JP2002235013A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition that causes no environmental pollution, when it is processed to resin moldings that are tentatively needed in shopping, and the like, and to be disposed of after the use, for example, plastic sheets or pouches for protectively wrapping fresh foods, and the like, or trash bags and provide the moldings from the resin composition. SOLUTION: This resin composition characteristically comprises a thermoplastic resin, powdered rice chaff, a resin-degrading agent wherein the resin- degrading agent comprises biodegradation components, an unsaturated fatty acid or a derivative thereof, a transition metal and a hindered phenol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, and more particularly, to a resin composition excellent in natural degradability, a sheet, a film, a garbage bag, a food container, and a method for producing compost.

[0002]

2. Description of the Related Art Conventionally, packaging materials made of various polyethylene films, for example, shopping bags, garbage bags, and the like have been manufactured and used in large quantities. Also, various food containers and other various molded products are manufactured from resins such as polypropylene, polyester, polystyrene, ABS resin, and AS resin.

[0003]

Of the above-mentioned packaging materials, for example, at the present time, it is difficult to collect all of the shopping bags, which is a major cause of environmental pollution.
In addition, although the disposal of the contents of garbage bags is partially processed by landfill or incineration, there is no other method of processing the garbage bags other than incineration. However,
Incinerators are damaged due to high calories during burning of polyethylene and the like, and construction of expensive incinerators is required. In supermarkets and convenience stores, food is packaged and sold in simple containers (for example, trays) and is consumed by each household. However, it is very difficult to separate and collect these used food containers. Even if collected, there is no effective disposal method other than incineration, and these food containers are also a major cause of environmental pollution.

As a method for solving the above-mentioned problems, various methods have been proposed for producing a shopping bag, a garbage bag, a food container, and the like by using a biodegradable resin. It is expensive and currently difficult to commercialize in terms of cost. Therefore, the object of the present invention is to
An object of the present invention is to provide a resin composition which does not cause environmental pollution due to a resin molded product which is discarded after temporary use such as a shopping bag, a garbage bag, and a food container, and a molded product thereof.

[0005]

The above object is achieved by the present invention described below. That is, the present invention includes a thermoplastic resin, rice husk powder, and a resin decomposer, wherein the decomposer comprises a biodegradable component, an unsaturated fatty acid or a derivative thereof, a transition metal, and a hindered phenol. And a resin composition characterized by the following. Further, the present invention provides a sheet,
The above resin composition molded into the shape of a film or a food container, a garbage collecting bag made of the film, and collecting garbage including garbage in the garbage collecting bag, and producing compost without opening the garbage bag. Provided is a method for producing compost to be composted in an apparatus.

According to the inventor's detailed research, these resin molded products can be obtained by kneading rice husk powder and a resin decomposer into a thermoplastic resin such as polyethylene to form a sheet, film or food container. It was found that even after disposal after use, it was easily decomposed into water and carbon dioxide within a certain period of time, and did not cause environmental pollution. In addition, the garbage bag can be composted simultaneously with its contents only by collecting garbage and the like in the garbage bag according to the present invention and collecting the garbage as it is in the composting machine. It has been found that there is no need to once remove the garbage from the garbage bag, and the costly process of collecting and incineration of the remaining garbage bag is omitted.

[0007]

Next, the present invention will be described in more detail with reference to preferred embodiments. The thermoplastic resin used in the present invention is a general-purpose resin such as polyethylene, polypropylene, polycarbonate, polystyrene, AS resin, ABS resin, and polyester, and these thermoplastic resins may be a novel virgin resin. And used various molded products such as PET bottles may be pulverized or granulated. In particular, the present invention is useful for polyethylene such as low density polyethylene, high density polyethylene, medium density polyethylene, linear low density polyethylene and high molecular weight polyethylene.

The rice hull powder used in the present invention is obtained by crushing rice hulls with, for example, a peanut mill manufactured by Aroma Kagaku Kikai Kogyo Co., Ltd.
The present inventors have found that a powder that can be sufficiently mixed with a thermoplastic resin and that can be molded is about 75 to 150 μm.
Although it is not impossible to make the particle size of the rice husk powder less than 50 μm, there is no economic advantage, while the particle size is 200 μm.
If it exceeds μm, kneading with a thermoplastic resin becomes extremely difficult.

[0009] The above rice husk powder is preferably used in a proportion of 1 to 55 parts by weight per 100 parts by weight of the thermoplastic resin. If the amount is less than 1 part by weight, the decomposition of the obtained resin composition is not promoted. On the other hand, if it exceeds 55 parts by weight, the moldability of the resin composition decreases, which is not preferable. In particular, when the molded product is a film, the used amount of the rice husk powder is preferably 1 to 30% by weight, and if it exceeds 30 parts by weight, it becomes difficult to form the film. On the other hand, in the case of a thick molded product, the amount of resin is reduced by using rice husk powder more than the resin,
As the cost of the product decreases, it is no longer regarded as a resin product, so that there is no obligation to collect the product, which leads to further cost reduction.

The decomposing agent used in the present invention comprises a biodegradable component, an unsaturated fatty acid or a derivative thereof, a transition metal, and a hindered phenol. Examples of the biodegradable component include starch, cellulose, derivatives of cellulose, other glucose derivatives, and biodegradable polyesters such as polycaprolactone and polylactic acid. The biodegradable component is present in the degrading agent in an amount from about 2% to about 95% by weight. For example, when the biodegradable component is granular starch, it is present in an amount of about 2-75% by weight.

The unsaturated fatty acids or derivatives thereof include:
Various drying oils and fats and unsaturated fatty acids obtained from the oils and fats are exemplified. For example, vegetable oils including corn oil, olive oil, rapeseed oil, soybean oil, cottonseed oil, sunflower oil, peanut oil and linseed oil, or unsaturated fatty acids obtained from these oils and fats may be mentioned. The unsaturated fatty acid or derivative thereof is preferably present in the decomposer in a range of about 0.25 to 5.0% by weight.

The transition metal is a compound of a transition metal such as iron or copper, and particularly preferably exists as a salt of a fatty acid. Fatty acids preferably have 10 to 20 carbon atoms. Particularly preferred are iron or copper stearate and / or hydroxystearate.
The transition metal is present in the decomposer in an amount of about 0.1-0.5% by weight.

Further, it is preferable to use an aromatic ketone in combination. Ketones make thermoplastic resins susceptible to degradation under the action of sunlight and / or ultraviolet light and heat. Examples of the aromatic ketone include benzophenone, anthraquinone, anthrone, acetylbenzophenone, 4-octylbenzophenone and the like, and a more preferred aromatic ketone is benzophenone. These ketones are about 0.02
Preferably it is present in the decomposer in an amount of 〜0.15% by weight.

As the hindered phenol, for example,
Benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxyoctadecyl ester (Irganox 1076 manufactured by Ciba Geigy). This latter compound is very effective in stabilizing low density polyethylene, but can also be used to stabilize other thermoplastics. The hindered phenol is present in the decomposer in any amount, but the amount will vary depending on the age of the final molding. Usually 0.01
It is present in an amount of ~ 3.0% by weight. If the amount of hindered phenol is small, the molded article is degraded quickly, and the higher the amount of hindered phenol, the longer the strength of the molded article is maintained.

The decomposing agent used in the present invention can be obtained by kneading the above components with a thermoplastic resin having good compatibility with polyethylene or the like, in particular, a copolymer of ethylene and another vinyl monomer. The decomposing agent can be kneaded with a thermoplastic resin such as polyethylene together with the rice husk powder to obtain the resin composition of the present invention. The decomposing agent is “Degra Novon” (for example, product number NBK310, OAQ002
5, LAD2025, NKK1172, etc.) and used in the present invention.

The decomposing agent used in the present invention is disclosed in Japanese Patent No. 2961138. In the present invention, a more excellent effect can be obtained by kneading the decomposing agent together with rice husk powder into a thermoplastic resin. Was obtained. That is, a molded product such as a film made of the conventional resin composition maintains its physical properties in an environment with few microorganisms, and deteriorates, that is, degrades in an environment with many microorganisms. The above-mentioned tendency is more remarkable for the object. That is, in an environment low in microorganisms (for example, when manufacturing, stocking, and using molded products), the antibacterial property of rice husk powder makes it less likely to be deteriorated by microorganisms. The film becomes porous due to the decrease in the molecular weight of the polymer, and the rice husk powder accelerates the porosity. As a result, the decomposition of the film is significantly accelerated in an atmosphere rich in microorganisms, for example, in the natural world or in a compost manufacturing device. Was found.

In the resin composition of the present invention, a double bond of an unsaturated fatty acid or a derivative thereof contained therein is oxidized by a catalytic action of a transition metal, a ketone or the like to generate free oxygen radicals. Oxygen radicals oxidize carbon-carbon bonds of the resin and decompose the polymer. At this time, the oxidative deterioration is suppressed while the hindered phenol is present. When the hindered phenol is consumed, the above-mentioned oxidative deterioration occurs, and the polymer starts to deteriorate. After this point, if the film is left in the natural world or put into a compost manufacturing device, biodegradable components such as starch will be decomposed,
The film becomes porous, and the low molecular weight polymer is similarly degraded by microorganisms. Although the reason for the chaff powder in the resin composition of the present invention is unknown, while maintaining the strength of the film for a certain period of time, after the film starts to be decomposed, it significantly promotes the degradation (decomposition) of the film. The effect was recognized.

The method for producing the resin composition of the present invention may be the same as a conventionally known method. For example, a thermoplastic resin, rice husk powder, and components of a decomposing agent or a decomposing agent (the above-mentioned commercially available product) may be prepared at a desired ratio. Lightly mix with a Henschel mixer or the like to attach the rice husk powder and the decomposing agent to the surface of the resin particles, continuously supply this to the feeder of the extruder, adjust the temperature in the extruder to about 100 to 150 ° C, It is obtained by continuously extruding from a die and pelletizing this. In this case, when a commercially available decomposing agent is used, it is preferable to use 10 to 30 parts by weight of the decomposing agent per 100 parts by weight of the resin.

The sheet or film or other molded article of the present invention is obtained by forming a film from the above resin composition in the same manner as in a conventional technique such as an inflation method, a T-die method, an injection molding method, and a vacuum molding method. Obtained by The film of the molded product thus obtained is suitable as a raw material for shopping bags and garbage bags in retail stores. The resin composition of the present invention may include other additives such as a coloring agent, an antioxidant, an antistatic agent, and other fillers as long as the object of the present invention is not hindered.

[0020] The plastic bag or garbage bag of the present invention is used for composting garbage, especially at home or in various garbage disposal sites, and the raw garbage is directly taken into the compost manufacturing apparatus without being taken out of the bag. Bags can also be composted at the same time, and even if these shopping bags and garbage bags are left in the environment, they undergo complete microbial degradation in a few months to several years, turning into mainly water and carbon dioxide. And does not pollute the environment.

[0021]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, “part” or “%” is based on weight unless otherwise specified. Example 1 77 parts of polyethylene, chaff powder (particle size: about 100 μm)
7.6 parts and decomposer (ODA0, manufactured by Novon Japan)
031) After lightly mixing 15.4 parts with a Henschel mixer, a 40 m / m extruder (L / D = 28, CR =
3.1, screw with dull mage, cylinder temperature 1
Kneading at 30 ° C. and a screw rotation speed of 70 rpm)
A pellet-shaped resin composition of the present invention was obtained.

Next, the above resin composition is put into an inflation apparatus (40 m / m extruder, inner diameter 50 m / m inflation die, cylinder temperature 140 ° C., screw rotation speed 60 rpm) to obtain a light brown polyethylene film having a film thickness of 40 μm. Was. Content 4 using this film
Bags were made in 5-liter garbage bags.

Examples 2 to 7 and Comparative Example 1 Several films were produced in the same manner as in Example 1, and garbage bags were produced in the same manner. Table 1 shows the composition of the film.

Test Example 1 (Thermal Deterioration Test) The films obtained in the above Examples and Comparative Examples were cut into a size of 2 inches in length and 0.6 inches in width and left at 80 ° C. The degree of elongation (%) (elongation at break) was measured using an Instron crosshead speed of 20 inches / mi.
n. Table 2 below shows the results.

Test Example 2 (Heat Deterioration Test) Film obtained by cutting the films obtained in the above Examples and Comparative Examples into a size of 2 inches in length and 0.6 inches in width and performing a weather ometer test at 50 ° C. The elongation (%) (elongation at break) of the Instron crosshead speed was 20 inches / min. Table 3 below shows the results of the measurement. From the results of Tables 2 and 3, it can be seen that the film according to the present invention is rapidly decomposed after maintaining a certain strength for a certain period.

Example 8 A shopping bag having a capacity of 2 liters was prepared from the film produced in Example 1, and garbage discharged from home was placed in the bag. It was put into a household compost manufacturing device together with the garbage and examined one week later. As a result, no trace of the film remained in the device.

[0027]

According to the present invention as described above, a resin composition, a sheet, a film, a container, and the like, which maintain strength for a certain period of time and then rapidly decompose, are provided, which is useful for preventing environmental destruction. it is obvious.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08K 3/08 C08K 3/08 5/13 5/13 C08L 91/00 C08L 91/00 97/02 97 / 02 (72) Inventor Kuniyoshi Sudo 2-23-8 Shimotani, Taito-ku, Tokyo Within Environmental Create Co., Ltd. (72) Yoshihiko Kusakabe 2-2-2, Yoyogi, Shibuya-ku, Tokyo Business Creation of East Japan Railway Company F-term in headquarters (reference) 3E064 BA12 BA22 BA60 BB01 BC20 EA22 FA01 3E086 AA23 AB01 AD01 BA02 BA04 BA15 BA29 BA35 BB75 CA40 4F071 AA02 AA09 AA71 AA73 AC11 AE05 AF52 AH04 BA01 BB05 BB06 AB01 BB05 AB01 BB05 BB06 BB05 BB06 BB05 BB06 BB05 BB05 BB06 BC03W BC05W BN15W CF00W CF18Y CF19Y CG00W EG047 EJ016 FD036 FD207 GG00

Claims (6)

[Claims] Claims 1. A thermoplastic resin, rice husk powder, and a resin decomposer, wherein the decomposer comprises a biodegradable component, an unsaturated fatty acid or a derivative thereof, a transition metal, and a hindered phenol. Characteristic resin composition. 2. The method according to claim 1, wherein the rice husk powder is contained in the resin composition in an amount of 1 to 2.
The resin composition according to claim 1, which accounts for 55% by weight. 3. The average particle size of the rice husk powder is 50 to 200 μm.
The resin composition according to claim 1, wherein m is m. 4. The resin composition according to claim 1, which is formed into a sheet, film or food container. 5. A garbage collection bag comprising the film according to claim 4. 6. A method for producing compost, comprising: collecting garbage including garbage in the garbage collection bag according to claim 5, and composting the garbage in the compost manufacturing apparatus without opening the garbage bag.