KR102559970B1 - Polyolefin based multilayer wrap film - Google Patents

Abstract

The present invention relates to a polyolefin-based multilayer wrap film with excellent transparency, flexibility, adhesiveness, rapid initial anti-fogging, elasticity, drawability (lap unwindability) and packaging suitability, wherein the first skin layer and the second skin layer are both sides of the support layer. The first skin layer and the second skin layer each include an ethylene-based polymer and an antifogging agent, and the support layer includes an ethylene-based polymer, an antifogging agent, and an anti-blocking agent, and the first skin layer and the first 2 The skin layer is a layer having the same or different components, and the antifogging agent used in each layer is different, and in the case where the first skin layer and the second skin layer are different layers, the components included in each layer are the same and the composition ratio is the same. This different polyolefin-based wrap film is provided.

Description

Polyolefin-based multilayer wrap film {POLYOLEFIN BASED MULTILAYER WRAP FILM}

The present invention relates to a polyolefin-based multilayer wrap film, and more particularly, to a polyolefin-based multilayer wrap film having excellent transparency, flexibility, adhesiveness, initial anti-fogging properties, elasticity, drawability (lap unwindability), and packaging suitability.

The physical properties of wrap film used as a packaging material used for preservation and cooking of food include adhesion during packaging, tensile strength and elongation that allows the film to stretch well, transparency, glossiness, and ability to unwind the film in a rolled state from a roll. Easy roll unwindability and the like are required.

Previously, polyvinyl chloride (hereinafter referred to as 'PVC') wrap film was used for food packaging such as livestock/frozen food, marine products, and delivery food due to its low price and excellent packaging aptitude, but environmental hormones when discarded/incinerated after use In addition to the generation of harmful gases and PVC in the recycling process, the problem of increasing processing costs continues to occur, so alternative wrap film products are being developed so far.

As the alternative wrap film product, for example, a wrap composed of polyethylene-based resin blended with triglyceride having a melting point of 10 ° C or less in order to provide a packaging wrap film composed of polyethylene-based resin that satisfies adhesion, drawability and cutability. film was developed.

However, the packaging wrap film had poor adhesion and mechanical properties compared to PVC-made wraps, and also had poor packaging properties, including packaging appearance and packaging retention, due to lack of rigidity and elasticity of the film.

Therefore, when discarding/incinerating after use, environmental hormones and harmful gases are not generated, and transparency, flexibility, adhesiveness, rapid initial anti-fogging, elasticity, draw-out (lap release) and packaging show correlation or trade-off relationships with each other. There is an urgent need to develop a wrap film for packaging with excellent aptitude.

Korean Patent Registration No. 10-0592087

The present invention is to solve the problems of the prior art, and is harmless to the human body and environmentally friendly, as well as polyolefin having excellent transparency, flexibility, adhesiveness, rapid initial anti-fogging, elasticity, drawability (wrapping ability) and packaging suitability. It is an object of the present invention to provide a multilayer wrap film.

Specifically, the present invention solves the problem of environmental hormones and dioxins in PVC wraps by manufacturing multi-layer packaging wrap films harmless to the human body based on ethylene-based polymers, and solves the problems of single-layer wrap films, resulting in transparency, flexibility, adhesiveness, and rapid initial It is an object of the present invention to provide a polyolefin-based multilayer wrap film excellent in anti-fogging properties, stretchability, drawability (lap unwindability) and packaging suitability.

The above and other objects of the present invention can all be achieved by the present invention described below.

In order to achieve the above object, the present invention

A wrap film in which a first skin layer and a second skin layer are laminated on both sides of a support layer,

The first skin layer and the second skin layer each include an ethylene-based polymer and an antifogging agent,

The support layer includes an ethylene-based polymer, an antifogging agent and an antiblocking agent,

The antifogging agents included in the first skin layer and the second skin layer are polyhydric alcohol fatty acid ester antifogging agents, respectively.

The antifogging agent included in the support layer provides a polyolefin-based wrap film, characterized in that at least one selected from polyhydric alcohol fatty acid ester antifogging agents and non-alcoholic saturated fatty acid ester antifogging agents.

The ethylene-based polymers included in the first skin layer, the second skin layer, and the support layer are independently ethylene alpha-olefin polymers, ethylene polymers using metallocene catalysts, low-density ethylene polymers, linear low-density ethylene polymers, and medium-density ethylene polymers. And it may be at least one selected from ultra-low density ethylene polymers.

The ethylene-based polymer may be composed of a metallocene catalyst-using ethylene polymer and a low-density ethylene polymer in a weight ratio of 0.1:99.9 to 99.9:0.1.

The polyhydric alcohol fatty acid ester antifogging agent may be independently a compound represented by Formula 1 below.

[Formula 1]

(In Formula 1, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R _{8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen or 1 carbon atom to 5 alkyl groups, natural oil-derived substituents or C ₆ -C ₂₂ fatty acid-derived substituents, or including them, of which at least 3 or more are hydrogen.)

The polyhydric alcohol fatty acid ester antifogging agent may be included in an amount of 0.1% by weight or more in 100% by weight of the total amount of components constituting each layer.

The polyhydric alcohol fatty acid ester antifogging agent may have a melting point of 10°C or less.

The non-alcoholic saturated fatty acid ester antifogging agent may be included in an amount of 5% by weight or less in 100% by weight of the total amount of components constituting the layer.

The antiblocking agent may contain one or more selected from among aluminophosphate, aluminosilicate, glycerin monostearate, and oleic acid amide in an amount of 5% by weight or less based on 100% by weight of the total components constituting the support layer.

If the laminate thickness (unit μm) of the first skin layer is a, the laminate thickness (unit μm) of the support layer is b, and the laminate thickness (unit μm) of the second skin layer is c, b≥ (a+c), 3c≥a≥(1/3)c, and the sum of a, b, and c may satisfy a relationship of 5 to 30.

The polyolefin-based wrap film has a tensile strength MD of 3 to 10 kgf / mm ² and a tensile strength TD of 1 to 5 kgf / mm ² measured according to ASTM D 882, and UTM (Instron's 4443 ) may have a tensile elongation MD of 200 to 1000% and a tensile elongation TD of 200 to 1000%.

The multilayer wrap film for packaging according to the present invention has excellent transparency, flexibility, adhesiveness, rapid initial anti-fogging properties, elasticity, drawability (wrapping ability) and packaging suitability.

1 is a view schematically showing a laminated structure of a multilayer wrap film according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail to aid understanding of the present invention.

Terms or words used in this specification and claims should not be construed as being limited to their usual or dictionary meanings, and given that the inventors may appropriately define the concept of terms in order to best describe the invention. Therefore, it should be interpreted as meaning and concept consistent with the technical spirit of the present invention.

The term "ethylene polymer using a metallocene catalyst" in this description refers to an ethylene polymer prepared using a metallocene catalyst unless otherwise specified.

The present inventors found that the outer layer of the wrap film (hereinafter referred to as 'skin layer') is laminated on both sides of the support layer, and the support layer and the outer layer each contain an ethylene-based polymer and an anti-fog agent, and the anti-fog agent included in the outer layer, respectively It is a polyhydric alcohol fatty acid ester antifogging agent, and the antifogging agent included in the support layer is polyalcohol fatty acid ester antifogging agent and non-alcohol saturated fatty acid ester antifogging agent, when at least one selected from the group consisting of, improved transparency, flexibility, tackiness, and rapid initial After confirming that it provides anti-fogging properties, elasticity, drawability (lap unwindability) and packaging suitability, the present invention was completed by further research.

According to one embodiment of the present invention, a wrap film having a multilayer structure composed of a first skin layer-support layer-second skin layer is provided by using a polyethylene-based polymer as a first essential component and an antifogging agent as a second essential component.

Hereinafter, a wrap film having a multilayer structure according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 is a view schematically showing a laminated structure of a multi-layer wrap film according to an embodiment of the present invention, and the wrap film 1 includes a first skin layer 10 and a second skin on both sides of a support layer 30 A structure in which layers 50 are stacked is provided.

Here, the first skin layer 10 and the second skin layer 50 are outer layers of the wrap film 1 and may be layers having the same or different thicknesses, components, and/or composition ratios, and in the case of different layers, each layer is preferably Layers may differ only in composition ratios of included components.

The first skin layer 10 and the second skin layer 50 may include a first essential component, a second essential component, and a third essential component.

Meanwhile, the support layer 30 is a middle layer of the wrap film 1 and may include a first essential component and a second essential component.

In one embodiment of the present invention, the first essential component, which is a basic component included in the first skin layer 10, the support layer 30, and the second skin layer 50, respectively, is an ethylene-based thermoplastic resin that does not generate dioxins. polymers can be used.

As the ethylene-based polymer, at least one selected from among ethylene-based alpha-olefin polymers, metallocene catalyst-using ethylene polymers, low-density ethylene polymers, linear low-density ethylene polymers, medium-density ethylene polymers, and high-density ethylene polymers may be used for each layer. .

The ethylene polymer using a metallocene catalyst may be low molecular weight crystalline polyethylene obtained by polymerizing ethylene using a metallocene catalyst.

The linear low-density ethylene polymer may be a copolymer of ethylene and an alpha-olefin having 3 to 20 carbon atoms, wherein the alpha-olefin may be at least one selected from the group consisting of 1-butene, 1-hexene, and 1-octene. there is.

The linear low-density ethylene polymer may have, for example, a density of about 0.850 to 0.940 g/cm ³ and a melt index of about 0.01 to 100 g per 10 minutes as measured by ASTM 1238, Condition I.

The low-density ethylene polymer is not specified as long as it is an ethylene-based polymer known in the art, and has a density of, for example, 0.910 to 0.930 g/cm ³ as measured by ASTM D-792.

The medium-density ethylene polymer is not specified as long as it is an ethylene-based polymer known in the art, and has a density of, for example, 0.925 to 0.940 g/cm ³ as measured by ASTM D-792.

The high-density ethylene polymer is not specified as long as it is an ethylene-based polymer known in the art, and has a density of, for example, 0.941 to 0.965 g/cm ³ as measured by ASTM D-792.

Each of the metallocene-catalyzed ethylene polymer, low density ethylene polymer, linear low density ethylene polymer, medium density ethylene polymer and high density ethylene polymer may be a homopolymer or a homopolymer.

As a specific example, the ethylene-based polymer may be preferably at least one selected from metallocene catalyst-derived polyethylene and linear low-density polyethylene.

The ethylene-based polymer may include polyethylene using a metallocene catalyst and linear low-density polyethylene at a weight ratio of, for example, 0.1:99.9 to 99.9:0.1, preferably 5:95 to 95:5, in this case It is possible to provide a fracture reduction effect by improving the mechanical properties that were reduced when linear low-density polyethylene was used alone.

As the ethylene-based polymer, a commercially available material may be used as long as it conforms to the definition of the present description.

As an example, examples of linear low-density polyethylene (m-LLDPE) using a metallocene catalyst include product name M1835HN (manufacturer Hanwha Solutions), product name XP3400 (manufacturer Daelim), and the like.

In addition, examples of linear low-density polyethylene (LLDPE) include product name 3325W (manufacturer Hanwha Solutions), product name UN324 (manufacturer Lotte Chemical), and the like.

In addition, low-density polyethylene (LDPE) includes product name 620L (manufacturer Hanwha Total), product name BF415E (manufacturer LG Chem), and the like.

Meanwhile, the ethylene-based polymer, which is the first essential component, has excellent mechanical strength, elongation, elastic modulus, and heat resistance, but may have poor flexibility, transparency, and rapid anti-fogging effect, and may have a high processing temperature. Therefore, in the present invention, an antifogging agent is used as the second essential component to quickly prevent fogging and maintain transparency of the surface of the wrap film. In this case, mechanical strength, elongation, modulus of elasticity, heat resistance, flexibility, transparency, and rapid anti-fogging effect are all excellent, and the advantages of low processing temperature arise.

In the present invention, the antifogging agent may be composed of different compositions for each layer in consideration of the role of the corresponding layer.

For example, the antifogging agent included in the first skin layer and the second skin layer may be a polyhydric alcohol fatty acid ester antifogging agent, respectively, and the antifogging agent included in the support layer is a polyhydric alcohol fatty acid ester antifogging agent and a non-alcoholic saturated fatty acid ester. At least one selected from antifogging agents may be used.

The polyhydric alcohol fatty acid ester antifogging agent may include, for example, a fatty acid ester compound obtained by reacting polyglycerol with natural oil or C ₆ -C ₂₂ fatty acid.

The polyhydric alcohol fatty acid ester antifogging agent may be, for example, a compound represented by Formula 1 below.

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R _{8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen, 1 to 10 carbon atoms 5 alkyl groups, natural oil-derived substituents, or C ₆ -C ₂₂ fatty acid-derived substituents, or including them, of which at least 3 or more are hydrogen.

In addition, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R _{7 , R 8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen or 1 to 5 carbon atoms. It is or contains an alkyl group, of which at least three or more are hydrogen.

In addition, all of R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R _{8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ may be hydrogen.

The polyhydric alcohol fatty acid ester antifogging agent may have, for example, a melting point of 10° C. or less, preferably a melting point of -50° C. to 10° C.

At this time, the melting point can be measured using various methods used in the field related to the present invention, for example, using a Differential Scanning Calorimeter (DSC, device name: DSC 2920, manufacturer: TA instrument). . Specifically, the melting point was heated to 200 ° C, maintained at that temperature for 5 minutes, cooled to -60 ° C, and then increased again. It can be measured by adjusting to °C.

The polyhydric alcohol fatty acid ester antifogging agent may have an acid value of 1 to 3, for example. If it is out of the above range, for example, if the acid value is high, it may cause a peculiar odor or adversely affect physical properties.

At this time, the acid value is the number of mg of KOH required to neutralize free fatty acids present in 1 g of the antifogging agent, and can be measured using a method commonly used in the art to which the present invention belongs. It can be measured by a titration method in which an antifogging agent is added to the mixed solution, stirred, and then a 1% phenolphthalein indicator is dropped into the mixed solution to observe the color change.

In addition, the polyhydric alcohol fatty acid ester antifogging agent may have a saponification value of 140 to 160, for example.

At this time, the saponification value is the number of mg of KOH required to saponify 1 g of the antifogging agent, and can be measured using a method commonly used in the art to which the present invention belongs. After heating for minutes, it can be measured by recovering and cooling, dropping 2 to 3 drops of phenolphthalein, and then titrating with 0.5 N/HCl.

In addition, the polyhydric alcohol fatty acid ester antifogging agent may have an iodine value of 30 to 55, for example.

At this time, the iodine value may mean the number of grams of iodine for halogen absorbed in 100 g of fat or oil sample, and if the total number of unsaturated double bonds present in fat or oil, which is a field related to the present invention, can be measured, it is not specified. As a specific example, 0.5 g of sample is put in a flask, mixed with CCl ₄ , stirred, left in the dark for 1 hour, 10% KI aqueous solution added, titrated with 0.1N-Na ₂ S ₂ O ₃ can be measured

In addition, the polyhydric alcohol fatty acid ester antifogging agent may have a moisture content of 0 to 1.5% by weight. If it is out of the above range, for example, when the water content is high, bubbles may be generated during film molding.

At this time, the moisture content can also be measured using various methods commonly used in the art to which the present invention belongs. As a specific example, a Moisture Analyzer (Dupont 903) that automatically measures moisture using the Karl-Fisher method or electrical characteristics of water can be measured using this method.

The polyhydric alcohol fatty acid ester antifogging agent is not particularly limited as long as the above definition is satisfied, and polyglycerol monooleate, polyglycerol monopalmitate, or a mixture thereof may be preferably used. In addition, as long as the definition of the present invention is followed, the polyhydric alcohol fatty acid ester antifogging agent may be used as a commercially available material.

The polyhydric alcohol fatty acid ester antifogging agent is, for example, 0.1% by weight or more, preferably 0.2 to 5% by weight, more preferably 0.2 to 3% by weight for each layer in 100% by weight of the total amount of components constituting each layer. can be included When the above-described range is satisfied, there is no concern that the antifogging agent is transferred to the surface while effectively providing rapid initial antifogging property and continuously permeates from the surface of the wrap film to reduce transparency.

The non-alcoholic saturated fatty acid ester antifogging agent may be, for example, a compound represented by Formula 2 below having a melting point of 10°C or less.

[Formula 2]

In Formula 2, R, R' and R" may be independently selected from C ₇ H ₁₅ , C ₉ H ₁₉ or C ₄ H ₈ CH (C ₂ H ₅ ).

As a specific example, all of R, R' and R" may be C ₇ H ₁₅ .

The non-alcoholic saturated fatty acid ester antifogging agent is, for example, 5% by weight or less, preferably 3% by weight or less, and most preferably 0.1 to 2.0% by weight for each layer out of 100% by weight of the total amount of components constituting the layer. In particular, when used in combination with the above-mentioned polyalcohol fatty acid ester antifogging agent, the synergistic effect of good adhesion, tensile strength and elongation, and antifogging effect up to the initial 24 hours can be maximized.

In addition, according to one embodiment of the present invention, an antiblocking agent may be included in the support layer as a third essential component.

The antiblocking agent may be, for example, at least one selected from aluminophosphate, aluminosilicate, glycerin monostearate, and oleic acid amide.

The antiblocking agent may preferably be a molecular sieve, and more preferably may be a zeolite.

In the present disclosure, molecular sieve means a solid material having pores of a certain size, and as a specific example, may be a solid material having pores of 1 to 10 Å. Here, the size of the pores may be measured by a measurement method commonly used in the art to which the present invention belongs.

The antiblocking agent may be a commercially available product as long as it conforms to the definition of the present disclosure, and for example, product name AB0040 (manufacturer Mantec) and the like.

The antiblocking agent may be included in an amount of, for example, 5% by weight or less, preferably 0.1 to 5% by weight, and more preferably 1 to 5% by weight, based on the total sum of components constituting the support layer. If the above range is satisfied, an excellent anti-blocking effect may be provided while balancing other physical properties.

Furthermore, the wrap film for packaging may be formulated with a polymer for sealing, which requires adhesion at a low temperature during use.

The sealing polymer is, for example, an ethylene vinyl acetate copolymer having a vinyl acetate content of 10 to 30% by weight, 10% by weight or more, preferably 10 to 30% by weight, based on 100% by weight of the total components constituting each layer. It is preferable to lower the processing temperature. Alternatively, an ethylene vinyl acetate copolymer (EVA) with linear low density polyethylene or the like can be directly fed into the extruder.

The ethylene vinyl acetate copolymer (EVA) can be replaced with low density polyethylene (LDPE), but in this case, the sealing temperature is not as low as that of the ethylene vinyl acetate copolymer (EVA), but the odor can be improved before and after film production. can provide.

In addition, in the present invention, petroleum resin, rosin, terpene resin, coumaron resin, coumaron indene resin and derivatives thereof are used in the first skin layer 10, the second skin layer 50, and the support layer 30 as necessary. Each may include one or more adhesive resins selected from among.

In the present description, a derivative of a compound or resin means a compound in which one or more hydrogen atoms or atomic groups of the compound or resin are substituted with an alkyl group of 1 to 10 carbon atoms, an aryl group of 6 to 15 carbon atoms, or a halogen group.

As the petroleum resin, aromatic petroleum resins, aliphatic petroleum resins, and alicyclic petroleum resins may be used, and commercially available products such as the Highlets series, Petrogen series, Arkon series, Clearlon series, Imab series, and Escorts series may be used. .

By blending these adhesive resins, the adhesiveness of the wrap film can be further improved, and the amount used is, for example, 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the ethylenic polymer, which is the first essential component. can be included with If the above-mentioned range is satisfied, there is a desirable advantage of adhesion and drawability (lap unwindability).

The wrap film according to one embodiment of the present invention provides a wrap film for packaging having a multi-layer structure.

In particular, by not using a processing temperature reducing agent in the support layer 30 constituting the wrap film according to another embodiment of the present invention, the deterioration of mechanical properties caused by the increased content of the processing temperature reducing agent is prevented and the mechanical properties as a whole are prevented. Provided is a wrap film having improved packaging suitability by maintaining optimal strength. Such a wrap film can be suitably used for general purposes, such as food packaging.

In addition, antibacterial agents applicable for food use may be included.

The total layer thickness constituting the wrap film of the present invention is, for example, 5 to 40 μm, preferably 8 to 20 μm, more preferably 9 to 15 μm, still more preferably 10 to 12 μm.

The thickness ratio of each layer constituting the wrap film can be configured in various ratios, but the laminated thickness (unit μm) of the first skin layer is a, the laminated thickness (unit μm) of the support layer is b, and the If c is the laminate thickness (unit μm) of the two skin layers, b≥(a+c), 3c≥a≥(1/3)c, and the sum of a, b, and c is 5 to 30. Satisfaction is desirable in terms of process stability.

In a preferred embodiment of the present invention, the first skin layer 10 and the second skin layer 50 each use 5 to 95% by weight of the first essential component linear low density polyethylene and the second essential component metallocene catalyst. 10 to 90% by weight of linear low-density polyethylene, 0.2 to 3% by weight of polyhydric alcohol fatty acid ester antifogging agent, 0.1 to 0.5% by weight of non-alcoholic fatty acid ester antifogging agent, 1 to 5% by weight of adhesive resin, and 0.1 to 3% by weight of the anti-blocking agent Within this range, transparency, heat resistance, flexibility, adhesiveness, rapid initial antifogging, cutability, and mechanical properties, which are characteristics of the wrap film, are all excellent.

In a more preferred embodiment of the present invention, as the first essential component contained in the first skin layer 10 and the second skin layer 50, respectively, 10 to 80% by weight of an ethylene polymer using a metallocene catalyst and a linear low density Ethylene polymers may be used by mixing 90 to 20% by weight. In this case, the weight % is based on the total amount of the first essential component included in the first skin layer 10 and the second skin layer 50.

In a more preferred embodiment of the present invention, the polyhydric alcohol fatty acid ester antifogging agent as the second essential component included in the first skin layer 10 and the second skin layer 50, respectively, has a structure represented by the following formula (1) that can be used

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R _{8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen, 1 to 10 carbon atoms 5 alkyl groups, natural oil-derived substituents, or C ₆ -C ₂₂ fatty acid-derived substituents, or including them, of which at least 3 or more are hydrogen.

On the other hand, in a preferred embodiment of the present invention, it was found that the support layer 30 is a layer that affects the physical properties of the surface although it is inside. Therefore, the support layer 30 contains 5 to 95% by weight of the first essential component, 0.1 to 3.0% by weight of the second essential component, 0.1 to 0.5% by weight of the non-alcoholic fatty acid ester antifogging agent, 1 to 3% by weight of the adhesive resin, and 0.1% by weight of the antiblocking agent. to 3% by weight, and within this range, transparency, heat resistance, flexibility, adhesiveness, rapid initial antifogging, cutability, and mechanical properties, which are characteristics of the wrap film, are all excellent.

The ethylene-based polymer may preferably include 20 to 90% by weight of the ethylene polymer using a metallocene catalyst and 10 to 80% by weight of the low-density ethylene polymer. At this time, the weight % is based on the total amount of the first essential component included in the support layer 30.

Furthermore, as a second essential component included in the support layer 30, a polyhydric alcohol fatty acid ester antifogging agent having a structure represented by the following formula (1) may be used as an example, and the non-alcoholic saturated fatty acid ester antifogging agent may be represented by the following formula (2) as an example. structure can be used.

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R _{8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen, 1 to 10 carbon atoms 5 alkyl groups, natural oil-derived substituents, or C ₆ -C ₂₂ fatty acid-derived substituents, or including them, of which at least 3 or more are hydrogen.

[Formula 2]

In Formula 2, R, R' and R" may be independently selected from C ₇ H ₁₅ , C ₉ H ₁₉ or C ₄ H ₈ CH (C ₂ H ₅ ).

The wrap film according to one embodiment of the present invention has an adhesiveness of 8 to 13 N, preferably 11 to 13 N, more preferably 12 to 13 N.

The wrap film according to one embodiment of the present invention has a tensile strength MD measured using UTM (Instron's 4443) in accordance with ASTM D 882 of 5 to 8 kgf/mm ² , preferably 5.2 to 8 kgf/mm. ² , more preferably 5.8 to 6.7 kgf/mm ² .

The wrap film according to one embodiment of the present invention has a tensile strength TD of 2 to 5 kgf/mm ² , and preferably 2.5 to 5 kgf/mm, as measured using UTM (Instron's 4443) in accordance with ASTM D 882. ² , more preferably 2.8 to 3.1 kgf/mm ² .

The wrap film according to one embodiment of the present invention has a tensile elongation MD of 450 to 600%, preferably 480 to 600%, more preferably is between 490 and 510%.

The wrap film according to one embodiment of the present invention has a tensile elongation TD of 800 to 1.000%, preferably 840 to 1,000%, more preferably is between 880 and 950%.

In addition, the wrap film according to one embodiment of the present invention has a degree of elasticity required for packaging work.

The wrap film according to one embodiment of the present invention may be manufactured using a conventional method such as a blowing method and a T-die molding method, but is not limited thereto.

The above-mentioned composition is separately supplied to an extruder at a predetermined ratio, or each component is mixed in advance to prepare a composition, and then supplied to several extruders, mixed and melted, and then passed through a die block to form a sheet composed of several layers in a die. Films can be made with the following target thicknesses.

Furthermore, when manufacturing the film according to the present invention as described above, in the case of using the blowing method, cooling is performed by blowing cold air, and in the case of using the T-die molding method, it is formed into a thin film using a cooling roll or mechanical strength is improved. stretch to increase

The heating temperature in the extruder is, for example, 200 to 300 ° C., and various layer ratios of the multilayer film can be achieved by adjusting the discharged amount with the number of revolutions of the extruder.

In describing the multilayer wrap film of the present disclosure, it is stated that other conditions or equipment not explicitly described may be appropriately selected within the range commonly practiced in the art and are not particularly limited.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

[Example]

Materials used in the following examples and comparative examples are as follows.

(A) ethylene-based polymer

(A-1) Linear Low Density Polyethylene (LLDPE): 3325W from Hanwha Solutions

(A-2) Linear low-density polyethylene (m-LLDPE) using metallocene catalyst: M1835HN manufactured by Hanwha Solutions

(A-3) Low Density Polyethylene (LDPE): 620L manufactured by Hanwha Total

(B) anti-fogging agent

(B-1) has a structure represented by Formula 1 below, wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R _{8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are Polyhydric alcohol fatty acid esters with all hydrogen and a melting point of 10°C or less

[Formula 1]

(B-2) Non-alcoholic saturated fatty acid ester having a structure represented by the following formula (2), wherein all of R are C ₇ H ₁₅ and a melting point of 10°C or less

[Formula 2]

(B-3) glycerol monooleate (melting point 36 to 40 ° C)

(C) Anti-blocking agent: Mantec's product name AB0040

Examples 1 to 2, Comparative Examples 1 to 7

As the first skin layer 10 and the second skin layer 50 according to the present invention, the ingredients and contents listed in Table 1 were respectively put into two extruders out of three extruders.

As the support layer 30 according to the present invention, the ingredients and contents listed in Table 2 are put into the remaining extruder, and the first skin layer 10: the support layer 30: the second skin layer 50 is formed through a die. A wrap film sequentially laminated in three layers was prepared.

division First and second skin layers Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 stratification 2:7:2 2:7:2 0:11:0 2:7:2 2:7:2 4:3:4 1:6:4 2:7:2 2:7:2 (a-1) LLDPE (wt%) 90.5 87.9 96.0 80.0 90.5 90.5 90.5 85.7 90.5 (a-2) m-PE (wt%) 8.5 9.0 - 19.0 8.5 8.5 8.5 11.0 8.5 (b-1) A9280 (wt%) 1.0 0.8 - 1.0 1.0 1.0 1.0 0.8 1.0 (b-2) Panacet (wt%) - - 3.0 - - - - 0.5 - (C) Arkon (wt%) - 2.3 1.0 - - - - 2.0 -

(In Table 1, the layer composition is the thickness of the first skin layer:support layer:second skin layer, and the unit is μm.)

division support layer Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 stratification 2:7:2 2:7:2 0:11:0 2:7:2 2:7:2 4:3:4 1:6:4 2:7:2 2:7:2 (a-1) LLDPE (wt%) 49.0 48.9 96.0 49.0 80.0 49.0 49.0 47.0 49.2 (a-2) m-PE (wt%) 48.0 48.0 - 48.0 17.0 48.0 48.0 49.7 48.5 (b-1) A9280 (wt%) 0.8 0.8 - 0.8 0.8 0.8 0.8 0.8 - (b-2) Panacet (wt%) 0.2 - 3.0 0.2 0.2 0.2 0.2 0.5 - (C) Arkon (wt%) 2.0 2.3 1.0 2.0 2.0 2.0 2.0 2.0 2.3

(In Table 2, the layer composition is the thickness of the first skin layer:support layer:second skin layer, and the unit is μm.)

[Test Example]

Mechanical strength (tensile strength, elongation), adhesion, initial antifogging, haze, and drawout (roll unwinding) of the wrap film specimens prepared in Examples 1 to 2 and Comparative Examples 1 to 7, respectively. was measured by the following method, and the results are shown in Table 3 below.

* Adhesion: A 4.5-pound wrap film was adhered to the specimen with a roller, and adhesion was evaluated using UTM (Instron's 4443) (unit N).

* Mechanical strength (tensile strength, elongation): Measured in accordance with ASTM D 882, and measured using UTM (Instron's 4443) for tensile strength (unit kgf/mm ² ) and tensile elongation (unit %) respectively did At this time, the higher the tensile strength, the higher the maximum strength when the film is broken, and the higher the value, the better the elongation and the better stretching of the film.

* Initial anti-fog property: The anti-fog function was evaluated at 5 minutes, 20 minutes, 4 hours, 8 hours, and 24 hours from immediately after the production of the anti-fog evaluation specimen (initial).

The antifogging property was visually observed on the surface of the sample and evaluated as follows.

◎: Completely transparent, no water droplets.

○: Transparency is relatively good, and a small amount of uneven large water droplets are present.

□ : It is basically transparent and contains many water droplets.

△: It is translucent and has many small water droplets.

x: Completely opaque and completely invisible.

* Haze: measured using toyoseiki's haze meter 2130 in accordance with KS M ISO 14782 and ASTM D1003.

* Pull-out: Pull-out workability was evaluated while performing roll unwinding. Specifically, evaluation tests were performed according to the following evaluation criteria using the following test equipment and test methods.

▷ Test equipment

- Device: A UTM device that can move at a constant speed and the breaking load of the test piece is in the range of 15 to 85% of the measuring capacity.

▷ Test method

- Samples were taken at random points 10 cm or more away from each edge.

- Prepare 5 1.5 cm X 21 cm 3 layers of collected samples. The surface condition of the sample was checked, and if there were any scratches or burrs, it was remanufactured.

- After separating one end of the sample into one layer and the other end into two layers, taking care not to damage the center of the sample, attach it to the grip of the test device, and then conduct the test.

▷ Evaluation Criteria

Excellent: 0.03N or less, when there is no defect in roll unwinding, Good: More than 0.03N and 0.06N or less, when roll unwinding is sometimes poor but the drawing operation is not difficult, Bad: More than 0.06N, roll unwinding is difficult and unwinding is difficult If you have problems with your work.

division wrap film Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 adhesiveness 12.8 11.2 10.2 9.9 12.5 11.1 8.5 8.8 12.5 Tensile strength (MD/TD) 5.8/
2.8 6.6/
3.1 4.1/
2.4 5.9/
2.9 4.9/
2.4 4.4/
2.3 4.1/
2.1 5.2/
2.5 5.4/
3.0 Elongation (MD/TD) 510/
950 490/
880 360/
650 490/
900 540/
970 520/
970 450/
790 480/
840 500/
890 Drawability (unrolling) Great Good Great Great Great Great Great Great Great anti-fog_initial ◎ ◎ ◎ ◎ ◎ ◎ □ ○ ○ Anti-fog_5 minutes ◎ ◎ ◎ ◎ ◎ ◎ □ ○ □ Anti-fog_20 minutes ◎ ◎ ◎ ◎ ◎ ◎ ○ ○ □ Anti-fog_4 hours ◎ ◎ ◎ ◎ ◎ ○ ○ ○ △ Anti-fog_8 hours ◎ ◎ ◎ ◎ ◎ ○ ○ ○ △ Anti-fog_24 hours ◎ ◎ ○ ◎ ◎ ○ □ ○ △ Cloudiness 1.25 1.13 1.67 1.15 1.31 1.35 1.20 0.87 1.29

As shown in Table 1, in Example 1 of the present invention, the first skin layer and the second skin layer are composed of 90.5% by weight of LLDPE, 8.5% by weight of m-LLDPE, and 1.0% by weight of A-9280, and the support layer is 49.0% by weight of LLDPE. A multilayer wrap film composed of 48.0 wt% m-LLDPE, 0.8 wt% A-9280, 0.2 wt% Panacet, and 2.0 wt% Arkon P-125 is provided.

As can be seen in Table 3, the multilayer wrap film according to Example 1 of the present invention was found to be superior in overall physical properties such as tensile strength, elongation, haze, and adhesiveness compared to Comparative Example 1 composed of a single-layer wrap film.

In addition, when compared to Comparative Example 2 in which the raw material ratio of the first skin layer and the second skin layer was changed, the multilayer wrap film according to Example 1 of the present invention had excellent adhesive strength, and the comparative example in which the raw material ratio of the support layer was changed When compared to 3, the multilayer wrap film according to Example 1 of the present invention was found to have excellent tensile strength.

In addition, when compared to Comparative Example 4 in which the thickness of the first skin layer and the second skin layer were designed to be thicker than the thickness of the support layer, the multilayer wrap film according to Example 1 of the present invention had excellent tensile strength, and the first skin layer Comparative Example 5, in which the thickness of the skin layer and the second skin layer were extremely differently adjusted, had poor overall physical properties compared to Example 1, and the thickness of either side of the multi-layer wrap film was too thin, resulting in severe curling of the film before and after winding. Confirmed.

In addition, as shown in Table 2, in Example 2 of the present invention, the first skin layer and the second skin layer are 87.9% by weight of LLDPE, 9.0% by weight of m-LLDPE, 0.8% by weight of A-9280 and 2.3% by weight of Arkon P-125. It is composed of % by weight, and the support layer provides a multilayer wrap film composed of 48.9% by weight of LLDPE, 48.0% by weight of m-LLDPE, 0.8% by weight of A-9280, and 2.3% by weight of Arkon P-125.

That is, as can be seen in Table 3, the multilayer wrap film according to the above-described Example 2 has adhesive strength and The antifogging function was found to be excellent.

In addition, it can be seen that the antifogging function and tensile strength in the MD direction are excellent compared to Comparative Example 7 in which the antifogging agent of the structure (B-1) is not prescribed in the support layer.

In conclusion, the first skin layer and the second skin layer are laminated on both sides of the support layer, the first skin layer and the second skin layer each contain an ethylene-based polymer and an anti-fog agent, and the support layer is an ethylene-based polymer, an anti-fog agent and an anti-blocking agent, wherein the first skin layer and the second skin layer are layers having the same or different components, the antifogging agents used in each layer are different, and the first skin layer and the second skin layer are different. In the case of these different layers, if the components included in each layer are the same and the composition ratio is different, the material has excellent initial anti-fogging properties and packaging suitability while securing basic physical properties such as transparency, flexibility, adhesiveness, elasticity and drawability (lap unwindability) It was confirmed that it was suitable for a polyolefin-based multilayer wrap film by providing a.

1: polyolefin wrap film
50: second skin layer
30: support layer
10: first skin layer

Claims (9)

A wrap film in which a first skin layer and a second skin layer are laminated on both sides of a support layer,
The first skin layer and the second skin layer each include an ethylene-based polymer and an antifogging agent,
The support layer includes an ethylene-based polymer, an antifogging agent and an antiblocking agent,
The antifogging agents included in the first skin layer and the second skin layer are polyhydric alcohol fatty acid ester antifogging agents, respectively.
The antifogging agent included in the support layer uses at least one selected from polyhydric alcohol fatty acid ester antifogging agents and non-alcohol saturated fatty acid ester antifogging agents,
The ethylene-based polymer included in the first skin layer, the second skin layer, and the support layer is a mixture of a metallocene catalyst-derived ethylene homopolymer and a low-density ethylene homopolymer in a weight ratio of 0.1:99.9 to 99.9:0.1, respectively. ,
Characterized in that the tensile elongation TD measured using UTM (Instron's 4443) in accordance with ASTM D 882 is 880 to 950%
Polyolefin-based wrap film. delete delete According to claim 1,
The polyhydric alcohol fatty acid ester antifogging agent includes a compound represented by Formula 1 below, characterized in that it is included in 0.1% by weight or more in 100% by weight of the total amount of components constituting each layer
Polyolefin-based wrap film.
[Formula 1]

(In Formula 1, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R _{8 ,} R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen or 1 carbon atom to 5 alkyl groups, natural oil-derived substituents or C ₆ -C ₂₂ fatty acid-derived substituents, or including them, of which at least 3 or more are hydrogen.) According to claim 1,
The polyhydric alcohol fatty acid ester antifogging agent is characterized in that the melting point is 10 ℃ or less
Polyolefin-based wrap film. According to claim 1,
The non-alcoholic saturated fatty acid ester antifogging agent is characterized in that it is included in 0.1 to 0.5% by weight in 100% by weight of the total amount of components constituting the layer
Polyolefin-based wrap film. According to claim 1,
The antiblocking agent is characterized in that at least one selected from aluminophosphate, aluminosilicate, glycerin monostearate and oleic acid amide is included in 5% by weight or less in 100% by weight of the total amount of components constituting the support layer
Polyolefin-based wrap film. According to claim 1,
If the laminate thickness (unit μm) of the first skin layer is a, the laminate thickness (unit μm) of the support layer is b, and the laminate thickness (unit μm) of the second skin layer is c, b≥ (a + c), 3c ≥ a ≥ (1/3) c, and the sum of a, b and c satisfies the relationship of 5 to 30
Polyolefin-based wrap film. According to claim 1,
The polyolefin-based wrap film has a tensile strength MD of 3 to 10 kgf / mm ² and a tensile strength TD of 1 to 5 kgf / mm ² measured according to ASTM D 882, and UTM (Instron's 4443 ) having a tensile elongation MD of 200 to 1000% measured using
Polyolefin-based wrap film.