effect, the wall material of the capsule is a cellulose derivative, gelatin resin, starch, polyamide, polyester, polycarbonate, polyurethane or polyurea polymer One or more are used, and are prepared by emulsion polymerization or supporting method. The particle size of the capsule is about 0.1um ~ 30um.

When the size of the capsule is less than 0.1um, it is very difficult to manufacture the capsule. When the size of the capsule is more than 30um, the film surface state such as pinhole may be poor.

In addition, the insect repellent filled in the capsule can be used any insect repellent known to be effective by direct spraying method. Specific examples include pyrethroid-based permethrin, alletrin, pyrethrin, bioresmethrin, tetramethrin, organophosphorus dichlorbose, phenytrothion, chlorpyriphos, organochlorine DDT, gamma-HCL, malachion, Carbamate Gain Propoxyl, PHC, etc. It is also possible to use one or two or more insect repellents.

When the amount of added insect repellent is used in 0.01 parts by weight to 10 parts by weight relative to the resin composition, when the content is 0.01 parts by weight, the insect repellent effect is not seen. When the amount exceeds 10 parts by weight, the insect repellent effect is excellent, When applied, it is difficult to handle due to odors, etc., and price competitiveness may be reduced due to rising manufacturing cost.

The resin composition used in the present invention is composed of a polyolefin resin and an inorganic filler, and the content of the inorganic filler is used at 20 wt% to 80 wt%. When the content of the inorganic filler is less than 20% by weight, it is difficult to obtain a desired moisture permeability during film molding, and when the content is 80% by weight or more, the extrusion processability is significantly reduced. Therefore, preferably 30 to 60% by weight is suitable.

Film molding can be formed by inflation or casting method, and in order to secure high moisture permeability, the uniaxial or biaxial stretching of the original sheet manufactured by the extruder can ensure the required moisture permeability.

The polyolefin resin in the present invention is a polyolefin-based thermoplastic resin comprising a homopolymer of ethylene or propylene or a copolymer of ethylene or propylene with another comonomer (a compound having 4 or more carbon atoms and having at least one double bond in a molecule), for example, For example, low density polyethylene, linear low density polyethylene, ultra low density polyethylene, high density polyethylene, ethylene vinyl acetate copolymer, polypropylene, ethylene propylene copolymer, ethylene propylene diene copolymer, ethylene methacrylic acid ester, or any of these mixtures, but preferably The density should be 0.91-0.95g / cm3 and the melt index is 0.5 ~ 2.0g / 10min (at 190 ℃).

The linear low density polyethylene is prepared by copolymerization with a Ziegler type catalyst or a metallocene catalyst as a copolymer of ethylene and other alpha olefins.

In the present invention, the inorganic filler is calcium carbonate, silica, barium sulfate, magnesium sulfate, calcium sulfate, talc, kaolin, aluminum hydroxide, magnesium hydroxide, zinc oxide, alumina, titanium oxide, mica, zeolite, diatomaceous earth, magnesium carbonate, cray or Mixtures of these are used. Examples of the inorganic filler include plate, needle and sphere, but spheres are most preferred, and the average particle diameter is in the range of 0.1 to 10 μm, preferably 0.1 to 3 μm. If the average particle diameter is less than 0.1 μm, the inorganic filler is difficult to disperse in the resin, and mechanical properties are deteriorated. If the average particle diameter is more than 10 μm, the film may have a poor surface due to pinholes or holes.

Meanwhile, the inorganic filler may be coated with stearic acid or the like to increase the dispersibility of the inorganic material in the resin.

Hereinafter will be described in detail a method for manufacturing a fruit film insect repellent film of the present invention.

Insect repellent capsules, polyolefin resins, inorganic fillers and conventional additives are adjusted in an appropriate amount and mixed in a conventional blender or mixer. As the mixer, a drum, a dumbler type mixer, a ribbon blender, a Henschel mixer supermixer, or the like may be used, but a high speed stirring type mixer such as a hexyl mixer is preferable.

Next, the mixture is kneaded, which is suitably carried out by a conventionally known apparatus such as a conventional single screw extruder, a twin screw mixer, a mixing roll, a balbaric mixer, a twin screw kneader and the like. The kneaded resin composition is then pelletized. The resin composition pellets are put into a hopper and the film is molded in accordance with a conventional film forming apparatus and molding method by extrusion processing. You may do it.

Film forming can be done differently according to the required moisture permeability. In case of low moisture permeability (for example, outer bag of double layered bag, moisture permeability of 1000g / 24hr, ㎡ or less) According to the thickness control, the moisture permeability can be adjusted to about 1,000g / 24hr, m2. The film thickness is good 15 ~ 50um level.

In the case of high moisture permeability (for example, for double bag encapsulation, moisture permeability 2,000 ~ 10,000g / 24hr, m2), the sheet formed by extrusion method is 1.2 ~ 6.0 at the temperature between glass transition point and melting point. In the range of times, the drawing is preferably drawn in the traveling direction MD in the range of 1.5 to 5.0 times. In this case, if the temperature is lower than the glass transition point, the film cannot be stretched because the film is broken before the elongation exceeds the yield point. If the temperature exceeds the melting point, the aeration rate can be obtained by the flow of the molecular chain. It is impossible.

In addition, when the draw ratio is less than 1.2 times, sufficient aeration amount is not obtained, and when the draw ratio exceeds 6 times, cutting phenomenon occurs frequently during stretching and a film cannot be stably obtained. Subsequently, the film stretched in the running direction is stretched in the width direction (TD) under the conditions and the draw ratio of the above temperature range to obtain a biaxially stretched insect repellent film.

In addition, it is also possible to perform uniaxial stretching without performing biaxial stretching as described above. That is, the method for producing a high moisture permeability insect repellent film according to the present invention can be produced by either uniaxial or biaxial stretching, and the total area stretching ratio It is preferable to extend | stretch to this 1.5 to 36 times range. If the area stretching ratio is less than 1.5 times, sufficient moisture permeability cannot be obtained. If the area stretching ratio is more than 36 times, moisture permeability is obtained, but there is a fear that the film breaks during the stretching process. In order to improve the dimensional stability, the film after extending | stretching may heat-fix.

The physical properties of the film impregnated with the insect repellent prepared according to the present invention, such as the type and physical properties of the polyolefin resin, the type and particle diameter of the inorganic filler and the mixing ratio, molding method, stretching temperature, stretching ratio, stretching method, etc. Freely adjustable accordingly.

The present invention can be understood in more detail through the following examples and comparative examples, the following examples and comparative examples are not intended to limit the scope of the present invention but are described for illustrative purposes.

(Example 1)

10 parts by weight of an insect repellent encapsulated in the base resin composition consisting of 20 parts by weight of linear low density polyethylene A (Samsung General Chemical 6220F), 30 parts by weight of linear low density polyethylene B (SK FT811), and 50 parts by weight of calcium carbonate (OMYA OMYACARB 2). (The content of permethrin as an insect repellent is 81% by weight based on 100% by weight of the entire insect repellent capsule), primary and secondary antioxidants, processing aids (3M FX5924), dispersants (Songwon Industry, Zn-st), UV stabilizer The mixture was mixed in a Henschel mixer, and the mixture was kneaded with a twin screw kneader and then pelletized.

The obtained resin composition pellets were introduced into a film molding extruder through a fold and melt-extruded at 220 DEG C to prepare a melted sheet as a disc sheet through a T-die. The obtained original sheet was stretched 1.7 times in the running direction (MD) at a stretching temperature of 60 ° C., and stretched 1.5 times in the width direction (TD) while maintaining the tenter temperature at 120 ° C., and finally, the drawn area was heat treated at 110 ° C. for 1 day. An insect repellent film having a thickness of 38 um processed to 2.6 was prepared.

After the prepared film was left to stand outdoors, the content of the insect repellent remaining in the film was measured (high pressure liquid chromatography method) at intervals of three weeks. The measurement results are shown in Table 1.

(Example 2, Comparative Example 2)

A film was prepared in the same manner as in Example 1 with the composition of Table 2. The moisture permeability and the insect repellent (insecticide against powdery beetle) were evaluated for the produced film. The evaluation results are shown in Table 2.

* Vapor permeability evaluation

The evaluation of the moisture permeability of the film was conducted according to KS A 1013. Since there is no requirement specification for the moisture permeability, the moisture permeability of the currently applied paper bag is set as a target value. In case of bag, outer bag is 100 ~ 1,000g / 24hrm2, and inner bag is 2,000 ~ 10,000g / 24hrm2.

* Insecticidal test for powdery beetle

With the breathable film before and after the insect repellent being placed on the test bench, place a 15cm x 15cm x 3cm acrylic box, spin 50 larvae larvae into it, contact it for 24 hours, and transfer it to the observation box for feeding. The number of experimental insects killed by giving was checked.

* Insect repellent content in insect repellent capsule: 81% by weight (permethrin, cis-, trans- ratio 4/6)

Insect repellent film prepared by the method of the present invention shows 1200ppm up to 18 weeks, as shown in Table 1, 2, and after 21 weeks the residual amount is reduced to around 100ppm has excellent effect of slowly releasing insect repellent, moisture permeability and insecticidal effect is also remarkable Appeared.

Claims (5)

20 to 80 parts by weight of polyolefin resin and 0.01 to 10 parts by weight of a capsule containing insect repellent are melt-mixed with respect to 20 to 80 parts by weight of an inorganic filler, and then prepared by inflation or tea-die casting method. Insect repellent film production method characterized in that the uniaxial or biaxial stretching of the film in the range of 1.5 to 36 times the total area stretching magnification. The insect repellent of claim 1, wherein the insect repellent is permethrin, alletrin, pyrethrin, bioresmethrin, tetramethrin, dichlorbose, phenytrothion, chlorpyriphos, DDT, gamma-HCL, malachion, propoxl, PHC Insect repellent film, characterized in that for use in the mixture consisting of one or two or more from the group consisting of wood vinegar. The method of claim 1, wherein the capsule containing the insect repellent is emulsified or polymerized using at least one of cellulose derivative, gelatin resin, starch, polyamide, polyester, polycarbonate, polyurethane or polyurea polymer as the wall material of the capsule. Insect repellent film manufacturing method characterized by the manufacturing method. The polyolefin resin according to claim 1, wherein the polyolefin resin is one of low density polyethylene, linear low density polyethylene, ultra low density polyethylene, high density polyethylene, ethylene vinyl acetate copolymer, polypropylene, ethylene propylene copolymer, ethylene propylene diene copolymer, ethylene methacrylic acid ester. At least one species, the density of 0.91 ~ 0.95g / cm 3, the melt index is 0.5 ~ 2.0g / 10min (at 190 ℃) characterized in that the insect repellent film production method. The method of claim 1, wherein the inorganic filler is calcium carbonate, silica, barium sulfate, magnesium sulfate, calcium sulfate, talc, kaolin, aluminum hydroxide, magnesium hydroxide, zinc oxide, alumina, titanium oxide, mica, zeolite, diatomaceous earth, magnesium carbonate, Insect repellent film production method characterized in that at least one of cray or stearic acid coatings thereof.