JPH05125718A - Degradable polymer sheet for civil construction work - Google Patents

Abstract

PURPOSE:To permit ground-reinforcing effect to continue as well as accelerate the decomposition of dusts by using a photo-or biodegradable polymer sheet with thick frames and thin window parts. CONSTITUTION:Discrete grooves and lines are formed alternately on photo- or biodegradable polymer sheets B, and the polymer sheet B is tensed to right- angled direction to at least the groove while heated to form thick frames 2 and thin window parts 3. In this case, the thickness of the thick frame is controlled to be 0.5-5mm and that of the thin window parts 3 is controlled to be 20-400mum. When covering wastes 5 with the polymer sheets B, degradation is started from the window parts 3 to accelerate the decomposition of the wastes 5, and the reinforcing effect of the ground by the sheets B is continued by the frames 2 considerably delayed in degradation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collapsible polymer sheet, and more particularly to a collapsible polymer sheet for civil engineering having a ground reinforcing effect.

[0002]

2. Description of the Related Art In recent years, artificial materials have been concentrated in cities, and in proportion to this, a large amount of scraps of paper, wood, metal, plastic, etc., and scraps of cooking residues such as vegetables and meat are generated, and this treatment is large. It's a problem. Although there are cases in which these refuse are incinerated or resources are recovered, they are generally discarded at landfill sites.

[0003] In this case, the soil is covered in a layer form of 0.5 to 1 m while the dust layer is 1 to 3 m. By such a treatment, the odor of dust is prevented, the appearance is improved by hiding the dust, and the occurrence of hunting food and flies for dogs and cats is also prevented. Decomposition of garbage by microorganisms and compression of the garbage due to the weight of the soil reduce the volume.

[0004]

However, even in this case, the waste remains abandoned until it reaches a certain amount, and therefore, the bad smell and scattering of the waste cannot be prevented, and
Since the soil has to be brought in, it takes time and labor to dispose of it and the cost of waste disposal is high. On the other hand, instead of covering the soil with soil, a sheet such as polyethylene may be covered to simply prevent the harmful effects of the garbage, but this polyethylene sheet will remain in the garbage forever. , Even if you cover it with soil,
It semi-permanently blocks the soil from the waste, prevents the decomposition of the waste by microorganisms in the soil, does not progress the soil into waste, and the waste treatment plant is left in an unstable state forever, making it a landfill. There is a drawback that the land cannot be used.

The present invention has been made in view of the above-mentioned conventional drawbacks, and relates to a sheet for covering a waste material to prevent a harmful effect due to the waste material, even if it is buried in the soil as it is. For the purpose of providing a collapsible polymer sheet that eliminates the boundary with garbage, does not prevent the decomposition of garbage by microorganisms in the soil, and that brings this into the soil to reinforce the ground. There is.

[0006]

The present invention achieves the above object by adopting the following configuration. That is, the gist of the present invention is that a polymer sheet that decomposes into light or microorganisms is engraved with a plurality of intermittent recesses alternately and biaxially with respect to at least the recesses during heating. The invention relates to a collapsible polymer sheet for civil engineering, characterized in that a large number of frame portions and thin window portions are formed by pulling in the direction, and the thick portion of the sheet has a thickness of 0.5. ~ 5 mm, the thin portion is 20 ~ 400μ.

The composition for disintegrating sheets of the present invention is a conventional kneading of each component mixture using a Banbury mixer, a pressure kneader, a twin-screw extruder, a roll kneader and the like. Method, the mixture is kneaded under heating (usually 80 to 200 ° C.) with sufficient shearing force, extruded and pelletized. The collapsible sheet is manufactured by an inflation tuber film manufacturing method, a T-die casting method or the like, and the thickness of the sheet before pulling is 0.5 to 20 mm, preferably 1 to 10 m.
It is assumed to be a sheet of m. A plurality of intermittent recesses are formed in this sheet, and the recesses are biaxially stretched during heating to form a large number of frame portions and thin window portions.

[0008]

Since the present invention employs the above construction, even if such a sheet is covered with dust, it will be destroyed by light or microorganisms in due course. This collapse naturally starts from the very thin part of the window, and therefore does not permanently block the dirt from the soil and promotes the soiling of the dirt.

Characteristically, since the collapse of the frame portion of the sheet is extremely slow with respect to the window portion, a net having a continuous frame portion exists in the soil. In the case where such a net-like sheet intervenes in the soil in several layers, for example, in the case of an embankment, the collapse is almost completely prevented and the ground sheet is strengthened.

In the present invention, the disintegrating polymer is a polymer which is disintegrated by light or microorganisms, and is a modified polyethylene, that is, an ethylene-carbon monoxide copolymer, an ethylene-carbon monoxide-ethylenically unsaturated compound copolymer. Examples include polymers, polycaprolactone, copolymers of vinyl aromatic monomers and conjugated dienes of 0.1 to 9.5% by weight, plastics containing a photodegradation accelerator, and plastics containing a transition metal compound. As the disintegrating polymer, ethylene-
A carbon monoxide- (ethylenically unsaturated compound) copolymer, and polycaprolactone as the microbial disintegrating property are particularly desirable in consideration of cost, processability, disintegrating property, and initial strength of the sheet.

The modified polyethylene used in the present invention comprises ethylene as a main constituent and carbon monoxide or a copolymer of carbon monoxide and an ethylenically unsaturated compound, wherein the amount of carbon monoxide is 0.5 to 5. It is 10% by weight. When the copolymerization ratio of carbon monoxide is less than 0.5% by weight, the photodecomposition rate is remarkably low, while when it is 10% by weight or more, the photodecomposition rate becomes too high and the strength is reduced in a short time, which is desirable. Absent.

The ethylenically unsaturated compound used in the present invention includes vinyl acetate, vinyl butyrate, (meth)
Acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, maleic acid, fumaric acid, etc. can be mentioned, but in terms of cost, film strength, heat resistance, gloss, phase, etc. Vinyl acetate and ethyl acrylate are preferred. Further, when carbon monoxide is copolymerized with an ethylenically unsaturated compound such as vinyl acetate or ethyl acrylate, photodegradation after a lapse of a certain period of time abruptly occurs, and the transparency of the sheet is further improved. When the ethylenically unsaturated compound is copolymerized, the copolymerization ratio is 1 to
20% by weight is preferred. If it is less than 1% by weight, the effect of copolymerization will not be exhibited, and if it exceeds 20% by weight, the effect of copolymerization will reach the saturation point and the strength of the sheet will decrease, which is not desirable.

The modified polyethylene in the present invention is specifically, for example, using a high-pressure process low-density polyethylene manufacturing apparatus, a reaction temperature of 150 to 300 ° C. and a pressure of 500 to 3
Under the condition of 000 atm, dilauroylperoxide,
A free radical generator such as tertiary butyl peroxide dissolved in an inert organic solvent such as benzene, kerosene or mineral oil was injected into the reactor, and ethylene and carbon monoxide and, if necessary, other Using a method of copolymerizing with an ethylenically unsaturated compound, a medium- and low-pressure method high-density polyethylene manufacturing apparatus, a reaction temperature of 50 to 300 ° C., a pressure of 0 to 2
In the presence of a coordination catalyst or a metal catalyst under the conditions of 00 atm, ethylene and carbon monoxide and, if necessary, other ethylenically unsaturated compounds are co-produced by a slurry method, a solution method or a gas phase method. It can be produced by a method of polymerizing.

The polycaprolactone used in the present invention means ε-caprolactone and ethylene glycol,
It is obtained by reacting with a diol such as diethylene glycol in the presence of a catalyst. As the catalyst used in this reaction, organotin compounds, organotitanium compounds, etc. are generally used.
The polycaprolactone resin is obtained by polymerization at ℃, preferably in an inert gas. These manufacturing methods are disclosed in, for example, Japanese Patent Publication No. 35-189, Japanese Patent Publication No. 35-497, and Japanese Patent Publication No. 40-23917.

In the present invention, examples of the photodegradation accelerator include benzophenone, anthraquinone, acetophenone, indandione, indanone and derivatives of these compounds. Examples thereof include 4-chlorobenzophenone, 4-methylbenzophenone and 2-chlorobenzophenone. , 2-methyl-4-hydroxybenzophenone, 4-nitrobenzophenone, 2-methylanthraquinone, 1-chloroanthraquinone, 3-bromoacetophenone, 4-bromoacetophenone, 2-methyl-4-chloroacetophenone, 3-nitroacetophenone, 2 -Chloroindandione, 2,2-dichloroindandione, 2-chloro-
2-bromoindandione, 6-chloroindanone,
2,2-dichloroindanone, 3,3-dichloroindanone and the like can be mentioned, and 0.01 to 10 parts by weight is added to 100 parts by weight of the polyolefin.

In the present invention, the transition metal compound is
Examples thereof include organic acid salts of iron, manganese, cobalt, or copper, organic chelate compounds, and the like, and specific examples thereof include iron acetate, iron naphthenate, iron stearate, iron oxalate, and iron acetylacetate. , Manganese acetate, manganese naphthenate, manganese oxalate, manganese acetylacetonate, cobalt acetate, cobalt naphthenate, cobalt acetylacetonate, copper acetate, copper naphthenate, copper acetylacetonate and the like, polyolefin 0.0 to 100 parts by weight
Add 1 to 10 parts by weight.

In the present invention, a deodorant, a deodorant, and a dog, a cat, or a bird that absorbs or chemically bonds the odor generated from waste to the disintegrating polymer so as not to make residents in the vicinity of the waste disposal site uncomfortable. Repellent, as well as antistatic agents, lubricants,
Antioxidants, pigments and the like can be added.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description will be given below with reference to the drawings. Figure 1
Is a plan view of the disintegratable sheet before being pulled (stretched),
The sheet A has a thickness (T) of 5 mm and the recess 1 has a diameter of 10 mm.
mm, and the recessed portion 1 was formed on both sides of the sheet, and the depth thereof was about 2 mm, respectively. The vertical and horizontal distances W ₁ and W ₂ between the recesses 1 and 1 are 30 mm, respectively. Simultaneous tensile forces were applied in the two axial directions at 125 ° C. to obtain a civil engineering disintegratable sheet B of the present invention shown in FIG. The obtained sheet B is a square frame 2 having a side of about 40 mm,
A window 3 in which a thin layer having a thickness of 150 μ is present in the frame 2 at substantially the center thereof.
It consists of The thickness of the frame 2 is about 1.2 mm
Met.

FIG. 3 shows a conceptual diagram of the case where the disintegratable polymer sheet B for civil engineering is used to cover the trash and is buried in the soil 4, as well as preventing the odor and scattering of the trash 5 and the like. In the soil 4, the thin part of the window 3 is disintegrated and the microorganisms in the soil 4 are mixed with the waste 5 through the window 3 while maintaining the environmental beauty. Decomposition, etc. will proceed. As a result, the refuse 5 layer and the soil 4 are integrated without being interrupted by the polymer sheet B. Of particular importance is that the frame portion 2 of the polymer sheet B is, of course, decomposed, but it remains in the state of being buried in the soil for a long time. The part 2) will be present in the embankment, for example, and the reinforcing effect of the ground will be particularly excellent.

FIG. 4 shows the above-mentioned example in which the recessed portion 1 is formed only on one surface of the sheet A, so that the thin layer becomes the window 3 which is biased to one side of the frame 2. It is a disintegratable polymer sheet B for civil engineering. Uses, characteristics, etc. are the same as in the above example.

[0021]

As described above, the present invention relates to a disintegrating polymer sheet which is decomposed by light and microorganisms, and even if it is buried in the soil with dust, only this protrusion is first decomposed. However, the decomposition of the waste was promoted, and the residual frame part provided the ground reinforcement effect.

[Brief description of drawings]

FIG. 1 is a plan view of a disintegratable sheet before tension (stretching).

FIG. 2 is a sectional perspective view of a collapsible polymer sheet for civil engineering of the present invention.

FIG. 3 is a conceptual diagram when the collapsible polymer sheet for civil engineering shown in FIG. 2 is buried in soil.

FIG. 4 is a sectional view showing another example of the collapsible polymer sheet for civil engineering of the present invention.

[Explanation of symbols]

A: Sheet before tension (stretching), B: Collapsible sheet for civil engineering, 1 ... Recessed portion, 2 ... Frame, 3 ... Window, 4 ... Soil, 5 ... Garbage, W ₁・ ・ ・ Gap in the longitudinal direction of the groove, W ₂・ ・ ・ Gap in the width direction of the groove.

Claims (2)

[Claims] 1. A polymer sheet that decomposes into light or microorganisms is provided with a plurality of intermittent recess grooves alternately and engraved, and this is pulled at least at right angles to the grooves during heating, A collapsible polymer sheet for civil engineering, comprising a large number of thick frame portions and thin window portions. 2. The thick portion is 0.5 to 5 mm, and the thin portion is 20.
The collapsible polymer sheet for civil engineering according to claim 1, wherein the disintegratable polymer sheet has a particle size of ˜400 μ.