DE4418634A1 - Made of biodegradable resin molded article - Google Patents

Abstract

A biodegradable article is molded from a material obtained by kneading or melting and mixing a biodegradable resin raw material and at least one of a biodegradable additive and an additive made of a substance existing in the nature. An injection molded article of a biodegradable resin containing a biodegradable resin and an antibiotic substance, an article moulded from a resin composition consisting of a polymer material having an ester bond in the polymer main chain thereof and an alkali or acid component in an amount effective for neutralizing an acidic or alkaline component contained in the polymer material, and a resin molded article having a layer of a biodegradable resin, and a layer of a photolytic resin covering the resin layer and containing an antibiotic are also disclosed.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

This invention relates to a molded article of biodegradable resin and a process for recovery Winning resources. In particular, the present concerns de invention a molded article of biodegradable resin, which is usable when durability is required and a method for recovering resources.

2. Description of the Related Art

Biodegradable resins made from soil bacteria completely decomposed and digested, have lately with one Growing environmental awareness is increasing attention pulled yourself.

Some patent applications for molded articles below Use of such a resin have already been incorporated ranges (eg Japanese Unexamined Patent Publications (Kokai) Nos. 3-290461, 4-146952 and 4-325526). This shape In particular, articles are considered to be film or video Packaging material used and it is not durability required.

However, it is expected that recovery of durable consumer goods, such as electrical products, Compu tern, etc., will be necessary in the near future, and therefore researches and developments were initiated to a Material for housing, etc., to get decomposed can. It is believed that biodegradable resins in this Aspect are advantageous because a decomposition treatment of recovered molded article with relatively low Ko can be carried out. To use a mold However, as a durable material, it must be one have sufficient strength and durability. Besides that is  a degradable resin, the satisfactory degradability, Strength and durability, for use as durable material currently not known.

In the case of an electrical circuit substrate suitable for electronic equipment is used in the mei Most cases a thermosetting resin used, with exception me inorganic materials, such as ceramics, and on the sub stratoberfläche a wiring is formed. It is very difficult to melt the thermosetting resin and liquid close. For separation and recovery of wiring A complicated procedure is required. There the thermosetting resin of the electric circuit substrate has no decomposability, it also remains at the Place where it is deposited and buried, semi permanently back.

From the aspect of the saving of resources it is ande on the other hand, not only to separate the materials, but also to recover raw materials.

Because the biodegradable resin of bacteria (eg, mold) decomposed, it is unlikely that it will its use is degraded by bacteria or decomposed. Therefore, the field of application has been on disposable products, such as Dust bag, restricted. For the long-term use of the biodegradable resin it must first be decomposed by bacteria be limited. Therefore, an attempt was made, the Biodegradation of the resin by the addition of an antibiotic too delay (Japanese Unexamined Patent Publication (Kokai) No.5-51073).

The direct addition of the antibiotic to the biodegradable Resin, however, involves the problem that control of the Emission of the antibiotic is difficult. In other words if the emission of the antibiotic is too rapid, the effect of the antibiotic inadequate. If you are too  is slow, on the other hand, the period before the beginning of biodegradation too long.

SUMMARY OF THE INVENTION

In view of the technical problems described above in the prior art, the present invention is thereon directed, a molded article of biodegradable resin with strength and durability as well as a procedure for To recover resources.

It is a further object of the present invention to provide a molded article of biodegradable resin, which controls the biodegradability.

To solve the problems described above sees the present invention a biodegradable molded article barem resin, which ge of a kneaded material is formed by kneading, melting or mixing a biodegradable resin raw material and at least one of an additive with biodegradability and an additive that consists of a substance existing in nature becomes.

The present invention also contemplates a molded Resin article containing a layer of a resin with Bio degradability and a layer of a photolytic resin, covering the resin layer and containing an antibiotic, includes.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an illustration showing the decomposability of a biodegradable resin molded article in the bottom according to an example of the present invention;

Fig. 2 is an illustration showing the decomposability of a biodegradable resin molded article in the bottom according to an example of the present invention;

Fig. 3 is an illustration showing the decomposability of a biodegradable resin molded article in a culture solution according to an example of the present invention;

Fig. 4 is an illustration showing the decomposability of a biodegradable resin molded article in the bottom according to an example of the present invention;

Fig. 5 is a diagram showing the decomposability of molded articles by injection molding in the ground according to an example of the present invention or a Ver same example;

Fig. 6 is a diagram showing the decomposability of molded articles by injection molding in the ground according to an example of the present invention or a Ver same example;

FIG. 7 is a diagram showing the decomposability of injection molded articles in the floor according to an example of the present invention and a comparative example, respectively; FIG.

Fig. 8 is a diagram showing the decomposability of molded articles by injection molding in an environment of high temperature and high humidity according to a case of playing the present invention and a comparison example;

Fig. 9 is a diagram showing the decomposability of molded articles by injection molding in an environment of high temperature and high humidity according to a case of playing the present invention and a comparison example;

Fig. 10 is a diagram showing the decomposability of molded articles by injection molding in an environment of high temperature and high humidity according to a case of playing the present invention and a comparison example;

Fig. 11 is a diagram showing the decomposability of molded articles by injection molding in an environment of high temperature and high humidity according to a case of playing the present invention and a comparison example;

Fig. 12 is an illustration showing an antibiotic property of a biodegradable resin molded article obtained according to an example of the present invention; and

Fig. 13 is an illustration showing the decomposability when a biodegradable resin molded article obtained in an example of the present invention is left standing outdoors.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The above-described kneaded material used for the present invention preferably contains a biopolymer as an additive, especially one with biodegradation bility. This biopolymer can be a vegetable oil, collagen or a high or ultra-high thermophilic bacterium.

The kneaded material described above contains preferably a fibrous or fine powdered material, that is selected from at least one member of carbon, Silica and silica as an additive, which consists of a in substance existing in nature, be stands. Alternatively, the kneaded material contains before preferably at least one of magnesium hydroxide and Aluminum hydroxide as an additive that comes from one in nature exists existing substance.

A biodegradable resin raw material is preferably too at least one member selected from a polyester, a aliphatic polyester, polyvinyl alcohol, polycaprolactone, Polyhydroxyalkanoate, denatured starch, natural poly mer and polyisocyanate produced by microorganisms become.  

The above-described biodegradable resin molded Article can be obtained by extrusion or injection molding of the ge kneaded article to be formed into a film. This one off For example, biodegradable resin molded article may include flat, plate-like electrical circuit substrate with be on the surface of this formed wiring.

According to the present invention, a method for Recovery of resources provided, which the Zerset zen of the biodegradable resin formed above Article by microorganisms and recovering the bioab buildable resin raw material that is in the microorganisms has built up, including.

The inventors of the present invention have a bio degradable resin found, the improved strength and Durability, and used as a durable material can be made by using various biodegradable resin raw materials alien mixed with an additive with biodegradability. The inventors have also found a biodegradable resin which has improved strength and durability, and as Durable material is usable by different bioab buildable resin raw materials mixed with a material which exists in large quantities in nature, like at least one member of carbon, silica and Silica.

Examples of such a biodegradable Harzrohmateri as include: a polyester, an aliphatic Polyester, polyvinyl alcohol, polycaprolactone, polyhydroxy alkanoate, denatured starch, a natural polymer and a polyisocyanate produced by microorganisms. On the other hand, the additive has the functions of a soft machers, a filler and a flame retardant of the type of material, and a biopolymer with Biodegradability is used as one of the additives. On  such biopolymer is a vegetable oil, collagen or a highly or superheated bacterium. You can by Bacteria are decomposed.

Furthermore, those articles can be used which from a substance existing in nature, such as coal material, silica or silicon dioxide, and to molded into a fibrous or fine powdered article become. It is particularly preferred magnesium hydroxide or Aluminum hydroxide as an inorganic flame retardant to the resin To add this to an electrical circuit substrate is set, its temperature is probably very high becomes. In addition, the existing in nature and as Additive admixed substance not biodegraded, but after the resin has decomposed, only the ones remain Components that exist in nature, back. Accordingly, can be a detrimental influence on the natural environment be reduced to a minimum.

The kneaded material of biodegradable resin, the by mixing the biodegradable resin raw material and the The additive described above is obtained by Extrusion molding or injection molding, and the strength of the resulting molded article is tested. As result They can have a tensile strength and an Izod impact value equivalent to, or higher than, polypropylene or an ABS resin. Unlike poly propylene and the ABS resin, the molded article can inside Half a year or so decomposed when in the ground is buried.

As described above, the biodegradable resin shaped articles according to the present invention biodegradation good strength and durability, suitable for use as a durable material, such as for electrical products and computer cases are required.  

The biodegradable resin described above is used in a culture solution or bacterial soil sets and disappears. Accordingly, the waste volume be reduced, and wiring metal of electrical Circuit substrates can be recovered. The in the Bacterial resin raw materials can be extracted and be returned.

According to the present invention, a further by Injection molding molded article from a biodegradable resin provided a biodegradable resin and an antibioti contains substance.

The use of biodegradable resins has in the last ten years of increasing environmental awareness. The biodegradable resin has such a property that it assimilated and decomposed by a certain bacterial species can be. Unlike ordinary general purpose resins The biodegradable resin is decomposed and disappears when it is left standing in nature. That's why it currently has As resin for injection molding considerable attention drawn as there is no adverse effect on the naturli environment. This resin, however, involves a prob lem that its long-term durability in the natural Environment or an analogous environment just because of its biodegradability is low. The by injection molding molded articles according to the present invention may include solve this problem.

The following six types of antibiotics can be considered as can be specified, although there are a large number of There are types of antibiotics which, depending on their effect can be used on the bacteria.

• (1) those which prevent the biosynthesis of peptidoglycan of a cell membrane:
  Β-lactam type compounds such as penicillin, cephalo sporin;
• (2) those which prevent the biosynthesis of bacterial proteins:
  Puromycin, tetracycline, chloramphenicol, erythromycin, streptomycin, etc .;
• (3) those which prevent the biosynthesis of nucleic acids
  Azasarin, acridine, actinomycin D, bathomycin, rifamycin, etc .;
• (4) those that change the ion permeability of a cell membrane:
  Ionophores, such as parinomycin, gramicidin A, nonactin, monensin, etc.,
• (5) those that destroy a cell membrane:
  Phenols such as chlorocresol, xylene, etc., quaternary ammonium salts such as benzalkonium chloride, biguanide compounds such as chlorohexydine, and cyclic peptides such as tyrocidine, gramicidin, polymyxin, etc .;
• (6) Metal ions:
  Silver ions and their complex compounds.

If one or more of these substances in a rela can be mixed in the resin in a small amount Biodegradability for a predetermined period below until this natural substance exists chemically degraded and inactivated or brought to it will flow out, through moisture, etc. A similar The effect can be obtained by adding a material beige which chemically mixes any of these substances having the polymer chain bound thereto.

In addition, each of these substances has a unterschiedli antibiotic, chemical stability and solubility humidity. That's why it's important the amount mixed with the resin thereof should be sufficient  into account. If at the same time also an economic Effect is considered, is a particularly ge suitable mixing amount 0.01 to 100 ppm for the substances of Groups (1), (2), (3) and (4), and 0.01 to 5% by mass for the substances of groups (5) and (6), based on the Resin.

The mixing is usually at the time of kneading the Resin in the same way as mixing other additives ve and the fillers performed. It will, however, be forthcoming zugt, the kneading at a temperature as low as possible and within a short time to carry out the Limit the decomposition of antibiotic substances. It The case may occur where even mixing under Such a condition can not be easily performed can, a method in which a basic batch in advance ago is, however, for mixing a trace amount the substance is particularly effective. The silver ion of (6) invol Fourth, the problem is that it is light by ultraviolet rays is decomposed, with chlorine contained in running water, etc. reacting ions to form a silver chloride and true is apparently inactivated. Therefore, a method ver in which the ion is caused by the fine Powder of a silica gel carrier is absorbed.

According to the present invention is also a Modifi Cation method of a resin provided, which is a resin in Maintains neutral by adding an alkaline or acidic Component is added or admixed in an amount to neutralize acidic or alkaline components, in a polymer material with an ester bond or bonds are contained in the main polymer chains thereof is effective.

The present invention also provides a resin Composition comprising a polymer material with an ester  bond in the polymer chain thereof and an alkaline or acidic component in an amount necessary to neutralize an acid or alkali contained in the polymer material component is effective, and one from a molded resin composition Resin article before.

Lately, the use of polymer material has alien with an ester bond (so-called "polyester resins") increased. The polyester resins can be roughly in two ways be divided, that is, thermosetting resins and ther moplastic resins. Although the present invention is in is effective in both species, it is special in the latter it's effective. Thermoplastic resins include a soge called "aromatic type", which has a benzene ring in its Molecular chain contains, such as polyethylene terephthalate (PET), and those made entirely of aliphatic hydrocarbons consist. The latter contain those resins, which by Bak decomposed, that is biodegradable resins, such as 3-hydroxybutyrate, poly-3-hydroxyvalerate, etc.

Since all of these resins have an ester bond, can they are relatively easily synthesized. They become chemically usually by polycondensation between dicaboxylic acids and Glycoles synthesized. Therefore, different resins can be used relatively easily under analogous conditions of synthesis Selecting and combining these materials synthesized become.

On the other hand, this point is the disadvantage of the resins In other words, when a resin occurs this species for a long period of time or under chemical harsh conditions is used, a problem that only hydrolyzed a limited part of the ester bond and the Polymer chain is cut off, so that the material properties deteriorate. From another investigation  It is known that when the part which is cut off, the Molecule chain is the deterioration of the material as the strength is greatly increased, even if the cut off part is only a very limited part. Therefore, it is very important to control this reaction.

The inventors of the present invention have sub conducted investigations on the mechanism of hydrolysis, to minimize these problems, and have the following Clarified points. Often, the resin comprises a trace amount an acidic or basic (alkaline) material Reason for in the starting materials at the time of synthesis the resin contained impurities or due to a pH environment at the time of synthesis. In general, the Hydrolysis by an acid or base (alkali) strongly geför changed. Accordingly, it was clarified when the material was wet Environment was given that these components of the resin the Schneider reaction of the polymer chain of the resin (Esteraus exchange reaction). The inventors of the present invention have a quantitative determination of these in the resin contained components performed to this reaction Restrict, and have found that the durability of the resin can be improved by this acid or alkaline content by a neutralization redu is graced. Thus, the present invention has been completed sen. In this case it is preferred that the alkaline or acidic component that can be added to the neutralization is, converted into fine powder in advance and sufficient is kneaded.

According to a second aspect of the present invention becomes the biodegradable resin molded article to a shaped laminar structure, and becomes an antibiotic only added to its outermost layer to prevent the resin is broken down by the bacteria. The utmost  Layer of this molded article is by applying of a resin having photolytic properties, so that the antibiotic retained by the photolytic resin can be.

Typical examples of the present invention usable, biodegradable resins are poly (3-hydroxy butyric acid), 3-hydroxybutyric acid / 3-hydrovaleric acid Copolymer, 3-hydroxybutyric acid / 4-hydroxybutyric acid copoly chitin-chitosan, cellulose chitosan, polylactic acid, Polyglycolic acid, polycaprolactone, amide-ester copolymers, Polyester ethers, polyvinyl alcohol, etc.

Examples of the photolytic resins are ethylene / carbon monoxide copolymer, vinyl ketone / vinyl monomer copolymer, poly isobutylene oxide, etc.

Examples of antibiotics are 2- (4-thiazolyl) - benzimidazole, 2- (methoxycarbonylamino) benzimidazole, bis (2- pyridylthio-1-oxide) zinc, dodecyl-p-tolylsulfone, Zeolite / silver, hydroxyapatite / silver, silica / silver, etc.

The described, made of biodegradable resin Arti The kel of the present invention is derived from the bacteria not degraded during its use and can take a long time be used. If the molded article becomes unnecessary, become visible light or ultraviolet rays on the shaped article irradiated to the photolytic resin decompose and remove. In this way, the anti removed biotic layer. The antibiotic layer can also be removed by the same procedure if the Article is a thin shaped article.

As described above, the bacteria resistance as well as the durability of the biodegradable resin it through the Applying the photolytic layer containing the Antibio contains tika, on the surface of the biodegradable resin improved. When the molded resin article becomes unnecessary,  he left standing outdoors, reducing the photolytic resin is decomposed, and the antibiotic is emitted and its loses antibiotic property. Then find the Zerset tion of the biodegradable resin.

Hereinafter, the present invention is under Reference to examples thereof explained in more detail.

Example 1: Molded article made of biodegradable plastic

In this example, a copolymer of the polyester Type (PHBV) consisting of hydroxyvalerate (HV) and hydroxybutyrate (HB) and a polymerization ratio of 5:95 used as a biodegradable plastic raw material, which has been decomposed by soil bacteria. A mix of one aliphatic acid ester as a plasticizer and a coal fiber or glass fiber with a cutting diameter of 0.3 to 1.0 microns and a length of 0.1 to 20 mm as a filler to improve the strength of the molded article was used as kneaded plastic material. For comparison The strength and decomposition activity were three types of samples with different mixing ratios of the soft machers and the filler.

Table 1 gives the composition ratio of each Plastic composition using the carbon fiber on.  

Table 1

Table 2 gives the composition ratio of each Plastic composition using the glass fiber on.

Table 2

Next, each plastic composition was added 165 ° C melted and kneaded in an injection molding machine, and was then injected into a shallow mold, with three Types of molded plastic articles have been formed which each in the form of a standard tensile test piece (JIS K7113, dumbbell shape).  

The tensile test was for each of the formed art fabric article according to JIS K7113. For comparison the same tensile test for polypropylene and the ABS Made of resin.

The results are shown in Tables 1 and 2. The Tensile strength is determined by the voltage (unit Mega-Pascal, MPa) at the time of breakage of the test piece.

In which the carbon fiber or the glass fiber containing Test pieces increased the tensile strength in proportion to the Extra amount of carbon fiber or glass fiber. If the Zu the same amount of carbon fiber or fiberglass, For example, the glass fiber had a greater tensile strength than the Carbon fiber. Furthermore, the biodegradable plastic saw a greater tensile strength than polypropylene and the ABS resin.

Next, each test piece was buried in a kitchen waste compost and its decomposition activity was measured over a period of six months. The result is shown in FIG . The abscissa represents the elapsed time (months), and the ordinate represents the remaining amount (%). In addition, the symbols in the figure, such as PHBV 80 / C19, represent a molded article formed of the kneaded material of 80% of the co-polymer (PHBV) and 19% of the carbon fiber (C), and other symbols have a similar meaning , where the symbol G denotes the glass fiber.

The results showed that the shaped Ar were decomposed more rapidly when the mixing ratio of Carbon fiber was smaller. The molded article with one Mixing ratio of 19% showed namely a remaining Quantity of 60% after six months, and those with a mixed ratio of 38% showed a remaining amount of 80% after six months. The glass fiber containing, molded The products were with a smaller mixing ratio of  Glass fiber in the same way as the carbon fiber ent holding molded article also degrades faster. The ge molded articles with a mixing ratio of 19% namely a remaining quantity of 65% after six months, and those with a mixing ratio of 38% showed one remaining amount of 85% after six months. These facts indicate that the molded articles with the lapse the time were constantly decomposed.

The biodegradability was essentially analogous to those Cases in which the filler has not been added, and only the carbon fiber remained in the soil after decomposition and did not harm the ecosystem.

Example 2: Molded article of biodegradable plastic

A copolymer (PHBV) of hydroxyvalerate (HV) and Hydroxybutyrate (HB) with a copolymerization ratio of 5:95 was used as a biodegradable plastic raw material set. A used kneaded plastic material was by the addition of killed Thermus thermophilis HB8 produced as a filler. To compare the strength and of decomposition activity were three kinds of molded articles with different mixing ratio of the thermophilic Bacteria generated.

Table 3 gives the composition ratio of each Plastic composition on.  

Table 3

Next, each plastic composition was added Melted 165 ° C in an injection molding machine and into a injection molded flat plate mold, with three types shaped Plastic articles were formed, each having a flat, plate-like shape of 8 × 100 × 100 mm.

The tensile test and the impact test were for each of the molded plastic articles according to JIS K7113 or 115 K7110 performed.

The results are shown in Table 3. The train strength is due to the tension (unit: mega-pascal, MPa) at the time of breakage of the test piece. The Izod impact number is determined by the energy size (J / M) the test piece was absorbed, expressed and by hitting each test piece with a hammer and Measuring the kickback height of the hammer determined.

The results showed that: the smaller the mixing ratio of the thermophilic bacteria, the greater was both the tensile strength and the Izod impact number. These values were substantially equal to the values of polypropylene and the ABS resin, and had the test pieces sufficient strength for use as durable material.  

Next, each test piece was buried in a kitchen waste compost and its decomposition activity was measured over a period of six months. The result is shown in FIG . In the figure, the abscissa represents the elapsed time (months), and the ordinal represents the remaining amount (%). In addition, the symbols in the figure, such as PHBV9O / t10, present a molded article formed from the kneaded material of 90% of the copolymer (PHBV) and 10% of the thermophilic bacteria (t), and the other symbols have similar meanings ,

The results showed that the shaped Ar were decomposed more rapidly when the mixing ratio of thermophilic bacteria was large. The molded article with a mixing ratio of 30% showed namely a stay 30% after six months, and the shaped Article with a mixing ratio of 10% showed a ver lasting amount of 35% after six months. According to one Extrapolation was expected to all test pieces within of about 10 months after being buried completely would be digested. The decomposition ratio was significant higher than the test pieces that do not contain thermophilic bacteria contained.

Example 3: Electric Circuit Substrate

Next, a method for manufacturing will be described below Position of an electrical circuit substrate, which from the molded article made of biodegradable plastic, he purifies.

Natural polymers such as polyhydroxyalkanoate, poly caprolactone, denatured starch, chitin-chitosan, etc., and Polyisocyanate, etc. were used as biodegradable plastic raw material materials used.  

A flame retardant was added to the exothermicity of the Circuit given the characteristics of the electrical Control circuit substrate. An inorganic flame retardant mer, such as harmless magnesium hydroxide or aluminum hydroxide, was used as a material that was the biodegradable unimpaired and also not detrimental river on living things in the natural environment. The Addition amount was preferably 10 to 20% by mass, since the Machinability dropped when the added amount was higher was.

Furthermore, the biodegradable plastic materials in the In general, a low softening point and involve hence the problem that their dimensional characteristics for Time of heating are not high. These disadvantages can however, by the addition of 30 to 60% by mass of a fiber be compensated as reinforcing agents. at games of such a reinforcing agent are a glass fiber, a carbon fiber, a cellulose fiber, a fibroin fiber, etc. All of them exist in large quantities in of nature and are biopolymers. Accordingly, they can Minimize influence on the bacteria. In addition, the Cellulose fiber and the fibro-fiber from the aspect of reduction the waste volume preferred.

The biodegradable plastic raw materials, the flame inhibitor and the reinforcing agent described above are blended, and kneaded biodegradable art fabric material was produced. This kneaded biodegradation bare plastic material was extruded, sprayed pour or film forming into a flat, plate-like Substrate shaped.

After a copper foil is formed on this substrate became a circuit by photolithography Verdrah was formed, and the electrical circuit substrate was  generated.

Specific Example 1

A polyester-type copolymer made of polyhydroxy butyrate (HB) and polyhydroxyvalerate (HV) was used as biodegradable plastic raw material used. In this Case were preferably 8 to 15% by mass of polyhydroxyvalerate in terms of the strength of the molded article and its machinability included. The flexibility the molded article could be increased by: the addition amount of polyhydroxyvalerate was increased 9 to 10% by mass, however, were especially from the aspect of maschi preferred for machinability.

10 to 20 mass% magnesium hydroxide powder were added to this raw material as a flame retardant, and further were 20 to 40% by mass, and preferably 30 to 40% by mass, of a cellulose fiber as reinforcing agent too set. The aspect ratio (length / diameter ratio) The cellulose fiber was suitable in the range of 50 to 100. When the cellulose fiber was excessively long, the upper became surface of the molded article coarse, and the aspect ratio was more preferably in the range of 80 to 90.

By injection molding this kneaded material was generates a substrate. The injection molding condition could be similar the injection molding condition of polyethylene terephthalate (PET) his. After that, a circuit wiring on the sub strat formed around an electrical circuit substrate deliver.

A dielectric constant of this electrical Circuit substrate is shown in Table 4. The measurement was performed according to ASTM D150.

substrate material permittivity concrete example 1 4.5 concrete example 2 5.0 Comparative Examples: @ epoxy 4.8 ceramics 4.0 polystyrene 2.5

From the above results, it was found that a value substantially equivalent to that of epoxy and Ceramics could be obtained.

Specific example 2

Polycaprolactone was called biodegradable Kunststoffroh material used, and a mixture of a chitin fiber (10 to 30% by mass) was used as filler. The chitin Fiber was a large amount contained in shellfish Polysaccharide and was rapidly decomposed in nature.

This kneaded article was injection-molded, wherein a substrate has been formed, and a circuit wiring was formed on the substrate to an electric scarf to form a substrate.

The dielectric constant of this electric scarf substrate is also shown in Table 4. According to this Result, it was seen that a value substantially equi valent to those obtained from epoxy and ceramics could.

When the circuit substrate of the concrete Example 2 was next buried in the compost, the remaining amount of the plastic reached about 30% within about four months, as shown in Fig. 4, and 70% of the starting material disappeared. In this case, the copper used for the wiring could not be recovered due to oxidation.

Example 4: Recovery method of resources

Next, a recovery process of bio degradable plastic explained. Here was the electric Circuit substrate of Example 3 as an example of the molded Used article.

After the electrical circuit substrate is generated was immersed in a culture solution containing Bacteria, such as Pseudomonas sp., Alcaligenes sp., Rhodo spirillium sp., Zoogloea sp., etc., contained. To this Way could the plastic of the substrate completely be decomposed.

In this case, the flame retardant, the enhancer fell kmittel, etc., contained in the plastic of the substrate were at the bottom of the culture tank while Metallkom remained components without decomposition. Accordingly, could both of these are easily recovered.

Further, the bacteria became after the decomposition treatment recuperated in the culture solution. Was next the plastic structure in the bacteria is extracted by were dissolved in a solvent. New plastic could in turn be formed from this extract.

Even if the article as waste in the natural order was disposed of after the decomposition of the Plastic only those components back in nature exist. Accordingly, any adverse influence could be exerted reduced to the natural environment to a minimum become.  

Specific Example 3

A culture solution shown in Table 5 was placed in a Culture container given, and Alcaligenes feacalis as Bakte were incubated. The electrical circuit substrate of the concrete example 1 was incorporated into this culture solution dives and left as such.

Table 5

Composition of the culture solution

When the substrate was 3 mm thick, as shown in Fig. 3, almost all the plastic components were decomposed and disappeared within 30 days at 30 ° C.

After the decomposition was completed, the fungus became body (bacteria) recovered by centrifugal separation and dissolved in a solvent to give polyhydroxybutyrate / To extract polyhydroxyvalerate copolymer. The return Winning ratio was as good as about 60%.

The flame retardant, reinforcing agent, etc., fell on the bottom of the culture container while the metal components remained undecomposed. Accordingly, both could be easily recovered from them.

Example 5

A resin with higher mechanical properties, however  while retaining the biodegradability, could by Co polymerizing 3-hydroxybutyrate (HB) and 3-hydroxy valerate (HV).

A basic batch was prepared in advance by mixing 1.0 mass% hexamethylene biguanide with a commercially available HB / HV copolymer ("Biopole 530", a product of Zeneka K.K., HV ratio of about 5%, pellet form) and a resin composition was prepared by mixing of 10% by mass of the base lot obtained with the same Resin generated. Care was taken in each procedure kneading as quickly as possible.

A plate-like test piece was produced by the injection molding of the obtained resin composition, buried in the wet soil and allowed to stand for 12 months (medium temperature: 20 ° C). When the test piece for measuring the mechanical properties was taken out periodically, large changes were made between the test pieces. Namely, the test pieces containing the antibiotic showed a low degree of degradation for a predetermined period of time, but thereafter degradation continued (see Fig. 5). A comparative example without addition of the anti-biotic material is given in FIG .

Example 6

A molded article from a composition, herge turns into a polyvinyl with the addition of starch Alcohol resin, collapses in a natural environment. Therefore, in a broader sense of the word, it can be called bioab buildable resin.

Fine silica gel powder (grain diameter: about 1 mm) absorbing silver nitride was added to "Mattervie", a product of Nippon Gosei Kagaku KK, as a resin type. Namely, a silver nitride aqueous solution (1.0%) was gradually sprayed on a silica gel pulverized by a ball mill to a grain diameter of not more than 0.1 mm (10 ml of the aqueous solution per 100 g of silica gel). and the silica gel was dried in a dark place for 10 hours at 60 ° C. 1% by mass of the antibiotic composition thus prepared was mixed by kneading with "Mattervie". By the injection molding of the resin composition produced by this method, plate-like test pieces were formed, buried in the wet soil and allowed to stand for 10 months (average temperature: 20 ° C). When the test pieces were periodically taken out, and the mass change was measured, large differences in the degree of decrease in mass were observed (see FIG. 6). A comparative example without addition of the antibiotic mate rials is shown in Fig. 6.

Example 7

Polycaprolactone (PCL) has biodegradability and is a resin containing an excellent injection molded article can form good mechanical properties.

A basic batch was made in advance by the addition of 1.0% by weight of trimethylphenylammonium chloride to an im Commercially available PCL ("Plaxell H-S", a product of Dicell Kagaku Kogyo K.K.), and a resin composition Composition was further added by adding 1% by mass of produced base lot to the same resin. It was Be sure to knead as quickly as possible in all procedures possible to effect. In particular, specific to the Temperature control at the time of melting the resin ge pay attention, and treatment was at a relatively low Temperature performed.

Plate-like test pieces were produced by injection-molding the resin composition thus obtained, buried, and allowed to stand in the wet soil for 12 months (average temperature: 20 ° C). The test pieces were taken out periodically and the mechanical properties were measured. As a result, a large change in the mechanical strength was found. The test pieces containing the antibiotic showed a low degree of degradation during a pre-determined period of time, but thereafter degradation continued (see Figure 7). A comparative example without addition of the antibiotic material is given in FIG .

Example 8

A resin with excellent mechanical properties but maintaining biodegradability by copolymerizing 3-hydroxybutyrate (HB) and 3-hydroxyvalerate (HV) can be obtained.

Sheet-like test pieces were produced by injection molding a commercially available HB / HV copolymer ("Biopole 530", a product of Zeneka KK, HV ratio = about 5%) and in an environment of 70 ° C and a humidity of 50 % ditched. A noticeable decrease in mechanical strength was noted ( Figures 8 and 9). The amount of the water-soluble components (acidic or alkaline components) in this molded article was analyzed.

The analysis procedure was as follows.

After the resin plate to a grain diameter of not more than 0.5 mm was finely pulverized, the powdery grains in a small amount of hot Dipped in ethanol and allowed to stand for about 24 hours. Then the solution was isolated by filtration. This solution was by a solvent in a water-ether system extracted, with the water-soluble components in the water were dissolved, and this aqueous solution was passed through a  titrated strong acid or strong alkali, the amount the acidic or alkaline components measured in the resin has been.

According to this method it could be stated that the commercially available "Biopole S30" 0.2 mmol of the acidic Component per 100 g of the resin contained.

Next, this resin was remelted using a resin kneader, and 0.1 mmol (0.2 mmol equivalent) of fine sodium carbonate powder (grain diameter not more than 0.5 mm) per 100 g of the resin was kneaded and mixed sufficiently. By injection molding of this resin, test pieces were prepared and stood for 2 months in a surrounding of 70 ° C and a humidity of 50%. In this case, the decrease in mechanical strength was not as pronounced as in the original resin ( Figs. 8 and 9).

Example 9

Generally, a PET resin for beverage bottles, etc., used. This resin plate was passed through a ball mill, etc., to a grain diameter of not more than 0.5 mm finely pulverized, and became a water-soluble component by the same method as that of Example 8 extra hiert. As the acidic or alkaline component in the resin ge was measured 0.026 mmol of the acidic component ent keep in 100 g of the resin found.

Next, this resin was prepared using a Resin kneader remelted, and 0.026 mmol fine Potassium carbonate powder (grain diameter = less than 0.05 mm) per 100 g were kneaded and sufficiently mixed. By injection molding of this resin, test pieces were prepared placed and in an environment of 70 ° C and a humid 50%.  

As a result, the decrease of the mechanical strength could be kept lower than the test result of the original resin ( FIGS. 10 and 11).

Example 10

A thermosetting polyester resin comes with a glass fiber reinforced for reinforcement into a composite and for Bathtubs, boats, skis, etc., widely used. A commercially available resin plate (reinforced with 35% by mass) the glass fiber) became a grain with a ball mill diameter of not more than 0.5 mm finely pulverized. The water-soluble component was prepared by the same method like that extracted from Example 8, and the amount of acidic or alkaline component in the resin was measured. As a result, 0.055 mmol of the alkaline component found per 100 g of the resin contained therein.

Next, this resin was passed through a resin kneader remelted, and 0.0275 mmol (0.055 mmol equivalent) Fine ammonium nitrate powder per 100 g of resin was kneaded and mixed enough. The test piece was used This resin is produced in a manual lay-up process posed. As the test piece at 100 ° C in boiling water and allowed to stand for 10 days the decrease of mechanical strength to a low value as the test result of the original resin be limited.

Example 11

In this example, a polyhydroxybutyrate-polyhydroxyvalerate copolymer as a biodegradable resin, an ethylene-carbon monoxide copolymer as a photolytic resin and a silver ion on a hydroxyapatite carrier were used as the antibiotic. A film of the photolytic resin containing the antibiotic was allowed to adhere to the biodegradable resin molded into a plate shape to protect the inner biodegradable resin. When the Plattenma material (1 cm × 1 cm, 3 mm thick) in a container for Inku bieren one of the genus Pseudomonas sp. belonging to bacteria that are known to be able to decompose biodegradable plastics, the number of living bacteria decreased with the lapse of time, and the bacteria were completely killed on the 20th day after the start of the test, as shown in FIG . 12. A similar test piece was left standing on black soil, and the amount of decomposition was recorded as a change in thickness, assuming that the sample was released under harsh weather conditions. As a result, the surface layer was decomposed and disappeared in the first week due to photolysis, as shown in Fig. 13, and then the part of the biodegradable resin fell to 66% of the initial thickness on the 60th day.

Example 12

In this example, cellulose chitosan was called bio degradable resin, polyisobutylene oxide as a photolytic resin and 2- (4-thiazolyl) benzimidazole used as an antibiotic. A photolytic resin film containing the antibiotic contained on both surfaces of the biodegradable resin shaped. The amount of the photolytic resin was 5 mass%, based on the mass of the biodegradable resin. As this plate-like, shaped article in a forest were buried both the mass and the territory the initial strength even after the lapse of three months at their initial values. If, however, on the same molded article, however, with ultraviolet rays a wavelength of 300 nm three days and nights  were irradiated, and then he was buried in the forest area, Three months after burial, there was a decrease in mass of 20% and a decrease in tensile strength of 40% posed.

As described above, the molded article exhibits biodegradable resin according to the present invention Buildability on and has sufficient strength and Durability for use as high-quality materials Durability, such as housings of electrical components and Computers, are required. In addition, those in the Natural substances that are mixed in as additives are not decomposed biologically. However, after the resin is decomposed, only the components remain in nature exist, back, and for this reason can be a disadvantage ger influence on the natural environment to a minimum being held. The molded article made of biodegradable resin is decomposed and disappears into a bacteria culture solution or in the soil. Accordingly, the waste volume, and wiring metals of the elek can be recovered trischen circuit substrate. The in the bacteria built resin raw materials can through their extraction be recycled.

Furthermore, the present invention can by a Injection molded articles made of the biodegradable resin with durability and a molded article from one Provide polyester resin.

In addition, the present invention can be a molded Provide resin article, which during use a high Has durability and biodegradation after use can induce, and can make a big contribution to the purpose moderate biodegradable resins.

Claims (21)

1. Made of biodegradable resin molded article, which a kneaded material is formed by kneading or melting and mixing a biodegradable resin raw material rials and at least one of an additive with biodegradable and an additive that exists in nature Substance is obtained. 2. Shaped article according to claim 1, wherein the ge Known material called a biopolymer as an additive with Biodegradability contains. 3. Shaped article according to claim 2, wherein the ge called Biopolymer a vegetable oil, collagen or a high- or ultrahigh thermophilic bacterium. 4. Shaped article according to claim 1, wherein the ge Kneaded material called a fiber or a fine part chenförmiges material selected from the group consisting of carbon, silicon monoxide and silica, as Additive comprising a substance existing in nature, contains. 5. Shaped article according to claim 1, wherein the ge Known material called at least one of magnesium hydroxide and aluminum hydroxide as an additive, which consists of an in contains the substance existing of nature. 6. Shaped article according to one of claims 1 to 5, at which said biodegradable resin raw material at least a member selected from the group consisting of Bacteria produced polyester, aliphatic polyester, Polyvinyl alcohol, polycaprolactone, polyhydroxyalkanoate, de natured starch, natural polymer and polyisocyanate is. 7. Shaped article according to one of claims 1 to 6, at which form said kneaded material by film or extruding or injection molding is formed.   8. Shaped article according to one of claims 1 to 7, which an electric circuit substrate of a flat plate form, on the surface of a circuit wiring ge is formed. 9. A method for recovering resources, which comprises
Decomposing said molded article according to any one of claims 1 to 8 by bacteria; and
Recovering said biodegradable raw materials which have built up in said bacteria. 10. By injection molding from a biodegradable resin ge molded article, characterized in that it is a bioab contains buildable resin and an antibiotic. 11. Shaped article according to claim 10, wherein the ge called biodegradable resin selected at least one member from the group consisting of aliphatic polyesters, poly caprolactone, polyvinyl alcohol, starch type polymers, Chitin-chitosan-type polymers, polyamino acids, Collagen, cellulose, lignin, polyurethane-type polymers and polyether-type polymers, either by a bio chemical process of bacteria or by polycondensa tion between aliphatic diols and aliphatic di contains carboxylic acids. 12. Shaped article according to claim 10, wherein the ge called at least one member antibiotic substance selects from the group consisting of connections from β-lactam type, puromycin, tetracycline, chloramphenicol, Erythromycin, streptomycin, azaserine, acridine, actinomycin D, bathomycin, rifamycin, ionophores, such as parinomycin, Gramicidin A, Nonactin, Monencine, etc., phenols, such as Chlorocresol, xylene, etc., quaternary ammonium salts, such as Benzalkonium chloride, biguanide compounds, cyclic Peptides such as tyrocidine, gramicidin S, polymyxin, etc., and  contains a compound comprising silver ions. 13. Shaped article according to claim 10, wherein the ge called antibiotic substance to said polymer Ver Bond is chemically bound, or on the said poly mer connection physically absorbed or sticking up is done. 14. Modification method of a resin, which comprises
Adding and mixing an alkaline or acidic component to and with a polymer material having an ester bond in a polymer chain thereof in an amount effective to neutralize an acidic or alkaline component contained in said polymer material; and
Maintaining the resin substantially at neutrality. A modification method according to claim 14, wherein said polymeric material is a thermoplastic or thermosetting resin containing an aromatic or aliphatic hydrocarbon in the molecular backbone thereof ent holds is. A modification method according to claim 14, wherein said polymeric material poly-3-hydroxybutyrate, 3-hydroxyvalerate or its copolymer. 17. A resin composition which is a polymer material, the having an ester bond in a polymer main chain thereof and an alkaline or acidic component in an amount, for neutralizing one in said polymeric material contained, acidic or alkaline component is effective, includes. 18. A resin composition according to claim 17, wherein the said polymer material is a thermoplastic or hot hardening resin containing an aromatic or aliphatic Contains hydrocarbon in the molecular main chain thereof is.   A resin composition according to claim 17, wherein the polymer material mentioned poly-3-hydroxybutyrate, 3-hydroxy valerate or its copolymer. 20. A molded resin article comprising said resin The composition according to any one of claims 17 to 19. 21. A molded resin article comprising a layer of a Resin with biodegradability and a layer of a photolyti resin, which covers said resin layer and a contains antibiotic substance.