KR100969999B1 - film for packing materials - Google Patents

Abstract

The present invention relates to a breathable film laminate used as a packaging material for storing grain or feed having excellent strength and breathability. More specifically, the present invention provides a breathable film having a nanometer-sized vent in order to maintain breathability, to prevent damage to pests, and to improve strength and resistance to moisture, and a component similar to the breathable film on one or both sides thereof. It relates to a packaging material using a laminated film bonded to a non-woven fabric prepared by.

Rice packaging material, breathable film, spunbond nonwoven fabric

Description

Film for packing materials for grain or feed packaging

The present invention relates to a breathable film laminate having excellent strength, antibacterial and breathable properties, and relates to a packaging material used as a packaging material for storing grain or feed. More specifically, the present invention provides a breathable film having a fine size vent to maintain breathability, to prevent pest damage, and to improve the strength and resistance to moisture, and on one or both sides of the composition similar to the breathable film It relates to a rice packaging material using a laminated film bonded to the prepared nonwoven fabric.

In general, the bag containing grain or feed is mainly made of paper or polymer film, and it is used in several layers to reinforce the strength of the paper, or only a part of the polymer film is used to show the contents. have. Such paper is excellent in moisture permeability and air permeability, but has a problem of low strength and tearing well. And the outer surface of the packaging material, it is printed a variety of letters or shapes, when printing the letters or shapes on the paper is not clear print, the appearance is degraded, and when exposed directly to moisture easily tears the contents spilled out Sometimes it happens.

In order to solve this problem, in recent years, by adding a film of a synthetic resin material on the paper to improve the printability, it is possible to prevent the problem that the bag is easily torn even in contact with moisture through securing waterproofness. However, as described above, the packaging material made of an outer skin in which a film of synthetic resin material is laminated on paper is not ventilated, resulting in poor shelf life of the contents, moisture generation, damage to the contents, and bugs.

Rice is piled in a layer of insulated rice hull, which can be protected from invasion of outside mold or pests during storage, and removes rice by about 20% in volume by removing the rice hull from rice, and removes rice bran from rice. White rice, which is divided into white rice through the processing process, is a kind of fresh rice, and it is a kind of fresh food that reacts sensitively to changes in external temperature and humidity, so it is easily deteriorated and easily invaded by pests. There is a problem of poor quality.

In this processed rice, brown rice is about 2 to 4 days after processing and white rice is about 1 to 2 days, and then it is placed on the packaging of various packing units formed of materials such as general general area or polyethylene (PE), aluminum (Al), etc. It is packaged and shipped to a direct store or a large store, and is generally distributed for a long time with an average storage period of 1 to 2 months.The distribution environment after rice packaging is distributed at room temperature because it is distributed at room temperature unlike fruits and vegetables operated by low temperature distribution system. In addition to the severe variation, in general, indoor food stores are left in a relatively high temperature with a mean storage temperature of 20 to 25 ° C and a relative humidity of 35 to 40%. Due to the deterioration of the quality of rice, we cannot supply high quality rice and satisfy the taste of consumers who prefer rice with excellent taste and nutrition. As it is not growing, it is urgently needed to develop a rice-only packaging material that can maintain the quality of rice for a certain period of time even in the actual temperature distribution environment where the distribution of rice cannot be changed into a cold chain.

The present invention includes an antimicrobial agent to protect against pests and stability during storage, excellent breathability, moisture permeability and mechanical strength to maintain the humidity of the package properly, for grain or feed packaging material that has an advantageous effect of storage and transport It is an object to provide a film laminate.

Specifically, the present invention maintains breathability, but has a small pore, so there is little risk of pests introduced, and furthermore, an object of the present invention is to provide a packaging material that blocks the influx of microorganisms by adding an antimicrobial agent when manufacturing the breathable film.

In addition, the spunbond non-woven fabric can be bonded to block the outflow of moisture as much as possible to maintain a constant moisture of the grain, the strength is excellent to provide a packaging material that is convenient to transport and storage.

The present invention for solving the above problems is to provide a film laminate for grain or feed packaging material, the breathable film stretched by melt extrusion extrusion of the compound composition for breathable film containing polyethylene resin, inorganic filler and antibacterial agent; On one or both sides of the breathable film, a spunbond nonwoven fabric or mesh reinforcement film made of filament made of a polyester core and a filament sheath made of polyethylene resin are laminated and hot-bonded by a hot roller. (heat sealing) or by spraying a solvent-free hot melt is characterized in that the adhesive.

Hereinafter, each configuration of the present invention will be described in more detail.

1) breathable film

In the present invention, the compound composition for breathable film is an area stretching ratio of the disc sheet melt-molded compound composition for breathable film containing 20 to 250 parts by weight of polyolefin resin, 0.1 to 5 parts by weight of antimicrobial agent with respect to 100 parts by weight of inorganic filler. Prepared by stretching in the range of 1.5 times to 36 times. The breathable film according to the present invention has a fine vent of micrometer or less. More specifically, vents ranging from tens of nanometers to several micrometers are formed.

In this case, the inorganic filler (a) the weight average molecular weight of 30,000 or less produced by extraction by boiling n-hexane during the production of high-density polyethylene-based resin, melt index (190 ℃, 2.16Kg) 50g / 10min or more ethylene-based polymer 70 ~ 95 When coating the surface by using a mixture consisting of 5% to 30% by weight and (b) 5 to 30% by weight of saturated fatty acid in the melting point of 40 ~ 80 ℃ range, it is possible to produce a breathable film with better dispersibility, 100 weight of inorganic filler during coating It is preferable to coat the mixture using 1 to 10 parts by weight with respect to parts.

In the case of manufacturing a breathable film by compounding a composition of a conventional polyolefin and an untreated inorganic filler, the surface of the inorganic filler is hydrophilic, so the compatibility with the polyolefin resin is very poor, the breakage occurs during the stretching process has a disadvantage of poor physical properties. In addition, the modified inorganic filler coated with an inorganic filler with a higher fatty acid is treated with an expensive higher fatty acid, thereby increasing the price naturally. Also, due to the nature of the higher fatty acid, the hydrophilic acid component is relatively easy and uniform on the surface of the hydrophilic inorganic filler. The coated and lipophilic aliphatic long chain is easily mixed with the polyolefin, which has a good overall compatibility between the modified inorganic filler and the polyolefin, which is a matrix resin, which advantageously reduces the fine dispersion, but does not form pores in the stretching process, and thus has excellent air permeability. Manufacture This is a disadvantage.

Therefore, the inorganic filler may not be excellent in compatibility with the matrix resin, and the usability is too low, and when crushing occurs during stretching, it is difficult to bring about a decrease in physical properties, so that the surface of the inorganic filler is coated in the present invention. If the surface condition after treatment is only partially coated, unlike the treatment with higher fatty acids, the inorganic filler and the matrix can be controlled by controlling the compatibility of the polyolefin resin with the untreated inorganic filler and the inorganic filler treated with the higher fatty acid. During the stretching process while improving the dispersibility with the polyolefin resin, the pore generation is promoted in the partially uncoated portion, it is possible to easily express a lot of pores while maintaining the overall mechanical properties as a whole to ensure high breathability.

Inorganic fillers used in the present invention include calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, calcium chloride, calcium sulfate, aluminum hydroxide, zinc oxide, magnesium hydroxide, titanium oxide, alumina, mica, asbestos powder, zeolite Clay, silicate or mixtures thereof are used. As the form of the inorganic filler, there are plate, needle, spherical and the like, but spherical is most preferred, and the average particle diameter is in the range of 0.1 to 5 탆, preferably 0.5 to 3 탆. If the average particle diameter is less than 0.1㎛ there is a fear that the coating state of the ethylene-based polymer according to the present invention is too poor, if it exceeds 5㎛ there is a disadvantage that the surface appearance of the stretched breathable film is poor.

The coating agent coating the inorganic filler of the present invention has a compatibility enough to coat a part of the inorganic filler, the weight average molecular weight of 30,000 or less produced by extraction by boiling n-hexane during the production of high-density polyethylene-based resin, melting An ethylene-based polymer having an index (190 ° C., 2.16 Kg) of 50 g / 10 min or more is used. These ethylene-based polymers usually occur in the form of cakes, but if they are well ground, they have a wax-like shape, and due to the inclusion of ethylene-based polymers with lower molecular weights of hundreds to thousands, they have some flowability even at tens of degrees Celsius. When it reaches about 100 ° C. or more, it has better flowability, and the coating property is expressed to some extent through the mixing and the high speed stirring process for the inorganic filler in the high speed mixer. However, since the ethylene-based polymer is lipophilic, and unlike high-fatty fatty acids having both hydrophilicity and lipophilic property, the coating property is poor, so that an inorganic filler having a partially coated structure can be obtained. A film can be manufactured.

In addition, the polyolefin resin is used by mixing a low density polyethylene, a linear low density polyethylene, a medium density polyethylene, and a homopolymer or copolymer containing ethylene as a main component and a polypropylene having an isotactic or syndiotactic structure. According to the present invention, the polypropylene having a stereoregularity of syndiotactic or isotactic structure is mixed and used as compared with conventional polyethylene, and thus the strength of the breathable film can be further reinforced.

The polyolefin resin is not limited as long as it has a molecular weight to form a film, but in the present invention, using a polyolefin resin having a melt index (190 ° C., 2.16 Kg) in the range of 1 to 10 g / 10 min maintains mechanical properties and breathability. It is useful for use.

The antimicrobial agent is added to increase the preservation rate of grains to prevent pests by providing antimicrobial activity, it is recommended to use a component registered in the FDA as an industrial antimicrobial agent. As the antimicrobial agent, any one or a mixture of two or more selected from a silver-containing zirconium phosphate compound represented by the following Chemical Formula 1, a silver or zinc-containing zeolite compound represented by the following Chemical Formula 2, isopropylmethylphenol, or a pyrithione-based compound may be used.

[Formula 1]

Ag _x H _y Zr ₂ (PO ₄ ) ₃ (x + y = 1)

[Formula 2]

_{M 2 / n O · Na 2} O · 2SiO 2 · xH 2 O (M: Ag, Zn)

Such antimicrobial agents include intrinsic chemicals Promicide Z1100, Promicide IZA, BioLock Z100, and the like.

The content of the antimicrobial agent is preferably used in an amount of 0.1 to 5 parts by weight, more preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the inorganic filler. If the amount is less than 0.1 part by weight, the effect is insignificant, and if it is more than 5 parts by weight, the production cost rises, and further excellent effects cannot be achieved, which is not preferable.

The compound composition for manufacturing the breathable film may further include 0.1 to 20 parts by weight of antioxidant and 0.1 to 20 parts by weight of sunscreen, in addition to the inorganic filler, the antimicrobial agent, and the polyolefin resin, in addition to 100 parts by weight of the inorganic filler. The additive used can be used without limitation.

In the present invention, the breathable film has a basis weight of 20 ~ 40 g / ㎡, moisture permeability of 9000 ~ 11000 g / ㎡ · 24hr, tensile strength in the MD direction 1500 ~ 2000 gf / 25mm, tensile strength in the CD direction 300 ~ 400 gf It is preferable to use / 25mm, an elongation in the MD direction of 150 to 190%, an elongation in the CD direction of 200 to 400%, a heat shrinkage of 6 to 10%, and a water resistance of 7.5 to 8.5 kPa.

2) Spunbond Nonwoven Fabric

In the present invention, the spunbond nonwoven fabric uses a spunbond nonwoven fabric made of a filament made of a core made of polyester resin and a sheath made of polyethylene resin. This can be achieved by the polyester-based resin and at the same time, the adhesiveness with the olefin-based resin used in the breathable film can be improved by the polyethylene-based resin surface-coated with the sheath structure, and thus the thermal bonding Since the adhesion was possible even when heated to a low temperature, it was possible to achieve improved adhesion while maintaining breathability.

More preferably, the spunbond nonwoven fabric is made of filament made of polyethylene terephthalate (PET) resin as a core, and is produced by spinning a fiber coated with a sheath structure of polyethylene resin having a melting point of 100 to 150 ° C. on the surface of the core. By using one, not only strength but also adhesiveness and air permeability can be achieved.

The spunbond nonwoven nonwoven fabric has a thickness of 0.1 to 0.5 mm, MD tensile strength of 10 to 25 kg / 5 cm, CD tensile strength of 5 to 15 kg / 5 cm, and MD direction elongation of 40 ~ 80%, CD direction elongation of 40 to 80%, tear strength of 0.1 ~ 1.5 kg is suitable to achieve the final physical properties, examples of such spunbond nonwoven fabric is Japan Unitika ELEVES from (UNITIKA).

3) Manufacturing of mesh reinforcement film

In the present invention, the mesh reinforcing film is a filament made of polyethylene terephthalate (PET) resin as a core, and the filament selected from the filament, polypropylene, polyethylene coated with a polyethylene resin sheath structure on the surface of the core to cross each other Use a woven film that is woven into a mesh shape and then thermocompressed. When using a film woven in such a mesh form has the effect that the strength is further reinforced. In this case, the filament may be manufactured in a plate shape or a circle.

Examples of such mesh reinforcement films include Nisseki Warifu (trademark, Nisseki Jushi Products Co.), Diacloth (trademark, Diatex Co.), Crenet (trademark, Kurare Co.), Sofunet (trademark, Shin-nihon Sofu Co.), HAGIHARA MELTAC series of the company.

4) Preparation of Film Laminate

In the present invention, the spunbond nonwoven fabric is laminated on one or both surfaces of the breathable film, and then heat-sealed by a hot roller or spray-coated with a solvent-free hot melt adhesive.

At this time, the temperature during the heat sealing (heat sealing) is in the range of 80 ~ 150 ℃ by preventing the breathable film is not completely melted, it is preferable to maintain the breathability even after bonding. According to the present invention, a spun bond using a filament coated with a polyethylene resin is applied to a polyester resin, and thus sufficient heat adhesion is possible in the range of 80 to 150 ° C., and thus the breathability of the breathable film can be maintained. The adhesion may be lowered below 80 ° C., and when the temperature exceeds 150 ° C., the breathable film may be completely melt-compressed to reduce breathability.

In addition, the solvent-free hot melt adhesive is any one or more polyolefin resin selected from polyethylene, polypropylene, polybutylene, ethylene-propylene copolymer, propylene-butylene copolymer, ethylene-propylene-butylene terpolymer 50 ~ 60 40 to 50% by weight of any one or more adhesive enhancers selected from weight%, petroleum resin, terpene resin, rosin resin, and at least one softening oil selected from aromatic oil, naphthenic oil, and paraffinic oil. It may be used to include in the 10 ~ 10% by weight. Such solvent-free hot melt adhesives include DM-7035 manufactured by National Starch Co., Ltd. But now it is not limited.

When applying the hot melt adhesive according to the present invention by spray coating method in the form of spots in the breathable film to maintain the oxygen permeability to the maximum, it was possible to improve the adhesion compared to the conventional grid-like adhesive method. In addition, the solvent-free hot melt adhesive is applied by using a spray after melting and heating to 200 ℃ or more, preferably 250 ~ 300 ℃. By spray application, small spot-shaped adhesives are formed on the surface of the breathable film to improve adhesion while not impairing breathability. The spunbonded nonwoven fabric released from the roller is bonded to the surface on which the hot melt adhesive is applied, and is rolled by the roller to be bonded.

According to the present invention, by laminating by the above-described method, it is possible to manufacture a film laminate having excellent air permeability without providing a separate air permeability after lamination.

In the case of using the film laminating agent according to the present invention as a packaging material for grain or feed, it is excellent in antibacterial ability to prevent pests, and excellent preservation of grain as it maintains appropriate moisture due to excellent breathability and moisture permeability. This is possible, and the strength is excellent, there is an advantageous effect when storing or moving.

Through the following examples will be described in more detail the present invention. The following examples are merely examples and are not limited to the examples.

Example 1

Untreated calcium carbonate (made by Omiya, calcium carbonate (A)) with an average particle diameter of 1.7㎛ and Samsung Total Chemical Co., Ltd. have a very wide weight average of the molecular weight distribution produced by extraction by boiling n-hexane A fine pulverized product of an ethylene polymer (ethylene polymer (A)) having a molecular weight of 8,500 and a melt index (190 ° C., 2.16 Kg) of 95 g / 10 min was prepared as a sample. First, calcium carbonate (A) is added to the Henschel mixer, and ethylene-based polymer (A) is gradually added at a compounding ratio of 3 parts by weight of ethylene-based polymer (A) to 100 parts by weight of calcium carbonate (A). After stirring at high temperature for 30 minutes, a sample of calcium carbonate (A) having a structure partially coated with an ethylene polymer (A) was finally obtained.

Linear low density polyethylene (SK Co., Ltd., FT811, polyolefin resin (A) having a melt index (190 ° C., 2.16 Kg) of 2.7 g / 10 min and a density of 0.932 g / cm ³ based on 100 parts by weight of the inorganic filler (I) in the Henschel mixer. )) 100 parts by weight and 2 parts by weight of an antimicrobial agent (Intrinsic Chemical Promicide Z1100) were added, mixed, and injected into a twin screw extruder having a screw diameter of 130 mm, followed by melt extrusion to obtain a compound composition for a breathable film in a pellet state. The obtained compound composition was put into a hopper and the disc sheet was shape | molded using the tee-die molding machine of a screw diameter of 130 mm. The molded disc sheet was uniaxially stretched 2.5 times at a stretching temperature of 70 ° C. to prepare a breathable film having a basis weight of 30 g / m 2.

A spunbonded nonwoven fabric made of a filament coated with a polyethylene sheath having a T _m of 130 ° C. on a breathable film (30 g / m 2) and a polyethylene terephthalate (PET) core thus manufactured (ELEVES, UNITIKA, Japan, 50 g / m 2) ) Was laminated and thermally bonded by passing through a roller preheated at 90 ° C. to produce a film laminate.

Using the film laminate thus prepared, making a 10kg rice bag, and storing the rice while keeping the rice, the presence or absence of worms, odors, changes in the appearance and moisture content of the factors that affect the quality of the rice according to the period Observations of the changes were made to comprehensively evaluate the shelf life of the rice.

[Example 2]

The breathable film was prepared in the same manner as in Example 1, after laminating a mesh reinforcing film woven in a mesh form filament coated with polyethylene sheath of 130 _m T _m on a polyethylene terephthalate (PET) core on one surface of the breathable film The film laminated body was manufactured by heat-sealing through the roller preheated at 90 degreeC.

Using the film laminate thus prepared, making a 10kg rice bag, and storing the rice while keeping the rice, the presence or absence of worms, odors, changes in the appearance and moisture content of the factors that affect the quality of the rice according to the period Observations of the changes were made to comprehensively evaluate the shelf life of the rice.

Comparative Example 1

Except for not using the antimicrobial agent in the Example was prepared in the same manner as in Example 1. Using this film, make a 10kg rice bag and store it in the rice while keeping the rice, the presence of worms, odors, changes in the appearance of the rice and changes in moisture content Was observed to comprehensively evaluate the storage of rice.

Comparative Example 2

Making a 10kg rice bag using a conventionally used area, and storing the rice while keeping it in place, whether there are insects, odors, changes in the appearance of the rice and changes in water content, which are factors that affect the quality of the rice according to the period Was observed to comprehensively evaluate the storage of rice.

Comparative Example 3

Using a general polypropylene film instead of a breathable film, make a 10kg rice bag, and put it in the storage, while the presence of insects, odors, changes in the appearance of the rice and factors affecting the quality of the rice according to the period and The storage of rice was comprehensively evaluated by observing changes in moisture content.

The evaluation results are shown in Table 1 below.

TABLE 1

-The presence or absence of insects: The presence of rice weevil was confirmed by visual inspection and the presence or absence was measured.

-The presence or absence of smell: Ten sensory panels were measured by sensory method to determine whether the smell of deodorant other than the indigenous aroma of rice is smelly.

-Appearance change of rice: Ten sensory panels were measured by 10 panelists to determine whether the color of rice was yellow or broken.

-Moisture content of rice (%): The moisture content of the rice was measured using a grain moisture meter (Jiwon Hi-Tech, GMK-303).

According to the Korea Food Research Institute, the best taste of rice is 16%. As shown in Table 1, the packaging material according to the present invention did not have a large change in moisture content even after 10 weeks, Comparative Examples 1 to 3 did not change significantly until 5 weeks, but the moisture content of 10 weeks after curing It could be seen that it falls sharply, and that bugs occur or smells and colors change.

In addition, the rice packaging material according to the present invention was found to have excellent strength and excellent durability.

Claims (9)

Polyethylene-based resin, (a) 70-95% by weight of an ethylene-based polymer having a weight average molecular weight of 30,000 or less and a melt index (190 ° C, 2.16Kg) of 50g / 10min or more extracted by boiling n-hexane during the production of high-density polyethylene-based resin And (b) a breathable film drawn by melt extrusion of a compound composition for breathable film comprising an inorganic filler and an antimicrobial agent coated on a surface by using a mixture composed of 5 to 30% by weight of saturated fatty acid in a melting point of 40 to 80 ° C., Film laminated body for grain or feed packaging material, characterized in that the spunbond non-woven fabric or mesh reinforcement film laminated on one or both sides of the breathable film by heat sealing by hot roller or sprayed by spraying a solvent-free hot melt Manufacturing method. The method of claim 1, The compound composition for air permeable film is a method for producing a film laminate for grain or feed packaging material, characterized in that it comprises 20 to 250 parts by weight of polyolefin resin, 0.1 to 5 parts by weight of antimicrobial agent with respect to 100 parts by weight of inorganic filler. 3. The method of claim 2, The antimicrobial agent is characterized by using any one or a mixture of two or more selected from a silver-containing zirconium phosphate compound of the formula (1), a silver or zinc-containing zeolite compound of the formula (2), isopropylmethylphenol, or a pyrithione-based compound Method for producing a film laminate for grain or feed packaging material. [Formula 1] Ag _x H _y Zr ₂ (PO ₄ ) ₃ (x + y = 1) [Formula 2] _{M 2 / n O · Na 2} O · 2SiO 2 · xH 2 O (M: Ag, Zn) 3. The method of claim 2, The inorganic filler is calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, calcium chloride, calcium sulfate, aluminum hydroxide, zinc oxide, magnesium hydroxide, titanium oxide, alumina, mica, asbestos The method of manufacturing a film laminate for grain or feed packaging, characterized in that any one or a mixture of two or more selected from powder, zeolite, clay silicate. The method of claim 1, The spunbond nonwoven fabric is a filament made of polyethylene terephthalate (PET) resin as a core, and the film for grain or feed packaging material, characterized in that produced by spinning a fiber coated with a polyethylene resin sheath structure on the surface of the core Method for producing a laminate. The method of claim 1, The mesh reinforcement film has a filament made of polyethylene terephthalate (PET) resin as a core, and a filament coated with a sheath structure of polyethylene resin on the surface of the core to cross a filament selected from polypropylene and polyethylene to form a mesh. A method of manufacturing a film laminate for grain or feed packaging material, characterized in that the fabric type film is squeezed after squeezing. The method of claim 1, Temperature during the heat sealing (heat sealing) is a method of producing a film laminate for grain or feed packaging material, characterized in that the breathability is maintained in the range of 80 ~ 150 ℃. The method of claim 1, The solvent-free hot melt adhesive is 50 to 55% by weight of at least one polyolefin resin selected from polyethylene, polypropylene, polybutylene, ethylene-propylene copolymer, propylene-butylene copolymer, ethylene-propylene-butylene terpolymer 40 to 45% by weight of at least one adhesive enhancer selected from petroleum resin, terpene resin, rosin resin, and at least one softening oil selected from aromatic oil, naphthenic oil, and paraffin oil. Method for producing a film laminate for grain or feed packaging material, characterized in that contained in weight%. It is prepared by the manufacturing method of any one of claims 1 to 8, wherein the polyethylene-based resin, (a) a weight average molecular weight of less than 30,000 produced by extraction with boiling n-hexane when producing a high density polyethylene resin, melt index (190 ° C, 2.16Kg) an inorganic filler coated with a surface using a mixture consisting of 70 to 95% by weight of an ethylene polymer of 50g / 10min or more and (5) 5 to 30% by weight of saturated fatty acid in the melting point of 40 to 80 ° C; Breathable film containing an antimicrobial agent; A film laminate for grain or feed packaging material comprising: a spunbond nonwoven fabric or mesh reinforcement film adhered to one or both surfaces of the breathable film by spray coating of a heat-bonded or solvent-free hot melt adhesive.