KR100523245B1 - Deodorant Polyethylene Resin Composition for Package - Google Patents

Abstract

Method for producing a polyethylene composition having a malodor removing function of the present invention is to wash, dry the shell powder pre-treatment; Modifying the surface of the pretreated shell powder; And it is made of a step of adding the shell powder is modified to the polyethylene resin. Surface modification of the shell powder is characterized by using a surfactant or a cation.

Description

Deodorant Polyethylene Resin Composition for Package

Field of invention

The present invention relates to a packaging polyethylene film having a odor removing function and a method of manufacturing the same. More specifically, the present invention relates to a packaging polyethylene resin composition excellent in mechanical strength as well as odor removal function by modifying the surface of the pretreated shell powder and adding it to the polyethylene resin.

Background of the Invention

In general, polyethylene resins are widely used in various packaging materials because of their excellent flexibility and tensile strength. However, the polyethylene packaging material does not have a deodorizing function for odors, and if the contents of the package are odor-inducing substances, there is a problem that causes severe discomfort due to odors when opening the package.

The main causes of malodors include hydrogen sulfide, ammonia, melcaptans and amines. These odor causing substances can be easily detected even at low concentrations because the odor detection limit concentration is very low in ppm. The human body effect of odor is mainly sensation, and it can be discomfort and aversion. In addition, there are irritation of the mucous membrane of the respiratory system and changes in blood pressure or pulse. Most of them are low in concentration and do not have a significant physiological effect, but they can also be factors such as loss of appetite, vomiting, headache, insomnia, and allergic symptoms and psychological effects. Therefore, the odor not only harms the health of the consumer, but may also have a significant influence on consumer perception, quality, and the like of the product, and thus, there is increasing interest in functional packaging materials having a odor removing function.

Odor removal methods include oxidation, enzymatic digestion, adsorption, and masking to simply conceal odors. The odor removal method by double adsorption is preferred.

Japanese Patent Laid-Open No. 11-293034 discloses a deodorizing resin composition prepared by mixing a deodorant component composed of an oxide or hydrate of an alkaline earth metal, a silicic acid hydrate, and a dihydrazide compound with a thermoplastic resin.

In Japan, a odor removing packaging film filled with CaCO ₃ , zeolite, and ceramics has been released based on polypropylene resin. However, the product uses expensive zeolites and the like as an odor removing material to increase the manufacturing cost, and there is a problem that it is not industrially preferable to use as a disposable packaging material.

Meanwhile, domestic B.F.M. Tech is using the inorganic additives to market packaging (PE, PP) having antibacterial, deodorant, and freshness retention function, but the function and principle have not yet been objectively evaluated.

In addition, some companies, including Ewha Trading, disclose a product having a odor removal, antibacterial, and freshness maintaining function using a functional filter, but this is not a film but a filter product, which is not suitable for use as a packaging material.

Although research on construction composites using shells is underway, most of them are believed to be effective and do not consider suitable pores, types of cations, carbonate ions and other component ratios. When the shell powder itself is added to the resin, the problem of seriously lowering the mechanical properties of the resin remains a problem to be solved.

Currently, a packaging material having an odor removing ability is generally manufactured by crushing a ceramic-based inorganic material having an odor removing and antibacterial function and then mixing the resin with a resin. However, an objective performance evaluation has not been made on these products, and the ceramic having the odor removal and antibacterial functions has been a cause of raising the manufacturing cost.

In order to solve the above problems, the present inventors can reduce the manufacturing cost by using the discarded waste shells, and by modifying the surface of the shells with a cation or a surfactant having a high charge, thereby improving mechanical properties. In addition, the development of a packaging polyethylene film having an adsorption function for various odor causes.

An object of the present invention is to provide a packaging polyethylene resin composition excellent in odor removal function and a method for producing the same.

Another object of the present invention is to provide a packaging polyethylene resin composition having excellent mechanical properties such as tensile strength and tear strength of 80% or more compared to the existing film, and a method of manufacturing the same.

Still another object of the present invention is to provide a polyethylene resin composition and a method for producing the same, which not only reduce manufacturing costs, but also utilize the shell powder that is discarded as waste.

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

Summary of the Invention

Method for producing a polyethylene resin composition having a malodor removing function of the present invention is to wash and dry shell shell powder pre-treatment; Modifying the surface of the pretreated shell powder; And it is characterized in that the surface consisting of the step of adding the shell powder modified to the polyethylene resin. The surface modification of the shell powder uses a C _11-19 cationic surfactant or cation. Hereinafter, the content of the present invention will be described in detail.

Detailed Description of the Invention

(1) First step: pretreatment of shell powder

The pre-treatment of shell powder is a process of purifying the shell by washing and drying the shell powder in order to increase the performance of the shell. Specifically, the shell is washed in nature, dried and then further washed again, and dried at high temperature at about 700 ^o C to remove salts, algae, microorganisms and the like. Next, after sterilization by a conventional method, the fine powder of about 3 to 5㎛ can be obtained to obtain a shell powder. Purification of shell powder is repeated several times of washing and drying to completely remove residual salts and odors and to keep the pH of the washed solution neutral.

(2) Second step: surface modification process

The surface of the pretreated shell powder is modified with a surfactant or cation.

Shell powder is mainly composed of calcium carbonate (CaCO ₃ ), and other components are CaO, SiO ₂ and trace metals of Mn, Fe, Zn and the like. Anionic charges are distributed on the shell surface, and calcium ions, which are counter ions, are combined by electrostatic attraction for electrical stability.

Due to such an electrostatic bond, the shell powder has a property of adsorbing odorous substances such as hydrogen sulfide, ammonia, melcaptans and amines. However, when the shell powder itself is mixed with the resin, the physical properties of the resin are lowered, so it is not suitable for use as a packaging material requiring mechanical properties.

In the present invention, by modifying the surface with calcium ions instead of other ions having excellent antimicrobial or gas adsorption properties, the resin composition not only has excellent absorbency against odors (or volatile organic substances), but also has good selective functionality and mechanical properties. It is.

1 is a model showing the principle that the odor is adsorbed in the shell film according to the present invention. In the case where the substance of bad odor is a compound of basic amines, it is adsorbed due to ionic bonds with cations on the surface of the film, and when the substance of bad smell is a sulfur compound of weak acidity, it is adsorbed by anions and ionic attraction on the surface of the film. In addition, polar compounds such as acetone and methyl ethyl ketone may be adsorbed on the surface of the film due to the attraction between the polar ions due to the ions of the surface and the ubiquitous electrons. If the odorous substance is BTX (Benzene, Toluene, Xylene), etc., it is adsorbed on the surface by hydrophobic attraction by the surface-substituted surfactant. These phenomena are a kind of equilibrium reaction, and if the odor continues to occur in the contents, the surface odor of the odor molecules continues to occur in response to the occurrence of odor. Will be reduced.

The surface modification of the shell powder according to the method of the present invention uses a cationic surfactant capable of binding to the negative inversion of the surface, or a divalent or trivalent cation.

When cationic surfactants are used for surface modification of shell powders, it is preferable to use cationic surfactants of C _11-19 . If the length of the chain is too short (C ₁₀ or less), there is no adsorption effect, and if the length of the chain is 20 or more (C ₂₀ or more), the fluidity of the chain is low and it is difficult to expect the adsorption effect. Accordingly, surfactants having a carbon number of C _11-19 are preferred, and in particular, high price competitiveness, reproducibility, and stability, such as DODAB (n-dodecyl trimethylammonium bromide), CTAB (n-cetyltrimethylammonium bromide), and HTAB (n-hexadecyl trimethylammonium bromide) Is most preferred.

When the surface of the shell powder is modified with a cation, divalent or trivalent cations are used. This is because when the monovalent ions having a low charge are used, the adsorption capacity of the ionic material decreases. Since the shell itself contains a large amount of Ca, the surface contains a large amount of divalent ions without modification, but can be substituted with a divalent cation other than Ca in order to provide various functionalities and desirable physical properties. As said divalent cation, Mg is preferable, and as trivalent ion, Al, Ce, etc. are preferable.

(3) Step 3: adding the modified shell powder to polyethylene resin

The modified shell is added to polyethylene resin to prepare a PE masterbatch. Shell powder is added to polyethylene resin which is a matrix resin in the range of 1-10 weight%. When the shell powder is added in excess of 10% by weight, the mechanical strength of the produced polyethylene film is lowered, when less than 1% by weight, the odor removal effect is weak.

As the matrix resin, a polypropylene resin may be used in addition to the polyethylene resin, and thermoplastic resins such as polyvinyl chloride, polystyrene, etc. may also be used according to respective applications.

In a preferred embodiment of the present invention, low density polyethylene resin (LDPE) is used, which is particularly excellent in fluidity and tensile strength.

Specifically, a master batch (M / B) of 20 wt% based on shells is prepared in a twin screw extruder using chemically modified shell powder and LDPE. The temperature condition is preferably maintained at 180 ^° C in the feeder (feeder zone), and 200 ^° C in the mixing zone (metering zone) and metering zone (metering zone).

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example 1

(1) pretreatment of shell powder

Shell shell powder is prepared by washing and drying in natural state for more than 2 years, and further grinding and grinding it into fine powder of 3 ~ 5㎛ after removing and sterilizing salinity, algae, microorganism through washing and high temperature drying (700 ^o C). Was used and purchased from Haesung Co., Ltd. The obtained shell powder was washed with secondary distilled water (using 1 liter of distilled water per kg of shell) for 1 day at room temperature, washed and filtered. The purified shell powder obtained by repeating this process about three times was dried in an oven at 150 ^° C. for 1 day to remove moisture. The shell powder after the purification process apparently changed from dark brown to light brown, the salt and sea odor almost disappeared, and the pH of the washed solution remained neutral.

(2) Modification of Shell Shell Surface

Purified shell powder was added to 1 liter of an aqueous 50 mM surfactant solution in which 15.4 g / l of DODAB (n-dodecyltrimethylammonium bromide, Aldrich Chemical Co., Ltd.) having a purity of 99% or more was added thereto. To be replaced. The shell powder was recovered by filtration, and then dried at 150 ^° C.

(3) Production of masterbatch using shell

The modified shell powder and LDPE, which is a matrix resin, were prepared in a 20 wt% master batch (M / B) based on a shell in a twin screw extruder. The modified shell powder to be added was added to 3, 5 and 10% by weight, respectively, based on the total weight. At this time, the temperature was maintained at about 180 ^o C in the feeder zone and about 200 ^o C in the mixing zone and metering zone. The masterbatch was prepared using a single screw blown film extruder having a diameter of 30 mm and a film having a width of 40 cm and a thickness of 40 μm.

As a result of analyzing the shell film using the infrared spectrophotometer (Infrared spectrophotometer), the absorption peak was observed at 1700 cm ^-1 and 700 cm ^-1 , respectively, compared to the general PE film. This indicates that the shells are evenly distributed in the film due to vibration absorption due to carbonate ions (CO ₃ ^2- ) and hydrocarbons, which are the main components of the shells. IR spectrum of the shell film is shown in FIG.

Example 2

In the modification of the shell powder surface, it was carried out in the same manner as in Example 1 except that 18.2 g / l of n-cetyl trimethylammonium bromide (CTAB) was used.

Example 3

In the modification of the shell powder surface, it was carried out in the same manner as in Example 1 except that 18.2 g / l of n-hexadecyl trimethylammonium bromide (HTAB) was used.

Example 4

In the modification of the shell powder surface, it was carried out in the same manner as in Example 1 except that the concentration of the aqueous solution was 0.1M using 33.2 g / l cation as a cation.

Example 5

In the modification of the shell powder surface, it was carried out in the same manner as in Example 1 except that the concentration of the aqueous solution to 0.1 M using Al as a cation Al to 10.1 g / l.

Example 6

In the modification of the shell powder surface, it was carried out in the same manner as in Example 1 except that the concentration of the aqueous solution to 0.1 M using 24.7 g / l as the cation.

Comparative Example 1

The same procedure as in Example 1 was carried out except that only LDPE was used without adding shell powder.

Comparative Example 2

The same procedure as in Example 1 was carried out except that the shell powder was not modified.

(1) Mechanical property evaluation

Experiments on tensile strength, elongation at break and tear strength of the films prepared from Examples 2, 4 and 6 and Comparative Examples 1 and 2 were performed, respectively.

end. Measurement of Tensile Strength

Lloyd's LR50K was used in the machine direction (MD) and transverse direction (TD) per film under standard conditions of 60% at room temperature and relative humidity. After measuring 10 specimens, the average value was plotted and 95% of Deviations are indicated with confidence intervals. The measurement results are shown in FIG. As a result of measuring the maximum stress of the shell film, Example 4 substituted with Ce showed the highest value of 19 MPa in M.D. (machine direction), and Comparative Example 2 using pure shell powder showed the lowest value of 15 MPa. Comparative Example 2 using pure shell powder also showed the lowest value of 11 MPa in the T.D. of the first prototype, and the remaining films showed similar values. As a result, the maximum stress of the shell film was able to maintain at least 80% of the properties of the conventional LDPE film.

I. Measurement of Elongation at Break

Figure 4 shows the elongation at break according to the content of shell powder. As a result of measuring the elongation at break of the shell film, M.D. And T.D. In both directions, the shell tends to decrease with increasing shell content. T.D. Slightly decreased in the direction of T.D. In the direction, it was found that the width was greatly reduced, and in particular, the pure shell was found to be the largest decrease.

All. Measurement of tear strength

Toyo Seiki's Elmendorf tear tester was used to measure the mean and the deviation using 10 samples, respectively. 5 shows the tear strength according to the content of shell powder. As a result of measuring the tear strength of the shell film, it shows a tendency to decrease as the content of the shell increases. Although the film containing 3 wt% shell has a lower physical properties than the LDPE film of Comparative Example 1, the shell of 5, 10 wt% Comparing the tear strength of the film containing was found that the fall of physical properties is not large.

From the experimental results, the mechanical properties of Comparative Example 2 containing pure shells had the worst physical properties, and Example 2 substituted with surfactants as in Example 4, 6, or N-16 substituted with metal ions such as Ce or Mg. It was found that the physical properties of the superior.

(2) odor removal ability evaluation

end. Comparison of Odor Removal Capability in Shell Films in Untreated Leather Goods Packaging

In order to measure the odor removal ability in the shell film, the shell film prepared in Examples 2, 4, 6 and Comparative Examples 1, 2 was 15 cm x 15 cm using a thermal adhesive machine (Tower Industries TH 300) A film bag of size was prepared. For the film bag contents, leather products that cause odors are purchased on the market, cut into square shapes (10 cm x 10 cm), placed in the inside, and sealed, and the gas-tight syringe is periodically sealed in the film bag. , Hamilton Co., Ltd.) were collected by 1ml each to investigate the gas concentration change inside the film bag using the change of peak area detected using gas chromatography (Gas Chromatography, HP 5890 series II) equipped with FID detector. The column used was HP-5 (crosslinked 5% Ph Me silicone), and carrier gas was hydrogen (20 psi), nitrogen (50 psi), air (40 psi). Initial odor generation of the leather fabric itself was very small when detected by sense of smell, and analyzed by gas chromatography. GC spectrum is shown in FIG.

At the time of sealing the untreated leather product as the contents, the gas inside the film bag was collected after 3 days, 4 days and 5 days, and the odor removal ability of each example was compared. The comparison results are shown in FIG. From the above test results, as a result of measuring the odor generated from the leather fabric itself, in the case of Comparative Example 2 using an unmodified shell powder and Example 2 using a shell powder modified with a surfactant, the odor gradually decreased, In Comparative Example 1, in which the shell powder was not used, it was found that the amount of odor generated increased over time.

I. Comparison of odor removal ability in shell film when packaging TEA (triethylamine) -containing leather products

In order to more accurately measure the odor removal ability of the shell film, it was necessary to increase the concentration of odorous substances, and the experiment was repeated using a leather fabric containing an organic compound of amines, which is one of the odor generating substances. Triethylamine (TEA) was used as amine. TEA was sprayed on the leather fabric to investigate the concentration change of the internal gas. The comparison of the odor removal ability in packaging TEA-containing leather products is shown in FIG. 8.

From the above experimental results, it was found that when the shell powder was added, the concentration of the amine in the film was rapidly decreased, whereas in Comparative Example 1 without the shell powder, the concentration of the amine was increased.

All. Comparison of Odor Removal Capacity in Shell Films when Pyridine-Containing Leather Products are Packaged

The experiment was conducted in the same manner as above except that undiluted pyridine was used as the malodor generating substance. A comparison of the malodor removal ability in packaging pyridine-containing leather products is shown in FIG. 9. From the above results, in the case of Example 2 surface-modified with a surfactant, it was found that the concentration of pyridine dropped sharply after 3 days and was hardly observed regardless of the content of the surfactant (3, 5, 10%). . Odor was also reduced in Comparative Example 2 using an unmodified shell powder, and Examples 4 and 6 modified with Ce and Mg showed a mild odor removal ability. On the other hand, in Comparative Example 1, which did not contain shell powder, the concentration of pyridine did not decrease, but rather increased.

As mentioned in the above odor removal principle, the surface of the surfactant has hydrophobic hydrocarbon chains, and these can assist surface adsorption of pyridine, TEA, etc., which are low polarity organic materials. On the other hand, since ordinary PE films do not have these adsorption points, there is no mechanism to reduce the internal amine concentration except for the method of release to the outside through the pupils in the film. I could confirm it.

In conclusion, the shell film modified with cationic surfactant showed the best odor adsorption and removal ability for all kinds of odors, and showed good physical properties at least 80% compared to LDPE films in terms of mechanical properties. In addition, in the case of Examples 4, 6 substituted with a cation showed a gentle odor removal ability, it was found that the mechanical properties are the best. In Comparative Example 2 using an unmodified shell powder, the odor removal ability was excellent, but the mechanical properties were deteriorated.

The present invention uses a shell powder whose surface is modified with a cation or a surfactant, which not only has excellent mechanical properties but also has an adsorption function for various odor causes, and is used for packaging leather products, plastic products, electronic products, chemicals, etc. It has the effect of providing the polyethylene composition which can be applied also to a material, and its manufacturing method.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

1 is a model diagram showing the principle that the odor is adsorbed in the film containing the shell powder according to the present invention.

2 is an IR spectrum of the shell film modified with DODAB according to the present invention.

3 is a graph comparing the maximum stress according to the shell content in the polyethylene film containing shell powder.

4 is a graph comparing the elongation at break according to the shell content in the polyethylene film containing the shell powder.

5 is a graph comparing the tear strength according to the shell content in the polyethylene film containing the shell powder.

6 is the GC spectrum of odor generated from the leather fabric itself.

7 is a graph comparing the odor removal ability of the shell film over time when packaging untreated leather products.

8 is a graph comparing the odor removal ability of the shell film with time when packaging leather products treated with triethylamine (TEA).

9 is a graph comparing the odor removal ability of the shell film with time when packaging leather products treated with pyridine.

Claims (7)

Shell powder is washed, dried and pretreated; Modifying the surface of the pretreated shell powder; And Adding 1-10% by weight of the shell-modified shell powder to the polyethylene resin; Method for producing a polyethylene resin composition, characterized in that consisting of steps. The method for producing a polyethylene resin composition according to claim 1, wherein the shell powder is modified using a cationic surfactant of C _11-19 . The method of claim 2, wherein the cationic surfactant is DODAB (n-dodecyl trimethylammonium bromide), CTAB (n-cetyltrimethylammonium bromide), or HTAB (n-hexadecyl trimethylammonium bromide). The method for producing a polyethylene resin composition according to claim 1, wherein the shell powder is modified using a divalent or trivalent cation. The method of claim 4, wherein the cation is Al, Ce, Mg. delete A polyethylene resin composition for packaging prepared by the method of any one of claims 1 to 5 and having an odor removal function containing 1-10% by weight of shell powder.