JP5556009B2 - Molding method and molded article of resin composition - Google Patents

Description

  The present invention relates to a method for molding a resin composition and a molded product.

  In recent years, biomass-derived resins have begun to be used from the viewpoint of environmental considerations in parts used in image output devices such as copiers and laser printers using electrophotographic technology, printing technology, or inkjet technology, and research and development have also started. It is active.

  Polylactic acid is a biomass-derived resin that is stably distributed in large quantities, but its low heat resistance is one of the issues that hinder its practical application. Polylactic acid is a crystalline aliphatic polyester, and crystallization of the resin is effective for improving heat resistance. Therefore, heat resistance is achieved by using a high-temperature mold suitable for crystallization during molding and cooling over a long period of time, or by heat-treating (annealing) the molded product again after molding to promote crystallization. Had improved. It has been found that the cooling time during the molding process can be shortened by adding a crystallization nucleating agent, plasticizing the polylactic acid resin, etc. The mold temperature suitable for the temperature exceeds 100 ° C., and it is difficult to use the mold of the most common water mold temperature controller. When the mold temperature exceeds 100 ° C., it becomes difficult to use the water mold temperature controller, and the oil mold temperature controller is used, which is a cause of increasing the molding cost. When the molded product is annealed after molding, not only the manufacturing cost of the molded product increases, but also there is a problem that the molded product is easily deformed in the process of crystallization.

  On the other hand, microbial-produced polyhydroxyalkanoate is a biomass-derived resin that has high mechanical strength and can be injection-molded, but, like polylactic acid, has a very slow crystallization rate and is sticky in an amorphous state. Therefore, there is a problem that the releasability from the mold is very poor and the productivity is low because the mold cannot be taken out immediately from the mold.

The main technologies related to resin compositions containing polylactic acid and molded articles are listed below.
Patent Document 1 discloses a polylactic acid resin having a sea-island structure in which polyamide is blended with polylactic acid, the island component has a domain size of 0.001 to 1 μm, and at least part thereof includes fibers. A shaped body of the composition is disclosed. This molded article has excellent mechanical properties, heat resistance, and abrasion resistance, and is capable of providing fibers and fiber products mainly composed of aliphatic polyester.

  Patent Document 2 discloses a crystalline biodegradable resin composition obtained by annealing a composition containing an aliphatic polyester and a modified elastomer. Since this crystalline biodegradable resin composition is composed of an aliphatic polyester and a modified elastomer, it has high interfacial adhesion, excellent mechanical properties such as strength and impact resistance, and is further crystallized by heat treatment for heat resistance. Improved.

  Patent Document 3 discloses a polymer having excellent heat resistance and impact resistance by adding a phosphoric acid ester metal salt and hydrous magnesium silicate (talc) as a crystal nucleating agent to a polymer capable of forming a stereocomplex mainly composed of polylactic acid. A method for producing a lactic acid polymer molded article is disclosed.

  In Patent Document 4, 5 to 40% by mass of an aromatic polyester containing 2 to 15% by mol or 2 to 15% by mass of a diol component having 6 or more carbon atoms with respect to the total amount of carboxylic acid is blended with an aliphatic polyester. A polyester resin composition characterized by the above is disclosed. This polyester resin composition is said to have excellent high-temperature mechanical properties and heat resistance that were not present in the past.

  In Patent Document 5, a thermoplastic resin containing a crystallization nucleating agent is melted to dissolve carbon dioxide, filled in a mold cavity that is in a pressurized state, and then cooled and solidified to increase the crystallization speed of the resin. An injection molding method of a crystalline thermoplastic resin characterized by speeding up is disclosed. Thus, an injection molding method has been proposed in which the molding cycle is shortened and the productivity is improved while increasing the crystallinity to the extent that necessary heat resistance can be obtained.

Patent Document 6 discloses a repeating unit structural formula [—CHR—CH ₂ —CO—O—] produced from a microorganism (wherein R is an alkyl group represented by C _n H _{2n + 1} , and n = 1 to 15). The crystallization rate of the aliphatic polyester polymer (abbreviated as P3HA) represented by (1) is improved with a crystal nucleating agent composed of one or more selected from polyvinyl alcohol, chitin and chitosan. A biodegradable polyester resin composition is disclosed.

  Patent Document 7 discloses a member characterized in that the degree of crystallinity of a polymer material having biodegradability is 0.7 or more, and a material mainly composed of a polymer material having biodegradability, There is disclosed a method for producing a member, which is characterized by performing injection molding at a mold temperature of 100 ° C. or higher. Thereby, it is said that the member which has biodegradability, sufficient heat resistance, and mechanical strength, and its manufacturing method can be provided.

  Patent Document 8 contains 99.9 to 80 parts by weight of a polylactic acid resin and 0.1 to 20 parts by weight of a polyhydroxyalkanoate copolymer, and has excellent transparency and improved tensile properties. Further, a polylactic acid resin composition for optical materials is disclosed.

  Patent Document 9 discloses a polylactic acid composition in which a polylactic acid and a resin other than polylactic acid are mixed, and the resin other than polylactic acid is an epoxidized polysiloxane having an epoxy group introduced into a polyhydroxyalkanoic acid derived from a microorganism. A polylactic acid composition characterized by being a hydroxyalkanoic acid is disclosed. This polylactic acid composition is said to have excellent biodegradability, high mechanical strength, easy molding, and excellent transparency.

  Patent Document 10 describes that when a crystalline biodegradable resin has a melting point and an amorphous biodegradable resin has a glass transition temperature as a transition temperature, it comprises two or more biodegradable resins having different transition temperatures. There is disclosed a biodegradable resin composite material molded article having high rigidity and impact resistance, wherein one or more biodegradable resins are dispersed in a fibrous form. According to the present invention, it is possible to provide a biodegradable resin composite material molded article having biodegradability, excellent rigidity, impact strength, and productivity and useful as a molding material for home appliances, portable information terminal casings, and plastic parts. It is said.

  Patent Document 11 discloses an aliphatic polyester, a polyhydroxyalkanoate having a specific melting point or a copolymer containing two or more hydroxyalkanoic acids as a constituent component, and polylactic acid or lactic acid as a main constituent component. It is disclosed that a polymer blend having excellent various characteristics can be obtained by mixing a copolymer containing a polyethylene glycol chain in a chain at a specific ratio and melt-kneading in a heat extrusion molding machine.

Patent Document 12 discloses a resin composition obtained by mixing polylactic acid with an aliphatic polyester having a melting point of 100 to 250 ° C. and a crystalline inorganic filler to achieve high heat resistance, and a molded product thereof. Examples of aliphatic polyesters include polyethylene oxalate, polybutylene oxalate,
At least selected from the group consisting of polyneopentyl glycol oxalate, polyethylene succinate, polybutylene succinate, polyglycolic acid, polyhydroxybutyric acid, and a copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid It has been proposed to use one type. This polylactic acid-based heat-resistant resin composition can be applied to a normal molding process with high productivity, and is capable of producing a molded article having excellent moldability and heat resistance.
Japanese Patent No. 3893995 Japanese Patent No. 3741084 Japanese Patent No. 39609797 Japanese Patent No. 3925176 JP 2007-269019 A Japanese Patent Laid-Open No. 2007-072232 JP 2005-138458 A JP 2006-274182 A Japanese Patent No. 3883116 JP 2005-171193 A Japanese Patent No. 3609543 Japanese Patent No. 3599533

  For biodegradable resins such as polylactic acid, many proposals have been made with the aim of improving the heat resistance and productivity of molded products. However, it cannot be said that it has sufficient heat resistance and moldability yet to be used for housings in the electrical and electronic fields where resin molded products are used in large quantities and general-purpose molded products for automobile parts. Remaining.

  For example, in the polylactic acid resin composition described in Patent Documents 1, 3, 7, and 10, a mold temperature of 100 ° C. or higher is required, and a mold for a general water mold temperature controller is required. It is impossible to mold using For this reason, compared with the conventional molding of petroleum-based resin, equipment investment, molding cycle time and energy loss become problems, resulting in an increase in production cost.

In Patent Document 2, an annealing process is required, and the process is complicated and costly as compared with the conventional petroleum resin molding method. In the resin composition described in Patent Document 4, when the physical properties are improved, the ratio of the resin derived from the biomass resource is lowered, which is not sufficient for environmental measures. In the injection molding method described in Patent Document 5, a pressure mold is required, and since carbon dioxide gas is used, there arises a problem of its recovery and processing.

  The polylactic acid-based resin composition and the aliphatic polyester-based polymer blend described in Patent Documents 8 and 11 are intended for a transparent resin having excellent optical characteristics, and are not intended to improve heat resistance. In the polylactic acid resin composition described in Patent Documents 9 and 12, it is necessary to introduce raw materials synthesized from petroleum or the like, and the ratio of raw materials derived from biomass resources may decrease, which is sufficient for environmental measures. It can not be said.

  In this way, the biodegradable resin with a high proportion of biomass resource-derived raw materials (biomass degree) is not lengthened by using the same water mold temperature controller as conventional petroleum resins. Therefore, it was not easy to mold as a general-purpose molded article having sufficient heat resistance.

  The object of the present invention is based on the above problems, and a molding method and a molding method for molding a molded article having excellent heat resistance from a thermoplastic resin having a high proportion of biomass resource-derived raw materials by a molding method similar to that of a conventional petroleum resin. Is to provide goods.

The present invention relates to a thermoplastic resin (A) comprising a microbial-produced polyhydroxyalkanoate copolymer containing structural units represented by the following chemical formula (1) and chemical formula (2), and a thermoplastic resin comprising a polylactic acid ( B) and a molding method of a resin composition (excluding those containing all of a plasticizer, an organic nucleating agent, and an inorganic nucleating agent) ,

［但し、ＲはＣ_ｎＨ_２ｎ＋１（ｎ=２〜１４）である。］
前記熱可塑性樹脂（Ａ）における前記化学式（１）で表される構成単位、すなわち、３−ヒドロキシブチレート（３ＨＢ）単位のモル分率をｃ、前記樹脂組成物の成形における金型温度をＴ℃としたとき、下記式（１）及び（２）、
１．２２９ｃ^２−３０．４≦Ｔ ・・・・・（１）
２５≦Ｔ≦９０ ・・・・・（２）
を満足することを特徴とする樹脂組成物の成形方法である。

[However, R is C _n H _{2n + 1} (n = 2 to 14). ]
The mole fraction of the structural unit represented by the chemical formula (1) in the thermoplastic resin (A), that is, the 3-hydroxybutyrate (3HB) unit is c, and the mold temperature in the molding of the resin composition is T. When set to ° C., the following formulas (1) and (2),
1.229c ² −30.4 ≦ T (1)
25 ≦ T ≦ 90 (2)
Is a method for molding a resin composition.

  According to the molding method of the resin composition of the present invention, a thermoplastic resin composed of polylactic acid, which has been cooled at a mold temperature of 100 ° C. or more at the time of injection molding and cannot obtain high heat resistance unless kept for a long time, Instead, a thermoplastic resin (A) composed of a microbial-produced polyhydroxyalkanoate copolymer containing structural units represented by chemical formula (1) and chemical formula (2), and a thermoplastic resin (B) composed of polylactic acid And a resin composition containing a high-heat-resistant general-purpose material that retains a high degree of biomass and can be molded at a low temperature by molding in a condition range represented by formulas (1) and (2). A highly flexible resin molded product can be obtained.

  In a preferred embodiment of the present invention, the molar fraction of the structural unit (3-hydroxybutyrate (3HB) unit) represented by the chemical formula (1) in the thermoplastic resin (A) is 70 to 95 mol%. The method for molding the resin composition.

  By setting the molar fraction of the 3-hydroxybutyrate (3HB) unit to 70 to 95 mol%, the production of the thermoplastic resin (A) is facilitated, and a molded product having high heat resistance is easily obtained.

  In a preferred embodiment of the present invention, the thermoplastic resin (A) is a copolymer of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) (when n = 2 in chemical formula (2)). It is the said resin composition characterized by these.

  A copolymer of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) is relatively easy to produce in microorganisms, and a molded product having high heat resistance is also easily obtained.

  The present invention is preferably a method for molding the resin composition, comprising 99% to 1 part by weight of the thermoplastic resin (B) with respect to 1 to 99 parts by weight of the thermoplastic resin (A).

  By containing 1 to 99 parts by weight of the thermoplastic resin (A), a molded product having high heat resistance can be obtained even if molded at a low temperature.

  In a preferred embodiment of the present invention, the thermoplastic resin (B) made of polylactic acid and the thermoplastic resin (B) are selected from poly L lactic acid, poly D lactic acid, and a stereocomplex made of poly L lactic acid and poly D lactic acid. It is a molding method of the said resin composition characterized by including two or more.

  A molded article having good moldability and high heat resistance can be obtained from a resin composition comprising polylactic acid that can be produced by microorganisms.

  The present invention is preferably a method for molding the resin composition, further comprising a crystallization nucleating agent.

  By promoting the crystallization by the crystallization nucleating agent, the crystallinity of the molded product can be quickly increased at a low temperature, and a molded product having high heat resistance can be molded with high productivity.

  In a preferred aspect of the present invention, the crystallization nucleating agent includes one or more selected from a talc nucleating agent, a nucleating agent made of a metal salt-based material having a phenyl group, and a nucleating agent made of a benzoyl compound. The method for molding the resin composition.

The present invention relates to a thermoplastic resin (A) composed of a microbial-produced polyhydroxyalkanoate copolymer containing structural units represented by the above chemical formula (1) and chemical formula (2), and a thermoplastic resin composed of polylactic acid ( B) and a molded product molded from a resin composition (excluding those containing all of a plasticizer, an organic nucleating agent, and an inorganic nucleating agent), and the deflection temperature under load is higher than 100 ° C. Is a molded product characterized by
The present invention can be molded by any molding method of the resin composition, and is preferably a molded product provided in an electric / electronic device.

  It is possible to provide molded products with low environmental impact that can be used for various general-purpose molded products such as electric and electronic devices.

  According to the present invention, it is possible to provide a molding method and a molded product for molding a molded product having excellent heat resistance from a thermoplastic resin having a high proportion of raw materials derived from biomass resources by a molding method similar to that of a conventional petroleum resin. it can.

[Resin composition]
(Polyhydroxyalkanoate (thermoplastic resin (A)))
Poly-3hydroxybutyrate (P3HB) can be produced by Pseudomonas, Ralstonia, Bacillus, and Corynebacterium in LB medium, MR medium, etc. using glucose as a carbon source.

In order to produce a 3-hydroxybutyrate copolymer which is a polyhydroxyalkanoate copolymer (thermoplastic resin (A)) in the present invention, the other target is added to the above-mentioned 3-hydroxybutyrate copolymer production medium. An organic acid having a carbon number corresponding to the hydroxyalkanoate is added as a culture substrate. For example, as a preferred polyhydroxyalkanoate embodiment, a 3hydroxybutyrate-3hydroxyvalerate copolymer, which is a copolymer of 3hydroxybutyrate (3HB) and 3hydroxyvalerate (valeric ester) (3HV) ( for P (3HB-Co-3HV) ) production may be added to propionic acid _{(C 3} carboxylic acid) as a culture substrate. By adjusting glucose and propionic acid added to the medium, the ratio of 3hydroxybutyrate and 3hydroxyvalerate can be controlled. In general, P (3HB-Co-3HV) is a cell growth process by using a production method such as Bacillus, Ralstonia, Pseudomonas, etc., by limiting the nitrogen and phosphate in the medium components. And polyester in two stages of production process.

By giving an even fatty acid of C ₆ or more to a microorganism having a PHA synthase gene derived from the genus Bacillus, a 3-hydroxybutyrate-3hydroxyhexanoate copolymer (P (3HB-Co-3HHx)) is obtained. Can be synthesized.

  The alkyl group R in the chemical formula (2), which is a structural unit of polyhydroxyalkanoate (PHA), is n = 2 to 14. However, from the viewpoint of the effect of improving heat resistance and ease of production, n = 2 to 4 In particular, n = 2 (3 hydroxyvalerate (3HV)) is preferable from the viewpoint of ease of production. The polyhydroxyalkanoate copolymer is preferably a block copolymer.

  The weight average molecular weight Mw of the resin (A) composed of polyhydroxyalkanoate in the present invention is preferably 5 to 5 million, more preferably 10 to 2 million in terms of standard polystyrene conversion by GPC analysis. If it is said range, production by microorganisms is possible and there is no problem also in the moldability and heat resistance of the resin composition of this invention.

(Polylactic acid)
The polylactic acid (thermoplastic resin (B)) used in the present invention may be any polylactic acid, but poly L lactic acid, poly D lactic acid, poly L lactic acid prepared by a conventionally known microbial production method. And those containing any of the stereocomplexes consisting of poly-D-lactic acid are preferably used. Of course, a mixture of these polylactic acids may be used. Since many commercially available polylactic acids are known, these may be used. The weight average molecular weight Mw of polylactic acid is a standard polystyrene conversion value by GPC analysis, and is preferably 5 to 500,000, more preferably 10 to 250,000.

(Crystal nucleating agent)
The crystallization nucleating agent used in the present invention may be any crystallization nucleating agent used in a thermoplastic resource derived from biomass resources such as polylactic acid. For example, a talc nucleating agent, a nucleating agent made of a metal salt-based material having a phenyl group, a nucleating agent made of a benzoyl compound, or the like is preferably used. Other known crystallization nucleating agents such as lactate, benzoate, silica, and phosphate ester salts may be used.

(Additive)
Various additives such as compatibilizers, plasticizers, antioxidants, ultraviolet absorbers, processing aids, antistatic agents, colorants, hydrolysis inhibitors, and the like are appropriately added to the resin composition used in the present invention. You can also As the plasticizer, known ones generally used as polymer plasticizers can be used without any particular limitation. For example, polyester plasticizers, glycerin plasticizers, polycarboxylic acid ester plasticizers, polyalkylene glycol plasticizers. And epoxy plasticizers. The compatibilizer is not particularly limited as long as it functions as a compatibilizer for the thermoplastic resin (A) and polylactic acid. Examples of the compatibilizer include an inorganic filler, a glycidyl compound, a polymer compound obtained by grafting or copolymerizing an acid anhydride, and an organometallic compound, and one or more of these may be used. As the hydrolysis inhibitor, known ones can be used without particular limitation, and examples thereof include polycarbodiimide resins.

(Preparation of resin composition)
The polyhydroxyalkanoate (thermoplastic resin (A)), polylactic acid (thermoplastic resin (B)), and, if necessary, the crystallization nucleating agent (C) and other additives in a predetermined ratio, When the mixture is kneaded and kneaded with a kneading extruder or the like to form a pellet, the resin composition used in the present invention becomes a pellet. The kneading extruder may be a normal single-screw kneading extruder or biaxial kneading extruder for petroleum resins, and may be kneaded at a kneading temperature of about 180 degrees and pelletized. The mixing ratio is preferably 1 to 99 parts by weight of thermoplastic resin (A), 99 to 1 part by weight of polylactic acid (thermoplastic resin (B)), 5 to 95 parts by weight of thermoplastic resin (A), poly More preferably, the lactic acid (thermoplastic resin (B)) is 95 to 5 parts by weight. What is necessary is just to set the mixing ratio of a thermoplastic resin (A) and polylactic acid (thermoplastic resin (B)) according to the physical property of the required molded article, for example, in manufacturing a molded article of high load deflection temperature. May increase the ratio of the thermoplastic resin (A) and decrease the mixing ratio of polylactic acid (thermoplastic resin (B)). When the mixing ratio of polylactic acid exceeds 99 parts by weight, heat resistance may not be sufficient or a molding temperature rise during molding may be undesirable.

[Molding of thermoplastic resin]
If the pellets of the resin composition produced as described above are injection-molded in the same manner as petroleum-based resins with a normal petroleum-based resin injection molding machine, the molded article of the present invention can be produced. The mold temperature in molding may be 40 to 90 ° C., and the cooling time may be 10 to 60 seconds. At that time, in the thermoplastic resin (A), it is represented by the chemical formula (1) with respect to the total number of moles of the structural unit represented by the chemical formula (1) and the mole number of the structural unit represented by the chemical formula (2). The molar fraction c of the structural unit (3-hydroxybutyrate (3HB) unit) represented by the chemical formula (1), which is the ratio of the number of moles of the structural unit, and the mold temperature T in the molding of the resin composition pellets The following formula (1) and formula (2) between ℃ (Celsius temperature)
1.229c ² −30.4 ≦ T (1)
25 ≦ T ≦ 90 (2)
Have a satisfying relationship. In addition, it is preferable that the molar fraction c of a 3-hydroxybutyrate (3HB) unit is 0.7-0.95 (70-95 mol%).

  The molding method of the thermoplastic resin in the present invention is not limited to the injection molding method. For example, any molding method such as press molding, extrusion molding, foam molding, hollow molding or the like is not problematic. . In addition, you may use the above-mentioned additive at the time of shaping | molding.

[Example 1]
(Production of thermoplastic resin (A1))
Using a Bacillus genus, etc., the nitrogen source is limited for a culture solution cultured for 16 hours in a medium (pH 6.95) containing peptone 5.0 g / L, yeast extract 5.0 g / L, meat extract 5.0 g / L Glucose and propionic acid were added to the minimal medium and cultured at 45 ° C. for 48 hours to obtain wet cells. The obtained wet cells were lyophilized, and 80 times the amount of chloroform as the amount of dry cells was added, and the cells were extracted at 80 ° C. Insoluble matter was filtered off, methanol was added to the filtrate to reprecipitate the cell extract, and the precipitate was filtered and purified. The purified product is dissolved in deuterated chloroform, and by NMR analysis, it is a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate (P (3HB-Co-3HV)), and 3-hydroxybutyrate (3HB) It was confirmed that the mole fraction of was 0.7 (70 mol%). The polymer content in the microbial cells was 30 to 50 wt%. The obtained P (3HB-Co-3HV) was used as the thermoplastic resin (A1).

The minimum medium composition is Na ₂ HPO ₄ · 12H ₂ O 9.0 g / L, KH ₂ PO ₄ 1.5 g / L, NH ₄ Cl 0.5 g / L, MgSO ₄ · 7H ₂ O 0.2 g / L, Trace Element 1.0ml / L. Trace elements _{FeCl 3 9.7g / L, CaCl 2} 7.8g / L, CoCl 2 · 6H2O 0.218g / L, CuSO 4 · 5H 2 O 0.156g / L, NiCl3 · 6H 2 O 0.118g / L, CrC l3 · 6H ₂ O 0.105 g / L dissolved in 0.1 M HCl.

(Preparation of molding pellet (1) containing resin composition (A1))
30 parts by weight of the thermoplastic resin (A1) and 70 parts by weight of poly-L lactic acid resin (thermoplastic resin (B): Lacia H-100 manufactured by Mitsui Chemicals, Ltd., weight average molecular weight Mw = 150,000) The mixture was melt-kneaded at a kneading temperature of 200 ° C. using a single-screw kneading extruder so as to be 100 parts by weight, and a molding pellet (1) of about 3 mm square was produced.

(Molding of pellets for molding (1))
The produced thermoplastic resin pellet (1) was dried at 50 ° C. for 12 hours using a shelf-type hot air dryer, and then a cylinder temperature of 180 ° C. using an electric injection molding machine having a clamping force of 50 tons. Then, a molded article (strip test piece) for a deflection temperature test under load was prepared at an injection speed of 20 mm / s and an injection pressure of 100 MPa. The size of the produced molded product is 130 mm in length, 3.2 mm in width, and 12.7 mm in height. Note that the temperature of the left side of the above formula (1) calculated from the molar fraction 0.7 of the thermoplastic resin (A1) is 29.8 ° C., and the mold temperatures are 30 ° C., 60 ° C., and 90 ° C., respectively. Three types of molded articles for load deflection temperature tests were prepared.

(Deflection temperature test of molded products, differential scanning calorimetry)
The load deflection temperature test of the manufactured molded article was a load deflection temperature test based on JIS K 7191. The distance between fulcrums was 100 mm, the heating rate was 2 ° C./min, and the bending stress was 0.45 MPa.

  In differential scanning calorimetry, the molded product was immediately heated at a rate of 10 ° C./min in the range of room temperature to 200 ° C. after molding, and the melting energy was measured using a differential scanning calorimeter DSC3100 manufactured by Mac Science. . Table 1 shows the deflection temperature test under load and the measurement results of melting energy together with the composition ratios of the thermoplastic resins (A) and (B). In Table 1, the compatibility of the formulas (1) and (2) is (◯) if both of the above formulas (1) and (2) are satisfied, and (x) if neither is satisfied. It was.

[Example 2]
(Production of thermoplastic resin (A2))
Using a Bacillus genus, etc., the nitrogen source is limited for a culture solution cultured for 16 hours in a medium (pH 6.95) containing peptone 5.0 g / L, yeast extract 5.0 g / L, meat extract 5.0 g / L In the same minimal medium as in Example 1, the addition ratio of glucose and propionic acid was added in the same manner as in Example 1, and cultured at 45 ° C. for 48 hours to obtain wet cells. The obtained wet cells were lyophilized, and 80 times the amount of chloroform as the amount of dry cells was added, and the cells were extracted at 80 ° C. Insoluble matter was filtered off, methanol was added to the filtrate to reprecipitate the cell extract, and the precipitate was filtered and purified. The purified product is dissolved in deuterated chloroform, and by NMR analysis, it is a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate (P (3HB-Co-3HV)), and 3-hydroxybutyrate (3HB) Was confirmed to be 0.85 (85 mol%). The polymer content in the microbial cells was 30 to 50 wt%. The obtained P (3HB-Co-3HV) was used as a thermoplastic resin (A2).

(Preparation of molding pellet (2) containing resin composition (A2))
The thermoplastic resin (A2) is mixed with the thermoplastic resin (B). At this time, in such a mixture, (A2) :( B) is mixed so that the weight ratio is 30:70, and this is melt-kneaded at a temperature of 200 ° C. using a single-screw kneading extruder, A molding pellet (2) of about 3 mm square was produced.

(Molding of pellets for molding (2), load deflection temperature test of molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (2) was used as a raw material instead of the molding pellet (1), the molding of the resin composition, the load deflection temperature test of the molded product, and the differential were performed in the same manner as in Example 1. Scanning calorimetry was performed.

  Table 1 shows the deflection temperature test under load and the measurement results of melting energy together with the composition ratio of the thermoplastic resin. In addition, the temperature of the left side of Formula (1) calculated from the molar fraction 0.85 of the thermoplastic resin (A2) is 58.4 ° C.

[Example 3]
(Production of thermoplastic resin (A3))
Using a Bacillus genus, etc., the nitrogen source is limited for a culture solution cultured for 16 hours in a medium (pH 6.95) containing peptone 5.0 g / L, yeast extract 5.0 g / L, meat extract 5.0 g / L Example 1 and Example 2 were added to the same minimal medium (containing glucose) as in Example 1, but the glucose-propionic acid addition ratio was changed, and cultured at 45 ° C. for 48 hours. Got. The obtained wet cells were lyophilized, and 80 times the amount of chloroform as the amount of dry cells was added, and the cells were extracted at 80 ° C. Insoluble matter was filtered off, methanol was added to the filtrate to reprecipitate the cell extract, and the precipitate was filtered and purified. The purified product is dissolved in deuterated chloroform, and by NMR analysis, it is a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate (P (3HB-Co-3HV)), and 3-hydroxybutyrate (3HB) Was confirmed to be 0.95 (95 mol%). The polymer content in the microbial cells was 30 to 50 wt%. The obtained P (3HB-Co-3HV) was used as a thermoplastic resin (A3).

(Preparation of molding pellet (3) containing resin composition (A3))
The thermoplastic resin (A3) is mixed with the thermoplastic resin (B). At this time, the mixture is melt-kneaded at a temperature of 200 ° C. using a single-screw kneading extruder so that (A3) :( B) is 30:70 in a weight ratio in these mixtures, and is about 3 mm square. A molding pellet (3) was produced.

(Molding of pellets for molding (3), temperature deflection test of molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (3) was used as a raw material instead of the molding pellet (1), the molding of the resin composition, the deflection temperature test of the molded product, and the differential were performed in the same manner as in Example 1. Scanning calorimetry was performed.

  Table 1 shows the deflection temperature test under load and the measurement results of melting energy together with the composition ratio of the thermoplastic resin. The temperature on the left side of the formula (1) calculated from the molar fraction 0.95 of the thermoplastic resin (A3) is 80.5 ° C.

[Example 4]
(Preparation of molding pellet (4) containing thermoplastic resin (A2))
In Example 2, except that the mixing ratio of the thermoplastic resin (A2) and the thermoplastic resin (B) was changed from 30:70 parts by weight to 10:90 parts by weight, the same as in Example 2, the molding pellets (4) was produced.

(Forming pellets for molding (4), temperature deflection test for molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (4) was used as a raw material instead of the molding pellet (1), the molding of the resin composition, the deflection temperature test of the molded product, and the differential were performed in the same manner as in Example 1. Scanning calorimetry was performed.

  The load deflection temperature test and the measurement results of the melting energy are shown in Table 2 together with the composition ratio of the thermoplastic resin. In addition, the temperature of the left side of Formula (1) calculated from the molar fraction 0.85 of the thermoplastic resin (A2) is 58.4 ° C. In Table 2, the compatibility of the formulas (1) and (2) is (◯) if both of the above formulas (1) and (2) are satisfied, and (x) if neither is satisfied. .

[Example 5]
(Preparation of molding pellet (5) containing resin composition (A2))
Molding pellets in the same manner as in Example 2, except that the mixing ratio of the thermoplastic resin (A2) and the thermoplastic resin (B) was changed from 30:70 parts by weight to 90:10 parts by weight. (5) was produced.

(Molding of pellets for molding (5), load deflection temperature test of molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (5) was used as a raw material instead of the molding pellet (1), the molding of the resin composition, the load deflection temperature test of the molded product, and the differential were performed in the same manner as in Example 1. Scanning calorimetry was performed.

  The load deflection temperature test and the measurement results of the melting energy are shown in Table 2 together with the composition ratio of the thermoplastic resin. In addition, the temperature of the left side of Formula (1) calculated from the molar fraction 0.85 of the thermoplastic resin (A2) is 58.4 ° C.

[Example 6]
(Preparation of molding pellet (6) containing thermoplastic resin (2A))
The crystallization nucleating agent 1, the crystallization nucleating agent 2, and the crystallization nucleating agent 3 were each dry blended at a ratio of 1.5 parts by weight to 100 parts by weight of the molding pellet (2). This mixture was melt-kneaded at a kneading temperature of 200 ° C. using a single-screw kneading extruder to produce a molding pellet (6) of about 3 mm square. The crystallization nucleating agent 1 is phenylphosphonic acid zinc salt (C ₆ H ₅ PO ₃ Zn), and the crystallization nucleating agent 2 is hydrous magnesium silicate ((OH) ₈ Mg with an average particle size of 1.0 μm). ₁₂ Si ₁₆ O ₄₀ or (OH) ₂ Mg ₃ (Si ₂ O ₅ ) ₂ ) and crystallization nucleating agent 3 using octanedicarboxylic acid-dibenzoyl hydrazide (C ₂₄ H ₃₀ N ₄ O ₄ ) It was.

(Molding of pellets for molding (6), load deflection temperature test of molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (6) is used as a raw material instead of the molding pellet (1), the molding of the resin composition, the load deflection temperature test of the molded product, and the differential are performed in the same manner as in Example 1. Scanning calorimetry was performed.

  The load deflection temperature test and the measurement results of the melting energy are shown in Table 2 together with the composition ratio of the thermoplastic resin. In addition, the temperature of the left side of Formula (1) calculated from the molar fraction 0.85 of the thermoplastic resin (A2) is 58.4 ° C.

[Comparative Example 1]
(Preparation of molding pellet (7) made of thermoplastic resin (B))
Example 1 except that only the thermoplastic resin (B) was used in place of the mixture of the thermoplastic resin (A1) and the thermoplastic resin (B) in the production of the molding pellet (1) of Example 1. In the same manner as above, a molding pellet (7) made of the thermoplastic resin (B) was produced.

(Molding of pellets for molding (7), load deflection temperature test of molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (7) was used instead of the molding pellet (1) as a raw material, the molding pellet was molded, the deflection temperature test of the molded product, the differential, and the like. Scanning calorimetry was performed. Table 3 shows the deflection temperature test under load and the measurement results of melting energy together with the composition ratio of the thermoplastic resin. In the table, the compatibility of the formulas (1) and (2) is (◯) if both of the above formulas (1) and (2) are satisfied, and (x) if neither is satisfied. Moreover, (-) represents that there is no thermoplastic resin (A).

[Comparative Example 2]
(Preparation of molding pellet (8) comprising thermoplastic resin (B) and crystallization nucleating agent)
In the production of the molding pellet (6) of Example 6, the thermoplastic resin (B) was used in the same manner as in Example 6 except that the thermoplastic resin (B) was used instead of the thermoplastic resin (A2). A molding pellet (8) comprising a crystallization nucleating agent was produced.

(Molding of pellets for molding (8), temperature deflection test of molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (8) was used as a raw material instead of the molding pellet (1), the molding of the molding pellet, the deflection temperature test of the molded product, and the differential were performed in the same manner as in Example 1. Scanning calorimetry was performed. Table 3 shows the deflection temperature test under load and the measurement results of melting energy together with the composition ratio of the thermoplastic resin.

[Comparative Example 3]
(Production of thermoplastic resin (A4))
Using a Bacillus genus, etc., the nitrogen source is limited for a culture solution cultured for 16 hours in a medium (pH 6.95) containing peptone 5.0 g / L, yeast extract 5.0 g / L, meat extract 5.0 g / L Glucose was added to the same minimal medium as in Example 1 and cultured at 45 ° C. for 48 hours to obtain wet cells. The obtained wet cells were lyophilized, and 80 times the amount of chloroform as the amount of dry cells was added, and the cells were extracted at 80 ° C. Insoluble matter was filtered off, methanol was added to the filtrate to reprecipitate the cell extract, and the precipitate was filtered and purified. The purified product was dissolved in deuterated chloroform, and was analyzed by NMR analysis to be poly-3-hydroxybutyrate (P3HB), a homopolymer having a 3-hydroxybutyrate (3HB) molar fraction of 1.0 (100 mol%). I confirmed that there was. The polymer content in the microbial cells was 30 to 50 wt%. The obtained P3HB was used as a thermoplastic resin (A4).

(Preparation of molding pellet (9) containing resin composition (A4))
The thermoplastic resin (A4) was mixed so that the weight ratio of the thermoplastic resin (A4) to the thermoplastic resin (B) was 30:70, and this was melt-kneaded at a temperature of 200 ° C. using a single-screw kneading extruder. About a molding pellet (9) was produced.

(Molding of molding pellets (9), deflection temperature test of molded products, differential scanning calorimetry)
In Example 1, except that the molding pellet (9) was used instead of the molding pellet (1), the molding of the resin composition, the load deflection temperature test of the molded product, and the differential were performed in the same manner as in Example 1. Scanning calorimetry was performed.

  Table 3 shows the deflection temperature test under load and the measurement results of melting energy together with the composition ratio of the thermoplastic resin. In addition, the temperature of the left side of Formula (1) calculated from the molar fraction 1.0 of a thermoplastic resin (A4) is 92.9 degreeC.

[Consideration of Examples and Comparative Examples]
It can be seen that the molded articles satisfying the formulas (1) and (2) of the resin compositions in Examples 1 to 6 have a deflection temperature under load higher than 100 ° C. and exhibit suitable heat resistance. On the other hand, it is considered that the molded articles of the resin composition in which the thermoplastic resin (A) does not exist from Comparative Examples 1 and 2 have a deflection temperature under load considerably lower than 100 ° C. and are difficult to use for general purposes. However, the molded articles shown in Examples 1 to 6 corresponding to the present invention can be used as very versatile molded articles.

  Further, looking at the relationship between the mold temperature of Examples 1 to 6 and the deflection temperature under load of the molded product, even when the resin composition is the same, the mold temperature does not satisfy the formula (1). It can be seen that the molded article satisfying the formula (1) has a high deflection temperature under load, and the formula (1) represents a critical value for exceeding the deflection temperature under load of 100 ° C. Formula (2) is a use range of a general-purpose water mold temperature controller, and examination was performed in this range.

  As can be seen from Comparative Example 3, when the thermoplastic resin (A4) having a too high content of 3HB is used, there is no mold temperature condition that satisfies both the formulas (1) and (2). A good molded product could not be obtained. The upper limit of the 3HB content (molar fraction) is approximately 99%. Moreover, also in Example 2, it turns out that the high heat resistance is shown also in Example 6 which added the crystallization nucleating agent with the same resin composition as Example 2. FIG.

  Thus, according to the present invention, it was found that a molded article of a thermoplastic resin having heat resistance that is the same as that of a conventional petroleum resin can be produced using almost 100% of a biomass resource-derived thermoplastic resin.

Claims (9)

A thermoplastic resin (A) composed of a microorganism-produced polyhydroxyalkanoate copolymer containing structural units represented by the following chemical formula (1) and chemical formula (2), and a thermoplastic resin (B) composed of polylactic acid It is a molding method of a resin composition (excluding those containing all of a plasticizer, an organic nucleating agent, and an inorganic nucleating agent) ,

[However, R is C _n H _{2n + 1} (n = 2 to 14). ]
When the molar fraction of the structural unit represented by the chemical formula (1) in the thermoplastic resin (A) is c, and the mold temperature in the molding of the resin composition is T ° C., the following formulas (1) and ( 2. A method for molding a resin composition, characterized by satisfying 2).
122.9c ² -30.4 ≦ T
(1)
25 ≦ T ≦ 90 (2)   The molding method of the resin composition according to claim 1, wherein a mole fraction of the structural unit represented by the chemical formula (1) in the thermoplastic resin (A) is 70 to 95 mol%.   3. The molding of the resin composition according to claim 1 or 2, wherein the thermoplastic resin (A) is a copolymer of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV). Method.   4. The resin composition according to claim 1, comprising 99% to 1 part by weight of the thermoplastic resin (B) with respect to 1 to 99 parts by weight of the thermoplastic resin (A). Molding method.   The thermoplastic resin (B) made of polylactic acid and the thermoplastic resin (B) contain one or more selected from poly L lactic acid, poly D lactic acid, and a stereo complex made of poly L lactic acid and poly D lactic acid. The molding method of the resin composition according to any one of claims 1 to 4.   The method for molding a resin composition according to claim 1, further comprising a crystallization nucleating agent. The crystallization nucleating agent is talc-based nucleating agent, claim 6, characterized in that it comprises a nucleating agent composed of a metal salt-type material having a phenyl group, and at least one selected from a nucleating agent consisting of a benzoyl compound-type The molding method of the resin composition as described in 2. A thermoplastic resin (A) composed of a microorganism-produced polyhydroxyalkanoate copolymer containing a structural unit represented by the following chemical formula (1) and the following chemical formula (2); and a thermoplastic resin (B) composed of polylactic acid; Is a molded product molded from a resin composition (except for those containing all of plasticizer, organic nucleating agent, and inorganic nucleating agent),
A molded article characterized by having a deflection temperature under load higher than 100 ° C.

[However, R is C _n H _{2n + 1} (n = 2 to 14). ]   The molded article according to claim 8, which is provided in an electric / electronic device.