KR20040046324A - Multi-degradable polyethylene composition and polyethylene product using the same - Google Patents

Abstract

PURPOSE: A composite degradable polyethylene composition and a polyethylene product using the composition are provided, to obtain a material which is structurally stable during effective use period and is degraded into unharmful materials under adjustable conditions. CONSTITUTION: The composite degradable polyethylene composition comprises 57-97 wt% of a polyethylene resin; 3-49 wt% of a polyethylene degradable master batch; 0-5 wt% of a coloring agent; and 0-20 wt% of a hydrocarbon resin. Preferably the polyethylene product is a vinyl, tube or film.

Description

MULTI-DEGRADABLE POLYETHYLENE COMPOSITION AND POLYETHYLENE PRODUCT USING THE SAME

Conventional polyethylene products have been used in various fields through the production of household goods, various films, vinyls, household goods, agricultural films, sanitary films (paper diapers, physiological products), paper coating films and the like through various manufacturing processes. However, the biggest problem is that they are not permanently decomposed when used after use, but exist semi-permanently, causing environmental pollution.They can generate and recycle harmful substances when incinerated, but they are difficult to collect, and there is an excessive cost to remove impurities contained in the collection. There is a problem such as that required.

The present invention can be completely decomposed into low-molecular compounds such as water and carbon dioxide by microorganisms such as bacteria, fungi, sunlight, enzymes, etc. in nature, and also relates to a degradable plastic having excellent water resistance, tensile strength, elongation, and flexibility, and a method of manufacturing the same. will be. Specifically, the present invention relates to a polyethylene resin composition which is decomposed in a natural state by adding 3-45% by weight of an ethylene decomposing agent, which is a composition for decomposing polyethylene resin, and a polyethylene prepared using such a composition, and a method of manufacturing the same. .

In the past, waste plastics such as waste vinyl are disposed of through landfilling, incineration, and recycling.However, when landfilling continues, landfills are scarce due to the steadily increasing amount of garbage. In addition, the ground is not stable due to plastic waste, which is difficult to decompose after landfilling, and there are many problems in the use of landfills.In case of incineration, air pollution is generated due to generation of fugitive dust and harmful gases such as dioxins and carbon monoxide. And cause serious harm to the human body. In addition, although recycling is possible, there are many problems such as economic difficulties due to the difficulty of collection and the excessive cost required to remove the mixed impurities even after collection.

On the contrary, regardless of the above problems, the demand for agricultural film products made of high density, low density and linear low density polyethylene is increasing in horticulture and agricultural sites, but it is difficult to collect and there are many problems in recycling, incineration, landfill, etc. It is a situation that is an important cause of soil pollution by neglect. In addition, the reduction of farming area due to neglect has reached 30%, and according to the Resource Reclamation Corporation, 32 out of 60 waste vinyl treatment plants nationwide have reached saturation, and the amount of waste plastics is increasing by 20,000 tons per year. . About half of the new plastic waste is being burned illegally, and currently 327,000 tons of plastic waste are stored in the yard. According to the Korea Resource Reclamation Corporation, in 2001, 258,000 tons of agricultural waste plastics were produced nationwide, and 121,000 tons (51%) were collected and disposed of properly, while the remaining 117,000 tons (49%) were illegally incinerated or landfilled. It is the situation that it is or is left unattended. Meanwhile, the Korea Resources Reclamation Corporation secured a budget to provide some of the waste plastic to North Korea, but North Korea demanded and rejected high-quality waste plastic.

In recent years, as the income level and the dietary changes have increased, the demand for disposable foods including hygienic, convenient and inexpensive plastics has been increasing.In the case of pottery and glass products, Due to the inconvenience, most instant food containers tend to use disposable products that are easy to use. In addition, fast food stores, convenience stores, and vending machines, etc., mostly use disposable products, and the use of disposable products is rapidly increasing.

In order to solve the above problems, various researches related to photodegradation, biodegradation, and complex decomposition have been made to decompose existing general-purpose plastics themselves. As the plastic degradable component, photodegradable additives, complex decomposition additives, biodegradable resins, pyrolysis and the like are known. Among these, interest in technology and its products that are decomposed by one or more mechanisms such as photolysis, biodegradation, chemical decomposition, and pyrolysis is increasing, and research on them is being actively conducted.

Degradable plastics are photodegradable products which are decomposed by natural light by a photosensitizer or the like; Synthetic biodegradable products such as PHAs, PLA, PCL, and aliphatic polyesters; Natural biodegradable products using natural materials such as fiber, starch and pulp; Complex decomposition products decomposed by one or more decomposition mechanisms such as pyrolysis, biodegradation, chemical decomposition, and photolysis; It can be divided into biodegradable products in which non-degradable synthetic resins such as polyethylene and polypropylene are added to biodegradable resins.

However, these products are difficult to commercialize due to economic reasons such as price, poor decomposition or lack of business due to machinery, equipment, investment needs, etc. to produce the product.

Polyethylene resin is widely used for food packaging and industrial materials because it is transparent, has proper strength, has good waterproof and moisture proof property, and has excellent heat sealability and processability. Korean Patent Application No. 195-702725 describes the preparation of a linear low density polyethylene (LLDPE) film of excellent physical properties by adding a metallocene catalyst, alpha olefin and the like to ethylene and feeding it to a reaction fluidized bed reactor for increasing elongation and decreasing extract. The composition of the present invention can be described, and Korean Patent Application No. 1996-41280 uses vinyl acetate as a comonomer and propionaldehyde as a modifier to provide excellent transparency, gloss, tensile strength, impact strength, tear strength and weather resistance. It describes about the polyethylene composition which has. The resin composition for high-density polyethylene film described in Korean Patent Application No. 1999-700974 manufactures a masterbatch made of an olefin resin having a molecular weight of less than 50 million tons and blends the masterbatch with a high-density polyethylene polymer to provide a smooth appearance and moisture barrier property. It is possible to produce improved high density polyethylene films. However, the polyethylene resins prepared according to the above methods are all excellent in physical properties, but have no decomposability at all, which causes waste problems. The degradable polymer composition described in Korean Patent Application No. 1990-7599 is degradable by adding plasticizer components such as ethylene / vinyl alcohol copolymer (EVOH) obtained by copolymerizing ethylene-vinyl acetate copolymer (EVOH), broken starch, and high ratio. It has the characteristics, but it is difficult to completely decompose. The resin composition having thermal and chemical degradability described in Korean Patent Application No. 1999-24248 has a degrading effect that is insignificant and the decomposition period is not controlled. Additive composition for promoting the decomposition of the polymer described in Korean Patent Application 2001-68377 is difficult to expect the decomposition effect from the experimental data presented in the sample. The degradable polymer composition described in Korean Patent Application No. 195-704415 has a complex decomposition property in which photodegradation and biodegradation occur simultaneously by adding a biodegradable thermoplastic compound, transition metal, oxidation promoter, stabilizer, and thermoplastic polymer component. This is too long and the price is too expensive, the industrialization is difficult. In addition, the bio / photodegradable agricultural mulching film composition and molded article described in Korean Patent Application No. 1996-64953 is a disintegratable product using biodegradable aliphatic polymer and starch in polyethylene, which is hardly referred to as degradable product, and also polycaprolactone, poly Polymeric materials such as lactic acid are simply added technologies and are difficult to industrialize due to high cost.

On the other hand, the degradable plastics described in US Pat. No. 39,41759 are capable of photolysis of the plastics by ultraviolet rays by adding a photosensitizer, which is an organic compound, and the degradable plastics described in US Pat. It shows the property of photodegradation by ultraviolet light in the natural state, but it has a limit that does not decompose in the absence of light such as long decomposition period and landfill in soil.

The manufacturing method of the synthetic resin product of Unexamined-Japanese-Patent No. 2000-110524 makes it possible to manufacture a synthetic resin product by adding a synthetic resin decomposable component to a synthetic resin and shape | molding. However, the synthetic resin product has a long decomposition period, and the price is expensive, there is a disadvantage that the commercial lack.

The present inventors have made diligent efforts to solve these problems of the prior art. As a result, the present inventors have developed a polydegradable polyethylene product which is excellent in moldability and can be completely decomposed in nature by using a polyethylene decomposition component as a main raw material and mixing it with an existing polyethylene resin. The present invention has been completed.

The composite decomposable polyethylene products according to the present invention are films for use in food packaging materials, extruded products such as degradable shopping bags, horticultural and agricultural films, foamable polyethylene products such as packaging cushioning materials, and the like. In addition, the composite decomposable polyethylene composition has properties similar to those of conventional polyethylene products, and it is easy to be commercialized due to the low manufacturing cost, and also has excellent applicability, so that it can be used without any change in the processing process of the existing polyethylene resin, and it is complex in nature. With excellent resolution, it does not cause environmental pollution at landfill and has the advantage that it can be collected and recycled.

Accordingly, it is an object of the present invention to provide a multidegradable plastic composition containing a polyethylene degradable component and a polyethylene resin.

Another object of the present invention is to provide a multidegradable plastic product made using such a composition.

This object of the present invention is achieved by the method of the present invention comprising the following steps: (A) a polyethylene degradable component; Mixing polyethylene resin pellets or masterbatches; (B) adding the mixture of (A) to a conventional film extruder or fluidized bed reactor to produce a polydegradable polyethylene product at 170-340 ° C.

In the present invention, the amount of the polyethylene complex decomposable component which is a composition capable of decomposing the polyethylene resin is 3-49% by weight, preferably 5-45% by weight, more preferably 7-30% by weight based on the total weight of the composition. Weight percent.

The polyethylene degradable component is a degradable polyethylene masterbatch composed of a direct biodegradable component, an oxidation accelerator component, a photolytic component, a stabilizer, a chemical decomposition accelerator component, and the like for DLT-101 (LDPE and LLDPE) and DLT. -102 (for HPDE)-DreamLife Tech Co., Ltd. was used.

The polyethylene pellets can be used by purchasing the pellets commonly used in the art, for example, polyethylene resin pellets of Hanwha Petrochemical or Samsung Petrochemical, and the amount of the polyethylene pellet is 50% by weight or more based on the total weight of the composition, preferably 70 -93% by weight.

In order to impart the color of the product, a colorant is used, and the colorant may be used by purchasing a commercially available product which sells a conventional carbon black or white agent, and the amount thereof may be 0-5% by weight if necessary.

In the present invention, the hydrocarbon resin may be a resin derived from the polymerization of pure monomers of styrene, α-methyl styrene, 4-methyl styrene and vinyltoluene and improving the barrier property of the film in forming the high density polyethylene resin film, The addition amount may be 0-20% by weight.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples and can be applied to products using all linear low density polyethylene, low density polyethylene, high density polyethylene.

Example 1

85 g of low density polyethylene resin, component for polyethylene complex decomposition-DLT-101; DreamLife Tech Co., Ltd.-15g was added to 100rpm, mixed for 10 minutes to prepare a composite degradable low density polyethylene pellet composition.

The obtained pellets were blown with a blown film molding machine (Eugene Engineering Co., Ltd.) commercially available according to the conventional film production method. Low density polyethylene film having a thickness of 60 microns at a resin temperature of 190 ° C, a screw rotation speed of 60 rpm, and a mold diameter of 150 mm. Was prepared.

Example 2

85 g of high density polyethylene resin, polyethylene complex degradable component-DLT-102 in a mixer; DreamLife Tech Co., Ltd.-15g was added to 100rpm, mixed for 10 minutes to prepare a composite decomposable high density polyethylene pellet composition.

The obtained pellets were blown with a blown film molding machine (Eugene Engineering Co., Ltd.) commercially available according to the conventional film production method. A high-density polyethylene film having a thickness of 60 microns at a resin temperature of 190 ° C, a screw rotation speed of 60 rpm, and a mold diameter of 150 mm. Was prepared.

Example 3

85 g of linear low density polyethylene resin, polyethylene complex degradable component-DLT-101 in a mixer; DreamLife Tech Co., Ltd.-15g was added to 100rpm, mixed for 10 minutes to prepare a composite degradable linear low density polyethylene pellet composition.

The obtained pellets were lined with a low-density polyethylene having a thickness of 60 microns at a resin temperature of 190 ° C, a screw rotation speed of 60 rpm, and a mold diameter of 150 mm using a blown film molding machine (Eugene Engineering Co., Ltd.) commercially available according to a conventional film production method. A film was prepared.

Example 4

85 g of low density polyethylene resin, polyethylene complex degradable component-DLT-101 in a mixer; DreamLife Tech Co., Ltd.-12g, 3g colorant, 4g styrene was added to 100rpm, mixed for 10 minutes in accordance with the general method to prepare a composite degradable low density polyethylene pellet composition.

The obtained pellets were prepared in a tubular container using a molding machine according to a general method.

Example 5

85 g of linear low density polyethylene resin, polyethylene complex degradable component-DLT-101 in a mixer; DreamLife Tech Co., Ltd.-12g, 3g colorant, 4g of styrene was added to 100rpm, mixed for 10 minutes according to the general method to prepare a multi-degradable polyethylene pellet composition.

The obtained pellets were prepared in a tubular container using a molding machine according to a general method.

The mechanical property test of the container according to the present invention was measured using a universal testing machine (manufactured by Instron Co., Ltd., USA), and the average value except the maximum and minimum values was measured 10 times for each measurement item. The results are shown in Table 1 below.

Table 1

division Tensile Strength (㎏ / ㎠) Wet Tension (dyne / cm) Elongation (%) Commercially available LDPE film 250 52 160 Example 1 223 45 155 Example 2 240 50 140 Example 3 220 42 145 Example 4 246 46 142 Example 5 223 44 141

* The LDPE film used PE film SG100 of Hwaseung Industries Co., Ltd.

As can be seen in Table 1, the multi-degradable polyethylene product of the present invention can be seen that the tensile strength, wet tension and elongation similar to the existing product. In addition, the biodegradability evaluation of the multi-degradable polyethylene product of the present invention was tested by modifying the method specified in Korean Patent Publication No. 95-14918. That is, after cutting the sample to a certain size, using a solid agar medium as a medium, Aspergillus niger , Penicillium funiculosum , Trichoderma sp. ), And mixed mycelium suspension of Pulularia pullulans aseptically sprayed under aseptic conditions to evaluate the degree of fungus covering the samples at 20 days intervals as follows to determine biodegradability.

0%: 0, 10% or less: 1, 10-30%: 2, 30-60%:

3, when 60-100%: 4

At the same time, the sample is taken out every 40 days while being kept in a constant temperature and humidity chamber fixed at a relative humidity of 70% and an internal temperature of 20 ° C. for 120 days, and the weight loss of the sample according to the degree of growth of the mold is measured as a ratio. It was.

The results are shown in Table 2 below.

Table 2

Evaluation results of biodegradation and weight loss test results

division Biodegradation degree (%) Weight loss rate (%) 20 days 40 days 60 days 80 days 100 days 120 days 40 days 80 days 120 days Commercially available LDPE film 0 0 0 0 0 0 99.9 99.9 99.9 Example 1 0 0 One 2 3 3 96.9 83.2 73.3 Example 2 0 0 One 2 3 3 97.1 83.7 74.9 Example 3 0 0 One 2 2 3 97.3 82.5 72.3 Example 4 0 0 One 2 2 3 98.0 82.7 71.6 Example 5 0 0 One One 2 3 97.2 81.1 69.8 * Weight loss rate (%) = weight after sampling / weight of original sample × 100

As can be seen in Table 2, the biodegradability of the multidegradable polyethylene product prepared by the present invention was much better than the conventional LDPE film. On the other hand, in the photodegradability test according to the ultraviolet light treatment test (ASTM D154) method using a UV light treatment tester (QUV Acdelerated Weathering Tester) was irradiated with UV light for 200 hours and then measured the tensile strength and elongation increase and decrease. At this time, the type of UV lamp was UV313 and the irradiance was 0.60w / nf (310nm), and the results are shown in Table 3.

Table 3

Photodegradability Test Results

division Strength retention rate (%) % Retention Commercially available LDPE film 96.1 95 Example 1 60.6 12.2 Example 2 35.6 2.1 Example 3 65.3 14.7 Example 4 59.2 11.5 Example 5 64.2 13.5

According to the method for producing a composite decomposable polyethylene product according to the present invention, in a general polyethylene product manufacturing process, a resin composition is added to a polypropylene resin to obtain a composite decomposable polyethylene resin composition, and the polyethylene molded article is molded from the obtained composition. can do. In addition, the existing molding equipment can be used as it is without additional equipment investment, and the product can be manufactured as it is. In addition, it has excellent formability, strength, and foldability, and has similar mechanical properties to existing polyethylene products, and its practical use is possible due to its low manufacturing cost, and environmental pollution during landfill due to complex decomposition such as biodegradation, photolysis, thermal decomposition, and chemical decomposition in nature. Not only does it cause a problem, but it is also possible to collect and recycle the product.

Claims (2)

A polydegradable polyethylene composition comprising 57-97 wt% polyethylene resin, 3-49 wt% polyethylene degradation component, 0-5 wt% colorant, and 0-20 wt% hydrocarbon resin. The vinyl, tube, or film article of claim 1, wherein the vinyl, tube, or film article is prepared using the multidegradable polyethylene composition. The multi-degradable polyethylene product according to claim 2, wherein the polyethylene vinyl, film or tubular product has the property of low molecular weight polyethylene resin and decomposes in the natural environment by light, heat, microorganisms, enzymes and the like.