JPH08183909A - Resin composition and film - Google Patents

Abstract

PURPOSE: To obtain the composition useful as a packing material, having excellent strength and lightweight, causing a low-calorie heat of combustion in an incinerator furnace by blending a synthetic resin with fine powder of old paper having an average particle diameter with a specific range. CONSTITUTION: This composition is obtained by blending (A) 100 pts.wt. of a synthetic resin with (B) 20-200 pts.wt., preferably 50-120 pts.wt. of fine powder of old paper having 50-200μm, preferably 75-150μm average particle diameter. The composition is preferably mixed with (C) an inorganic filler (e.g. barium sulfate) in an amount, for example, 5-100 pts.wt. of based on 100 pts.wt. of the component B.

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, lightweight, have a low calorific value when burning 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 calories burned when the molded product is incinerated after use. That is, since the combustion heat of synthetic resin is usually very high, the incinerator may be damaged during incineration. Therefore, an inorganic filler such as calcium carbonate is added to reduce the combustion heat. However, when a molded product containing a large amount of the above-mentioned inorganic filler 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 problems, there is a method of using wood powder, paper powder or the like as a filler. Organic materials such as wood powder and paper powder are mainly composed of cellulose. Since it is a material, it is difficult to pulverize it, and when mixing a large amount of these wood powder and paper powder with each other, the miscibility of both is poor, and the quality of the resulting molded product is significantly deteriorated. is there. When a powerful kneading machine is used to improve the kneading property, there is a problem that frictional heat is remarkably generated and an ignition occurs. Further, 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 at the time of incineration cannot be reduced.

Further, conventional synthetic resin films are used in large amounts as various packaging materials such as shopping bags, garbage bags, etc. If these materials are abandoned and not recovered, they are naturally degradable (microbial decomposition). It is a major cause of environmental pollution. Therefore, an object of the present invention is to provide a resin composition and a film which are excellent in strength and light in weight, have a low calorific value when burning, and do not damage the incinerator.

[0005]

The above object can be achieved by the present invention described below. That is, the present invention is based on the synthetic resin 100.
20 parts of fine powder of waste paper having a weight part and an average particle diameter of 50 to 200 μm
The resin composition is characterized by being kneaded with about 200 parts by weight, and a film obtained by forming a film of the resin composition.

[0006]

According to a detailed study by the present inventor, when finely crushed waste paper such as newspapers and magazines to extremely shorten the length of the fibers, a large amount of these fine powders was added to the synthetic resin. It was found that kneading is possible. Further, the resin composition thus obtained and a molded product molded from the resin composition have a remarkably reduced heat of combustion during incineration, and do not damage the incinerator. It was also found that when the fine powder of waste paper is 40% by weight or more in the composition, it is lightweight and microbial degradability occurs in the presence of water.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the 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, polypropylene, etc., especially when used in a packaging film such as a garbage bag, a low density Polyethylene is preferably used.

The fine powder of used paper used in the present invention and mainly characterizing the present invention is used finely pulverized used paper such as used newspapers, magazines and cardboards. Conventionally, an example of crushing used paper is known, but the conventional method of crushing used paper is to cut the used paper into fine paper pieces, and cannot be called fine powder. There is also an example in which waste paper cut into fine pieces is crushed, but in this case, the crushed product was in a cotton dust-like fluffy state, and uniform mixing with the synthetic resin was impossible.

The present inventor further finely pulverizes the above waste paper pulverized into cotton dust into a fine powder by a pulverizer for producing matcha, for example, Super Cyclone pulverizer manufactured by Murata Co., Ltd. It was found that the fibers of waste cotton-like waste paper were finely cut into a smooth powder. Upon this pulverization, 5 to 100 parts by weight of an inorganic filler such as calcium carbonate and barium sulfate is added to 100 parts by weight of the waste paper and finely crushed at the same time to obtain a fine powder of waste paper that is easier to mix with the synthetic resin.

The particle size of the fine powder of waste paper is about 50 to 200 μm.
According to the research conducted by the present inventor, the fine powder that can be sufficiently kneaded with the synthetic resin is about 75 to 150 μm. Fine particle size of waste paper 50μ
It is not impossible to make it less than m, but it is not economically advantageous. On the other hand, when the particle size exceeds 200 μm, the kneading with the synthetic resin becomes extremely difficult, and the heat generated during the kneading causes the kneaded product to be There is a fear of catching fire.

The fine powder of waste paper can be mixed in a ratio of 20 to 200 parts by weight to 100 parts by weight of the synthetic resin. If the amount added is less than 20 parts by weight, the combustion heat at the time of incineration is not sufficiently suppressed, while if it exceeds 200 parts by weight, it becomes difficult to knead with the synthetic resin, and it is also difficult to mold it into a film or the like. . A particularly preferable amount of addition is synthetic resin 10
It is 50 to 120 parts by weight per 0 parts by weight. Particularly when the amount of fine powder of waste paper in the synthetic resin composition exceeds 40% by weight,
Molded articles from the resulting composition become microbially degradable 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 the conventionally known method. For example, synthetic resin and fine powder of waste paper are mixed lightly in a desired ratio with a Henschel mixer or the like to form resin particles on the surface. Fine powder of waste paper is attached and continuously fed to the feeder of the extruder, and the temperature inside the extruder is about 1
It can be obtained by adjusting the temperature to 0 to 150 ° C, continuously extruding it from a die, and pelletizing this, but in order to improve the dispersibility of the fine powder of waste paper, a small amount of synthetic resin and low Add a dispersant such as high-molecular-weight polyethylene or low-molecular-weight polypropylene and knead with a heating roll to prepare a masterbatch with a waste paper fine powder concentration of 50 to 80% by weight, and add resin pellets to dilute it. However, 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 the prior art such as the inflation method. The film 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 colorants, antioxidants, antistatic agents, and other fillers as long as the object of the present invention is not impaired.

[0014]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. In addition, unless otherwise specified, "parts" and "%" in the text are based on weight. Example 1 50 parts of low-molecular weight polyethylene wax, 100 parts of low-density polyethylene resin, and 350 parts of waste paper fine powder (average particle size 75 μm) obtained by crushing old newspapers with a Super Cyclone matcha crusher manufactured by Murata Co., Ltd. (Including 50 parts of calcium carbonate) was lightly mixed with a Henschel mixer, and then kneaded with a heating three-roll mill at about 150 ° C. to form a sheet. After cooling, this was coarsely pulverized to obtain a master batch (waste paper fine powder concentration: about 60%). This master batch 10
4 parts by mixing 0 parts by weight and 100 parts of low density polyethylene
The pelletized resin composition of the present invention was kneaded with a 0 m / m extruder (L / D = 28, CR = 3.1, screw with dullage, cylinder temperature 130 ° C., screw rotation speed 70 rpm). A fine powder concentration of waste paper of about 30%) was obtained.

Then, the above resin composition was charged into an inflation device (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. It was The surface of this film is smooth and has sufficient strength, and its combustion heat is about 7,500 Kca.
It was l.

Examples 2 to 7 and Comparative Example 1 Several fine powders of waste paper 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.

Table 1 * 1: Biodegradable (when the film was buried in field soil for 6 months and then taken out, it became extremely brittle).

[0018]

As described above, according to the present invention, there are provided a resin composition and a film which are excellent in strength and light in weight, have a low heat of combustion during incineration and do not damage an incinerator.

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Claims (6)

[Claims] 1. A synthetic resin having 100 parts by weight and an average particle diameter of 50.
A resin composition, which is obtained by kneading 20 to 200 parts by weight of fine powder of used paper of ˜200 μm. 2. The resin composition according to claim 1, wherein the added amount of fine powder of waste paper is 50 to 120 parts by weight per 100 parts by weight of the synthetic resin. 3. The method according to claim 1, further comprising an inorganic filler.
The resin composition according to. 4. The resin composition according to claim 1, wherein the fine powder of waste paper has a particle size of 75 to 150 μm. 5. The resin composition according to claim 1, wherein the synthetic resin is low density polyethylene. 6. A film obtained by forming a film of the resin composition according to claim 1.