Method for molding biodegradable resin composition, and biodegradable resin molded article

Abstract

To provide a method for molding a biodegradable resin composition giving a biodegradable resin molded article having high flexibility and to provide the biodegradable resin molded article.SOLUTION: The method for molding the biodegradable resin composition comprises a grinding process for grinding the biodegradable resin composition and a molding process for kneading the ground product obtained through the grinding process with a plasticizer and then molding the kneaded product. The content of the plasticizing agent in the biodegradable resin-molded product is not less than 21phr.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for molding a biodegradable resin composition and a biodegradable resin molded article. [Background technology]

[0002] Biodegradable resins have long been attracting attention as alternatives to petroleum-derived plastics from the perspective of reducing environmental impact. Biodegradable polyesters in particular are widely produced, and their widespread use in various applications is being considered.

[0003] Patent Document 1 discloses a molded article of a resin composition containing a branched biodegradable polyester, which has a block structure including a random copolymer segment of lactide and caprolactone and a homopolymer segment of lactide, and in which a polyhydric alcohol having a valence of three or more is bonded to the end of the block structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-058335 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for highly flexible biodegradable resin molded articles. The problem to be solved by the present invention is to provide a method for molding a biodegradable resin composition that gives a highly flexible biodegradable resin molded article, and the biodegradable resin molded article. [Means for solving the problem]

[0006] The present inventors have conducted extensive research in light of the above-mentioned problems and have found that a method for molding a biodegradable resin composition, which includes a pulverization process in which a biodegradable resin composition is pulverized, and a molding process in which the pulverized product obtained through the pulverization process is mixed with a plasticizer and then molded, can provide a biodegradable resin molded product with high flexibility. The present invention was completed based on these findings.

[0007] The present invention relates to a method for molding a biodegradable resin composition, which includes a pulverization process in which the biodegradable resin composition is pulverized, and a molding process in which the pulverized material obtained through the pulverization process is kneaded with a plasticizer and then molded. The biodegradable resin composition preferably contains at least one selected from the group consisting of polybutyl adipate terephthalate, polylactic acid, and polycaprolactone. The biodegradable resin composition may further contain thermoplastic starch. The plasticizer preferably includes an ester-based plasticizer. The content of the plasticizer in the biodegradable resin molded article obtained through the molding process is preferably 21 phr or more.

[0008] The present invention relates to a biodegradable resin shaped article, which contains a biodegradable resin and a plasticizer, and the content of the plasticizer in the biodegradable resin shaped article is 21 phr or more.

[0009] The biodegradable resin molded article is preferably at least one part selected from the group consisting of artificial baits, artificial baits, fishing tackle, and fishing equipment. [Effects of the Invention]

[0010] The method for molding the biodegradable resin composition of the present invention provides a biodegradable resin molded article with high flexibility. The biodegradable resin molded article of the present invention is a biodegradable resin molded article with high flexibility. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will now be described in further detail. Unless otherwise specified, a numerical range of "X to Y" represents a range from X to Y, including both endpoints. When a numerical range is indicated, the upper and lower limits can be combined as appropriate, and the resulting numerical range is also considered to be disclosed.

[0012] The method for molding the biodegradable resin composition of the present invention includes a pulverization process in which the biodegradable resin composition is pulverized, and a molding process in which the pulverized material obtained through the pulverization process is kneaded with a plasticizer and then molded.

[0013] <Biodegradable resin> The biodegradable resin composition includes a biodegradable resin. The biodegradable resin preferably includes a biodegradable polyester. The biodegradable polyester is not limited to a specific biodegradable polyester. The biodegradable polyester preferably includes at least one selected from the group consisting of polylactic acid, polyhydroxyalkanoate, polybutylene succinate, cellulose acetate, polyvinyl alcohol, polyglycolic acid, polybutylene succinate-co-adipate, polybutylene adipate terephthalate, and polyethylene terephthalate succinate, more preferably at least one selected from the group consisting of polybutyl adipate terephthalate, polylactic acid, and polycaprolactone, and even more preferably at least one selected from the group consisting of polybutyl adipate terephthalate, polylactic acid, and polycaprolactone.

[0014] <Plasticizer> The biodegradable resin composition contains a plasticizer. The plasticizer is not limited to a specific type. The plasticizer preferably contains at least one selected from the group consisting of ester-based plasticizers such as phthalates, adipates, trimellitates, polyesters, sebacates, azelates, maleates, benzoates, and phosphates, and epoxidized vegetable oils, and is more preferably an ester-based plasticizer. The ester-based plasticizer is commercially available. Examples of commercially available ester-based plasticizers include DAIFATTY-101 (registered trademark) manufactured by Daihachi Chemical Industry Co., Ltd., Monocizer PB-3A manufactured by DIC Corporation, Monocizer PB-10 manufactured by DIC Corporation, Monocizer W-83 manufactured by DIC Corporation, Biocizer manufactured by Riken Vitamin Co., Ltd., and Elecut manufactured by Takemoto Oil & Fat Co., Ltd.

[0015] The biodegradable resin composition may contain thermoplasticized starch. The starch used as a raw material for the thermoplasticized starch is not limited to a specific starch. Examples of the starch include corn starch, waxy corn starch, tapioca starch, rice starch, wheat starch, potato starch, sweet potato starch, mung bean starch, potato chestnut starch, kudzu starch, bracken starch, and sago starch. The starch may also be at least one type of starch that has been improved by breeding or genetic engineering techniques, such as non-glucan, waxy, or high-amylose varieties of the starch. The starch used in the present invention may be a modified starch, so long as the starch particle shape is maintained. The processed starch can be modified starch obtained by subjecting raw starch to chemical treatments such as oxidation, esterification, etherification, crosslinking, acid treatment, or alkali treatment, or modified starch obtained by physical treatments such as granulation, moist heat treatment, hot water treatment, bleaching, sterilization, oil / fat processing, heat treatment, pressure treatment, vacuum treatment, milling, powder collision treatment, friction treatment, pulverization, or extrusion. Modified starch obtained by combining two or more of these treatments can also be used. Each of the chemical and physical treatments can be applied to starch that has already been subjected to at least one of physical processing and enzymatic treatment. Furthermore, each of the chemical and physical treatments can be applied to starch before the physical processing and / or enzymatic treatment. An example of such a modified starch is oxidized cornstarch. In the present invention, at least one of the starches described above may be used.

[0016] The biodegradable resin composition may contain general additives that are added to resin compositions. Examples of the additives include compatibilizers, nucleating agents, UV absorbers, weathering agents, heat stabilizers, light stabilizers, binders, antiblocking agents, lubricants, neutralizing agents, crystallization accelerators, colorants, foaming agents, waterproofing agents, water repellents, antibacterial agents, anti-fogging agents, and impact resistance modifiers. The additive contains at least one of the additives described above, and is preferably at least one of the additives described above.

[0017] The biodegradable resin composition pulverized in the pulverization process contains a raw resin, the plasticizer, and additives other than the plasticizer that are added as needed. The biodegradable resin composition may be a dry blend or pellets. The raw resin is commercially available. Examples of commercially available raw resins include Mater-bi (manufactured by Novamont), Origo-Bi (registered trademark) ES01G (manufactured by Novamont), Kaneka Biodegradable Polymer PHBH (manufactured by Kaneka Corporation), BioPBS (manufactured by Mitsubishi Chemical Corporation), Ecoflex (manufactured by BASF), and Ecobio (manufactured by BASF).

[0018] The particle size of the pulverized product obtained through the pulverization process is preferably 1000 μm or less, more preferably 500 μm or less. The pulverized product is passed through a sieve with a predetermined mesh size to obtain the pulverized product having a particle size within the predetermined range.

[0019] The biodegradable resin composition obtained by kneading the pulverized pellets with the plasticizer may contain a larger amount of the plasticizer than the biodegradable resin composition obtained by kneading the pellets with the plasticizer. For example, the content of the plasticizer in the biodegradable resin molded product obtained through the molding process is 21 phr or more, preferably 25 phr or more, and more preferably 30 phr or more.

[0020] Therefore, the biodegradable resin molded article of the present invention has high flexibility and is suitable for use as at least one part selected from the group consisting of artificial baits, fishing tackle, and fishing equipment.

[0021] The molding method in the molding process is not limited to a specific molding method, and examples of the molding method include injection molding, extrusion molding, vacuum molding, blow molding, and bead foam molding. [Example]

[0022] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0023] The raw material resins and plasticizers used in the examples and comparative examples are as follows. <Raw material resin> Polybutyl adipate terephthalate containing thermoplastic starch (Novamont Mate-Bi EF04P): Starch-containing PBAT Polybutyl adipate terephthalate (Oligo-BI ES01O manufactured by Novamont): PBAT <Plasticizer> DAIFATTY-101 (registered trademark) manufactured by Daihachi Chemical Industry Co., Ltd.: DAIFATTY DIC Corporation Monosizer PB-3A:PB-3A

[0024] [Comparative Example 1] 50 parts by mass of starch-containing PBAT, 50 parts by mass of PBAT, and 10 parts by mass of DAIFATTY were kneaded in a twin-screw extruder (TEX34αIII manufactured by The Japan Steel Works, Ltd.), and then 10 parts by mass of DAIFATTY was added to the resulting kneaded mixture and kneaded in the twin-screw extruder to produce pellets. The pellets were injection molded.

[0025] Comparative Example 2 50 parts by mass of starch-containing PBAT, 50 parts by mass of PBAT, and 10 parts by mass of PB-3A were kneaded in the twin-screw extruder, and then 10 parts by mass of PB-3A was added to the resulting kneaded mixture and kneaded in the twin-screw extruder to produce pellets. The pellets were injection-molded.

[0026] [Examples 1 and 2] 50 parts by weight of starch-containing PBAT and 50 parts by weight of PBAT were dry blended, the resulting blend was pulverized, and the resulting powder was sieved through a 500 μm x 500 μm sieve to obtain a pulverized product with a particle size of 500 μm or less. 100 parts by weight of the pulverized product and 33.3 parts by weight of DAIFATTY or PB-3A were mixed in the twin-screw extruder to produce pellets. The pellets were injection molded.

[0027] [Examples 3 and 4] 50 parts by weight of starch-containing PBAT and 50 parts by weight of PBAT were dry blended, the resulting blend was pulverized, and the resulting powder was sieved through a 1000 μm x 1000 μm sieve to obtain a pulverized product with a particle size of 1000 μm or less. 100 parts by weight of the pulverized product and 33.3 parts by weight of DAIFATTY or PB-3A were mixed in the twin-screw extruder to produce pellets. The pellets were injection molded.

[0028] [Table 1]

[0029] When mixing starch-containing PBAT or PBAT-containing pellets with a plasticizer, it was not possible to mix more than 20 phr of the plasticizer. On the other hand, when mixing ground starch-containing PBAT or PBAT-containing pellets with a plasticizer, it was possible to mix more than 21 phr of the plasticizer, and a molded product with high flexibility was obtained.

Claims

1. A method for molding a biodegradable resin composition, comprising: a grinding process in which the biodegradable resin composition is ground; and A method for molding a biodegradable resin composition, comprising a molding process in which the pulverized product obtained through the pulverization process is kneaded with a plasticizer and then molded.

2. 2. The method for molding a biodegradable resin composition according to claim 1, wherein the biodegradable resin composition comprises at least one selected from the group consisting of polybutyl adipate terephthalate, polylactic acid, and polycaprolactone.

3. 3. The method for molding a biodegradable resin composition according to claim 2, wherein the biodegradable resin composition further contains thermoplastic starch.

4. 2. The method for molding a biodegradable resin composition according to claim 1, wherein the plasticizer comprises an ester-based plasticizer.

5. 2. The method for molding a biodegradable resin composition according to claim 1, wherein the content of the plasticizer in the biodegradable resin molded body obtained through the molding process is 21 phr or more.

6. A biodegradable resin molded article, Contains a biodegradable resin and a plasticizer, A biodegradable resin molded body, wherein the content of the plasticizer in the biodegradable resin molded body is 21 phr or more.

7. 7. The biodegradable resin molded article according to claim 6, which is a part of at least one selected from the group consisting of artificial baits, fishing tackle, and fishing equipment.

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