JP2002129043A - Biodegradable resin composition, biodegradable resin molded body and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable resin composition and a biodegradable resin molding body, whereby sludge is effectively used and which is more excellent in performance than conventional degradable resin, and to provide a production method thereof. SOLUTION: The degradable resin composition has a resin component having the degradable resin and sludge component. For example, at least one of aluminum, calcium, iron, silicon, magnesium, titanium, antimony, chlorine, fluorine, fiber component, phosphorus or nitrogen is contained as a component of sludge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, a biodegradable resin composition having biodegradability, a biodegradable resin molded article obtained by molding the biodegradable resin composition, and a method for producing the same.

[0002]

2. Description of the Related Art Plastics are used everywhere in containers, packaging materials, household goods, agricultural equipment, house building materials, automobile and home electric parts. Although plastics are lightweight, high-strength, and have excellent workability, they are bulky when discarded after use, which causes a shortage of disposal sites and has a problem that they hardly decompose even after landfill. From the above problems, in recent years, global environmental problems have been highlighted, and biodegradable resins have come into the spotlight as environmental load reducing materials (materials that can be returned to soil).

[0003]

However, the above-mentioned conventional biodegradable resins are expensive compared with general synthetic non-biodegradable plastics and have mechanical properties such as impact resistance. The inferior performance in terms of flame retardancy, chargeability and the like is a major cause of the demand for biodegradable resins not increasing as expected. On the other hand, sludge accounts for the highest volume of general and industrial waste generated.Although the amount of sludge discharge is increasing year by year, some is used as compost, but most of it is used as compost. At present, they are landfilled or incinerated and are not being used effectively. In recent years, global environmental problems including garbage problems have come to be called out, and the need for effective utilization technology of this sludge discharge is increasing at a global level.

[0004] In view of the above-mentioned problems and the social background of the prior art, the present invention provides a biodegradable resin composition which is capable of effectively utilizing sludge and which is superior in performance to conventional biodegradable resins. An object of the present invention is to provide a resin molded product and a method for producing the same.

[0005]

Means for Solving the Problems As a result of intensive studies to overcome the above-mentioned problems, the present inventors have found that the performance of a biodegradable resin can be improved by adding a sludge component to the biodegradable resin. And completed the present invention. That is, the biodegradable resin composition of the present invention and the biodegradable resin molded article obtained by molding the biodegradable resin composition,
It contains a resin component containing a biodegradable resin and a sludge component.

For example, the sludge component includes an inorganic sludge component, and preferably, the sludge component includes at least one of aluminum, calcium, iron, silicon, magnesium, titanium, antimony, chlorine and fluorine. In the present specification, a sludge component mainly containing an inorganic substance is called an inorganic sludge, and the inorganic sludge component refers to a component contained in the inorganic sludge.

[0007] For example, the sludge component includes an organic sludge component, and preferably, the sludge component includes at least one of a fiber component, phosphorus, and nitrogen. In the present specification, a sludge component mainly containing an organic substance is called an organic sludge, and the organic sludge component refers to a component contained in the organic sludge.

According to the present invention, a resin component containing a biodegradable resin and a sludge component are contained as components of the biodegradable resin composition and the biodegradable resin molded product. In sludge,
Various substances are included, for example, inorganic substances such as various metals and organic substances such as fiber components are included. Therefore, for example, organic sludge obtained from domestic wastewater, etc.
In general, since a fiber component is mixed, when this is mixed with a resin component such as a biodegradable resin, mechanical properties such as impact resistance of the resin are improved. Further, the biodegradability and flame retardancy of the biodegradable resin composition can be improved by phosphorus and nitrogen contained in the organic sludge. On the other hand, by adding inorganic sludge to the resin component, the metal component in the state of oxides, hydroxides, or halides contained in the inorganic sludge, due to its flame retardancy and mechanical properties such as Young's modulus. It is also possible to improve the chargeability.

In order to achieve the above object, a method for producing a biodegradable resin composition according to the present invention comprises forming a biodegradable resin composition by adding a sludge component to a resin component containing a biodegradable resin. It is characterized by doing. Further, the method for producing a biodegradable resin molded article of the present invention includes a step of forming a biodegradable resin composition by adding a sludge component to a resin component containing the biodegradable resin; And molding the same.

For example, in the step of adding a sludge component to the resin component, an inorganic sludge component is added.
An inorganic sludge component containing at least one of aluminum, calcium, iron, silicon, magnesium, titanium, antimony, chlorine and fluorine is added.

For example, in the step of adding a sludge component to the resin component, an organic sludge component is added.
An organic sludge component containing at least one of a fiber component, phosphorus and nitrogen is added.

Preferably, before the step of adding a sludge component to the resin component, the method further comprises a step of drying the sludge to form a dried sludge product. The sludge dried product is added as a sludge component.

According to the present invention, the biodegradable resin composition and the biodegradable resin which can effectively utilize the sludge discharged as waste and have excellent performance while reducing costs. A molded article can be manufactured.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a biodegradable resin composition, a biodegradable resin molded product, and a method for producing the same according to the present invention will be described.

As described above, the biodegradable resin composition and the resin molded product of the present invention contain a resin component containing a biodegradable resin and a sludge component.

In the present invention, a biodegradable resin refers to a resin that can be decomposed by microorganisms. The biodegradable resin that can be used in the present invention is not particularly limited as long as it has the above properties. For example, polylactic acid, polyglycolic acid, hydroxyvalerate / butyrate copolymer, Butylene succinate, polycaprolactone, bacterial cellulose, curdlan, pullulan,
Filamentous fungi, cellulose, fatty acid polyester, starch,
Polycaprolactam, poly (-β-) propionlactone,
Chitin / chitosan, alginic acid, gluten, collagen, polyvinyl alcohol (PVA), polyamino acid (poly (-L-) glutamic acid, poly (-L-) lysine), polyethylene glycol (PEG), polypropylene glycol, celluloid, polylactide, polyurethane , Polycarbonate, polyglutamate, various polyamides, and the like.

As the resin component in the biodegradable resin composition of the present invention, the above-mentioned biodegradable resin may be used alone, or two or more of the above-mentioned biodegradable resins may be used in an arbitrary ratio. They may be mixed and used as a mixture.

Further, as a resin component in the biodegradable resin composition of the present invention, a mixture of the above-mentioned biodegradable resin and another synthetic non-biodegradable resin may be used.

The synthetic non-biodegradable resin includes:
There is no particular limitation as long as it is generally used for plastic materials and the like other than the above-mentioned biodegradable resins. For example, polystyrene (PS), high impact polystyrene (HIPS), styrene-acrylonitrile (SA)
N) resin, ABS (acrylonitrile-butadiene-styrene) resin, polyacrylonitrile (PAN) resin,
Nylon resin, polyolefin (polyethylene, polypropylene, polyisoprene) resin, polyphenylene ether (PPE), polyphenylene sulfide, polyacrylonitrile-butadiene (nitrile rubber), polycarbonate (PC), polyethylene terephthalate (PE
T), polybutylene terephthalate (PBT), polysulfone, polyallyl sulfone, polyether sulfone,
Polythioether sulfone, polyetherketone, polyetherimide, polyetheretherketone, polyamide, polyamideimide, polyimide, polyarylate, aromatic polyester, polyurethane, polyvinyl chloride, chlorinated polyether, polychloromethylstyrene,
Polyacrylate, polymethacrylate,
Examples include celluloid, epoxy resin, phenol-formalin resin, melamine resin, amber resin, terpene resin, various liquid crystal polymers, and the like.

As the resin component of the biodegradable resin composition of the present invention, the above-mentioned synthetic non-biodegradable resin may be independently mixed with the biodegradable resin, or the above-mentioned synthetic non-degradable resin may be used. A mixture obtained by mixing two or more kinds of biodegradable resins at an arbitrary ratio may be mixed with the biodegradable resin. In the specification of the present application, the term “mixture” refers to a general term for multi-component materials including two or more types of resins such as polymer alloys. The term includes the types that are dispersed by chemical treatment.

Both the biodegradable resin and the synthetic non-biodegradable resin may be virgin products, or may be used waste materials. From the viewpoint of effective use of waste materials, it is more preferable to use used resin as a raw material.

The mixing ratio at the time of mixing the above-mentioned biodegradable resin as a resin component is not particularly limited, but the content of the biodegradable resin is generally in the range of 0.1 to 99.9% by weight. is there.

The sludge in the present invention refers to semi-liquid waste generated during various treatments such as purification of various industrial wastewater or domestic wastewater. Examples of the above-mentioned sludge from various industrial wastewaters include those obtained from various industrial wastewaters such as electric / electronics in semiconductor production, automobiles, metals such as steelmaking, papermaking, chemicals, pharmaceuticals, and civil engineering.

The above-mentioned sludge originally contains various elements in the form of compounds and the like. However, in the case of wastewater treatment, a sulfuric acid band (aluminum sulfate), ferrous chloride and ferric chloride are used.
Since inorganic coagulants such as iron and PAC (polyaluminum chloride) are generally used, more kinds of elements or compounds thereof are mixed into the sludge.

For example, in the sludge obtained from various industrial wastewaters, although the sludge components differ in various industries, for example, aluminum, calcium, iron, silicon, magnesium, titanium, antimony, phosphorus, nitrogen,
At least one element of chlorine and fluorine is contained in the form of oxides, hydroxides, halides, sulfates, carbonates and the like, and such compounds are originally used as flame retardants. And these will greatly contribute to the flame retardancy of the resin.

In sludge obtained from various industrial wastewaters, metal elements such as aluminum, calcium, iron, silicon, magnesium and titanium contain oxides, hydroxides, halides, sulfates, carbonates and the like. When they are contained in the form of various metal salts, they will impart antistatic properties to the resin. Similarly, there is an effect of improving mechanical properties such as Young's modulus.

Also, for example, sludge obtained from domestic wastewater and the like generally contains a fiber component, and when this is mixed with a resin such as a biodegradable resin, mechanical properties such as impact resistance of the resin are obtained. Will be improved. Alternatively, sludge obtained from domestic wastewater and the like contains nitrogen and the like in addition to phosphorus derived from components such as detergents, and these can improve the biodegradability and flame retardancy of the resin. Become.

Here, in the specification of the present application, a sludge component mainly containing an inorganic substance is called an inorganic sludge, and a sludge component mainly containing an organic substance is called an organic sludge. It is considered that sludge obtained from the above-mentioned domestic wastewater mainly belongs to organic sludge, and sludge obtained from the above-mentioned industrial wastewater mainly belongs to inorganic sludge. In the biodegradable resin composition of the present invention, both the above-mentioned organic sludge and inorganic sludge may be mixed with a resin for use.

For example, the amount of the sludge component added in a dry state is 0.01 to 300% by weight, preferably 0.2 to 100% by weight, more preferably 1 to 100% by weight, based on the weight of the resin.
50% by weight. If the amount is too small, the effect of improving the performance of the biodegradable resin composition will be low, while if it is too large, the inherent properties of the resin such as moldability and impact resistance will be impaired.

Here, it is considered that the components of the sludge may change depending on each factory and time, but the components are added to the resin in consideration of a slight difference in the components. However, actually, as a result of the analysis, it has been confirmed that, for example, the components of sludge obtained from the same factory are almost the same.

Further, the biodegradable resin composition of the present invention may be mixed with a resin additive represented by carbon black or the like generally blended with the resin, if necessary, to reduce the processability such as kneading and molding. It can be added in a range not to do. Examples of the resin additives include, for example, antistatic agents, coloring agents such as pigments and dyes, phenolic antioxidants, phosphorus antioxidants, antioxidants such as sulfur antioxidants, aluminum hydroxide, Flame retardants such as antimony oxide, chlorine-based flame retardants, bromine-based flame retardants, phosphorus-based flame retardants, phthalate esters, fatty acid-based plasticizers, phosphate-based plasticizers, plasticizers such as polyester-based plasticizers, phosphites, epoxies Compounds, polyols, perchlorates, zeolites, heat stabilizers such as hydrotalcite, hindered amine light stabilizers, glass fibers,
Reinforcing fibers such as carbon fibers, inorganic fillers such as calcium carbonate and talc, reinforcing agents such as PTFE (polytetrafluoroethylene) powder, ultraviolet absorbers, compatibilizers, surface treatment agents,
Modifiers and the like can be mentioned.

According to the biodegradable resin composition of the present embodiment, the organic sludge obtained from domestic wastewater or the like generally contains a fiber component. In this case, the mechanical properties of the resin, such as impact resistance, are improved. Further, the biodegradability and flame retardancy of the resin can be improved by phosphorus and nitrogen contained in the organic sludge. On the other hand, by adding inorganic sludge to the resin, the metal component in the state of oxides, hydroxides or halides contained in the inorganic sludge,
In addition to mechanical properties such as Young's modulus, flame retardancy and chargeability can be improved. Accordingly, it is possible to effectively use sludge that has been conventionally treated as waste, and obtain a biodegradable resin composition containing a biodegradable resin excellent in performance and a resin molded article of the biodegradable resin composition. Can be. In addition, the present invention not only provides a biodegradable resin having excellent performance and a molded product thereof, but also contributes to environmental conservation of the earth from the viewpoint of reduction of waste emissions and effective use of resources. it can.

Next, a method for producing the biodegradable resin composition of the present invention will be described. First, sludge components obtained from various factory wastewaters and domestic wastewaters are analyzed, and at least one type of sludge suitable for use is determined. At this time, in consideration of returning the biodegradable resin composition and the resin molded body of the biodegradable resin composition to soil in the future, harmful substances such as mercury and arsenic use sludge containing as little as possible. Is preferred.

Since sludge from various types of industrial wastewater usually contains 70% to 80% of water, it is heated by heating with a hot air or using a rotary kiln, reduced in pressure, frozen, burned, and cooled to mix with resin. The sludge is dried by a method such as the day to produce a dried sludge. At this time, if the sludge is dried at a very high temperature, the color will turn dark due to carbonization, etc.
It is preferred to dry at the lowest possible temperature. For example, it is preferable to dry at a temperature lower than the resin molding temperature, and it is more preferable to dry at a temperature 20 ° C. or lower than the resin molding temperature.

Next, for mixing with a biodegradable resin or the like,
If necessary, the dried sludge is pulverized or classified into fine powder having a small particle size distribution.

Next, the above-mentioned dried powdery sludge, a biodegradable resin, and, if desired, a synthetic non-biodegradable resin and other resin additives are blended in a predetermined ratio. It is manufactured by a general method of compounding a synthetic resin using a mixer such as a roll mill, a kneader, an intermix, and a Banbury mixer.

When producing a resin molded article of the obtained biodegradable resin composition, the biodegradable resin composition obtained by the above method is subjected to, for example, compression molding, transfer molding, injection molding. , Casting, slash molding,
A biodegradable resin molded article can be obtained by selecting an appropriate method from various molding methods such as vacuum molding, lamination molding, and extrusion molding depending on the components of the biodegradable resin composition and the shape of the molded product.

According to the method for producing the biodegradable resin composition and the biodegradable resin molded article according to the present embodiment, the sludge discharged as waste can be effectively used without the necessity of providing a new production step. Thus, a biodegradable resin composition and a biodegradable resin molded product having excellent performance can be manufactured while reducing costs.

The biodegradable resin composition, the biodegradable resin molded product and the method for producing the same according to the present invention are not limited to the above embodiments. For example, as described above, the types of the biodegradable resin, the synthetic non-biodegradable resin, and the resin additive used in the biodegradable resin composition are not particularly limited. Others
Various changes can be made without departing from the spirit of the present invention.

[0040]

Next, the present invention will be described in more detail with reference to examples. Note that what is described below is merely an embodiment of the present invention, and does not depart from the gist of the present invention.
The type of the resin, the mixing ratio of the sludge component, and the like can be freely changed.

Example 1 Sludge (containing 70% water) discharged from a semiconductor factory was subjected to a pressure drier at a pressure of 1.33 kPa (10 Torr).
It was dried at a temperature of 100 ° C. for 4 hours to obtain a dried sludge in the form of a white powder. As a result of the analysis, the dried sludge contained 21.8% by weight of aluminum, 15% by weight of calcium,
2.1% by weight of magnesium, 9.5% by weight of silicon
Was included. Next, a mixture of the dried sludge and a commercially available polylactic acid, which is a biodegradable resin, in an amount of 20% by weight was molded using a heat press machine to obtain a sheet-shaped resin plate.

Example 2 10% by weight of the dried sludge obtained by dewatering the mixed raw sludge from the sewage treatment plant was added to the same commercially available polylactic acid as used in Example 1.
The mixture was added and molded using a heat press to obtain a sheet-shaped resin plate. In addition, as a result of the analysis,
For example, 9.7% of the fiber component and 1.2% of the phosphorus component which are fibers such as organic fiber and paper of food were contained.

Example 3 Each of the sludge dried products of Examples 1 and 2 was added to the same commercially available polylactic acid as used in Example 1 in an amount of 10% by weight, and the mixture was formed by a heat press to form a sheet. Was obtained.

Comparative Example 1 As Comparative Example 1, a commercially available polylactic acid which is the same biodegradable resin as used in Examples 1 to 3 was used, and was formed by a heat press without adding a dried sludge. Was performed to obtain a sheet-shaped resin plate.

As described above, the surface resistance (JIS C 231) of the resin plates obtained in Examples 1 to 3 and Comparative Example 1 was obtained.
Table 1 shows the results of measurement of 8), flammability (UL Subject 94 HB method), and Izod strength (JIS K 7110).

[0046]

[Table 1]

As is clear from Table 1, the addition of the inorganic sludge discharged from the semiconductor factory to the biodegradable resin greatly improves the electrical properties such as surface resistance and the flame retardancy, while the sewage It can be seen that the mechanical properties are improved by adding the organic sludge from the treatment plant.

Example 4 A mixture of the dried sludge obtained in Example 1 and 30% by weight of a commercially available aliphatic polyester (a dehydration condensate of diol and dicarboxylic acid) as a biodegradable resin was molded by a heat press machine. Then, a sheet-shaped resin plate was obtained.

Example 5 15% by weight of the dried sludge of Example 2 was added to the same commercially available aliphatic polyester as used in Example 4, and the mixture was molded by a heat press to obtain a sheet-like resin plate. Was.

Example 6 15% by weight of each of the dried sludge products of Example 1 and Example 2
Each of them was added to the same commercially available aliphatic polyester as used in Example 4, and molded by a heat press to obtain a sheet-shaped resin plate.

Comparative Example 2 As Comparative Example 2, a commercially available aliphatic polyester which is the same biodegradable resin as used in Examples 4 to 6 was used, and a heat press machine was used without adding dried sludge. Molding was performed to obtain a sheet-shaped resin plate.

As described above, the Izod strength (kgf · cm / cm) of the resin plates obtained in Examples 4 to 6 and Comparative Example 2 was measured in an atmosphere at 23 ° C., and the flexural modulus (kg) was measured. / M ² ) and the biodegradation rate (%) after 16 weeks in soil are shown in Table 2.

[0053]

[Table 2]

As is clear from Table 2, the addition of the dried sludge to the biodegradable resin significantly improves the mechanical properties (impact resistance, elastic modulus) and biodegradability.

[0055]

According to the present invention, a biodegradable resin composition containing a biodegradable resin and a biodegradable resin containing the biodegradable resin having excellent performance can be achieved while effectively utilizing sludge conventionally treated as waste. A resin molded article of the composition can be obtained. In addition, the present invention not only provides a biodegradable resin having excellent performance and a molded product thereof, but also contributes to environmental conservation of the earth from the viewpoint of reduction of waste emissions and effective use of resources. it can.

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Claims (22)

[Claims] 1. A biodegradable resin composition comprising a resin component containing a biodegradable resin and a sludge component. 2. The biodegradable resin composition according to claim 1, wherein said sludge component includes an inorganic sludge component. 3. The biodegradable resin composition according to claim 2, wherein the sludge component contains at least one of aluminum, calcium, iron, silicon, magnesium, titanium, antimony, chlorine and fluorine. 4. The biodegradable resin composition according to claim 1, wherein said sludge component contains an organic sludge component. 5. The biodegradable resin composition according to claim 4, wherein the sludge component contains at least one of a fiber component, phosphorus and nitrogen. 6. A biodegradable resin molded article containing a resin component containing a biodegradable resin and a sludge component. 7. The biodegradable resin molded article according to claim 6, wherein said sludge component includes an inorganic sludge component. 8. The biodegradable resin molded article according to claim 7, wherein said sludge component contains at least one of aluminum, calcium, iron, silicon, magnesium, titanium, antimony, chlorine and fluorine. 9. The biodegradable resin molded article according to claim 6, wherein said sludge component includes an organic sludge component. 10. The biodegradable resin molded article according to claim 9, wherein the sludge component contains at least one of a fiber component, phosphorus and nitrogen. 11. A method for producing a biodegradable resin composition, comprising adding a sludge component to a resin component containing a biodegradable resin to form a biodegradable resin composition. 12. The method for producing a biodegradable resin composition according to claim 11, wherein an inorganic sludge component is added as said sludge component. 13. The biodegradable resin composition according to claim 12, wherein an inorganic sludge component containing at least one of aluminum, calcium, iron, silicon, magnesium, titanium, antimony, chlorine and fluorine is added as said sludge component. Method of manufacturing a product. 14. The method for producing a biodegradable resin composition according to claim 11, wherein an organic sludge component is added as said sludge component. 15. The method for producing a biodegradable resin composition according to claim 14, wherein an organic sludge component containing at least one of a fiber component, phosphorus and nitrogen is added as said sludge component. 16. The biodegradable resin composition according to claim 11, wherein the sludge is dried to form a dried sludge before adding the sludge component to the resin component, and the dried sludge is added as the sludge component. Method of manufacturing a product. 17. A biodegradable resin comprising: a step of adding a sludge component to a resin component containing a biodegradable resin to form a biodegradable resin composition; and a step of molding the biodegradable resin composition. A method for producing a molded article. 18. The method for producing a biodegradable resin molded article according to claim 17, wherein in the step of adding a sludge component to the resin component, an inorganic sludge component is added. 19. The process of adding a sludge component to the resin component, wherein aluminum, calcium, iron, silicon,
The method for producing a biodegradable resin molded product according to claim 18, wherein an inorganic sludge component containing at least one of magnesium, titanium, antimony, chlorine and fluorine is added. 20. The method for producing a biodegradable resin molded article according to claim 17, wherein in the step of adding a sludge component to the resin component, an organic sludge component is added. 21. In the step of adding a sludge component to the resin component, at least one of a fiber component, phosphorus and nitrogen is added.
The method for producing a biodegradable resin molded product according to claim 20, wherein an organic sludge component containing at least one of the following components is added. 22. A process for drying a sludge to form a dried sludge before the step of adding a sludge component to the resin component, wherein the step of adding the sludge component to the resin component comprises the step of: The method for producing a biodegradable resin molded product according to claim 17, wherein the sludge dried product is added as a component.