WO2019107626A1 - Composition containing carbon-reduction type biomass polyethylene for stretch film and method for preparing same - Google Patents

Abstract

The present invention relates to a composition for a carbon-reduction type biomass stretch film having high strength and high stretchability, and to a method for preparation the same and, more specifically, to a carbon-reduction type biomass stretch film, which has excellent tensile strength, leading to reductions in packaging weight and volume, thereby reducing logistic costs; is environmentally friendly due to a carbon dioxide reduction effect; and has improved tensile strength and stretching rates so as to be used for packaging by stretch films, by resolving the problems of conventional biomass-containing films, that is, the disadvantages that films are difficult to distribute for a long period of time due to weakness to heat and too fast biodegradation thereof, through a bio polyethylene resin containing biomass derived from a natural material, such as sugarcane, a linear low-density polyethylene resin obtained by polymerization under a Ziegler-Natta catalyst, and a linear low-density polyethylene resin obtained by polymerization under a metallocene catalyst, and the polymer matrix design.

Description

COMPOSITION FOR STRETCH FILM COMPRISING CO-REDUCING BIOMASS POLYETHYLENE AND METHOD FOR MANUFACTURING THE SAME

The present invention relates to a carbon-reduced biomass stretch film composition having high strength and high extensibility, and more particularly, to a biomass stretch film composition having a low bioabsorbability and a high biodegradability under a metallocene catalyst containing biomass derived from sugarcane Polymerized linear low density polyethylene resin and polymerized linear low density polyethylene resin polymerized under Ziegler-Natta catalyst catalyst have superior tensile strength through the design of the polymer matrix to reduce the cost of logistics by reducing the weight and volume of the package, Reduction type biomass stretch film improved in tensile strength, elongation and the like so that it can be used for packaging of a stretch film, and a stretch film produced thereby .

The packaging film market has rapidly developed along with the growth of high value-added industries such as pharmaceuticals, cosmetics, household goods, and food. Industrial polyethylene packaging film consumes 4.1 billion pounds annually, accounting for 24% of total polyethylene film, 8% annual growth, and stretch film accounts for 34% of the polyethylene market. Stretch film is used for the packaging of small products or for the external protection or fixing of products placed on a pallet for the purpose of packaging the goods. The growth rate of this polyethylene-based packaging material industry is increasing due to the importance of the environment globally, It is emerging as the mainstream of packaging. Environmental regulations for packaging materials such as regulations on the content of harmful substances used in plastic packaging materials such as stretch film are being reinforced, and examples of overcoming environmental protection and trade barriers by utilizing eco-friendly packaging materials such as recycling and biodegradation are also emerging. Production of polyethylene packaging film Through the efforts to save resources in the process of disposal, the development of degradable plastic packaging and environmentally friendly packaging materials that are continuously available packaging, biodegradable raw materials, and biodegradable plastics have been actively developed. Currently, biodegradable plastics are used as starch, aliphatic polyester, It is a product made of biodegradable resin such as cellulose and has a characteristic of decomposing in nature after disposal. Such a packaging material film using a biodegradable plastic has disadvantages that it is difficult to circulate for a long time due to its weak biodegradability due to its heat and biodegradability, and it has a disadvantage that it is difficult to apply to stretch films such as cosmetics and parts packaging materials having a long distribution period.

Biobased plastic is a plastic containing biomass derived from plants such as corn, sugarcane and cellulose. It has the effect of inhibiting the increase of atmospheric carbon dioxide concentration, and it can reduce the consumption of petroleum, which is a limited resource. It can be used in production process as it is, and it plays a pivotal role in expanding the bioplastics market in recent years. Bio-based plastics are synthesized by using biomass as a raw material instead of using existing fossil fuel. Because biomass, which is a raw material, is produced by photosynthesis, it needs carbon dioxide in the air. It is very useful material in terms of reduction.

 However, the biomass film using powdered agricultural products such as wheat husks, rice hulls, wheat bran, and starch has a problem in that the processability is very low due to moisture generation during processing, and the yield is low due to a large amount of gelation and carbide production. In addition, when it is used for the purpose of loading or packing a product such as a stretch film, it has a variety of problems such as being limited in stretching characteristics and being difficult to store for a long time due to lack of flexibility and the like.

In this way, when the environmentally friendly element is added to the stretch film at present, the workability, the price, and the physical properties of the product are not satisfied, and therefore the interest in developing a general packaging material is poor. On the other hand, the growth rate of the stretch film global market is expected to grow by more than 7% per year, and the demand is expected to reach 3 million tons. As the use of pallets in transportation and end-user industries grows rapidly, have.

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a bio-polyethylene resin containing biomass derived from corn, potatoes, sugarcane, etc. and a polymer matrix polymerized with polyethylene resins polymerized under different catalysts, And to provide a carbon-reduced biomass stretch film suitable for the packaging use of a stretch film because of its excellent tensile strength and elongation and carbon reduction effect.

In order to achieve the above object, 20 to 70% by weight of a biosynthetic low density polyethylene resin containing biomass derived from a natural raw material such as corn, potato, sorghum and the like, 10 to 50% by weight of a linear low density polyethylene resin polymerized under a Ziegler- And 20 to 60% by weight of a linear low-density polyethylene resin polymerized under a low-density polyethylene resin.

In order to achieve the above object, the biodegradable low-density polyethylene The resin is preferably 20 to 70 wt% of a linear low density polyethylene resin composed of bio-olefin and having a density of 0.910 to 0.920 g / cm ³ and a melt index (190, 2.16 kg) of 0.8 to 2.5 g / 10 min, Is made of a copolymer of ethylene and an? -Olefin having 4 or more carbon atoms, and has a density of 0.915 to 0.925 g / cm < ³ > And 10 to 50% by weight of a linear low density polyethylene resin having a melt index (190, 2.16 kg) of 2.0 to 4.5 g / 10 min, wherein the linear low density polyethylene resin polymerized under metallocene catalyst is a copolymer of ethylene and at least 6 carbon atoms and 20 to 60% by weight of a linear low-density polyethylene resin composed of a copolymer of? -olefin having a density of 0.905 to 0.920 g / cm ³ and a melt index (190, 2.16 kg) of 2.5 to 4.2 g / 10 min, It is possible to manufacture a stretch film using casting of a multilayer structure through mixing of resin.

The production of the biomass stretch film according to the present invention can be carried out by mixing a biodegradable low density polyethylene resin containing biomass derived from a natural material such as corn, potatoes and sugarcane, a linear low density polyethylene resin polymerized under a Ziegler- It is preferable to perform melt blending of an extruder at a melt temperature of 170 ° C to 230 ° C through a proper combination with a linear low density polyethylene resin polymerized under a curing catalyst and to melt the blended pellets in a film having a thickness of 10 μm to 200 μm It is preferable that the temperature of the extrusion die die block is between 180 ° C and 250 ° C and that the cooling roller having the cooling water circulating device therein is extruded at a temperature of 15 ° C to 30 ° C. It is more preferable to perform extrusion under the temperature condition of one process.

According to the carbon-reduced high strength and high-elongation biomass stretch film composition and the manufacturing method of the present invention, the carbon thin film has a physical property suitable for a stretch film which is conventionally insufficient despite containing biomass. Accordingly, the carbon-reduced, high-strength and high-elongation biomass stretch film composition according to the present invention can be used as a substitute for petrochemical-based polymers, and thus exhibits an excellent effect in that it can provide carbon-neutral eco-friendly products.

1 to 5 are the results of measuring the biomass content of the biomass stretch film produced according to the method of the present invention.

6 is a graph showing the tensile strength and elongation of the biomass stretch film produced according to the method of the present invention in longitudinal and transverse directions.

FIGS. 7 and 8 are graphs showing variations in the elongation according to the orientation characteristics of the biomass stretch film produced according to the method of the present invention. FIG.

9 is a graph showing elongation and tensile strength according to orientation characteristics of the biomass stretch film produced according to the method of the present invention.

10 is a graph showing the melt index of a biomass stretch film produced according to the method of the present invention.

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

The term " stretch film " in the present invention is a film having elasticity and tackiness, which is mainly used for packaging, and should have excellent durability, tackiness, moisture resistance, stretchability and the like.

The present invention relates to a technique for providing a biomass stretch film through a polymer matrix design with bio-polyethylene resins containing biomass, polyethylene resins polymerized under different catalysts. Unlike the conventional biomass film, the composition according to the present invention suitable for a stretch film satisfies workability, tensile strength, elongation, and the like.

In the present invention, the biosynthetic low density polyethylene resin containing the biomass, relative to 100 wt% of the total composition, has a linear density of 0.910 to 0.920 g / cm ³ and a melt index (190, 2.16 kg) of 0.8 to 2.5 g / 20 to 70% by weight of a low-density polyethylene resin; The linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst is composed of a copolymer of ethylene and an? -Olefin having 4 or more carbon atoms and has a density of 0.915 to 0.925 g / cm ³ And 10 to 50% by weight of a linear low density polyethylene resin having a melt index (190, 2.16 kg) of 2.0 to 4.5 g / 10 min; And a linear low density polyethylene resin polymerized under a metallocene catalyst are made of a copolymer of ethylene and an? -Olefin having 6 or more carbon atoms, and have a density of 0.905 to 0.920 g / cm ³ and a melt index (190, 2.16 kg) And 20 to 60% by weight of a linear low density polyethylene resin having a density of 4.2 g / 10 min.

The biosynthetic low-density polyethylene resin can be prepared by extracting sugar from corn, potatoes, sugar cane, etc., and polymerizing it by alcohol fermentation, using a biomass as a raw material. Preferably, the biodegradable low density polyethylene resin may contain biomass derived from sugarcane. The present invention is advantageous in that it can be regenerated unlike a petroleum-based petroleum-based fuel producing carbon dioxide while it is possible to use carbon dioxide in the air.

The? -Olefin comonomer of the linear low density polyethylene resin polymerized under the Ziegler-Natta catalyst is 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-dodecene. More preferably at least 6 carbon atoms, more preferably at least 6 carbon atoms, and most preferably 1-hexene. The Ziegler-Natta catalyst is a catalyst for olefin polymerization, which means a catalyst system comprising a combination of a main catalyst which is a main component of a transition metal compound, a promoter which is an organometallic compound, and an electron donor. In the present invention, Catalysts known as catalysts can be used without limitation.

The alpha -olefin comonomer of the linear low density polyethylene resin polymerized under the metallocene catalyst is a copolymer of 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-dodecene More preferably at least 6 carbon atoms, more preferably at least 6 carbon atoms, and most preferably 1-hexene. The metallocene catalyst is a catalyst having a structure in which a metal is sandwiched between two kinds of cyclopentadiene, and is a catalyst having a single active site. In the present invention, catalysts known as metallocene catalysts known in the present invention can be used without limitation.

As a further aspect, the low-density polyethylene resin composition for a stretch film according to the present invention may further comprise additional additives necessary for the production of a known stretch film. For example, such additional additives may include, but are not limited to, lubricants, plasticizers, fillers, waxes, tackifiers, antistatic agents, and the like. The lubricant may be selected from the group consisting of zinc stearate, calcium stearate, magnesium stearate, and stearic acid. The lubricant is added in order to improve the flowability of the resin during film processing and to cause the extrusion process to occur smoothly. The plasticizer may be selected from the group consisting of glycerol, propylene glycol, and sorbitol. The plasticizer weakens the intermolecular force and lowers the glass transition temperature, thereby imparting flow properties, flexibility, extensibility, elasticity, adhesiveness, processability and the like and increasing compatibility. The filler may be selected from the group consisting of calcium carbonate (CaCO), talc, ilite, clay mineral, and zeolite. The filler is added to improve the mechanical or thermal properties and processability of the film. The pressure-sensitive adhesive may preferably be polyisobutylene . The other additives may be selected from the group consisting of an oxidizing agent, an organic acid, a stabilizer and a coloring agent. The wax may be at least one selected from the group consisting of paraffin wax, liquid paraffin wax, wax, mold wax, emulsifying wax, candelilla wax, PE wax and PP wax.

The low density polyethylene resin composition for a stretch film according to the present invention can be produced by a casting extrusion or the like, as a low density polyethylene film for a stretch film having a three-layer structure composed of an outer layer, an intermediate layer and an inner layer.

Accordingly, in another aspect, the present invention relates to a low-density polyethylene film for a biomass stretch film produced by the low-density polyethylene resin composition for a stretch film. Preferably, the film has a three-layer structure of an outer layer, an intermediate layer and an inner layer, and includes a blended resin in which the three resins described in the composition according to the present invention are kneaded, and the outer layer is polymerized under a Ziegler- A copolymer of ethylene and an? -Olefin having 4 or more carbon atoms and having a density of 0.915 to 0.925 g / cm ³ And 10 to 50% by weight of a linear low density polyethylene resin having a melt index (190, 2.16 kg) of 2.0 to 4.5 g / 10 min. The resin of the outer layer exhibits excellent processing characteristics and optical characteristics and is applied to the sealability and transparency characteristics when applied as an outer layer, in a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst.

The intermediate layer preferably comprises a biodegradable low density polyethylene resin and 20 to 70% by weight of a linear low density polyethylene resin having a density of 0.910 to 0.920 g / cm ³ and a melt index (190, 2.16 kg) of 0.8 to 2.5 g / 10 min. When the biodegradable low density polyethylene resin is applied to the middle layer, the resin composition of the present invention has improved characteristics in terms of tensile strength in the machine direction and enhances color stability when a master batch which imparts color to the middle layer is contained.

Wherein the inner layer comprises a copolymer of ethylene polymerized with a metallocene catalyst and an alpha -olefin having 6 or more carbon atoms and has a density of 0.905 to 0.920 g / cm ³ and a melt index of 190 to 2.16 kg of 2.5 to 4.2 g / 10 min By weight of a linear low density polyethylene resin. The resin of the inner layer is excellent in gloss and transparency, and particularly excellent in high-speed processability. It has high melt viscosity, thermal stability and high flexibility and is excellent in compatibility with various polymers. When mixed with an additive such as a pressure sensitive adhesive, the adhesive property is distributed throughout the film due to uniform mixture. When the main resin in the inner layer is poorly mixed with the pressure-sensitive adhesive, it migrates in the resin and tends to deteriorate its properties over time and may cause processing problems in processing. However, the present invention solves this problem with the inner layer .

The resin formulation of the above-described biomass stretch film of the three-layer structure is carried out by mixing a linear low density polyethylene resin polymerized with a Ziegler-Natta catalyst and a linear low density polyethylene polymerized under a metallocene catalyst in order to supplement the characteristics of bio- It is necessary to formulate the resin within the above-mentioned range. The metallocene linear low density polyethylene resin is polymerized under a metallocene catalyst and exhibits a narrow molecular weight distribution and exhibits excellent mechanical properties due to a uniform distribution of the comonomer. However, the resin pressure excessively increases during cast extrusion molding, Necking occurs at the time of molding, and transparency is poor. On the other hand, the linear low density polyethylene resin polymerized under the Ziegler-Natta catalyst has a lower mechanical strength than the metallocene linear low density polyethylene resin, but exhibits excellent processing characteristics and excellent optical characteristics with a wide molecular weight distribution.

The low density linear polyethylene film for a stretch film comprising the biomass of the present invention Accurate biomass content can be measured through experiments in accordance with ASTM D6866. The regenerable carbon content of the film can be calculated from the total carbon, with the principle that the carbon isotope radioactive carbon (C14) is present in the biomass material, while the petrochemical polyethylene does not contain any C14. Carbon dioxide emitted from burning biomass materials is called carbon-neutral carbon dioxide, and carbon-neutral carbon dioxide has zero carbon footprint because it has no effect on the global carbon dioxide concentration. When the biomass rises, the plant emits the carbon dioxide absorbed in the air as it is, and the carbon dioxide absorbed by the plant is released into the air again for the photosynthesis, which is called carbon neutrality. It is preferable that the concentration value of C14 is higher than 25 pCM (percent modern carbon) in the low density linear polyethylene film for stretch film including biomass, and the concentration value of C14 is more preferably 40 pCM or more for reducing the carbon dioxide emission. Generally, it has been reported that the amount of carbon dioxide produced in the petrochemical polyethylene discharges 1,860 g of carbon dioxide per kg of polyethylene. When the concentration of C14 is 25pCM, the reduction of carbon dioxide is about 47 tons when the daily production is 100 tons, and about 141 tons when the production is 300 tons. When the concentration of C14 is 40 pCM, the reduction of carbon dioxide is about 75 tons when the production is 100 tons per day, and about 225 tons when the production is 300 tons.

 In the present invention, it is most preferable that the three or more kneaded resins constituting the low density linear polyethylene film for a stretch film containing biomass have a melt index of 2.0 to 3.5 g / 10 min. When the melt index of the kneaded resin is 2.0 g / 10 min or less, the tensile strength is lowered in the transverse direction (TD) direction, and when the melt index is 1.0 g / min or less, the tensile strength is rapidly lowered, In addition, the elongation rate of the MD (Machine Direction) is also drastically decreased. On the other hand, when the melt index is 3.5 g / 10 min or more, the tensile strength is sharply decreased in the longitudinal direction, and is less than the level suitable for the physical properties of the stretch film.

In the present invention, the number average molecular weight (Mn) of the three or more kneaded resins constituting the low density linear polyethylene film for a stretch film containing biomass is 30,000 to 70,000, the weight average molecular weight , Mw) of 100,000 to 300,000, and a Z-average molecular weight (Mz) of 200,000 to 700,000. The molecular weight distribution of the polymer sample can be judged through the Poly Disperse Index (PDI). If the polydispersity index is 1, it is monodisperse and if it is larger than 1, it is polydisperse . When the polydispersity index value is large, the molecular weight distribution is large and when the polydispersity index value is small, the molecular weight distribution is small. This value is related to the mechanical properties of the stretch film. As the polydispersity index value becomes smaller, the elongation in the MD direction increases and the tensile strength in the TD direction increases. The polydispersity index of the kneaded resin of the present invention is most preferably from 1.5 to 5.0.

In the present invention, the low density linear polyethylene film for a stretch film containing biomass can measure tensile strength and elongation through an experiment according to the ASTM D882 standard. Tensile strength and elongation, and physical properties to the most important should the preparation of the stretch film, usually a tensile strength of the longitudinal direction, and 550kgf / cm ² or more to the lateral direction more than 350kgf / cm ^2, elongation longitudinally more than 500% and a transverse direction A physical property of 700% or more is preferable.

In another aspect, the present invention relates to a method of making a low density linear polyethylene film for a stretch film comprising the steps of:

(a) 20 to 70% by weight of a bi-linear low density polyethylene resin containing biomass, 10 to 50% by weight of a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst, and By weight of a low density polyethylene resin composition for a stretch film comprising 20 to 60% by weight of a linear low density polyethylene resin; And

(b) injecting the compound of step (a) into an extruder, melting it, and extruding it.

In a preferred embodiment, step (b) of the above production method is carried out in an extruder, melted at a melting temperature of 170 to 230 ° C, passed through a thermodiode block having a temperature of 180 to 250 ° C, ≪ / RTI > to < RTI ID = 0.0 > 30 C. < / RTI > In such a case, a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst forms an outer layer, a biosynthetic low density polyethylene resin containing biomass forms an intermediate layer, and a linear low density polyethylene resin polymerized under a metallocene catalyst A film having a three-layer structure for forming an inner layer and having mechanical properties such as excellent gloss, transparency and tensile strength, processing characteristics, optical characteristics and the like is produced.

The present invention will be explained in more detail through the following examples. It is to be understood that these embodiments are provided by way of illustration only, and are not intended to limit the scope of the invention.

[Example]

Comparative Example 1

The Ziegler-Natta catalyst polymerized in a linear low density polyethylene (density: 0.920g / cm ^3, melt index: 4.0g / 10min) 24 parts by weight of a linear low-density polyethylene polymerized with the metal under metallocene catalyst (density: 0.914g / cm ^3, melt index: 4.0g / 10min) 50 parts by weight of a linear low-density polyethylene polymerized with the metal under metallocene catalyst (density: 0.915g / cm ^3, melt index: 3.7g / 10min) as 25 parts by weight of the pressure-sensitive adhesive polyisobutylene 1 The polymer blend was melt-melted at a casting extruder melt temperature of 200 DEG C, and the molten blended resin was passed through a thermo-block temperature of 220 DEG C and passed through a cooling roller equipped with a cooling water circulating device at 25 DEG C, Layer stretch film was obtained.

Example 1

The Ziegler-Natta catalyst polymerized in a linear low density polyethylene (density: 0.920g / cm ^3, melt index: 4.0g / 10min) 24 parts by weight of linear low density polyethylene containing biomass (density: 0.916g / cm ^3, a melt index (Density: 0.915 g / cm ³ , melt index: 3.7 g / 10 min) and 1 part by weight of polyisobutylene as a pressure-sensitive adhesive Casting extruder melting the polymer at a melting temperature of 200 ° C and passing the molten blended resin through a tie die block temperature of 220 ° C and a cooling roller equipped with a cooling water circulating device at 25 ° C to form a three- Of a stretch film.

Example 2

Bio linear low density polyethylene (density: 0.916g / cm ^3, melt index: 1.0g / 10min) 74 parts by weight of a linear low-density polyethylene polymerized with the metal under metallocene catalyst (density: 0.915g / cm ^3, melt index: 3.7g / 10 min) and 1 part by weight of polyisobutylene as a pressure-sensitive adhesive were melt-melted at a casting extruder melting temperature of 200 ° C, and the molten compounded resin was passed through a thermo-block temperature of 220 ° C, Lt; RTI ID = 0.0 > 25 C < / RTI > to obtain a stretch film having a three-layer structure with a thickness of 25 mu m.

Example 3

99 parts by weight of biodegradable low density polyethylene (density: 0.916 g / cm ³ , melt index: 1.0 g / 10 min) and 1 part by weight of polyisobutylene as a pressure-sensitive adhesive were melt-melted at a casting extruder melting temperature of 200 ° C, The compounded resin was passed through a Tie die block temperature of 220 占 폚 and passed through a cooling roller equipped with a cooling water circulating device at 25 占 폚 to obtain a stretch film having a three-layer structure with a thickness of 25 占 퐉.

Example 4

In order to measure the biomass C14 concentration values of the films of Comparative Example 1, Example 1, Example 2 and Example 3, the biobased testing of Beta analytic was measured based on the standard of ASTM D6866. The pMC value according to ASTM D6866 may also mean the content of effective biocomponents. The results of this experiment are summarized in the following Table 1, and the results are shown in FIGS. 1 to 5.

Contents	Comparative Example 1	Example 1	Example 2	Example 3
Percent Modern Carbon (pMC)	1.62 (+/- 0.04)	44.81 (+/- 0.17)	69.94 (+/- 0.23)	91.70 (+/- 0.28)
Atmospheric Adjustment Factor (REF) 101.0; = pMC / 1.010

Example 5

A universal tensile tester (UTM SGS-X STD, SHIMADZU) was used in accordance with the standard of ASTM D882 for testing the mechanical properties of the films of Comparative Example 1, Example 1, Example 2 and Example 3, (MD) and transverse direction (TD), and the maximum load and elongation were measured for a certain area. According to the result of Example 4, the biomass content of Comparative Example 1, Example 1, Example 2, and Example 3 is increased to 1.62pMC, 44.81pMC, 69.94pMC, and 91.70pMC. The changes in tensile strength and elongation can be confirmed by the biomass content and the experimental results are compared in Table 2 below.

		Comparative Example 1	Example 1	Example 2	Example 3
Tensile strength (kgf / cm 2 )	Longitudinal direction	536.6043	602.1447	630.5849	644.5450
	Lateral direction	404.8576	413.8186	378.0882	282.5422
Elongation (%)	Longitudinal direction	625.1470	589.0218	520.4384	440.9382
	Lateral direction	830.1468	845.0218	830.0218	859.8969
C14 pMC (%)		1.975 + 0.040	44.635 ± 0.170	69.565 + 0.235	91.765 ± 0.280

Table 2 shows values of tensile strength and elongation in the longitudinal and transverse directions of Comparative Examples 1 and 2, The mechanical properties in the machine direction (Machine Direction, MD) determine the quality of the product when the actual stretch film is used. In the above table results biomass content increases the tensile strength in the longitudinal direction (MD) and gradually increased from 536kgf / cm ² to 644 kgf / cm ² in accordance with the elongation gradually see, down from 625% to 440% . The tensile strength of the longitudinal 550kgf / cm ² or more to the lateral direction more than 350kgf / cm ² in usual stretch film, since the elongation is preferably the longitudinal direction over 500% and the transverse direction at least 700% The physical properties of Comparative Example 1 is its tensile strength Values are low, and Examples 2 and 3 show low values in elongation. In the case of Example 1, the pCM is 44% or more, and the stretch film shows a satisfactory level at the tensile strength and elongation. A graph of this is shown in Fig.

Example 6

Its mechanical properties change depending on the orientation direction of the polymer. In order to confirm the change of the elongation according to the orientation characteristics according to the content of biosynthetic low density polyethylene, the prepared films of Comparative Example 1, Examples 1, 2 and 3 were stretched at 0 °, 30 °, 60 °, 90 °, 120 °, 150 ° and 180 °, respectively. As the content of bio-linear low-density polyethylene increases, it is confirmed that the range of the change of elongation from 0 ° to 90 °, that is, the longitudinal direction to the transverse direction increases, and the graphs thereof are shown in FIGS.

Example 7

The gel permeation chromatography (Gel Permeation) of Comparative Example 1, Examples 1, 2, and 3 was carried out in the same manner as in Comparative Example 1 and Example 2, in anticipation of increasing the variation of elongation according to the content of the bio- Chromatograph, GPC) were measured and their molecular weight values and distribution were analyzed. The temperature was measured using a high-temperature GPC test equipment (PL-GPC 220 system). The solvent was set at a flow rate of 1.0 ml / min at a detection temperature of 160 trichlorobenzene. The number average molecular weight (Mn), weight average molecular weight (Mw) and Z-average molecular weight (Mz) of Comparative Example 1, Examples 1, 2 and 3, ) And the polydispersity index (PDI) values of the polymer are shown in Table 3 below.

	Mn	Mw	Mz	Mw / Mn
Comparative Example 1	56,062	164,422	356,413	2.933
Example 1	48,626	194,077	503,764	3.991
Example 2	52,556	209,148	554,272	3.980
Example 3	49,071	221,765	603,746	4.519

The polydispersity index (PDI) is a measure for measuring the molecular weight distribution of a polymer film. Monodisperse is a polydispersity index of 1, and polydisperse is a polydispersity index. That is, when the polydispersity index is large, the molecular weight distribution is large, while when the polydispersity index is small, the molecular weight distribution is small. It was confirmed that the variation of the elongation according to the content of the bio resin was increased according to the results of Example 6, and the molecular weight distribution was expected to be larger. The results showed that the polydispersity index increased to 2.933, 3.991, 3.980 and 4.519 depending on the content of bio - resin.

Example 8

Melt index (MWLD-600) of Comparative Example 1, Examples 1, 2 and 3 was measured to determine the change of tensile strength and elongation according to Melt Index (MI) Respectively. Under the conditions of a cut-off time of 30 seconds and a preheating time of 5 minutes at a temperature of 190 占 폚, the results shown in Table 4 were obtained.

	The melt index (g / 10 min)
Comparative Example 1	2.960 + 0.048
Example 1	2.606 + 0.040
Example 2	1.440 + 0.044
Example 3	1.006 + 0.018

It was confirmed that as the content of bio resin increased, the melt index decreased. A graph of this is shown in Fig. As the melt index increased, the tensile strength decreased sharply in the longitudinal direction (MD) and the tensile strength decreased in the transverse direction (TD) as the melt index decreased. The polydispersity index obtained by the above-mentioned high temperature gel chromatography, that is, the molecular weight distribution and the melt index are correlated, the molecular weight distribution is wide, and the melt index is decreased as the polydisperse.

Example 9

Bio-polyethylene resins are synthesized from biomass, which is a renewable plant-derived resource, instead of using existing fossil raw materials. Since biomass, which is a raw material, is produced by photosynthesis, carbon dioxide is required in the air It is important in terms of carbon dioxide emission reduction. The pMC value measured by the biobased testing of Beta analytic based on ASTM D6866 standard is the content of effective biocomponents. Generally, the amount of carbon dioxide produced in the petrochemical polyethylene is 1,860 g per kg of polyethylene, The amount of carbon dioxide reduction in Example 1 is shown in Table 5 below.

Production (ton)	Carbon dioxide Emission (ton)		Carbon dioxide reduction (ton)
	Comparative Example 1	Example 1
0	0	0	0
50	93	55.8	37.2
100	186	111.6	74.4
150	279	167.4	111.6
200	372	223.2	148.8
250	465	279	186
300	558	334.8	223.2
350	651	390.6	260.4
400	744	446.4	297.6

Table 5 shows the carbon dioxide reduction amount according to the daily production amount. In the case of Example 1 containing 44% of pCM, the carbon dioxide reduction effect of 148 ton per day of production 200 ton per day and about 300 ton per 400 ton production standard . A graph of this is shown in Fig.

Claims (16)

1. 20 to 70 wt% of a linear low density polyethylene resin containing biomass, 10 to 50 wt% of a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst, and a linear low density polyethylene resin polymerized under a metallocene catalyst And 20 to 60% by weight of the low-density polyethylene resin composition for a biomass stretch film.
2. The method according to claim 1,

   Wherein the linear low density polyethylene resin containing the biomass is a linear low density polyethylene resin having a density of 0.910 to 0.920 g / cm ³ and a melt index (190, 2.16 kg) of 0.8 to 2.5 g / 10 min. Low density polyethylene resin composition.
3. The method according to claim 1,

   The linear low density polyethylene resin polymerized under the above-mentioned Ziegler-Natta catalyst is composed of a copolymer of ethylene and an? -Olefin having 4 or more carbon atoms polymerized under a Ziegler-Natta catalyst and has a density of 0.915 to 0.925 g / cm ³ And a linear low density polyethylene resin having a melt index (190, 2.16 kg) of 2.0 to 4.5 g / 10 min. The low density polyethylene resin composition for a biomass stretch film according to claim 1,
4. The method according to claim 1,

   The linear low density polyethylene resin polymerized under the metallocene catalyst is a copolymer of ethylene and an? -Olefin having 6 or more carbon atoms polymerized under a metallocene catalyst and has a density of 0.905 to 0.920 g / cm ³ and a melt index (190, 2.16 kg) of 2.5 to 4.2 g / 10 min. The low-density polyethylene resin composition for a biomass stretch film according to claim 1, wherein the low-density polyethylene resin is a linear low-density polyethylene resin.
5. The method according to claim 1,

   The? -Olefin comonomer of the linear low density polyethylene resin polymerized under the Ziegler-Natta catalyst is 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-dodecene. Or more of the total weight of the biomass stretch film.
6. The method according to claim 1,

   The alpha -olefin comonomer of the linear low density polyethylene resin polymerized under the metallocene catalyst is a copolymer of 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-dodecene Or more of the total weight of the biomass stretch film.
7. 20 to 70 wt% of a linear low density polyethylene resin containing biomass, 10 to 50 wt% of a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst, and a linear low density polyethylene resin polymerized under a metallocene catalyst By weight, and 20 to 60% by weight, based on the total weight of the low-density polyethylene film and the low-density polyethylene film.
8. 8. The method of claim 7, wherein the film comprises an outer layer comprising a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst, an intermediate layer comprising a linear low density polyethylene resin containing biomass, and a linear low density polyethylene polymerized under a metallocene catalyst Layer structure of an inner layer containing a resin.
9. 8. The method of claim 7, wherein the film is formed by casting a blend resin comprising a linear low density polyethylene resin containing the biomass, a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst, and a linear low density polyethylene resin polymerized under a metallocene catalyst And then extruded through a cooling roller having a temperature of 15 ° C to 30 ° C after passing through a tidiadi block having a temperature of 180 ° C to 250 ° C by melting at a melting temperature of 170 ° C to 230 ° C A low density polyethylene film for a biomass stretch film.
10. 8. The method of claim 7,

    Characterized in that the concentration of C14 in the low density polyethylene film for stretch film is not less than 25 pCM (percent modern carbon) in the biomass.
11. 8. The method of claim 7,

    And a melt index of the kneaded blended resin is 2.0 to 3.5 g / cm < ³ >. The low density polyethylene film for a biomass stretch film according to claim 1,
12. The method of claim 7, wherein

    The kneaded compounding resin has a number average molecular weight (Mn) of 30,000 to 70,000, a weight average molecular weight (Mw) of 100,000 to 300,000 and a Z-average molecular weight (Z- average molecular weight, Mz). < / RTI >
13. The method of claim 7, wherein

    Wherein the blended resin blend has a polydispersity index of 1.5 to 5.0. ≪ RTI ID = 0.0 > 11. < / RTI >
14. A packaging material comprising the low density polyethylene film for a biomass stretch film of claim 7.
15.  (a) 20 to 70% by weight of a bi-linear low density polyethylene resin containing biomass, 10 to 50% by weight of a linear low density polyethylene resin polymerized under a Ziegler-Natta catalyst, and By weight of a low density polyethylene resin composition for a stretch film comprising 20 to 60% by weight of a linear low density polyethylene resin; And

    (b) introducing the compound of step (a) into an extruder, melting the extruder, and extruding the extruded product.
16. 16. The method of claim 15,

    The step (b) is carried out in an extruder, melted at a melting temperature of 170 to 230 ° C., passed through a tidadi block having a temperature of 180 to 250 ° C., and then cooled to a temperature of 15 ° C. to 30 ° C. Lt; RTI ID = 0.0 > of: < / RTI >

Images