JP3123011B2 - Resin composition and film - Google Patents

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 a film, and more particularly, to a resin composition and a film which are excellent in strength and light in weight, and have low calorie during combustion and do not damage an incinerator. .

[0002]

2. Description of the Related Art Conventionally, various molded products made of various synthetic resins have been manufactured and used in large quantities. Various fillers are added and mixed to these resin molded products according to various purposes. There are various purposes for adding the filler, and one of them is to reduce the calorie burned during incineration after use of the molded article. That is, since the heat of combustion of the synthetic resin is usually very high, the incinerator may be damaged at the time of incineration. Therefore, the heat of combustion is reduced by adding an inorganic filler such as calcium carbonate. However, when a molded article to which a large amount of the above-mentioned inorganic filler is added is incinerated, a large amount of ash remains after incineration, which causes another problem of treating this ash.

[0003]

As a method for solving the above-mentioned problems, there is a method using wood powder, paper powder or the like as a filler. However, organic substances such as wood powder and paper powder are mainly composed of cellulose. Since it is a material, it is difficult to pulverize it. If a large amount of these wood powders and paper powders are mixed with synthetic resin, the mixing properties of the two are poor and the quality of the resulting molded products is significantly reduced. is there. When a strong kneader is used to improve the kneading properties, frictional heat is remarkably generated, and there is a problem that ignition occurs. When a small amount of wood powder, paper powder, or the like is mixed, the above problem does not occur, but in this case, the combustion heat during incineration cannot be reduced.

Further, conventional synthetic resin films are used in large quantities as various packaging materials such as shopping bags and garbage bags. Nature), which is a major cause of environmental pollution. Accordingly, an object of the present invention is to provide a resin composition and a film which are excellent in strength and light in weight, and have low calorie in combustion heat and do not damage an incinerator.

[0005]

The above object is achieved by the present invention described below. That is, the present invention has an average particle size of the thermoplastic synthetic resin 100 parts by Ri name by kneading a paper powder 20 to 200 parts by weight of 50 to 200 [mu] m,該古paper fines
Powder is 100 parts by weight of waste paper and 5 to 100 parts by weight of inorganic filler
Resin composition, characterized in der Rukoto those obtained by finely pulverizing preparative simultaneously, and obtained by forming the resin composition
A film characterized in that:

[0006]

According to a detailed study of the present inventor, when waste paper such as newspaper or magazine is finely pulverized to make the fiber length extremely short, a large amount of these fine powders is contained in the synthetic resin. It has been found that kneading is possible. In addition, the resin composition obtained in this manner and the molded article molded therefrom have significantly reduced combustion heat during incineration, and do not damage the incinerator. Further, it has been found that when the used paper fine powder accounts for 40% by weight or more in the composition, it is light in weight and has microbial decomposability in the presence of moisture.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. The synthetic resin used in the present invention is a general-purpose resin such as low-density polyethylene, high-density polyethylene, polyvinyl chloride, polystyrene, and polypropylene, and particularly when used for packaging films such as garbage bags, low-density polyethylene. Polyethylene is preferably used.

The used paper fine powder used in the present invention and mainly characterizing the present invention is obtained by finely pulverizing used paper such as used newspaper, magazine, and corrugated cardboard. Conventionally, an example in which used paper is pulverized is known. However, the conventional method of pulverizing used paper is such that the used paper is cut into fine pieces of paper, and cannot be called fine powder. In addition, there is an example in which waste paper cut into fine pieces is crushed, but in this case, the crushed material is in a fluffy fluffy state, and uniform mixing with a synthetic resin is impossible.

The inventor of the present invention has found that when the waste paper pulverized into the cotton lint is further finely pulverized by a pulverizer for producing matcha, for example, a super cyclone pulverizer manufactured by Murata Co., Ltd. It has been found that the fibers of the waste cotton-like waste paper are finely cut into a smooth powder. At the time of this pulverization, 5 to 100 parts by weight of an inorganic filler such as calcium carbonate and barium sulfate are added to 100 parts by weight of the used paper and pulverized at the same time.

The waste paper fine powder has a particle size of about 50 to 200 μm.
m, and according to the study of the present inventors, it has been found that the fine powder which can be sufficiently kneaded with the synthetic resin is about 75 to 150 μm. Particle size of used paper fine powder 50μ
m is not impossible, but there is no economical advantage. On the other hand, if the particle size exceeds 200 μm, kneading with the synthetic resin becomes extremely difficult, and the kneaded material is heated by the heat generated during kneading. There is a risk of fire.

The fine powder of the used paper can be mixed at a ratio of 20 to 200 parts by weight with respect to 100 parts by weight of the synthetic resin. If the addition amount is less than 20 parts by weight, the suppression of combustion heat during incineration is not sufficient. On the other hand, if it exceeds 200 parts by weight, kneading with a synthetic resin becomes difficult, and it is also difficult to form a film or the like. . A particularly preferred addition amount is 10
It is 50 to 120 parts by weight per 0 parts by weight. In particular, when the amount of the used paper fine powder in the synthetic resin composition exceeds 40% by weight,
Molded articles from the resulting composition become biodegradable in the presence of moisture, which is beneficial for solving environmental problems.

The method for producing the resin composition of the present invention may be the same as a conventionally known method. For example, a synthetic resin and a used paper fine powder are gently mixed at a desired ratio with a Henschel mixer or the like to form a mixture on the surface of the resin particles. The waste paper fine powder is adhered and continuously supplied to the feeder of the extruder, and the temperature in the extruder is reduced to about 1
It is obtained by adjusting the temperature to 00 to 150 ° C., continuously extruding from a die, and pelletizing it. To improve the dispersibility of the fine powder of waste paper, a small amount of synthetic resin is added to the fine powder of waste paper. A dispersant such as high molecular weight polyethylene or low molecular weight polypropylene is added and kneaded with a heating roll or the like to prepare a masterbatch having a used paper fine powder concentration of 50 to 80% by weight, and resin pellets are added thereto for dilution. Thus, a resin composition having a desired concentration can be obtained.

The film of the present invention can be obtained by forming a film of the above resin composition in the same manner as in a conventional technique such as an inflation method. The film obtained in this way 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.

[0014]

Next, the present invention will be described more specifically with reference to examples. In the following, "parts" and "%" are based on weight unless otherwise specified. Example 1 50 parts of low-molecular-weight polyethylene wax, 100 parts of low-density polyethylene resin, and 350 parts of used paper fine powder (average particle size of 75 μm) obtained by pulverizing old newspaper with Matcha crusher Super Cyclone manufactured by Murata Co., Ltd. After mixing lightly with a Henschel mixer, the mixture was kneaded with a heated three-roll at about 150 ° C. to form a sheet. After cooling, this was roughly pulverized to obtain a master batch (concentration of used paper fine powder: about 60%). This master batch 10
0 parts by weight and 100 parts of low density polyethylene
Kneading with a 0 m / m extruder (L / D = 28, CR = 3.1, screw with dalmage, cylinder temperature 130 ° C., screw rotation speed 70 rpm), pellet-shaped resin composition of the present invention ( Waste paper fine powder concentration: about 30%).

Next, the above resin composition is charged 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 gray polyethylene film having a film thickness of 50 μm. Was. The surface of this film is smooth and has sufficient strength, and its heat of combustion is about 7,500 Kca.
l.

Examples 2 to 7 and Comparative Example 1 Some used paper fine powders were prepared in the same manner as in Example 1, and these fine powders were used. A resin composition and a film were produced. The physical properties of these films are shown in Table 1 below.

[0017]

[0018]

According to the present invention as described above, there are provided a resin composition and a film which are excellent in strength and light in weight, have low calorie during combustion, and do not damage an incinerator.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C08L 97/02 C08L 97/02 (56) References JP-A-60-233134 (JP, A) JP-A-57-12060 (JP, A) JP-A-5-269736 (JP, A) JP-A-8-48855 (JP, A) JP-A-6-73231 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08 C08J 5/18

Claims (5)

(57) [Claims] 1. A mean particle size of the thermoplastic synthetic resin 100 parts by Ri name by kneading a paper powder 20 to 200 parts by weight of 50 to 200 [mu] m,該古paper fine powder, paper 100 parts by weight
And 5 to 100 parts by weight of inorganic filler are simultaneously pulverized to obtain
Resin composition characterized der Rukoto what was. 2. The resin composition according to claim 1, wherein the amount of the used paper fine powder is 50 to 120 parts by weight per 100 parts by weight of the synthetic resin. 3. The resin composition according to claim 1, wherein the particle size of the waste paper fine powder is 75 to 150 μm. 4. The resin composition according to claim 1, wherein the synthetic resin is a low density polyethylene. 5. A film, characterized in that obtained by forming a resin composition according to any one of claims 1-4.