Polyester carbonate, production method for same, and molded article

Abstract

A demand has existed for a resin that excels in various properties including biodegradability and thermal stability. Moreover, a need has also existed for an efficient method for producing a biodegradable resin.　The above problems are solved by the following polyester carbonate resin and method for producing a branched polyester carbonate.　That is, the present invention provides a branched polyester carbonate resin, the polyester carbonate resin containing an aliphatic diol, an aliphatic dicarboxylic acid, a triol compound, and a constituent unit derived from a diester carbonate, wherein a terminal OH amount and a phenyl terminal amount of the polyester carbonate resin are adjusted within prescribed ranges described in the description of the present application. The present invention also provides a method for producing the branched polyester carbonate (PEC), wherein, in a polymerization step, the OH amount contained in the triol compound as a monomer and the amount of the diester carbonate satisfy a prescribed relationship described in the description of the present application.

Description

Polyester carbonate, method for producing the same, and molded article

[0001] This invention relates to polyester carbonates and the like, and more particularly to branched polyester carbonates with excellent biodegradability, methods for producing the same, and molded articles containing the same.

[0002] Conventionally, biodegradable branched polyester carbonate resins have been used in a wide range of fields (for example, Patent Document 1 below).

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 10-45884

[0004] Conventional biodegradable resins have not always achieved efficient manufacturing methods or superior properties. In particular, the polymerization process for the production of branched polyester carbonate resins sometimes resulted in unexpected polymerization reactions, leading to gelation and making it difficult to remove the product from the reaction vessel. Furthermore, resins that were particularly excellent in both biodegradability and properties such as thermal stability had not yet been realized.

[0005] Therefore, an efficient method for manufacturing branched polyester carbonate resin was needed. Furthermore, there was a demand for polyester carbonate resin with excellent properties, including biodegradability and thermal stability.

[0006] The present invention provides the following polyester carbonates, molded articles, etc.: [1] A branched polyester carbonate resin comprising structural units derived from an aliphatic diol, an aliphatic dicarboxylic acid, a triol compound, and a diester carbonate, wherein the terminal OH content of the polyester carbonate resin is 850 ppm to 1600 ppm and the phenyl terminal content is 100 ppm to 1500 ppm. [2] A branched polyester carbonate resin comprising structural units derived from an aliphatic diol, an aliphatic dicarboxylic acid, a triol compound, and a diester carbonate, wherein the terminal OH content of the polyester carbonate resin is 10 ppm to 600 ppm and the phenyl terminal content is 3500 ppm to 6000 ppm. [3] The polyester carbonate resin according to [1] or [2] above, wherein the molar ratio of the aliphatic diol to the aliphatic dicarboxylic acid is 1.05 to 2.00. [4] The polyester carbonate resin according to any one of [1] to [3] above, for example, [1] or [2] above, wherein the molar ratio of the number of moles of the triol compound to the total number of moles of the aliphatic dicarboxylic acid and the aliphatic diol is 100 to 100,000. [5] The polyester carbonate resin according to any one of [1] to [4] above, for example, [1] or [2] above, wherein the molecular weight retention rate in a heating test in which the polyester carbonate resin is heated at 225°C for 10 or 20 minutes under a nitrogen atmosphere is 93 to 117%, which is the ratio of the weight-average molecular weight after heating to the weight-average molecular weight before heating. [6] The polyester carbonate resin according to any one of [1] to [5] above, for example, [1] or [2] above, wherein the number of carbon atoms of the aliphatic diol and the aliphatic dicarboxylic acid is 20 or less. [7] A polyester carbonate resin according to any one of [1] to [6] above, for example, according to [6] above, wherein the aliphatic diol comprises butanediol and the aliphatic dicarboxylic acid comprises succinic acid. [8] A polyester carbonate resin according to any one of [1] to [6] above, for example, according to [1] or [2] above, wherein the diester carbonate is diaryl carbonate.[9] A polyester carbonate resin according to any of [1] to [8] above, for example, the one according to [8] above, wherein the diaryl carbonate ester comprises diphenyl carbonate.

[10] A polyester carbonate resin according to any of [1] to [8] above, for example, the one according to [1] or [2] above, wherein at least one of the raw material substances, the aliphatic diol, the aliphatic dicarboxylic acid, the triol compound, and the diester carbonate, is derived from biomass.

[11] A polyester carbonate resin according to any of [1] to [8] above, for example, the one according to [1] or [2] above, wherein the diester carbonate raw material is CO. ２ The origin is any of the above [1] to

[10] , for example, the polyester carbonate resin described in [1] above.

[0007]

[12] A method for producing a branched polyester carbonate (PEC) having a weight-average molecular weight (Mw) of 160,000 or more, comprising constituent units derived from an aliphatic diol, an aliphatic dicarboxylic acid, a triol compound, and a diester carbonate, comprising: a first polymerization step of polymerizing a polyester (PE) comprising constituent units derived from at least the aliphatic diol and the aliphatic dicarboxylic acid; and a second polymerization step of polymerizing the polyester (PE) and the diester carbonate to produce a branched polyester carbonate, wherein the triol compound is further polymerized in at least one of the first polymerization step and the second polymerization step, and the relationship between the amount of OH contained in the triol compound as a monomer in the polymerization step and the amount of diester carbonate is represented by the following formula (1) or the following formula (2), the method for producing a polyester carbonate resin.

[0008]

[13] A molded article comprising any of [1] to

[11] above, for example, the polyester carbonate resin described in [1] or [2] above.

[14] A biodegradable agricultural material comprising any of [1] to

[11] above, for example, the polyester carbonate described in [1] or [2] above.

[15] A biodegradable fishing material comprising any of [1] to

[11] above, for example, the polyester carbonate described in [1] or [2] above.

[16] A biodegradable civil engineering material comprising any of [1] to

[11] above, for example, the polyester carbonate described in [1] or [2] above.

[17] A biodegradable fiber comprising any of [1] to

[11] above, for example, the polyester carbonate described in [1] or [2] above.

[0009] The polyester carbonate of the present invention has excellent biodegradability and also exhibits excellent properties such as thermal stability. Furthermore, in the manufacturing process of branched polyester carbonate, problems such as gelation easily progressing even after the completion of the original polymerization reaction can generally occur. However, the manufacturing method of the present invention makes it possible to efficiently produce branched polyester carbonate while preventing unwanted reactions. In addition, the present invention can provide molded articles containing polyester carbonate with excellent properties that can be used in a wide range of applications such as agriculture, fisheries, and civil engineering.

[0010] This is the NMR chart of polyester (PE) obtained in Manufacturing Example 1. This is the NMR chart of polyester carbonate (PEC) obtained in Example 1. This is a magnified section of the NMR chart in Figure 2. This is a magnified section of the NMR chart in Figure 2, showing a different area from that shown in Figure 3. This is the NMR chart of polyester carbonate (PEC) obtained in Example 5. This is a magnified section of the NMR chart in Figure 5. This is a magnified section of the NMR chart in Figure 5, showing a different area from that shown in Figure 6.

[0011] The polyester carbonate of the present invention is a branched polyester carbonate comprising structural units derived from aliphatic diols, aliphatic dicarboxylic acids, triol compounds, and diester carbonates, wherein the terminal OH content is 850 ppm to 1600 ppm and the phenyl terminal content is 100 ppm to 1500 ppm, or the terminal OH content is 10 ppm to 600 ppm and the phenyl terminal content is 3500 ppm to 6000 ppm.

[0012] Furthermore, the present invention provides a method for producing a polyester carbonate, which is a method for producing a branched polyester carbonate (PEC) having a weight-average molecular weight (Mw) of 160,000 or more, comprising: a first polymerization step of polymerizing polyester (PE) containing constituent units derived from at least an aliphatic diol and an aliphatic dicarboxylic acid; and a second polymerization step of polymerizing polyester (PE) and diester carbonate to produce a branched polyester carbonate. In the present invention's method for producing a polyester carbonate, in at least one of the first polymerization step and the second polymerization step, a triol compound is polymerized together with other monomers, and the relationship between the amount of OH contained in the triol compound as a monomer in the polymerization step and the amount of diester carbonate is represented by formula (1) or formula (2) above. Preferred embodiments of the present invention will be described in detail below.

[0013] <1. Components of Polyester Carbonate> 1-1. Components forming the main chain of polyester carbonate The polyester carbonate of the present invention has at least constituent units derived from aliphatic diols, aliphatic dicarboxylic acids, triol compounds and diester carbonates, which are included in the main chain of polyester carbonate. In this specification, the main chain of branched polyester carbonate includes the longest polymer chain as well as all polymer chains except for very short side chains, such as side chains with 10 or fewer carbon atoms.

[0014] The position of the hydroxyl group in the aliphatic diol used in the formation of polyester carbonate is not particularly limited, but it is preferable to have hydroxyl groups at both ends. An aliphatic diol is represented, for example, by the following general formula (I): HO-Ra-OH ... (I) The aliphatic diol preferably has 20 or fewer carbon atoms, and in general formula (I), Ra is preferably an alkylene group having 1 to 20 carbon atoms, which may have substituents. Ra in formula (I) may be either a linear or branched alkylene group, but it is preferably linear. The number of carbon atoms in the aliphatic diol is preferably 1 to 16, more preferably 2 to 12 or 2 to 16, even more preferably 3 to 8 or 3 to 10, and particularly preferably 3 to 6 or 4 to 8.

[0015] In equation (I), Ra is, for example, (CH ２ ) is represented by n, where n is preferably an integer from 1 to 16. Ra may also be an alkylene group having 2 to 12 or 2 to 16 carbon atoms, preferably an alkylene group having 3 to 8 or 3 to 10 carbon atoms, and more preferably an alkylene group having 3 to 6 or 4 to 8 carbon atoms. Furthermore, in the diol compound represented by formula (I), it is preferable that Ra is formed only of carbon atoms, excluding substituents, and does not contain oxygen atoms, nitrogen atoms, etc. Note that if Ra is an alkylene group having substituents described later, the carbon atoms of the substituents are not included in the above range of carbon atoms.

[0016] Preferred examples of aliphatic diols as monomer compounds include ethylene glycol, propanediol, butanediols such as 1,4-butanediol, pentanediols such as 1,5-pentanediol, hexanediol, octanediol, and cyclohexanedimethanol. Of these, propanediol, butanediols such as 1,4-butanediol, and pentanediols such as 1,5-pentanediol are more preferred, and butanediols such as 1,4-butanediol are even more preferred. A single compound may be used as the aliphatic diol for polymerizing polyester carbonate, or two or more may be used in combination.

[0017] In aliphatic dicarboxylic acids for polymerizing polyester carbonates, the position of the carboxyl group is not particularly limited, but it is preferable to have carboxyl groups at both ends. An aliphatic dicarboxylic acid is represented, for example, by the following general formula (II). １ OOC-Rb-COOR ２ ... (II) The aliphatic dicarboxylic acid is preferably one having 20 or fewer carbon atoms, and in general formula (II), Rb is preferably an alkylene group having 1 to 20 carbon atoms, which may have substituents. Rb in formula (II) may be either a linear or branched alkylene group, but is preferably linear. The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 1 to 16, more preferably 2 to 12 or 2 to 16, even more preferably 3 to 8 or 3 to 10, and particularly preferably 3 to 6 or 4 to 8.

[0018] In equation (II), Rb is, for example, (CH ２)(m) is represented by m, and m is preferably an integer of 2 to 16. Also, Rb may be an alkylene group having 2 to 12, 2 to 16 carbon atoms, etc., preferably an alkylene group having 3 to 8 or 3 to 10 carbon atoms, and more preferably an alkylene group having 3 to 6 or 4 to 8 carbon atoms. Further, in the aliphatic dicarboxylic acid represented by the formula (II), it is preferable that Rb is formed only of carbon atoms excluding substituents and not containing oxygen atoms, nitrogen atoms, etc. When Rb is an alkylene group having a substituent described later, the carbon number range described above does not include the carbon number of the substituent.

[0019] Also, R in the general formula (II) １ and R ２ are each independently a linear or branched alkyl group having 1 to 6 carbon atoms which may contain a hydrogen atom or a substituent. R １ and R ２ are preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms which may contain a substituent, more preferably each independently a hydrogen atom or an alkyl group having 1 or 2 carbon atoms which may contain a substituent, and still more preferably each independently a hydrogen atom or a methyl group. Also, the substituents of R １ and R ２ can each independently be selected from a halogen, a hydroxyl group, a cyano group, an alkenyl group having 1 to 5 carbon atoms, an aryl group having 6 to 12 carbon atoms, etc. These substituents are preferably a halogen, a hydroxyl group, a cyano group, etc. When R １ or R ２ is an alkyl group having a substituent, the carbon number range described above does not include the carbon number of the substituent.

[0020] The monomer compound of formula (II) may be a dicarboxylic acid compound, a monoester compound, or a diester compound, or a mixture thereof. Preferred specific examples of monomer compounds represented by general formula (II) include compounds such as succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, and dodecanoic acid, or derivatives such as anhydrides and esters thereof. Of these, succinic acid, glutaric acid, and adipic acid are more preferred, and succinic acid and succinic acid derivatives are even more preferred. A single compound may be used as the aliphatic dicarboxylic acid for polymerizing the polyester carbonate, or two or more may be used in combination.

[0021] The position of the hydroxyl group in the triol compound used to form polyester carbonate is not particularly limited, but it is preferable that it has a hydroxyl group at least at the terminal end. The triol compound is represented, for example, by the following general formula (III). The triol compound is preferably one with 20 or fewer carbon atoms, and in general formula (III), Rc is preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms, which may have substituents. The triol compound preferably has 1 to 16 carbon atoms, more preferably 2 to 12 or 2 to 16 carbon atoms, even more preferably 3 to 8 or 3 to 10 carbon atoms, and particularly preferably 3 to 6 or 4 to 8 carbon atoms. In the triol compound represented by formula (III), Rc is preferably formed only of carbon atoms, excluding substituents, and not containing oxygen atoms, nitrogen atoms, etc. If the triol compound has substituents described later, the carbon atoms of the substituents are not included in the above range of carbon atoms.

[0022] Preferred examples of triol compounds include glycerin, butanetriol (such as 1,2,4-butanetriol), and trimethylolpropane, with trimethylolpropane being even more preferred. A single triol compound may be used as the triol compound for polymerizing the polyester carbonate, or two or more compounds may be used in combination.

[0023] The substituents in Ra, Rb, and Rc described above can each be independently selected from halogens, hydroxyl groups, cyano groups, C1-C5 alkenyl groups, and the like. These substituents are preferably halogens, hydroxyl groups, cyano groups, and the like.

[0024] Diester carbonates are used to form carbonyl (CO) moieties in polyester carbonates. There are no particular limitations on the type of diester carbonate; dialkyl carbonates, monoalkyl monoaryl carbonates, diaryl carbonates, etc., are used, but diaryl carbonates are preferred.

[0025] Examples of diaryl carbonates include bisaryl carbonates such as diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate. Of these, diphenyl carbonate is more preferred. A single compound may be used as the diester carbonate, or two or more may be used in combination.

[0026] In polyester carbonate resins, the molar ratio of constituent units derived from aliphatic diols to constituent units derived from aliphatic dicarboxylic acids (moles of constituent units of aliphatic diols / moles of constituent units of aliphatic dicarboxylic acids) is preferably 1.01 to 2.00, more preferably 1.05 to 1.80, even more preferably 1.05 to 1.30, 1.10 to 1.40, or 1.10 to 1.50, and particularly preferably 1.10 to 1.25, 1.15 to 1.30, or 1.10 to 1.20.

[0027] In polyester carbonate resins, the molar ratio of the number of moles of constituent units derived from triol compounds to the total number of moles of constituent units derived from aliphatic dicarboxylic acids and aliphatic diols is preferably 100 to 100,000, more preferably 150 to 10,000, even more preferably 200 to 5,000, and particularly preferably 200 to 1,000, 200 to 800, or 250 to 500.

[0028] In polyester carbonate, it is preferable that the constituent units derived from diester carbonate are slightly in excess of the total number of moles of terminal hydroxyl groups of polyester. Specifically, it is preferable that the constituent units derived from diester carbonate are present in a number of moles greater than 1.00 and less than 1.20 times the total number of moles of terminal hydroxyl groups of polyester. The amount (number of moles) of constituent units derived from diester carbonate is more preferably 1.02 to 1.15 times the total number of moles of terminal hydroxyl groups of polyester, even more preferably 1.03 to 1.10 times the total number of moles of terminal hydroxyl groups of polyester, and particularly preferably 1.04 to 1.09 times, for example 1.07 or 1.04 times the total number of moles of terminal hydroxyl groups of polyester. Furthermore, in polyester carbonate, it is preferable that the constituent units derived from diester carbonate are slightly insufficient compared to the total number of moles of terminal hydroxyl groups of polyester. Specifically, it is preferable that the constituent units derived from diester carbonate are present in a number of moles greater than 0.90 and less than 1.00 times the total number of moles of terminal hydroxyl groups of polyester. The amount (in moles) of constituent units derived from diester carbonate is more preferably 0.90 to 0.99 times the total number of moles of terminal hydroxyl groups of polyester, even more preferably 0.90 to 0.98 times the total number of moles of terminal hydroxyl groups of polyester, and particularly preferably 0.90 to 0.97 times, for example 0.93 or 0.95 times, the total number of moles of terminal hydroxyl groups of polyester.

[0029] In the present invention, the branched polyester carbonate is preferably produced by polymerization of polyester moieties by a manufacturing method described in detail later. In the polyester carbonate, it is preferable that multiple polyester moieties are linked by structural units that form branched portions derived from triol compounds and carbonyl structural units made of diester carbonate.

[0030] Polyester carbonate is preferably manufactured from biomass-derived raw materials. Biomass-derived raw materials are so-called biomass resources, which are biologically derived and renewable organic resources, excluding fossil resources. In other words, biomass-derived raw materials are organic matter produced by living organisms through photosynthesis from water and carbon dioxide using solar energy, and are sustainably renewable resources. In polyester carbonate, it is preferable that at least one of the raw material substances, aliphatic diols, aliphatic dicarboxylic acids, and triol compounds, is biomass-derived. For example, aliphatic dicarboxylic acids obtained by fermenting biomass resources with microorganisms, and aliphatic diols obtained by reducing such aliphatic dicarboxylic acids, are preferred as raw materials for polyester carbonate.

[0031] Regarding diester carbonate, which is a raw material for polyester carbonate, it is preferable to use one obtained by a manufacturing method that minimizes environmental impact, even if it is not biomass-derived. For example, carbon dioxide (CO2) ２ It is preferable to use diester carbonates obtained from alkyl carbonates produced from ) and alcohols as precursors as raw materials for polyester carbonates. In other words, from the viewpoint of reducing environmental impact, it is preferable to use diester carbonates derived from carbon dioxide as raw materials for polyester carbonates. Particularly in recent years, there has been growing concern about global warming and efforts are being made to reduce greenhouse gas emissions, and among the greenhouse gases emitted artificially, carbon dioxide is estimated to have the greatest impact. For this reason, the development of countermeasures technologies to reduce carbon dioxide is being actively carried out in various places, and several attempts have been proposed to convert carbon dioxide emitted into the atmosphere into useful substances. Thus, in order to convert carbon dioxide into other substances and utilize them while reducing the environmental impact, it is desirable to synthesize diester carbonates from carbon dioxide and use them as raw materials for polyester carbonates.

[0032] 1-2. Secondary components may be added to the secondary component polyester carbonate. For example, when polyester carbonate is used as a raw material for a molded body or the like described later, depending on its use, resins other than polyester carbonate, such as thermoplastic resins, and other appropriate additives may be added. Thus, in the polyester carbonate resin composition to which secondary components are added, it is preferable that, based on the total weight of the resin composition, for example, 20 to less than 100% by mass or 25 to 100% by mass of polyester carbonate is contained. The content of polyester carbonate in the resin composition is preferably 20 to 85% by mass or 25 to 80% by mass, more preferably 25 to 70% by mass or 30 to 75% by mass, particularly preferably 30 to 70% by mass or 33 to 75% by mass, based on the total weight of the resin composition.

[0033] Examples of additives that can be included in the polyester carbonate resin composition include inorganic fillers. Examples of inorganic fillers include talc, anhydrous silica, mica, vermiculite, titanium oxide, calcium carbonate, diatomaceous earth, allophane, bentonite, potassium titanate, zeolite, sepiolite, smectite, kaolin, kaolinite, glass, limestone, carbon, wollastonite (wollastonite), calcined perlite, calcium silicate, sodium silicate and other silicates, aluminum oxide, magnesium carbonate, calcium hydroxide and other hydroxides, ferric carbonate, zinc oxide, iron oxide, aluminum phosphate, barium sulfate and other salts, montmorillonite, hectorite, fluorine hectorite, saponite and other smectite minerals, glass fiber and the like are used. Preferred specific examples of inorganic fillers include talc, mica, wollastonite and the like. By adding a small amount of inorganic filler, an effect of improving the gas barrier property in the resin composition can be recognized.

[0034] In the polyester carbonate resin composition, for example, 20 to 60% by mass or 30 to 50% by mass of an inorganic filler is contained based on the total weight of the resin composition. The content of the inorganic filler in the resin composition is preferably 30 to 45% by mass, more preferably 30 to 40% by mass, and still more preferably 32 to 40% by mass, based on the total weight of the resin composition.

[0035] The polylactic acid that can be contained in the polyester carbonate resin composition is a polymer composed substantially only of monomer units derived from L-lactic acid and / or D-lactic acid. Further, the polylactic acid may contain monomer units other than L-lactic acid and D-lactic acid as long as the effects of the resin composition are not impaired.

[0036] As a method for producing polylactic acid, any known polymerization method can be adopted. The most typically known method is the ring-opening polymerization method of lactide, which is an anhydrous cyclic dimer of lactic acid (lactide method), but lactic acid may be directly condensation-polymerized. Further, as the molecular weight of polylactic acid, a weight-average molecular weight in the range of 50,000 to 1,000,000 is preferable.

[0037] In the polyester carbonate resin composition, polylactic acid may be contained. For example, 0 to 50% by mass of polylactic acid is contained based on the total weight of the resin composition. The content of polylactic acid in the resin composition is preferably 3 to 40% by mass or 5 to 45% by mass, more preferably 5 to 40% by mass or 5 to 35% by mass, and still more preferably 10 to 35% by mass, based on the total weight of the resin composition.

[0038] In the polyester carbonate resin composition, additives other than the above-described components may be contained. For example, in the resin composition, a mold release agent, an antioxidant, etc. may be contained, and a phosphorus-based compound that can be contained as a flame retardant etc. may not be contained.

[0039] The polyester carbonate resin composition preferably contains an antioxidant as an additive. While commercially available antioxidants can be used, it is preferable that the composition contains at least one of, for example, an acid-phenol antioxidant and a phosphite-based antioxidant.

[0040] As phenolic antioxidants, 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'-butylidenedi-m-cresol, ocladecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, Examples 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, pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and preferably pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].Phosphate antioxidants include 2-ethylhexyldiphenyl phosphite, isodecyldiphenyl 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, 2,2'-methylenbis(4,6-di-tert-butylphenyl)2-ethylhexyl phosphite, and tri Examples include s(2,4-ditert-butylphenyl) phosphite, tris(nonylphenyl) phosphite, tetra-C12-15-alkyl(propane-2,2-diylbis(4,1-phenylene))bis(phosphite), 3,9-bis(2,6-ditert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and preferably 3,9-bis(2,6-ditert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane. As an antioxidant, one of the above types may be used alone, or a mixture of two or more types may be used.

[0041] The amount of antioxidant added is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, based on the total mass of the polyester carbonate resin composition. Furthermore, the amount of antioxidant added based on the total mass of the resin composition is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less. The polyester carbonate resin composition may contain only one type of antioxidant or two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0042] The polyester carbonate resin composition preferably contains a release agent as an additive. Examples of release agents include ester compounds, such as glycerin fatty acid esters such as mono- and diglycerides of glycerin fatty acids, glycol fatty acid esters such as propylene glycol fatty acid esters and sorbitan fatty acid esters, higher alcohol fatty acid esters, and full or mono fatty acid esters of aliphatic polyhydric alcohols and aliphatic carboxylic acids. When using an ester of aliphatic polyhydric alcohol and an aliphatic carboxylic acid as a release agent, monoesters, full esters, etc., can all be used, but other than full esters such as monoesters may also be used.

[0043] Specific examples of release agents 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 monohydroxystearate, glycerin monooleate, glycerin monobehenate, glycerin monocaprylate, glycerin monocaprate, and glycerin mono-hydroxystearate, glycerin monooleate, glycerin monobehenate, glycerin monocaprylate, and glycerin mono-caprate. Examples include monoglycerides such as monolaurate; mono-diglycerides such as glycerin mono-distearate, glycerin mono-distearate, glycerin mono-diolate; glycerin fatty acid ester monoglycerides such as glycerin diacetone monolaurate; glycerin fatty acid ester organic acid monoglycerides such as citrate fatty acid monoglyceride, succinate fatty acid monoglyceride, and diacetyltartrate 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 polyricinolate.

[0044] The proportion of the release agent added is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, based on the total mass of the polyester carbonate resin composition. Furthermore, the proportion of the release agent added based on the total mass of the resin composition is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less. The resin composition may contain only one type of release agent or two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0045] The polyester carbonate resin composition may contain additives other than the antioxidants and release agents mentioned above. For example, additives that the resin composition may contain include compounding agents, catalyst deactivators, heat stabilizers, plasticizers, fillers, UV absorbers, rust inhibitors, dispersants, defoamers, leveling agents, flame retardants, lubricants, dyes, pigments, bluing agents, nucleating agents, clearing 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-resistant agents (specifically, bis(2,2,6,6-tetramethyl-1(octyloxy)-4-piperidinyl) ester decandioate, reaction product of 1,1-dimethylethyl hydroperoxide and 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, 1-[2-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl]-4-[3-(3,5-di-ter Examples include hindered amine-based stabilizers such as t-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}], and end-cap encapsulants.

[0046] Examples of nucleating agents (crystal nucleating agents) and antiblocking agents that may be included in the polyester carbonate resin composition include talc, mica, calcium carbonate, and boron nitride. Calcium carbonate is a preferred specific example of a nucleating agent and antiblocking agent. Furthermore, the same additive, such as talc or mica, can be used in combination as both a nucleating agent and an inorganic filler. The addition of small amounts of nucleating agents and antiblocking agents can be expected to improve the properties of the resin composition.

[0047] The addition ratio of the nucleating agent and antiblocking agent is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more, based on the total mass of the resin composition. Furthermore, the addition ratio of the nucleating agent and antiblocking agent is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less, based on the total mass of the resin composition.

[0048] The total mass of all additives contained in the resin composition is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and particularly preferably 3% by mass or less or 2% by mass or less, based on the total mass of the polyester carbonate resin composition.

[0049] <2. Properties of Polyester Carbonate> The properties of polyester carbonate will be described below. 2-1. Properties of Polyester It is preferable that polyester carbonate be produced by first forming polyester in a first polymerization step, and then further polymerizing the polyester with diester carbonate in a second polymerization step, as will be described in detail later. The properties of polyester as a prepolymer that can be produced in the first polymerization step will be described below.

[0050] The weight-average molecular weight (Mw) of the polyester portion contained in the polyester carbonate is preferably 1,000 to 20,000, more preferably 1,500 to 18,000, even more preferably 2,000 to 15,000, and particularly preferably 2,500 to 12,000. The number-average molecular weight (Mn) of the polyester portion contained in the polyester carbonate is preferably 500 to 10,000, more preferably 600 to 8,000, even more preferably 800 to 6,000, and particularly preferably 1,000 to 5,500.

[0051] In the polyester used to form polyester carbonate, the amount of terminal hydroxyl groups (OH amount or OH terminal amount), measured by the method described in detail later, is preferably 0.10 to 10.0 (weight%), more preferably 0.30 to 8.00 (weight%), even more preferably 0.50 to 6.00 (weight%), and particularly preferably 1.00 to 4.00 (weight%), based on the weight of the polyester. Furthermore, the amount of terminal hydroxyl groups (OH amount) in the polyester for polyester carbonate formation is preferably 0.01 to 1.00 (mol / g), more preferably 0.02 to 0.60 (mol / g), even more preferably 0.04 to 0.40 (mol / g), and particularly preferably 0.05 to 0.25 (mol / g), based on the weight of the polyester.

[0052] In the polyester used for forming polyester carbonates, the OH value, as measured by the method described in detail later, is preferably 10 to 300 (mg KOH / g), more preferably 15 to 250 (mg KOH / g), even more preferably 20 to 200 (mg KOH / g), and particularly preferably 30 to 150 (mg KOH / g). In addition, in the polyester for forming polyester carbonates, the acid value, as measured by the method described in detail later, is preferably 0.10 to 2.00 (mg KOH / g), more preferably 0.20 to 1.50 (mg KOH / g), even more preferably 0.30 to 1.20 (mg KOH / g), and particularly preferably 0.40 to 1.00 (mg KOH / g).

[0053] In polyesters used to form polyester carbonates, the intrinsic viscosity (η) is preferably 0.02 to 0.60 (dl / g), more preferably 0.03 to 0.40 (dl / g), even more preferably 0.05 to 0.30 (dl / g), more preferably 0.07 to 0.20 (dl / g), and particularly preferably 0.08 to 0.19 (dl / g).

[0054] 2-2. Properties of Polyester Carbonate In polyester carbonate, the preferred range for the amount of terminal hydroxyl groups (OH amount or OH terminal amount), which is measured by the method described in detail later, is as follows. First, in the first form of polyester carbonate, which has a large amount of terminal hydroxyl groups and a small carbon dioxide molar ratio, which will be described in detail later, the amount of terminal hydroxyl groups is preferably 850 to 1600 ppm (ppm by weight), more preferably 900 to 1400 ppm (ppm by weight), even more preferably 920 to 1300 ppm (ppm by weight), and particularly preferably 920 to 1150 ppm (ppm by weight) or 950 to 1200 ppm (ppm by weight), based on the weight of the polyester carbonate.

[0055] Furthermore, in the second form of polyester carbonate, which has a small amount of terminal hydroxyl groups and a large molar ratio of diester carbonate (details to be described later), the amount of terminal hydroxyl groups is preferably 10 to 600 ppm (ppm by weight), more preferably 40 to 500 ppm (ppm by weight), even more preferably 60 to 350 ppm (ppm by weight), and particularly preferably 70 to 300 ppm (ppm by weight) or 60 to 250 ppm (ppm by weight), based on the weight of the polyester carbonate.

[0056] In the first embodiment of the polyester carbonate, the amount of terminal hydroxyl groups (OH amount or OH terminal amount), measured by a method described in detail later, is preferably 0.01 to 2.00 (mg KOH / g), more preferably 0.03 to 1.50 (mg KOH / g), even more preferably 0.05 to 1.00 (mg KOH / g), and particularly preferably 0.10 to 0.90 (mg KOH / g) or 0.15 to 0.80 (mg KOH / g), based on the weight of the polyester carbonate.

[0057] In the second embodiment of the polyester carbonate, the amount of terminal hydroxyl groups (OH amount or OH terminal amount), measured by a method described in detail later, is preferably 1.00 to 6.00 (mg KOH / g), more preferably 1.50 to 5.50 (mg KOH / g), even more preferably 2.00 to 5.00 (mg KOH / g), and particularly preferably 2.50 to 4.00 (mg KOH / g) or 3.00 to 4.50 (mg KOH / g), based on the weight of the polyester carbonate.

[0058] In the polyester carbonate, the acid value measured by the method described in detail later is preferably 0.01 to 1.00 (mg KOH / g), more preferably 0.05 to 0.50 (mg KOH / g), and even more preferably 0.10 to 0.30 (mg KOH / g). In the first embodiment of the polyester carbonate, the acid value measured by the method described in detail later is preferably 0.01 to 0.60 (mg KOH / g), more preferably 0.05 to 0.40 (mg KOH / g), and even more preferably 0.10 to 0.20 (mg KOH / g) or 0.11 to 0.16 (mg KOH / g). Furthermore, in the second form of polyester carbonate, the acid value, as measured by the method described in detail later, is preferably 0.01 to 0.80 (mg KOH / g), more preferably 0.05 to 0.60 (mg KOH / g), and even more preferably 0.10 to 0.30 (mg KOH / g).

[0059] In the first embodiment of the polyester carbonate, the amount of phenyl terminals, as measured by the method described in detail later, is preferably 100 ppm to 1500 ppm, more preferably 300 ppm to 1200 ppm, and even more preferably 400 ppm to 1000 ppm or 500 ppm to 900 ppm.

[0060] Furthermore, in the second form of polyester carbonate, the amount of phenyl terminals, as measured by the method described in detail later, is preferably 3,500 ppm or more and 6,000 ppm or less, more preferably 3,700 ppm or more and 5,800 ppm or less, and even more preferably 4,000 ppm or more and 5,700 ppm or less or 4,200 ppm or more and 5,800 ppm or less.

[0061] The weight-average molecular weight (Mw) of the polyester carbonate is preferably 160,000 or more, but is not limited thereto, and may be, for example, 10,000 to 500,000. The Mw value of the polyester carbonate is preferably 30,000 to 450,000 or 40,000 to 500,000, more preferably 50,000 to 400,000 or 60,000 to 350,000, even more preferably 70,000 to 35,000 or 80,000 to 350,000, and particularly preferably 100,000 to 300,000, 150,000 to 270,000, 160,000 to 250,000 or 180,000 to 230,000. Furthermore, the quantity-average molecular weight (Mn) of the polyester carbonate is, for example, 6,000 to 280,000, preferably 18,000 to 250,000 or 20,000 to 270,000, more preferably 30,000 to 220,000 or 32,000 to 200,000, even more preferably 36,000 to 180,000 or 42,000 to 200,000, and particularly preferably 60,000 to 180,000, 70,000 to 160,000, 80,000 to 140,000 or 90,000 to 120,000.

[0062] In the thermal stability test, which is described in detail later, the molecular weight retention rate of the polyester carbonate, i.e., the ratio of the weight-average molecular weight after heating to the weight-average molecular weight before heating, is preferably 90 to 120%, and more preferably within the range of 93 to 117%, and involves heating at 225°C for 10 or 20 minutes under a nitrogen atmosphere. A polyester carbonate exhibiting a molecular weight retention rate within this range in the thermal stability test is said to have excellent thermal stability and possess at least practically acceptable thermal stability.

[0063] In a thermal stability test conducted by heating for 10 minutes under conditions described in detail below, the molecular weight retention range is more preferably 90-115%, even more preferably 92-113%, and particularly preferably 93-110% or 93-109%. Furthermore, in a thermal stability test conducted by heating for 20 minutes under conditions described in detail below, the molecular weight retention range is more preferably 93-120%, even more preferably 95-119%, and particularly preferably 97-117% or 99-118%.

[0064] For example, in a hydrolysis test (hydrolysis retention test) under predetermined conditions, such as immersion in pure water at 80°C for four days, the molecular weight retention rate of the polyester carbonate, that is, the ratio of the weight-average molecular weight after immersion to the weight-average molecular weight before immersion, is preferably 40% or more. Furthermore, the range of the molecular weight retention rate in the hydrolysis test is more preferably 50% or more, even more preferably 60% or more, and particularly preferably 70% or more, 72% or more, 75% or more, or 80% or more.

[0065] In a biodegradability test of polyester carbonate in accordance with JIS K 6953-2, it is preferable that the biodegradability value 60 days after the start of the test is 40% or more. That is, in accordance with JIS K 6953-2, it is preferable that the biodegradability (%) of the polyester carbonate test piece under 58°C composting conditions is 40% or more of the biodegradability (%) of the cellulose test piece, which is the standard substance. The biodegradability value of polyester carbonate calculated in this way is more preferably 50% or more, even more preferably 70% or more, and particularly preferably 80% or more or 85% or more.

[0066] <3. Method for producing polyester carbonate> The method for producing polyester carbonate includes a process for producing polyester as a prepolymer and a polymerization process in which polyester molecules are bonded together with diester carbonate.

[0067] 3-1. Polyester Manufacturing Process (First Polymerization Step) Polyester, as a prepolymer used as a raw material for polyester carbonate, can be manufactured by conventional methods. For example, as follows: At least the above-mentioned aliphatic diol and the above-mentioned aliphatic diols can be polymerized by esterification reactions (dehydration or dealcoholization reactions) to produce polyester.

[0068] In the production of polyester, the molar ratio of aliphatic diol to aliphatic dicarboxylic acid is preferably 1.05 to 2.00, more preferably 1.20 to 1.80, and even more preferably 1.40 to 1.60.

[0069] 3-2. Polymerization Process of Polyester Carbonate (Second Polymerization Process) Polyester carbonate can be produced by further polymerizing polyester, which is a prepolymer. For example, methods such as a direct reaction between polyester and phosgene (phosgene method) or a transesterification reaction between polyester and carbonate esters such as bisaryl carbonate (two-step transesterification method) can be employed. Although any of these methods for producing polyester carbonate resin can be employed, the two-step transesterification method is preferred because it can reduce the environmental impact and achieve good reactivity.

[0070] Triol compounds are used to form branched regions in polyester carbonates, and may be added in either the first polymerization step or the second polymerization step described above. However, from the viewpoint of adjusting the amount added, it is preferable that the triol compound is added to the reaction system in only one of the first polymerization step or the second polymerization step. That is, it is preferable that the triol compound is added to the reaction system in either the first polymerization step or the second polymerization step.

[0071] In the first or second polymerization step in which a triol compound is added to the reaction system as a monomer, it is preferable that the relationship between the amount of OH contained in the triol compound as a monomer and the amount of diester carbonate is expressed by the following formula (1) or formula (2). That is, in the first embodiment of the method for producing polyester carbonate described above, it is preferable that the relationship of formula (1) is satisfied, and in the second embodiment of the method for producing polyester carbonate described above, it is preferable that the relationship of formula (2) is satisfied.

[0072] When the triol compound is added only in the first polymerization step, the [OH content of PE (mol)] in formulas (1) and (2) above means the (terminal) OH content of the polyester obtained in the first polymerization step. When the triol compound is added only in the second polymerization step, the [OH content of PE (mol)] in formulas (1) and (2) above means the (terminal) OH content of the polyester used in the polymerization of the polyester carbonate already obtained at the start of the second polymerization step. Furthermore, when the triol compound is used in both the first and second polymerization steps, the [OH content of PE (mol)] in formulas (1) and (2) above means the sum of the (terminal) OH content of the polyester obtained in the first polymerization step and the (terminal) OH content of the polyester used in the polymerization of the polyester carbonate already obtained at the start of the second polymerization step. In this manner, when the triol compound is added to the reaction system in both the first and second polymerization steps and used in combination, the [OH amount of the triol compound] in formulas (1) and (2) above refers to the total OH amount of the triol compound used in the first and second polymerization steps.

[0073] The molar ratio of diester carbonate in formula (1) is preferably 0.91 or more and less than 0.97, or greater than 0.90 and 0.96 or less, more preferably in the range of 0.92 to 0.96, and even more preferably in the range of 0.93 to 0.95. The molar ratio of diester carbonate in formula (2) is preferably in the range of 1.02 to 1.16, more preferably in the range of 1.03 to 1.12, even more preferably in the range of 1.04 to 1.10 or 1.03 to 1.09, and particularly preferably in the range of 1.05 to 1.09 or 1.04 to 1.08.

[0074] For the formation of polyester carbonate, it is preferable to use a slightly excess amount of diester carbonate relative to the total number of moles of terminal hydroxyl groups of polyester. Specifically, it is preferable to use more than 1.00 times and less than 1.20 times the number of moles of diester carbonate relative to 0.5 times the total number of moles of terminal hydroxyl groups of polyester (the number of moles of one of the terminal hydroxyl groups at both ends of the polyester). The amount of diester carbonate used (in moles) is more preferably 1.02 to 1.15 times the total number of moles of terminal hydroxyl groups of polyester, even more preferably 1.03 to 1.10 times the total number of moles of terminal hydroxyl groups of polyester carbonate, and particularly preferably 1.04 to 1.09 times the total number of moles of terminal hydroxyl groups of polyester, for example 1.07 or 1.04 times. It is also preferable to use a slightly insufficient amount of diester carbonate relative to 0.5 times the total number of moles of terminal hydroxyl groups of polyester. Specifically, it is preferable to use diester carbonate in a mole amount exceeding 0.90 times and less than 1.00 times the total number of moles of terminal hydroxyl groups of polyester. The amount (moles) of diester carbonate used is more preferably 0.90 to 0.99 times the total number of moles of terminal hydroxyl groups of polyester, even more preferably 0.09 to 0.98 times the total number of moles of terminal hydroxyl groups of polyester, and particularly preferably 0.90 to 0.97 times the total number of moles of terminal hydroxyl groups of polyester, for example 0.93 or 0.95 times.

[0075] The molar ratio of the total number of moles of the triol compound to the total number of moles of the aliphatic dicarboxylic acid and aliphatic diol in the first and second polymerization steps is preferably 100 to 100,000, more preferably 300 to 10,000, even more preferably 400 to 5,000, and particularly preferably 500 to 1,000.

[0076] The polymerization reaction of polyester carbonate, i.e., the second polymerization step, is usually carried out at a temperature in the range of 150 to 350°C, preferably 200 to 300°C, and the degree of reduced pressure is preferably 1 mmHg or less in the final stage to remove phenols generated by the transesterification reaction from bisaryl carbonate. The reaction time depends on the reaction temperature and degree of reduced pressure, but is usually about 1 to 24 hours, preferably 2 to 12 hours, and more preferably 3 to 6 hours. The polymerization reaction of polyester is preferably carried out under an inert gas atmosphere such as nitrogen or argon, and antioxidants and branching agents may be added to the reaction as desired.

[0077] In the polymerization reaction of polyester carbonate by the transesterification method described above, the use of a transesterification catalyst is preferred. As a transesterification catalyst, for example, a compound containing a salt of at least one of the following metals is used: Y, La, Zn, Sn, Ga, Mn, Co, Mg, In, Ti, Zr, and Hf. Examples of such transesterification catalysts include fatty acid salts of the above-mentioned metals, hydroxides, alcoholates, phenolates, acetylacetonates, benzoylacetonates, halides, carbonates, sulfates, nitrates, oxides, etc. One type of compound may be used as the transesterification catalyst, or two or more types may be used in combination. Preferably, the transesterification catalyst is used in an amount of 5 × 10⁶ per 100 parts by weight of the raw material mixture. －５ It is used in the range of up to 1 part by weight.

[0078] <4. Molded Articles and Various Materials> The molded articles of the present invention contain the polyester carbonate described above. Preferably, the molded articles contain biodegradable polyester carbonate as the main component. Molded articles containing biodegradable polyester carbonate as the main component are easily decomposed by microorganisms in soil, compost, seawater, rivers, lakes, etc. For this reason, polyester carbonate can be widely used even in cases where recycling is difficult. Furthermore, because polyester carbonate has excellent moldability, it can be processed and used in various molded articles such as films, sheets, laminates, fibers, nonwoven fabrics, yarns, and laminates.

[0079] Specific examples of such molded products include agricultural materials, fishing materials, civil engineering materials, and fibers, all of which are biodegradable. The following are examples of specific uses of resin compositions that can be specifically utilized. A specific example of agricultural materials is agricultural mulch film with excellent gas barrier properties. Agricultural mulch film is used for purposes such as covering the soil surface to retain soil heat and control weeds, preventing pest damage, and creating an environment suitable for growing vegetables and fruits by creating fine irregularities on the film surface to diffuse sunlight. Films stretched on the outside of greenhouses are used for purposes such as suppressing the generation of fog and mist, improving heat retention, and dust prevention.

[0080] Other agricultural materials include multipurpose films, pots and strings for plants, fertilizer coating materials, sustained-release coverings, horticultural films, pesticide wrap films, greenhouse films, fertilizer bags, seedling pots for transplanting, seedling pots, waterproof sheets, sandbags, construction films, weed control sheets, vegetation nets made of tape and yarn, water-retaining films for greening barren land and deserts, sandbags, vegetation nets, vegetable sunburn prevention tape, tree shelters, winter coverings, animal damage prevention nets, mulch films for paddy fields, hydroponic sheets, urethane alternative growing media, and floral foam for flower arranging.

[0081] Specific examples of fishing materials include fishing lines, fishing nets, seaweed nets, artificial bait, artificial seaweed, foam floats, oyster farming pipes, and buoys. Examples of civil engineering materials include underground pipes, sandbags, building films, sandbags, buried pipes for soil modification, drainage drains, wood waterproofing, waterproof sheets, weed control sheets, civil engineering sheets, and fumigation sheets. Polyester carbonate is also suitably used, for example, as sutures, or as a fiber for nonwoven fabrics, woven fabrics, and bandages.

[0082] Other specific examples of molded products include helmets, various bags such as shopping bags, packaging materials for magnetic tape cassette products such as video and audio, flexible disc packaging materials, printing plate materials, packaging bands, adhesive tapes, tapes, yarn, cups, trays, cartons, lunch boxes, prepared food containers, food and confectionery packaging materials, food wrap materials, internal coating materials for food and beverage packs, shrink film for PET bottles, trays for fresh food, fast food containers and lunch boxes, garbage bags, cups, plates, chopsticks, spoons, forks, straws, and cosmetic wrap materials. Examples of applications include plastic shopping bags, diapers, sanitary napkins, medical wraps, pharmaceutical packaging materials, surgical adhesive patches for conditions such as stiff shoulders and sprains, various packaging materials for food, electronics, medical equipment, pharmaceuticals, cosmetics, etc., parts of artificial hair and wigs, artificial turf, body bags, pipette tips, biological research tags, signposts, bollards, scrubbing materials, shampoo and toothpaste tubes, 3D printer filaments, contact lenses, absorbent sheets for diapers, and polyester for fleece materials. If the molded product has a film-like shape, it can also be heat-sealed. In addition, it can be used for purposes such as garbage bags and compost bags.

[0083] The molded products can be used as medical and hygiene products, such as medical materials like sutures and bandages, and hygiene materials like disposable diapers and parts of sanitary products (superabsorbent polymers, waterproof films). They can also be used as disposable leisure goods for golf, fishing, and marine sports, as well as water treatment materials such as precipitants, dispersants, and detergents.

[0084] While there are no particular limitations on the shape of the molded body, for example, in the case of a molded body as a component other than a film, the thickness is, for example, 0.1 mm or more, preferably 0.3 mm or more. Furthermore, the thickness of a molded body as a film may be, for example, 500 μm or less, or 300 μm or less.

[0085] The following describes examples of polyester carbonate. 1) Amount of OH (terminal hydroxyl groups) in PE (polyester) The amount of terminal hydroxyl groups in polyester, which is the raw material for polyester carbonate, was calculated from NMR analysis as follows. NMR apparatus: Bruker AVNEO500 Solvent: Deuterated chloroform Analysis method: The amount of terminal hydroxyl groups was calculated from the integral value of σ3.7, which indicates terminal hydroxyl groups, and the integral value of σ4.2, which indicates ester bonds of succinic acid, using the following formula. Degree of polymerization n = ((integral value of σ4.2 - integral value of σ3.7) / integral value of σ3.7) + 1 Theoretical molecular weight M = n × 172.17 + 90.12 Amount of OH (mol / g) = 2 / M OH value (mgKOH / g) = 56.1 × 1000 × 2 / M

[0086] Furthermore, the OH value (mg KOH / g) can also be measured by the titration method described below, and there was no difference in the results obtained by the NMR method and the titration method. (Titration method) 1. Weigh 5.1045 g of acetic anhydride into a 100 ml volumetric flask and make up to 100 ml with pyridine. (Acetylation reagent below) 2. Weigh 0.5 g of polyester (PE sample below) into a 100 ml vial and record the weight (Y g). Each sample was weighed N=2. 3. Add a stirring bar and acetylation reagent (weighed 10.0 g: approximately 10 ml) to the vial containing the PE sample and close the lid. At this time, two blank vials without the PE sample were prepared. 4. Heat in an oil bath heated to 98°C for 90 minutes. 5. Remove from the oil bath, allow to cool to room temperature for 10 minutes, then rinse the walls with ultrapure water (UPW (approx. 10 ml)) and stir for about 5 minutes. At this time, the mixture will heat up due to the neutralization heat of acetic acid and pyridine, so add the UPW slowly while observing the mixture. For the blank, add UPW (approx. 10 ml) carefully to avoid splashing, and stir for about 5 minutes. 6. Add a few drops of phenolphthalein, and titrate the Blank twice with 0.2 N NaOH aqueous solution, and the solution containing the PE sample twice. 7. If there is no significant difference in the titration results of the blank, calculate the blank average (Z １ The amount of 0.2N NaOH aqueous solution required for the neutralization titration of the solution containing the PE sample (ml) and Z ２ The OH value was calculated from the difference (Z1 - Z2 ml) between the two values. 8. The amount of OH (mass %) was determined using the following formula (a). Furthermore, a smaller value for terminal hydroxyl groups indicates that the polymerization reaction during polyester production was more advanced.

[0087] 2) Acid value of PE (polyester) and PEC (polyester carbonate) was measured by titration using phenolphthalein in accordance with JIS K0070-1992. However, the base used for titration was changed from a 0.1 mol / L KOH aqueous solution to a 0.02 mol / L NaOH aqueous solution, and ethanol was added first. Apparatus: burette, magnetic stirrer, stirrer bar, Erlenmeyer flask Solvent: chloroform, ethanol, 0.02 mol / L NaOH aqueous solution, phenolphthalein (indicator) (Measurement method) 1. Weigh out approximately 1 g each of PE and PEC resin and record the weight. 2. Weigh out 30 ml of chloroform and completely dissolve the resin. 3. After confirming complete dissolution, weigh out 30 ml of ethanol and add it to the solution. 4. Add 4 drops of phenolphthalein as an indicator and titrate with 0.02 mol / L NaOH solution. 5. The difference in titration volume between the solution and the blank (chloroform: 30 ml, ethanol: 30 ml) was recorded. 6. The acid value was calculated using the following formula (b): Acid value (mg KOH / g) = 0.02 × difference in titration volume (ml) × 56.1 / resin weight (g) ... (b)

[0088] 3) Weight-average molecular weight (Mw) and number-average molecular weight (Mn) in polystyrene equivalent were analyzed by GPC. Instrument: Tosoh Corporation high-speed GPC HLC-8320 GPC column: Tosoh Corporation GPC column SuperMultiporeHZ-M (4.6mm I.D. × 150mm), 3 columns used in series. Flow rate: 0.35 mL / min Eluent: Chloroform Sample concentration: 0.2 w / v% Detection unit: Bryce type differential refractometer (RI detector)

[0089] 4) Diester carbonate (DPC) molar ratio and amount of diester carbonate charged The diester carbonate (DPC) molar ratio was calculated using the following formula (c) based on the OH content of polyester (PE) and the ratio of diester carbonate amounts. Diester carbonate theoretically reacts with two hydroxyl groups. Therefore, the amount of diester carbonate to be charged was calculated according to the reaction conditions using one of the following formulas (d-1), (d-2), (e-1), and (e-2). (i) When the subsequent reaction (production of branched polyester carbonate) is polyester (a) + triol compound + diester carbonate ⇒ branched polyester carbonate (A) (ii) When the subsequent reaction (production of branched polyester carbonate) is polyester (b) + diester carbonate ⇒ branched polyester carbonate (B)

[0090] 5) Amount of OH end groups (ppm) and phenyl (Ph) end groups of polyester carbonate (PEC) were calculated by NMR analysis, similar to the amount of OH end groups of polyester described above. Instrument: Bruker AVNEO500 Solvent: Deuterated chloroform (CDCl3) Analysis method: End group analysis was performed 1The molar ratios of each component were calculated from the integral ratios of the 1H NMR (solvent: CDCl3), and the molar ratios of each component were defined as follows from the integral values ​​of each peak. In the following equations, BD represents the integral value of the peak originating from 1,4-butanediol, SA represents succinic acid, and the Ph terminus represents the integral value of the peak originating from diphenyl carbonate (DPC). A: (δ4.16 + δ4.11) / 4 = BD B: δ3.67 / 2 = OH terminus C: δ2.63 / 4 = SA D: (δ4.16 + δ4.11 - δ2.63) / 4 = Carbonate binding ratio E: δ7.37 / 2 = Ph terminus (phenyl terminus originating from DPC) The amount of OH terminus (ppm) of PEC was calculated using the following equations. Calculation formula: OH terminal amount (ppm) = 17×B / (88.12×A+84.09×C+28×D+17×B+93.11×D)×1000000...(f) Ph terminal amount (ppm) = 93.11×E / (88.12×A+84.09×C+28×D+17×B+93.11×D)×1000000...(g) OH terminal concentration (mol / g) = B / (88.12×A+84.09×C+28×D+17×B+93.11×D)...(h) Ph terminal concentration (mol / g) = E / (88.12×A+84.09×C+28×D+17×B+93.11×D)...(i)

[0091] 6) Hydrolysis Test / Molecular Weight (Weight-Average Molecular Weight Mw) Retention Rate The molecular weight retention rate of polyester carbonate (PEC) was measured by hydrolysis test as follows: PEC was placed in a vial and immersed in pure water in an incubator set to 80°C. The change in weight-average molecular weight (Mw) before and after immersion was calculated using the same method as described above for GPC measurement. The molecular weight retention rate (%) after 4 days was calculated, with the weight-average molecular weight (Mw) before immersion set to 100%. Incubator: FMU-1801-HC low-temperature incubator manufactured by Fukushima Galilei Co., Ltd.

[0092] 7) Stability during extraction The stability of the polyester carbonate resin when it is extracted as strands from the reaction vessel after polymerization was evaluated from a handling perspective. Specifically, it is as follows: "Stable": When the resin can be stably stranded and pelletized when extracted from the reaction vessel. "Somewhat stable": When the resin can be stranded and pelletized, although it is somewhat unstable (there are variations in strand thickness) when extracted from the reaction vessel. "Unstable": When the resin cannot be stably stranded and pelletized when extracted from the reaction vessel.

[0093] 8) Thermal Stability Test / Molecular Weight (Weight-Average Molecular Weight Mw) Retention Rate Polyester carbonate resin (PEC) immediately after polymerization was sampled from the reaction vessel and heated and retained in TG-DTA at 225°C for 10 minutes and 20 minutes under a nitrogen atmosphere. The weight-average molecular weight (Mw) was measured before and after retention, and the molecular weight retention rate was calculated using the following formula (j): Molecular Weight Retention Rate (%) = Molecular Weight after Heating and Retention (Mw) / Molecular Weight before Heating and Retention (Mw) × 100 ... (j)

[0094] <Manufacturing Example 1> Manufacturing Example 1 of Polyester (PE) Prepolymer A 10L reaction vessel equipped with a stirrer, thermometer, glass tube, and fractionation receiver was filled with 3451.4g of succinic acid (manufactured by Nippon Shokubai Co., Ltd.), 3687.9g of 1,4-butanediol (manufactured by Mitsubishi Chemical Corporation) as raw materials, and Zr (acac) as a catalyst. ４ 122 mg (manufactured by Fujifilm Wako Pure Chemical Co., Ltd.) was charged and reacted under a nitrogen atmosphere at 225°C for 1 hour, after which water was drained. At this time, the amount of 1,4-butanediol charged was 1.4 times (molar ratio) the amount of succinic acid charged. Subsequently, the mixture was aged for 2 hours and 30 minutes under a reduced pressure of 200 to 20 hPa to allow the dehydration reaction to proceed. Furthermore, the reduced pressure was gradually increased until it was finally below 1 hPa, and water and 1,4-butanediol were distilled off for a total of 4 hours and 30 minutes during polymerization. The resulting polyester had a number-average molecular weight of 2464, terminal hydroxyl groups of 1.98% by mass, and an acid value of 0.84 KOH mg / g.

[0095] (Example 1) 2500 g of polyester (PE) obtained in Production Example 1 was placed in a 10 L reaction vessel equipped with a stirrer, thermometer, glass tube, and fractionation receiver. 12.7 g of trimethylolpropane as a triol compound, 317.9 g of diphenyl carbonate (DPC) in an amount equal to half the total number of moles of terminal hydroxyl groups of the polyester and branching agent, 0.93 times the molar amount, and 1 mg of zinc acetate dihydrate as a catalyst were added. The reaction was carried out at a temperature of 225°C, with the pressure gradually reduced, and the phenol was removed by distillation, until the pressure was finally reduced to less than 1 hPa, for 4.5 hours. The pressure was released with nitrogen, and the resin was withdrawn from the reaction vessel. The obtained polyester carbonate resin was a colorless resin that did not gel. In the polyester carbonate resin, the weight-average molecular weight (Mw) was 230,000, the OH-terminus content was 1107 ppm, the Ph-terminus content was 504 ppm, and the acid value was 0.27 mgKOH / g.

[0096] (Examples 2-5, Comparative Examples 1-4) Polyester carbonate resin was obtained in the same manner as in Example 1, except that the amount of DPC used (DPC molar ratio) was changed as shown in Table 1. The properties of the obtained polyester carbonate resin are shown in Table 1.

[0097] (Reference Example) In addition to the above-mentioned examples and comparative examples, the properties of the polyester carbonate resin in Example 2 of Japanese Patent Publication No. 10 (1998)-45884 are shown below as a reference example. Properties of the Reference Example Polyester Carbonate Resin DPC molar ratio: 0.97 Mw: 18400 Stability during extraction: moderately stable

[0098] As is clear from the above results, the polyester carbonate resins of each example were confirmed to have excellent biodegradability as well as high thermal stability. Furthermore, although the polymerization rate tends to be faster and excessive polymerization and gelation more likely when the polyester carbonate resins have a branched structure with a large number of reaction ends, as in each example and comparative example, it was confirmed that each example exhibited excellent extraction stability, suppressing excessive polymerization and gelation. As is clear from the above, according to the above examples, it is possible to efficiently produce branched polyester carbonates with excellent properties.

[0099] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these examples. It is clear to any person with ordinary skill in the art to which the present invention pertains that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these are also understood to naturally fall within the technical scope of the present invention.

Claims

1. A branched polyester carbonate resin comprising structural units derived from aliphatic diols, aliphatic dicarboxylic acids, triol compounds, and diester carbonates, wherein the terminal OH content of the polyester carbonate resin is 850 ppm or more and 1600 ppm or less, and the phenyl terminal content is 100 ppm or more and 1500 ppm or less.

2. A branched polyester carbonate resin comprising structural units derived from aliphatic diols, aliphatic dicarboxylic acids, triol compounds, and diester carbonates, wherein the terminal OH content of the polyester carbonate resin is 10 ppm or more and 600 ppm or less, and the phenyl terminal content is 3500 ppm or more and 6000 ppm or less.

3. The polyester carbonate resin according to claim 1 or 2, wherein the molar ratio of the aliphatic diol to the aliphatic dicarboxylic acid is 1.05 to 2.

00.

4. The polyester carbonate resin according to claim 1 or 2, wherein the molar ratio of the number of moles of the triol compound to the total number of moles of the aliphatic dicarboxylic acid and the aliphatic diol is 100 to 100,000.

5. The polyester carbonate resin according to claim 1 or 2, wherein the molecular weight retention rate in a heating test in which the polyester carbonate resin is heated at 225°C for 10 or 20 minutes under a nitrogen atmosphere is 93 to 117%, and the molecular weight retention rate, which is the ratio of the weight-average molecular weight after heating to the weight-average molecular weight before heating, is 93 to 117%.

6. The polyester carbonate resin according to claim 1 or 2, wherein the aliphatic diol and the aliphatic dicarboxylic acid have 20 or fewer carbon atoms.

7. The polyester carbonate resin according to claim 6, wherein the aliphatic diol comprises butanediol and the aliphatic dicarboxylic acid comprises succinic acid.

8. The polyester carbonate resin according to claim 1 or 2, wherein the diester carbonate is a diaryl carbonate.

9. The polyester carbonate resin according to claim 8, wherein the diaryl carbonate ester comprises diphenyl carbonate.

10. The polyester carbonate resin according to claim 1 or 2, wherein at least one of the raw material substances, the aliphatic diol, the aliphatic dicarboxylic acid, the triol compound, and the diester carbonate, is derived from biomass.

11. The raw material, the diester carbonate, is CO ２ The polyester carbonate resin according to claim 1 or 2, which is derived from the present invention.

12. A method for producing a branched polyester carbonate (PEC) having a weight-average molecular weight (Mw) of 160,000 or more, comprising constituent units derived from an aliphatic diol, an aliphatic dicarboxylic acid, a triol compound, and a diester carbonate, comprising: a first polymerization step of polymerizing a polyester (PE) comprising constituent units derived from at least the aliphatic diol and the aliphatic dicarboxylic acid; and a second polymerization step of polymerizing the polyester (PE) and the diester carbonate to produce a branched polyester carbonate, wherein the triol compound is further polymerized in at least one of the first polymerization step and the second polymerization step, and the relationship between the amount of OH contained in the triol compound as a monomer in the polymerization step and the amount of diester carbonate is represented by the following formula (1) or the following formula (2), the method for producing a polyester carbonate resin.

13. A molded article comprising the polyester carbonate resin according to claim 1 or 2.

14. A biodegradable agricultural material comprising the polyester carbonate described in claim 1 or 2.

15. A biodegradable fishing material comprising the polyester carbonate described in claim 1 or 2.

16. A biodegradable civil engineering material comprising the polyester carbonate described in claim 1 or 2.

17. A biodegradable fiber comprising the polyester carbonate according to claim 1 or 2.

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