Biodegradable resin composition

Abstract

Provided are: a biodegradable resin composition having excellent melt fluidity while maintaining favorable mechanical strength; and a molded body using the biodegradable resin composition.　This biodegradable resin composition comprises: a polyester (PE) that contains a constitutional unit (A) derived from a monomer represented by general formula (1) and a constitutional unit (B) derived from a monomer represented by general formula (2); and a polyester carbonate (PEC) that contains a constitutional unit (A) derived from a monomer represented by general formula (1) and a constitutional unit (B) derived from a monomer represented by general formula (2).　Formula (1): HO-(CH2)n-OH (In general formula (1), n represents an integer of 4-16.)　Formula (2): R1OOC-(CH2)m-COOR2

Description

Biodegradable resin composition

[0001] The present invention relates to a biodegradable resin composition. More specifically, the present invention relates to a biodegradable resin composition containing a polyester and a polyester carbonate.

[0002] Traditionally, plastic materials such as polyethylene, polypropylene, polyethylene terephthalate, and nylon have been used and consumed in large quantities as molding materials. While some of these plastic materials are recycled, they are generally collected and then incinerated or buried underground. However, because recovery requires a great deal of effort and expense, or because recovery is difficult, they are sometimes left unrecovered. In response to these environmental issues, there has been a demand for the development of polymeric materials that can be decomposed in the natural environment. Among these, biodegradable plastics, which can be decomposed by microorganisms, have been particularly anticipated as environmentally friendly materials and new types of functional materials.

[0003] Polyester carbonate resin (hereinafter also referred to as "PEC") is known as a biodegradable plastic (see, for example, Patent Documents 1 and 2). In recent years, environmental issues have been given more attention, and biodegradability has become an important feature of resins. Against this background, various developments have been made on biodegradable resin compositions.

[0004] JP-A No. 8-193125 JP-A No. 8-134196

[0005] Although polyester carbonate has excellent mechanical strength, there is room for improvement in melt fluidity, for example, when molding precision molded articles. Therefore, the present invention provides a biodegradable resin composition that maintains good mechanical strength and has excellent melt fluidity, and a molded article using the biodegradable resin composition.

[0006] As a result of extensive research, the present inventors have discovered that the above-mentioned problems can be solved by adding a polyester (hereinafter also referred to as "PE") containing a structural unit (A) represented by general formula (1) and a structural unit (B) represented by general formula (2) to a polyester carbonate containing the structural unit (A) represented by general formula (1) and the structural unit (B) represented by general formula (2), and have arrived at the present invention. That is, the present invention provides the following aspects. <1> A biodegradable resin composition comprising a polyester (PE) containing a structural unit (A) derived from a monomer represented by the following general formula (1) and a structural unit (B) derived from a monomer represented by the following general formula (2), and a polyester carbonate (PEC) containing a structural unit (A) derived from a monomer represented by the following general formula (1) and a structural unit (B) derived from a monomer represented by the following general formula (2). ２ ) n-OH (1) (In the general formula (1), n ​​represents an integer of 4 to 16.) R １ OOC-(CH ２ ) m-COOR ２ (2) (In general formula (2), R １ and R ２are each independently selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms, and m represents an integer of 2 to 16.) <2> The resin composition according to <1>, wherein the mass ratio (PE:PEC) of the polyester (PE) to the polyester carbonate (PEC) is 0.1:99.9 to 50:50. <3> The resin composition according to <1> or <2>, wherein the hydroxyl value (OH value) of the polyester (PE) is 30 to 140 mgKOH / g. <4> The resin composition according to any one of <1> to <3>, wherein the weight average molecular weight (Mw) of the polyester (PE) is 3,000 to 8,000. <5> The resin composition according to any one of <1> to <4>, wherein the weight average molecular weight (Mw) of the polyester carbonate (PEC) is 100,000 to 300,000. <6> The resin composition according to any one of <1> to <5>, wherein the monomer represented by the general formula (1) includes 1,4-butanediol, and the monomer represented by the general formula (2) includes succinic acid or adipic acid. <7> The resin composition according to any one of <1> to <6>, wherein at least one of the monomer represented by the general formula (1) and the monomer represented by the general formula (2) is derived from a biomass resource. <8> A molded article comprising the biodegradable resin composition according to any one of <1> to <7>.

[0007] According to the present invention, it is possible to provide a biodegradable resin composition having good mechanical strength and excellent melt flowability, and also to provide a molded article using the biodegradable resin composition.

[0008] The present invention will be described in more detail below, but the explanations of each constituent element described below are representative examples of embodiments of the present invention, and the present invention is not limited thereto. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​written before and after "to" as the lower and upper limits. In this specification, a lower limit or upper limit means a range including the value of the lower limit or upper limit.

[0009] [Biodegradable Resin Composition] The biodegradable resin composition of the present invention comprises a polyester (PE) containing a structural unit (A) derived from a monomer represented by the following general formula (1) and a structural unit (B) derived from a monomer represented by the following general formula (2), and a polyester carbonate (PEC) containing a structural unit (A) derived from a monomer represented by the following general formula (1) and a structural unit (B) derived from a monomer represented by the following general formula (2): HO—(CH ２ ) n-OH (1) (In the general formula (1), n ​​represents an integer of 4 to 16.) R １ OOC-(CH ２ ) m-COOR ２ (2) (In general formula (2), R １ and R ２ are each independently selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms, and m represents an integer of 2 to 16.

[0010] The polyester (PE) and polyester carbonate (PEC) contained in the biodegradable resin composition of one embodiment of the present invention may have the same structural unit (A) and structural unit (B), or either one of the structural unit (A) and the structural unit (B) may be the same, or the structural unit (A) and the structural unit (B) may be different. In a preferred embodiment of the biodegradable resin composition of the present invention, the polyester (PE) and polyester carbonate (PEC) contain the same structural unit (A) and structural unit (B).

[0011] In one embodiment of the present invention, the biodegradable resin composition may contain one type of monomer represented by the general formula (1) and one type of monomer represented by the general formula (2) alone, or may contain two or more types in combination.

[0012] In the general formula (1), n ​​may be an integer of 4 to 16, 4 to 14, 4 to 12, 4 to 10, 4 to 8, 4 to 6, or 4.

[0013] Specific examples of the monomer represented by the general formula (1) include aliphatic dihydroxy compounds such as 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, and 1,16-hexadecanediol.

[0014] In the general formula (2), R １ and R ２ are each independently selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms. １ and R ２ The number of carbon atoms in the alkyl group that can be selected as may be 1 to 4, 1 to 3, 1 or 2, 2 to 5, 2 to 4, 2 or 3, 3 to 5, 3 or 4, or 4 or 5.

[0015] R １ and R ２ The alkyl group that can be selected as may be a linear or branched alkyl group, and specific examples thereof include a methyl group, an ethyl group, a propyl group such as an n-propyl group or an isopropyl group, and a butyl group such as an n-butyl group, an isobutyl group, an s-butyl group or a t-butyl group.

[0016] In the general formula (2), m may be an integer of 2 to 16, 2 to 14, 2 to 12, 2 to 10, 2 to 8, 2 to 6, 2 to 4, or 2.

[0017] Specific examples of the monomer represented by the general formula (2) include aliphatic dibasic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, sebacic acid, and dodecanoic acid (lauric acid). These aliphatic dibasic acids may be their esters or acid anhydrides.

[0018] In one embodiment of the biodegradable resin composition of the present invention, in the general formula (1), n ​​represents an integer of 4 to 6, and in the general formula (2), R １and R ２ are each independently selected from a hydrogen atom and an alkyl group having 1 to 3 carbon atoms, and m represents an integer of 2 to 4.

[0019] In a biodegradable resin composition according to one embodiment of the present invention, the monomer represented by the general formula (1) includes 1,4-butanediol, and the monomer represented by the general formula (2) includes succinic acid or adipic acid.

[0020] In the biodegradable resin composition of one embodiment of the present invention, the monomer represented by the general formula (1) and the monomer represented by the general formula (2) may be made using raw materials derived from fossil resources such as petroleum and coal, or may be made using raw materials derived from biomass resources such as plants. In a preferred embodiment of the biodegradable resin composition of the present invention, at least one of the monomer represented by the general formula (1) and the monomer represented by the general formula (2) is derived from a biomass resource. In a more preferred embodiment of the biodegradable resin composition of the present invention, both the monomer represented by the general formula (1) and the monomer represented by the general formula (2) are derived from a biomass resource.

[0021] Biomass resources include the stored energy of sunlight converted into starch, cellulose, etc. by photosynthesis in plants, the bodies of animals that grow by eating plants, and products made by processing plants or animals.Specific examples include wood, rice straw, rice bran, used rice, corn, sugarcane, cassava, sago palm, soybean pulp, corn cob, tapioca dregs, bagasse, vegetable oil cake, potatoes, buckwheat, soybeans, oils and fats, used paper, papermaking residues, seafood residues, livestock excrement, sewage sludge, and food waste. Among these, plant resources such as wood, rice straw, old rice, corn, sugarcane, cassava, sago palm, soybean pulp, corn cob, tapioca dregs, bagasse, vegetable oil cake, potato, buckwheat, soybean, oils and fats, waste paper, and papermaking residue are preferred, more preferably wood, rice straw, old rice, corn, sugarcane, cassava, sago palm, potato, oils and fats, waste paper, and papermaking residue, and most preferably corn, sugarcane, cassava, and sago palm.

[0022] In one aspect of the present invention, the mass ratio (PE:PEC) of the polyester (PE) to the polyester carbonate (PEC) is preferably 0.1:99.9 to 50:50, and also preferably 0.1:99.9 to 40:60, 1.0:99.0 to 30:70, 1.0:99.0 to 20:80, 1.0:99.0 to 10:90, or 1.0:99.0 to 5.0:95.0. By setting the PE:PEC ratio within the above range, it is possible to prepare a biodegradable resin composition that has excellent melt fluidity while maintaining good mechanical strength.

[0023] In one embodiment of the present invention, the weight average molecular weight (Mw) of the polyester (PE) is preferably 3000 to 8000, more preferably 3500 to 7000, and even more preferably 4000 to 6000. By setting the Mw within the above range, it is possible to prepare a biodegradable resin composition that has excellent melt fluidity while maintaining good mechanical strength.

[0024] In one embodiment of the present invention, the weight-average molecular weight (Mw) of the polyester carbonate (PEC) is preferably 100,000 to 300,000, more preferably 130,000 to 280,000, and even more preferably 150,000 to 260,000. Furthermore, the weight-average molecular weight (Mw) of the polyester carbonate (PEC) of one embodiment of the present invention may have a lower limit of 190,000 or more, 200,000 or more, or more than 210,000. In this case, the upper limit of Mw may be within any of the above ranges. By setting the Mw within the above range, a biodegradable resin composition having excellent melt fluidity while maintaining good mechanical strength can be prepared. Note that, in this specification, the weight-average molecular weight (Mw) refers to the weight-average molecular weight in terms of polystyrene and can be measured by the method described in the Examples below.

[0025] In one embodiment of the present invention, the hydroxyl value (OH value) of the polyester (PE) is preferably 30 to 140 mgKOH / g, more preferably 55 to 85 mgKOH / g, and even more preferably 60 to 80 mgKOH / g. By setting the hydroxyl value (OH value) in the range of 30 mgKOH / g or more, affinity with the polyester carbonate (PEC) can be improved, and the physical properties of the resulting biodegradable resin composition can be maintained at a good level. Furthermore, by setting the hydroxyl value (OH value) in the range of 140 mgKOH / g or less, the hydrolysis tendency of the resulting biodegradable resin composition can be prevented from becoming too high. In this specification, the hydroxyl value (OH value) refers to a value measured in accordance with JIS K-1557.

[0026] [Method for Producing Biodegradable Resin Composition] The method for producing the biodegradable resin composition of the present invention is not particularly limited. For example, the biodegradable resin composition of one embodiment of the present invention can be produced by a stepwise method including the first-stage reaction and the second-stage reaction shown below. Examples of methods for producing a biodegradable resin composition in a stepwise manner include those described in Japanese Patent Application Laid-Open Nos. 8-134196 and 8-301999. (First-stage reaction) A compound containing a structural unit (A) derived from a monomer represented by the general formula (1) and a compound containing a structural unit (B) derived from a monomer represented by the general formula (2) are subjected to a polycondensation reaction in the presence of a catalyst to obtain a polyester (PE) as a prepolymer. (Second-stage reaction) A polyester carbonate (PEC) is obtained by a polycondensation reaction of the polyester (PE) obtained in the first-stage reaction with a carbonate diester in the presence of a catalyst.

[0027] The catalyst used in the first-stage reaction and the second-stage reaction can be a basic compound catalyst, a transesterification catalyst, or a mixed catalyst comprising both. Examples of basic compound catalysts include alkali metal compounds, alkaline earth metal compounds, and nitrogen-containing compounds. Examples of preferred transesterification catalysts include zinc, tin, zirconium, and lead salts, which can be used alone or in combination. Specific examples include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin(II) chloride, tin(IV) chloride, tin(II) acetate, tin(IV) acetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead(II) acetate, and lead(IV) acetate.

[0028] Examples of the carbonate diester used in the latter reaction include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc. Among these, diphenyl carbonate is particularly preferred.

[0029] In the biodegradable resin composition of one embodiment of the present invention, unreacted monomers and carbonate diesters may remain. The acceptable concentration of residual monomers is 0 ppm to 5000 ppm, preferably 1 ppm to 3000 ppm. The acceptable concentration of residual carbonate diesters is 0 ppm to 5000 ppm, preferably 1 ppm to 1000 ppm.

[0030] Phenol by-produced during the polycondensation reaction may remain in the biodegradable resin composition of one embodiment of the present invention. The acceptable residual phenol concentration is 1 ppm to 5,000 ppm, preferably 10 ppm to 3,000 ppm. Furthermore, for example, a cyclic dimer composed of succinic acid and 1,4-butanediol may remain. The acceptable cyclic dimer concentration is 1.0% by mass or less, preferably 0.6% by mass or less. The concentration of the cyclic dimer in the biodegradable resin composition may be reduced by immersing and extracting a pelletized biodegradable resin composition in a solvent that has low solubility in the biodegradable resin composition, such as water or acetone, at a temperature of 20°C to less than 100°C.

[0031] The biodegradable resin composition of one embodiment of the present invention may be used in combination with a resin other than polyester (PE) and polyester carbonate (PEC). Such resins are not particularly limited, but examples include at least one resin selected from the group consisting of polycarbonate resin, (meth)acrylic resin, polyamide resin, polystyrene resin, cycloolefin resin, acrylonitrile-butadiene-styrene copolymer resin, vinyl chloride resin, polyphenylene ether resin, polysulfone resin, polyacetal resin, and methyl methacrylate-styrene copolymer resin. Various known resins can be used, and one type can be used alone, or two or more types can be used in combination.

[0032] The biodegradable resin composition of one embodiment of the present invention preferably contains an antioxidant as an additive. As the antioxidant, generally commercially available antioxidants can be used, but it is preferable to contain, for example, at least one of an acid phenol-based antioxidant and a phosphite-based antioxidant.

[0033] Phenolic antioxidants include 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine e-2,4,6(1H,3H,5H)-trione, 4,4',4''-(1-methylpropanyl-3-ylidene)tris(6-tert-butyl-m-cresol), 6,6'-di-tert-butyl-4,4'-butylidene-m-cresol, ocladecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentyl methyl acrylate ... Examples of the hydroxybenzoate include pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxospiro[5.5]undecane, and pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and preferably pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].Phosphite antioxidants include 2-ethylhexyl diphenyl phosphite, isodecyl diphenyl phosphite, triisodecyl phosphite, triphenyl phosphite, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxy-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and 2,2'-methylenebis(4,6-di-tert-butylphenyl)2-ethylhexyl phosphite. Examples of the antioxidant include tris(2,4-di-tert-butylphenyl)phosphite, tris(nonylphenyl)phosphite, tetra-C12-15-alkyl(propane-2,2-diylbis(4,1-phenylene))bis(phosphite), and 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and preferably 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane. As the antioxidant, any one of the above may be used alone, or a mixture of two or more may be used.

[0034] In the biodegradable resin composition according to one embodiment of the present invention, the antioxidant is preferably contained in an amount of 1 ppm by weight to 3,000 ppm by weight, more preferably 50 ppm by weight to 2,500 ppm by weight, even more preferably 100 ppm by weight to 2,000 ppm by weight, particularly preferably 150 ppm by weight to 1,500 ppm by weight, and even more preferably 200 ppm by weight to 1,200 ppm by weight, based on the total weight of the biodegradable resin composition.

[0035] The biodegradable resin composition of one embodiment of the present invention preferably contains a release agent as an additive. Examples of the release agent include ester compounds, such as glycerin fatty acid esters such as mono- and diglycerides of glycerin fatty acid, glycol fatty acid esters such as propylene glycol fatty acid esters and sorbitan fatty acid esters, higher alcohol fatty acid esters, and full esters or mono-fatty acid esters of aliphatic polyhydric alcohols and aliphatic carboxylic acids. When an ester of aliphatic polyhydric alcohols and aliphatic carboxylic acids is used as the release agent, either a monoester or a full ester can be used, but a release agent other than a full ester, such as a monoester, may also be used.

[0036] Specific examples of the release agent include the following: sorbitan fatty acid esters such as sorbitan stearate, sorbitan laurate, sorbitan oleate, sorbitan trioleate, sorbitan tribehenate, sorbitan stearate, sorbitan tristearate, and sorbitan caprylate; propylene glycol fatty acid esters such as propylene glycol monostearate, propylene glycol monooleate, propylene glycol monobehenate, propylene glycol monolaurate, and propylene glycol monopalmitate; higher alcohol fatty acid esters such as stearyl stearate; glycerin monohydroxystearates such as glycerin monostearate and glycerin mono-12-hydroxystearate, glycerin monooleate, glycerin monobehenate, glycerin monocaprylate, glycerin monocaprate, and glycerin Examples of the monoglycerides include monoglycerides such as monolaurate, and mono-diglycerides such as glycerin monodistearate, glycerin monodistearate, glycerin monodibehenate, and glycerin monodiolate; acetylated monoglycerides of glycerin fatty acid esters such as glycerin diacetomonolaurate; organic acid monoglycerides of glycerin fatty acid esters such as citric acid fatty acid monoglyceride, succinic acid fatty acid monoglyceride, and diacetyltartaric acid fatty acid monoglyceride; and polyglycerin fatty acid esters such as diglycerin stearate, diglycerin laurate, diglycerin oleate, diglycerin monostearate, diglycerin monolaurate, diglycerin monomyristate, diglycerin monooleate, tetraglycerin stearate, decaglycerin laurate, decaglycerin oleate, and polyglycerin polyricinoleate.

[0037] In the biodegradable resin composition according to one embodiment of the present invention, the release agent is preferably contained in an amount of 1 ppm by weight to 5,000 ppm by weight, more preferably 50 ppm by weight to 4,000 ppm by weight, even more preferably 100 ppm by weight to 3,500 ppm by weight, particularly preferably 500 ppm by weight to 13,000 ppm by weight, and even more preferably 1,000 ppm by weight to 2,500 ppm by weight, based on the total weight of the resin composition.

[0038] The biodegradable resin composition of one embodiment of the present invention may contain other additives in addition to the antioxidant and mold release agent described above.For example, compounding agents, catalyst deactivators, heat stabilizers, plasticizers, fillers, ultraviolet absorbers, rust inhibitors, dispersants, antifoaming agents, leveling agents, flame retardants, lubricants, dyes, pigments, bluing agents, nucleating agents, clarifying agents (specifically, sorbitol derivatives, hydroxy fatty acid amides, triaminobenzene compounds, nonitol compounds, various celluloses, etc.), starch (specifically, corn starch, waxy corn starch, high amylose corn starch, wheat starch, rice starch, potato starch, sweet potato starch, tapioca starch, pea starch, etc.), light stabilizers (specifically, bis-decanoic acid (2,2,6,6-tetramethyl-1(octyloxy)-4-piperidinyl)ester, reaction products of 1,1-dimethylethyl hydroperoxide with octane, bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate hindered compounds such as bacate, 1-[2-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-2,2,6,6-tetramethylpiperidine, and poly[[6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}] amine-based stabilizers, etc.), end-capping agents, inorganic fillers (specifically, anhydrous silica, mica, talc, titanium oxide, calcium carbonate, diatomaceous earth, allophane, bentonite, potassium titanate, zeolite, sepiolite, smectite, kaolin, kaolinite, glass, limestone, carbon, wollastonite, calcined perlite, silicates such as calcium silicate and sodium silicate, hydroxides such as aluminum oxide, magnesium carbonate and calcium hydroxide, salts such as ferric carbonate, zinc oxide, iron oxide, aluminum phosphate and barium sulfate, etc.), and the like.

[0039] In the biodegradable resin composition of one embodiment of the present invention, the content of additives other than the antioxidant and the mold release agent is preferably 10 ppm by weight to 5.0% by weight, more preferably 100 ppm by weight to 2.0% by weight, and even more preferably 1000 ppm by weight to 1.0% by weight, but is not limited thereto. The above-mentioned additives may adversely affect the transmittance, so it is preferable not to add them in excess, and for example, the total amount added is within the above-mentioned range.

[0040] [Uses of Biodegradable Resin Composition] The biodegradable resin composition of the present invention can be easily decomposed by microorganisms in soil, compost, seawater, rivers, lakes, etc., and can therefore be widely used, for example, in cases where recycling is difficult. In addition, because it has excellent moldability, it can be processed into various molded articles such as films, sheets, laminates, fibers, nonwoven fabrics, threads, and laminates.

[0041] Specific applications include various bags such as shopping bags, packaging materials for video and audio magnetic tape cassettes, packaging materials for flexible disks, plate-making materials, packaging bands, adhesive tape, tape, yarn, cups, trays, cartons, lunch boxes, containers for prepared foods, food and confectionery packaging materials, food wrap materials, internal coating materials for food and drink packages, shrink film for PET bottles, fresh food trays, fast food containers and lunch boxes, garbage bags, cups, plates, chopsticks, spoons, forks, straws, wrap materials for cosmetics and toiletries, shopping bags, diapers, sanitary napkins, wrap materials for pharmaceuticals, pharmaceutical packaging materials, packaging materials for surgical medicinal patches used for stiff shoulders, sprains, etc., various packaging materials for food, electronics, medical care, drugs, cosmetics, etc., parts of artificial hair and wig components, artificial turf, body bags, etc. When in a film form, heat sealing is also possible.

[0042] Agricultural mulch films are used to cover the soil surface to insulate and weed, prevent pest damage, and create a more suitable environment for growing vegetables and fruit or raising seedlings by creating a finely textured surface to diffuse sunlight and create a more suitable environment for growing vegetables and fruit or raising seedlings. Films deployed on the exterior of greenhouses are used to suppress fog and mist, improve heat retention, and protect against dust. Other agricultural materials include multipurpose film, plant pots and string, fertilizer coating materials, sustained-release coatings, horticultural film, pesticide wrap, greenhouse film, fertilizer bags, transplanting seedling pots, seedling raising pots, waterproof sheets, sandbags, construction film, weed control sheets, vegetation netting made from tape or yarn, water-retaining films for greening wastelands and deserts, sandbags, vegetation netting, fishing line, fishing nets, seaweed nets, and artificial bait, all of which are used in agriculture, civil engineering, and fisheries. They can also be used for garbage bags and compost bags.

[0043] It can be used in medical and sanitary products, such as sutures, bandages, and other medical materials, as well as in disposable diapers and some sanitary products (polymer absorbents, waterproof films), in disposable leisure products for golf, fishing, marine sports, and other activities, and as a water treatment material, such as a precipitant, dispersant, or detergent.

[0044] [Physical Properties of Biodegradable Resin Composition] The biodegradable resin composition of one embodiment of the present invention preferably has a weight average molecular weight (Mw) of 150,000 or more, more preferably 155,000 or more, and even more preferably 160,000 or more. Furthermore, the weight average molecular weight (Mw) is preferably 300,000 or less, more preferably 280,000 or less, and even more preferably 260,000 or less. The biodegradable resin composition of another embodiment of the present invention preferably has a weight average molecular weight (Mw) of 160,000 or more, more preferably 170,000 or more, and even more preferably 180,000 or more. Furthermore, the weight average molecular weight (Mw) is preferably 250,000 or less, more preferably 240,000 or less, and even more preferably 230,000 or less. In yet another embodiment of the biodegradable resin composition of the present invention, the weight average molecular weight (Mw) is preferably 150,000 or more, more preferably 155,000 or more, and even more preferably 160,000 or more. Furthermore, the weight average molecular weight (Mw) is preferably 200,000 or less, more preferably 190,000 or less, and even more preferably 180,000 or less. In yet another embodiment of the biodegradable resin composition of the present invention, the weight average molecular weight (Mw) is preferably 90,000 or more, more preferably 100,000 or more, and even more preferably 120,000 or more. Furthermore, the weight average molecular weight (Mw) is preferably 200,000 or less, more preferably 190,000 or less, and even more preferably 180,000 or less.

[0045] The biodegradable resin composition of one embodiment of the present invention has a melt volume flow rate (MVR) of 5.50 cm ３ / 10 min or more is preferable, and 6.00 cm ３ / 10 min or more is more preferable, and 6.50 cm ３ The upper limit of the MVR is not particularly limited, but from the viewpoint of moldability, it is more preferable that the MVR is 20 cm / min or more. ３ / 10 min or less is preferable, and 15 cm ３ / 10 min or less is more preferable, and 10 cm ３ In another embodiment of the biodegradable resin composition of the present invention, the melt volume flow rate (MVR) is 15.0 cm / min or less. ３ / 10 min or more is preferable, and 15.2 cm ３ The upper limit of the MVR is not particularly limited, but from the viewpoint of moldability, it is more preferable that the MVR is 40 cm / min or more. ３ / 10 min or less is preferable, ３ / 10 min or less is more preferable, ３ In yet another embodiment of the biodegradable resin composition of the present invention, the melt volume flow rate (MVR) is 4.50 cm / 10 min or less. ３ / 10 min or more is preferable, and 5.00 cm ３ / 10 min or more is more preferable, and 7.50 cm ３ The upper limit of the MVR is not particularly limited, and as will be described in the examples below, it is more preferable that the MVR is 100 cm / min or more. ３ Even if the time exceeds 10 min, molding is possible. For example, ３ / 10min or less, 150cm ３ The MVR may be measured by the method described in the Examples below.

[0046] The molded article produced from the biodegradable resin composition of one embodiment of the present invention preferably has a tensile elongation (%) of 170% or more, more preferably 172% or more, and even more preferably 174% or more. The tensile elongation (%) is preferably 200% or less, more preferably 195% or less, and even more preferably 192% or less. The molded article produced from the biodegradable resin composition of another embodiment of the present invention preferably has a tensile elongation (%) of 175% or more, more preferably 185% or more, and even more preferably 195% or more. The tensile elongation (%) is preferably 230% or less, more preferably 220% or less, and even more preferably 215% or less. The molded article produced from the biodegradable resin composition of yet another embodiment of the present invention preferably has a tensile elongation (%) of 200% or more, more preferably 250% or more. The tensile elongation (%) is preferably 500% or less, and more preferably 480% or less. As will be described in the Examples below, a molded article with a low tensile elongation is not necessarily inferior. For example, a molded article with a high flexural modulus may be highly useful even if it has a low tensile elongation. Therefore, the molded article of one embodiment may have a tensile elongation (%) of 5% or more, 10% or more, or 11% or more, or 50% or less, 30% or less, or 20% or less. The method for measuring the tensile elongation (%) is as described in the Examples below.

[0047] The molded article produced from the biodegradable resin composition of one embodiment of the present invention preferably has a maximum tensile strength (MPa) of 33.5 MPa or more, more preferably 34.0 MPa or more, and even more preferably 34.2 MPa. The maximum tensile strength (MPa) is preferably 38.0 MPa or less, more preferably 37.5 MPa or less, and even more preferably 37.0 MPa. The molded article produced from the biodegradable resin composition of another embodiment of the present invention preferably has a maximum tensile strength (MPa) of 30.0 MPa or more, more preferably 31.5 MPa or more, and even more preferably 33.0 MPa or more. The maximum tensile strength (MPa) is preferably 45.0 MPa or less, more preferably 44.5 MPa or less, and even more preferably 43.0 MPa. The method for measuring the maximum tensile strength (MPa) is as described in the Examples below.

[0048] The molded article produced from the biodegradable resin composition of one embodiment of the present invention preferably has a tensile yield strength (MPa) of 32.0 MPa or more, more preferably 32.5 MPa or more, and even more preferably 32.8 MPa or more. The tensile yield strength (MPa) is preferably 36.0 MPa or less, more preferably 35.5 MPa or less, and even more preferably 35.0 MPa or less. The molded article produced from the biodegradable resin composition of another embodiment of the present invention preferably has a tensile yield strength (MPa) of more than 28.0 MPa, more preferably 28.5 MPa or more, and even more preferably 30.0 MPa or more. The tensile yield strength (MPa) is preferably 35.0 MPa or less, more preferably 33.5 MPa or less, and even more preferably 32.0 MPa or less. The method for measuring the tensile yield strength (MPa) is as described in the Examples below.

[0049] The molded article produced from the biodegradable resin composition of one embodiment of the present invention preferably has a flexural modulus (MPa) of 630 MPa or more, more preferably 632 MPa or more, and even more preferably 634 MPa or more. The flexural modulus (MPa) is preferably 670 MPa or less, more preferably 668 MPa or less, and even more preferably 664 MPa or less. The molded article produced from the biodegradable resin composition of another embodiment of the present invention preferably has a flexural modulus (MPa) of 590 MPa or more, more preferably 592 MPa or more, and even more preferably 594 MPa or more. The flexural modulus (MPa) is preferably 615 MPa or less, more preferably 613 MPa or less, and even more preferably 610 MPa or less. The molded article produced from the biodegradable resin composition of yet another embodiment of the present invention preferably has a flexural modulus (MPa) of 430 MPa or more, more preferably 450 or more, and even more preferably 465 or more. The flexural modulus (MPa) is preferably 615 MPa or less, more preferably 613 MPa or less, and even more preferably 610 MPa or less. The method for measuring the flexural modulus (MPa) is as described in the Examples below.

[0050] The molded article produced from the biodegradable resin composition of one embodiment of the present invention preferably has a bending stress (MPa) of 34.0 MPa or more, more preferably 34.4 MPa or less, and even more preferably 34.7 MPa or more. The bending stress (MPa) is preferably 37.0 MPa or less, more preferably 36.8 MPa or less, and even more preferably 36.6 MPa or less. The molded article produced from the biodegradable resin composition of another embodiment of the present invention preferably has a bending stress (MPa) of 33.7 MPa or more, more preferably 33.7 MPa or more, and even more preferably 34.0 MPa or more. The bending stress (MPa) is preferably 35.5 MPa or less, more preferably 35.0 MPa or less, and even more preferably 34.8 MPa or less. The molded article produced from the biodegradable resin composition of yet another embodiment of the present invention preferably has a bending stress (MPa) of 26.0 or more, more preferably 26.5 MPa or more, and even more preferably 28.0 MPa or more. The bending stress (MPa) is preferably 35.5 MPa or less, more preferably 35.0 MPa or less, and even more preferably 34.8 MPa or less. The method for measuring the bending stress (MPa) is as described in the Examples below.

[0051] A molded article produced from the biodegradable resin composition of one embodiment of the present invention has a notched Charpy impact strength (KJ / m ２ ) is 8.8KJ / m ２ More preferably, it is greater than 8.9 KJ / m ２ More preferably, it is 9.0 KJ / m or more. ２ It is more preferable that the notched Charpy impact strength (KJ / m ２ ) is 12.0 KJ / m ２ Preferably, it is 11.5 KJ / m or less. ２ More preferably, it is 11.0 KJ / m or less. ２ It is more preferable that the molded article produced from the biodegradable resin composition of another aspect of the present invention has a notched Charpy impact strength (KJ / m ２ ) is 8.3KJ / m２ More preferably, it is greater than 8.4 KJ / m ２ More preferably, it is 8.5 KJ / m or more. ２ It is more preferable that the notched Charpy impact strength (KJ / m ２ ) is 10.0 KJ / m ２ Preferably, it is 9.5 KJ / m or less. ２ More preferably, it is 9.0 KJ / m or less. ２ It is more preferable that a molded article produced from the biodegradable resin composition of yet another embodiment of the present invention has a notched Charpy impact strength (KJ / m ２ ) is 7.5KJ / m ２ Preferably, it is 8.0 KJ / m or more. ２ More preferably, it is 10.0 KJ / m or more. ２ It is more preferable that the notched Charpy impact strength (KJ / m ２ ) is 15.0 KJ / m ２ Preferably, it is 14.0 KJ / m or less. ２ More preferably, it is 13.0 KJ / m or less. ２ It is more preferable that the notched Charpy impact strength (KJ / m ２ The measurement method for the above-mentioned saturation coefficient is as described in the Examples below.

[0052] The present invention will be described below with reference to examples, but is not limited to these examples. The values ​​measured in the examples were measured using the following methods or devices.

[0053] <Methods for measuring various physical properties and characteristics> (1) Hydroxyl value (OH value) The hydroxyl value was measured in accordance with JIS K-1557.

[0054] (2) Polystyrene-equivalent weight-average molecular weight (Mw) and number-average molecular weight (Mn) Apparatus: Tosoh Corporation High-Performance GPC HLC-8320 GPC Column: Tosoh Corporation GPC column SuperMultiporeHZ-M (4.6 mm I.D. x 150 mm), three columns used in series Flow rate: 0.35 mL / min Eluent: Chloroform Sample concentration: 0.2 w / v% Detector: Bryce-type differential refractometer (RI detector)

[0055] (3) Tensile properties (tensile elongation, maximum tensile strength, tensile yield strength) The obtained resin was molded into a dumbbell-shaped test piece (A12 type test piece) in accordance with JIS K 7139: 2009, and the tensile elongation, maximum tensile strength, and tensile yield strength were measured in accordance with JIS K 7161-2: 2014. The detailed conditions of the test piece and the measurement method are described below. Test specimen: Molding machine: C,Mobile-0813 manufactured by Epson Techform Corporation Molding temperature: Manifold 150°C, body 170°C, tip 70% Mold setting temperature 40°C Extrusion screw rotation speed: 90 rpm Metering speed: 2 mm / s Injection speed: 20 mm / s Measurement method: Measuring machine: Autograph AGS-X manufactured by Shimadzu Corporation Maximum load cell capacity: 500 N Test speed: 0.5 mm / min, 25 mm / min after elastic deformation Grip distance: 50 mm Tensile elongation: Calculated from the stroke travel distance of the test device based on the initial grip distance. Maximum tensile strength: Calculated from the maximum strength from the start of the test to the breakage of the test specimen. Tensile yield strength: Calculated from the first point where the test force decreased by 0.1% relative to the full scale of the load cell. Number of test repetitions: 3

[0056] (4) Flexural properties (flexural modulus and flexural stress) Using the same test specimens as those used in (3) Tensile properties (tensile elongation, maximum tensile strength, and tensile yield strength) above, the flexural modulus and flexural stress were measured by a three-point bending test in accordance with JIS K 7171:2016. Detailed conditions for the measurement method are listed below. Measuring instrument: Autograph AGS-X manufactured by Shimadzu Corporation Maximum load cell capacity: 500N Distance between supports: 32mm Standard sample thickness: 2mm Test speed for flexural modulus: 1mm / min Test speed for flexural stress: 5mm / min Number of test repetitions: 3

[0057] (5) Notched Charpy Impact Strength Notched Charpy impact strength was measured in accordance with JIS K 7111-1:2012 / 1eA. Detailed conditions for the test specimen and measurement method are listed below. Test specimen: Molding machine: C,Mobile-0813 manufactured by Epson Techform Corporation Molding temperature: Manifold 150°C, body 170°C, tip 70% Mold setting temperature 40°C Extrusion screw rotation speed: 90 rpm Metering speed: 2 mm / s Injection speed: 20 mm / s Test specimen shape: Rectangular test specimen 10 mm x 80 mm x 2 mm Notching machine: Notching tool A-4E type manufactured by Toyo Seiki Seisakusho Co., Ltd. Impact direction: Edgewise Notch shape: A Notch tip radius: 0.25 Remaining width after notch: Standard 8.0 mm Measurement: Measuring machine: DG-CB manufactured by Toyo Seiki Seisakusho Co., Ltd. Number of test repetitions: 3

[0058] <Polymerization Example 1 (PE1) of Polyester (PE; Prepolymer)> 75.445 kg (639 mol) of succinic acid, 80.605 kg (894 mol) of 1,4-butanediol, and 557 g (4.2 mol) of trimethylolpropane were charged as raw materials to a 400 L reactor equipped with a condenser and a stirring blade. After the reactor was purged with nitrogen, the reactor was heated to an internal temperature of 215°C under atmospheric pressure (101.33 kPa). Water produced by the dehydration condensation reaction of succinic acid and 1,4-butanediol was condensed and removed using a condenser. When 90% of the theoretically produced water had distilled off, the reactor was heated and controlled so that the internal temperature was between 200 and 205°C, and the pressure inside the reactor was reduced stepwise to 0.25 kPa. The reaction was continued under conditions of an internal temperature of 200 to 205°C and 0.25 kPa, yielding a polyester (prepolymer). The physical properties of the resulting polyester (PE1) are shown in Table 1.

[0059] <Polymerization Example 2 (PE2) of Polyester (PE; Prepolymer)> Polyester (PE2) was obtained in the same manner as in the above-mentioned Polymerization Example 1 of Polyester (PE; Prepolymer), except that trimethylolpropane was not used as a raw material. The physical properties of the obtained polyester (PE2) are shown in Table 1.

[0060] Polyestercarbonate (PEC) Polymerization Example 1 (PEC1) 77.025 kg of polyester (PE1) obtained in Polymerization Example 1 of Polyester (PE; Prepolymer) described above, 11.023 kg (51 mol) of diphenyl carbonate (DPC), and 5.860 g (2.7E-02 mol, 75 ppm relative to the prepolymer) of zinc acetate dihydrate as a catalyst were charged into a 300 L reactor equipped with a condenser and a stirring blade. After purging the reactor with nitrogen, the reactor was heated to an internal temperature of 220°C under atmospheric pressure (101.33 kPa), and the phenol produced by the transesterification reaction was condensed and removed in the condenser. Subsequently, the pressure in the reactor was gradually reduced to 0.25 kPa, yielding polyestercarbonate (PEC1). The physical properties of the resulting polyestercarbonate (PEC1) are shown in Table 2.

[0061] <Polymerization Example 2 (PEC2) of Polyester Carbonate (PEC)> Polyester carbonate (PEC2) was obtained in the same manner as in Polymerization Example 1, except that 71.730 kg of polyester (PE1) obtained in Polymerization Example 1 of Polyester (PE; Prepolymer), 8.725 kg (41 mol) of diphenyl carbonate (DPC), and 2.910 g (1.3E-02 mol, 40 ppm relative to the prepolymer) of zinc acetate dihydrate were used as a catalyst. The physical properties of the obtained polyester carbonate (PEC2) are shown in Table 2.

[0062] Polyestercarbonate (PEC) Polymerization Example 3 (PEC3) Polyestercarbonate (PEC) was obtained in the aforementioned Polyester (PE; Prepolymer) Polymerization Example 2 using 77.025 kg of polyester (PE2), 10.734 kg (50 mol) of diphenyl carbonate (DPC), and 5.860 g (2.7E-02 mol, 75 ppm relative to the prepolymer) of zinc acetate dihydrate as a catalyst in the same manner as in Polyestercarbonate Polymerization Example 1. The physical properties of the obtained polyestercarbonate (PEC3) are shown in Table 2.

[0063]

[0064] (Example 1) 99% by mass of the aforementioned PEC1 as polyester carbonate and 1% by mass of the aforementioned PE2 as prepolymer were melt-kneaded. The kneading conditions are shown below. The physical properties of the obtained biodegradable resin composition are shown in Table 3. Extruder: Toyo Seiki Seisakusho Co., Ltd., small twin-screw segment extruder 2D15W, L / D: 17, temperature settings: C1 / C2 / die = 130°C / 150°C / 150°C, feeder rotation speed: 10 rpm, discharge rate: set to 400 g / h

[0065] (Examples 2 to 6, Comparative Examples 1 and 2) Melt kneading was carried out in the same manner as in Example 1, except that the polyester carbonates and polyester (prepolymers) shown in Tables 3 and 4 were used. The physical properties of the resulting biodegradable resin compositions are shown in Tables 3 and 4. (Examples 7 to 10, Comparative Example 3) Melt kneading was carried out in the same manner as in Example 1, except that the polyester carbonates and polyester (prepolymers) shown in Table 5 were used. The physical properties of the resulting biodegradable resin compositions are shown in Table 5. In Table 5, "-" indicates that no clear yield point was observed (in this case, the maximum tensile strength can also be considered as the tensile yield strength).

[0066]

[0067] Examples 1 to 3 and Comparative Example 1 shown in Table 3 are physical properties in systems where the Mw of the biodegradable resin composition is large. Also, Examples 4 to 6 and Comparative Example 2 shown in Table 4 are physical properties in systems where the Mw of the biodegradable resin composition is small. Also, Examples 7 to 10 and Comparative Example 3 shown in Table 5 are systems using PEC3 obtained without blending trimethylolpropane (branching agent). As shown in Tables 3 to 5, in all systems, the biodegradable resin compositions of Examples 1 to 3, Examples 4 to 6, and Examples 7 to 10, which contain a polyester containing a structural unit (A) derived from a monomer represented by general formula (1) and a structural unit (B) derived from a monomer represented by general formula (2), and a polyester carbonate containing a structural unit (A) derived from a monomer represented by general formula (1) and a structural unit (B) derived from a monomer represented by general formula (2), are superior in melt fluidity to Comparative Examples 1, 2, and 3, respectively. Furthermore, from the various physical property values, it can be seen that the molded articles produced from the biodegradable resin compositions of Examples 1 to 3, Examples 4 to 6, and Examples 7 to 10 have better mechanical strength overall than the molded articles of Comparative Examples 1, 2, and 3, respectively. In Table 5, Examples 9 and 10 (containing 30% or more prepolymer) had extremely low tensile elongation and lost ductility, but had improved flexural modulus and excellent flexural strength. As described above, the biodegradable resin composition of the present invention maintained good mechanical strength while exhibiting excellent melt fluidity.

Claims

1. A polyester (PE) containing a structural unit (A) derived from a monomer represented by the following general formula (1) and a structural unit (B) derived from a monomer represented by the following general formula (2), A biodegradable resin composition comprising: a polyester carbonate (PEC) containing a structural unit (A) derived from a monomer represented by the following general formula (1) and a structural unit (B) derived from a monomer represented by the following general formula (2): HO-(CH) ２ )n-OH (1) (In general formula (1), n ​​represents an integer of 4 to 16.) R １ OOC-(CH ２ )m-COOR ２ (2) (In general formula (2), R １ and R ２ are each independently selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms, and m represents an integer of 2 to 16.

2. The resin composition according to claim 1, wherein the mass ratio (PE:PEC) of the polyester (PE) to the polyester carbonate (PEC) is 0.1:99.9 to 50:

50.

3. The resin composition according to claim 1 or 2, wherein the polyester (PE) has a hydroxyl value (OH value) of 30 to 140 mg KOH / g.

4. The resin composition according to claim 1 or 2, wherein the weight average molecular weight (Mw) of the polyester (PE) is 3,000 to 8,000.

5. The resin composition according to claim 1 or 2, wherein the weight average molecular weight (Mw) of the polyester carbonate (PEC) is 100,000 to 300,000.

6. the monomer represented by the general formula (1) contains 1,4-butanediol, The resin composition according to claim 1 or 2, wherein the monomer represented by the general formula (2) includes succinic acid or adipic acid.

7. The resin composition according to claim 1 or 2, wherein at least one of the monomer represented by the general formula (1) and the monomer represented by the general formula (2) is derived from a biomass resource.

8. A molded article comprising the biodegradable resin composition according to claim 1 or 2.