Method for producing polyester carbonate and polyester

Abstract

It has been required to develop a new production method capable of controlling the polymerization reactivity of a polyester carbonate resin and a polyester resin.　Provided is a method for producing a polyester carbonate or a polyester comprising a structural unit (A) derived from a diol and a structural unit (B) derived from a dicarboxylic acid, the method comprising adjusting the phosphorus atom content in the dicarboxylic acid to be less than 1.3 mass ppm on the basis of the total amount of the dicarboxylic acid.

Description

Polyester carbonate and method for producing polyester

[0001] The present invention relates to a method for producing polyester carbonates. The present invention also relates to a method for producing polyesters.

[0002] Dicarboxylic acids (e.g., succinic acid), which are raw materials for polyester carbonate resins and polyester resins, are produced, for example, by a fermentation method in which fermentable carbohydrates such as glucose are converted by microorganisms (Patent Document 1), or by a method in which maleic anhydride derived from petroleum is hydrogenated (Patent Document 2). However, the fermentation method using microorganisms has the problem of unstable quality. Furthermore, the method using maleic anhydride as a raw material requires multi-step processes, such as adding hydrogen in water, followed by crystallization, filtration, washing, and drying, which are complicated. Furthermore, in this method, repeated purification is required to achieve high quality of the target product.

[0003] Japanese Patent Application Laid-Open No. 2005-139287 Japanese Patent Application Laid-Open No. 2001-302781 Japanese Patent Application Laid-Open No. 2009-221482

[0004] As described above, dicarboxylic acids such as succinic acid are not stably produced in large quantities at high enough quality for industrial use, and differences in production lot or manufacturer can cause unexpected fluctuations in polymerization reactivity, which has been a problem. Patent Document 1 cites the ammonia content in the dicarboxylic acid raw material, while Patent Document 3 cites the sulfur atom content in the dicarboxylic acid raw material as a cause of such fluctuations. However, many aspects of the causes of such fluctuations remain unknown, and there has been a need for the development of a new production method that can control the polymerization reactivity of polyester carbonate resins and polyester resins.

[0005] The inventors' investigations revealed that the above problems could not be solved by the ammonia content or the sulfur atom content alone. Therefore, the inventors believed that there must be other factors that affect polymerization reactivity. As a result of extensive research, the inventors discovered that the polymerization reactivity of polyester carbonate resins and polyester resins is affected by the presence of phosphorus (P) in dicarboxylic acids, leading to the completion of the present invention.

[0006] That is, the present invention provides the following aspects. <1> A method for producing a polyester carbonate comprising a diol-derived structural unit (A) and a dicarboxylic acid-derived structural unit (B), comprising adjusting the phosphorus atom content in the dicarboxylic acid to less than 1.3 ppm by mass, based on the total amount of the dicarboxylic acid. <2> A method for producing a polyester comprising a diol-derived structural unit (A) and a dicarboxylic acid-derived structural unit (B), comprising adjusting the phosphorus atom content in the dicarboxylic acid to less than 1.3 ppm by mass, based on the total amount of the dicarboxylic acid. <3> The production method according to <1> or <2>, wherein the phosphorus atom content in the dicarboxylic acid is adjusted to 0.001 ppm by mass or more and less than 1.3 ppm by mass. <4> The production method according to any one of <1> to <3>, wherein the total content of sodium atoms and calcium atoms in the dicarboxylic acid is 2 ppm by mass or less, based on the total amount of the dicarboxylic acid. <5> The method for producing a polyester carbonate or polyester obtained by the ...

[0007] According to the present invention, there is provided a production method capable of controlling the polymerization reactivity of a polyester carbonate made from a dicarboxylic acid. The present invention also provides a production method capable of controlling the polymerization reactivity of a polyester made from a dicarboxylic acid. The present invention also provides a molded article using the polyester carbonate or polyester.

[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] [Raw materials for producing polyester carbonate] One aspect of the present invention provides a method for producing polyester carbonate. The method for producing polyester carbonate of the present invention uses a polyester as a prepolymer. The polyester is produced using a diol raw material containing a diol-derived structural unit (A) and a dicarboxylic acid raw material containing a dicarboxylic acid-derived structural unit (B). First, these diol raw materials and dicarboxylic acid raw materials will be explained. In the following explanation, "dicarboxylic acid raw material" and "diol raw material" respectively refer to a dicarboxylic acid component and a diol component as raw materials in the production of polyester. Furthermore, "dicarboxylic acid component" is a general term for dicarboxylic acids and dicarboxylic acid derivatives such as dicarboxylic acid alkylates.

[0010] In one embodiment of the present invention, among the dicarboxylic acid raw materials used in the production of the polyester prepolymer, aromatic dicarboxylic acid components include terephthalic acid, isophthalic acid, and their lower alcohol esters, with terephthalic acid and dimethyl terephthalate being preferred from the viewpoint of polymerizability. Aliphatic dicarboxylic acid components include dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, and dodecanedioic acid, as well as their lower alcohol esters and anhydrides (e.g., succinic anhydride and adipic anhydride). From the viewpoint of the physical properties of the resulting polyester, preferred aliphatic dicarboxylic acid components are succinic acid, adipic acid, sebacic acid, dodecanedioic acid, or their anhydrides or lower alcohol esters, with succinic acid being particularly preferred. These dicarboxylic acid raw materials may be used alone or in combination of two or more. The term "lower alcohol" generally refers to an alcohol having 1 to 4 carbon atoms.

[0011] In one embodiment of the present invention, specific examples of the diol raw material used in the production of the polyester prepolymer include ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and isosorbide. From the viewpoint of the physical properties of the resulting polyester, ethylene glycol, 1,3-propanediol, and 1,4-butanediol are preferred as the diol raw material, with 1,4-butanediol being particularly preferred from the viewpoint of heat resistance. These diol raw materials may be used alone or in combination of two or more.

[0012] The combination of the dicarboxylic acid raw material and the diol raw material is not particularly limited as long as it allows the production of a polyester, but preferred combinations include terephthalic acid and 1,4-butanediol, dimethyl terephthalate and 1,4-butanediol, and succinic acid and 1,4-butanediol. That is, the production method of the present invention is suitable for producing polybutylene terephthalate (PBT) by copolymerizing terephthalic acid and 1,4-butanediol, producing polybutylene terephthalate (PBT) by copolymerizing dimethyl terephthalate and 1,4-butanediol, and producing polybutylene succinate (PBS) by copolymerizing succinic acid and 1,4-butanediol.

[0013] In the production of polyesters, adding a small amount of a trifunctional or higher hydroxycarboxylic acid, a trifunctional or higher alcohol, or a trifunctional or higher carboxylic acid to the raw materials along with the dicarboxylic acid component and diol component can easily produce a polyester with high viscosity. Among these trifunctional or higher polyfunctional compounds, hydroxycarboxylic acids such as malic acid, citric acid, and fumaric acid are preferred, with malic acid being particularly preferred. When a trifunctional or higher polyfunctional compound is used, the upper limit of its amount relative to the total dicarboxylic acid components is preferably 5 mol %, more preferably 0.5 mol %, and the lower limit is preferably 0.001 mol %, more preferably 0.05 mol %. If the amount exceeds the upper limit of this range, gel (unmelted material) is likely to form, while if the amount is below the lower limit, the viscosity increase effect is difficult to achieve.

[0014] The dicarboxylic acid raw material used in the present invention may be a dicarboxylic acid obtained from a fossil fuel such as petroleum, or a dicarboxylic acid derived from a biomass resource produced from a biomass resource through a fermentation process or the like, or a combination of these dicarboxylic acids. In a preferred embodiment of the present invention, the dicarboxylic acid raw material is a dicarboxylic acid derived from a biomass resource. Furthermore, the diol raw material used in the present invention may be a diol obtained from a fossil fuel such as petroleum, or a diol derived from a biomass resource produced from a biomass resource through a fermentation process or the like, or a combination of these diols. In a preferred embodiment of the present invention, the diol raw material is a diol derived from a biomass resource.

[0015] 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.

[0016] These biomass resources are converted into carbon sources through known pretreatment and saccharification processes, including, but not limited to, chemical treatment with acids or alkalis, biological treatment using microorganisms, and physical treatment. These processes often include a pretreatment step of pulverizing the biomass resources by chipping, scraping, or grinding, and, if necessary, a further pulverization step using a grinder or mill. The pulverized biomass resources are usually further converted into carbon sources through pretreatment and saccharification. Specific methods include chemical methods such as acid treatment with strong acids such as sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid, alkali treatment, ammonia freeze-steam explosion, solvent extraction, supercritical fluid treatment, and oxidizing agent treatment; physical methods such as pulverization, steam-steam explosion, microwave treatment, and electron beam irradiation; and biological treatments such as hydrolysis using microorganisms or enzymes.

[0017] Examples of carbon sources derived from the above-mentioned biomass resources typically include fermentable carbohydrates such as hexoses such as glucose, mannose, galactose, fructose, sorbose, and tagatose; pentoses such as arabinose, xylose, ribose, xylulose, and ribulose; disaccharides and polysaccharides such as pentosan, saccharose, starch, and cellulose; oils and fats such as butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, monoctic acid, arachidic acid, eicosenoic acid, arachidonic acid, behenic acid, erucic acid, docosapentaenoic acid, docosahexaenoic acid, lignoceric acid, and selacholenic acid; and polyalcohols such as glycerin, mannitol, xylitol, and ribitol.

[0018] Typically, these carbon sources are used to synthesize biomass-derived dicarboxylic acids and diols by fermentation through microbial conversion, chemical conversion methods including reaction steps such as hydrolysis, dehydration, hydration, and oxidation, or a combination of these fermentation and chemical conversion methods.

[0019] As described above, the present inventors have found that the polymerization reactivity of polyester carbonate is affected by the presence of phosphorus in the dicarboxylic acid raw material. From the viewpoint of controlling the polymerization reactivity, the production method of the present invention includes adjusting the phosphorus atom content in the dicarboxylic acid raw material to less than 1.3 ppm by mass, based on the total amount (100% by mass) of the dicarboxylic acid. The phosphorus atom content in the dicarboxylic acid, based on the total amount (100% by mass) of the dicarboxylic acid, is preferably less than 1.3 ppm by mass, more preferably 1.2 ppm by mass or less, and even more preferably 1.1 ppm by mass or less. It is also preferable to set the phosphorus atom content in the dicarboxylic acid to 1.0 ppm by mass or less, 0.9 ppm by mass or less, 0.8 ppm by mass or less, 0.7 ppm by mass or less, 0.6 ppm by mass or less, 0.5 ppm by mass or less, 0.4 ppm by mass or less, 0.3 ppm by mass or less, 0.2 ppm by mass or less, or 0.1 ppm by mass or less. On the other hand, the lower limit of the phosphorus atom content in the dicarboxylic acid is not particularly limited, and may be, for example, 0.0001 ppm by mass or more, 0.0005 ppm by mass or more, or 0.001 ppm by mass or more.

[0020] In one aspect of the present invention, adjusting the phosphorus atom content includes confirming the content of phosphorus atoms contained in the dicarboxylic acid as a raw material. The method for confirming the phosphorus atom content is as described in the Examples below. In addition, a case where the phosphorus atom content is found to be less than 1.3 ppm by mass without confirming the phosphorus atom content is also included in the "adjusting the phosphorus atom content" of the present invention. In addition, in one aspect of the present invention, when the phosphorus atom content is 1.3 ppm by mass or more, it is preferable to include treating the dicarboxylic acid by a method such as recrystallization so that the phosphorus atom content in the dicarboxylic acid is less than 1.3 ppm by mass.

[0021] In particular, when using dicarboxylic acids derived from biomass resources, the dicarboxylic acid may contain sodium, calcium, and the like in addition to phosphorus. In the production method of one embodiment of the present invention, it is preferable that the content of such sodium and calcium is also low. Specifically, the content of sodium atoms in the dicarboxylic acid is preferably 1.0 ppm by mass or less, 0.9 ppm by mass or less, 0.8 ppm by mass or less, 0.7 ppm by mass or less, 0.6 ppm by mass or less, or 0.5 ppm by mass or less, based on the total amount (100% by mass) of the dicarboxylic acid. Furthermore, the content of calcium atoms in the dicarboxylic acid is preferably 1.0 ppm by mass or less, 0.9 ppm by mass or less, 0.8 ppm by mass or less, 0.7 ppm by mass or less, 0.6 ppm by mass or less, or 0.5 ppm by mass or less, based on the total amount (100% by mass) of the dicarboxylic acid. The total content of sodium atoms and calcium atoms in the dicarboxylic acid is preferably 2.0 ppm by mass or less, 1.8 ppm by mass or less, 1.6 ppm by mass or less, 1.4 ppm by mass or less, 1.2 ppm by mass or less, 1.0 ppm by mass or less, 0.9 ppm by mass or less, 0.8 ppm by mass or less, 0.7 ppm by mass or less, 0.6 ppm by mass or less, or 0.5 ppm by mass or less, based on the total amount (100% by mass) of the dicarboxylic acid. The lower limit of the sodium atom and / or calcium atom content in the dicarboxylic acid is not particularly limited, and may be, for example, 0.0001 ppm by mass or more, 0.0005 ppm by mass or more, or 0.001 ppm by mass or more. The method for adjusting the content of sodium atoms and calcium atoms in the dicarboxylic acid can be the same as the method for adjusting the phosphorus atom content.

[0022] [Method for Producing Polyester Carbonate] One aspect of the present invention provides a method for producing a polyester carbonate comprising a diol-derived structural unit (A) and a dicarboxylic acid-derived structural unit (B), the method comprising adjusting the phosphorus atom content in the dicarboxylic acid to less than 1.3 ppm by mass based on the total amount of the dicarboxylic acid. The method for producing a polyester carbonate of the present invention is sufficient as long as it comprises adjusting the phosphorus atom content in the dicarboxylic acid to less than 1.3 ppm by mass, and the method is as described above in [Raw Materials for Producing Polyester Carbonate]. The polyester carbonate of one aspect of the present invention can be produced, for example, by a stepwise method comprising the following first-stage reaction and second-stage reaction. For example, the methods described in JP-A-8-134196 and JP-A-8-301999 can be referenced as methods for obtaining polyester carbonate resins in steps. (First-stage reaction) A compound containing a diol-derived structural unit (A) and a compound containing a dicarboxylic acid-derived structural unit (B) are subjected to a polycondensation reaction in the presence of a catalyst to obtain a polyester (PE) as a prepolymer. (Second-stage reaction) The polyester (PE) obtained in the first-stage reaction is subjected to a polycondensation reaction with a carbonate diester in the presence of a catalyst to obtain a polyester carbonate (PEC).

[0023] 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.

[0024] 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.

[0025] The polyester carbonate produced by the production method of one embodiment of the present invention may contain unreacted monomers and carbonate diesters. The acceptable residual monomer concentration is 0 ppm to 5000 ppm, preferably 1 ppm to 3000 ppm. The acceptable residual carbonate diester concentration is 0 ppm to 5000 ppm, preferably 1 ppm to 1000 ppm.

[0026] Phenol by-produced during the polycondensation reaction may remain in the polyester carbonate produced by the production method of one embodiment of the present invention. The allowable residual phenol concentration is 1 ppm to 5000 ppm, preferably 10 ppm to 3000 ppm. Furthermore, for example, a cyclic dimer composed of succinic acid and 1,4-butanediol may remain. The allowable cyclic dimer concentration is 1.0 mass% or less, preferably 0.6 mass% or less. The cyclic dimer concentration in the polyester carbonate may be reduced by immersing and extracting pelletized polyester carbonate in a solvent that has low solubility in polyester carbonate, such as water or acetone, at a temperature of 20°C to less than 100°C.

[0027] The polyester carbonate produced by the production method of one embodiment of the present invention may be mixed 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.

[0028] In the production method according to one aspect of the present invention, it is preferable to add an antioxidant as an additive. As the antioxidant, commercially available antioxidants can be used, but it is preferable to include, for example, at least one of an acid phenol-based antioxidant and a phosphite-based antioxidant.

[0029] 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, 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.

[0030] In the production method according to one embodiment of the present invention, the antioxidant is preferably added in an amount such that the content of the antioxidant in the resulting polyester carbonate is 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 resulting polyester carbonate.

[0031] In the manufacturing method of one embodiment of the present invention, it is preferable to add 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.

[0032] 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.

[0033] In the production method according to one aspect of the present invention, the release agent is preferably added in an amount such that the content of the release agent is 1 ppm by weight to 5,000 ppm by weight, based on the total weight of the polyester carbonate to be obtained. The content of the release agent in the polyester carbonate to be obtained is 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.

[0034] In the manufacturing method according to one aspect of the present invention, other additives may be added 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.

[0035] In the production method of one embodiment of the present invention, the amount of additives other than the antioxidant and the mold release agent added is preferably such that the content of the other additives in the resulting polyester carbonate is 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 transmittance, so it is preferable not to add them in excess, and for example, the total amount added is within the above-mentioned range.

[0036] [Raw Materials for Producing Polyester] One aspect of the present invention provides a method for producing a polyester. The polyester is produced using a diol raw material containing a diol-derived structural unit (A) and a dicarboxylic acid raw material containing a dicarboxylic acid-derived structural unit (B). The same applies to the diol raw material and the dicarboxylic acid raw material as described above in [Raw Materials for Producing Polyester Carbonate].

[0037] [Method for Producing Polyester] One aspect of the present invention provides a method for producing a polyester containing a diol-derived structural unit (A) and a dicarboxylic acid-derived structural unit (B), the method comprising adjusting the phosphorus atom content in the dicarboxylic acid to less than 1.3 ppm by mass based on the total amount of the dicarboxylic acid. The method for producing a polyester of the present invention may include adjusting the phosphorus atom content in the dicarboxylic acid to less than 1.3 ppm by mass, and the method described above in [Raw Materials for Producing Polyester Carbonate] also applies to this aspect. The polyester of one aspect of the present invention can be produced, for example, by polycondensation of a compound containing the diol-derived structural unit (A) and a compound containing the dicarboxylic acid-derived structural unit (B) in the presence of a catalyst. For details of the method for producing a polyester that includes this polycondensation reaction, see, for example, the methods described in JP-A-8-134196 and JP-A-8-301999.

[0038] The catalyst used in the polycondensation reaction may 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 may 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.

[0039] The polyester produced by the production method of one embodiment of the present invention may contain residual unreacted monomers. The acceptable residual monomer concentration is 0 ppm to 5000 ppm, preferably 1 ppm to 3000 ppm.

[0040] A cyclic dimer composed of, for example, succinic acid and 1,4-butanediol may remain in the polyester produced by the production method of one embodiment of the present invention. The acceptable concentration of the cyclic dimer is 1.0% by mass or less, preferably 0.6% by mass or less. The concentration of the cyclic dimer in the polyester may be reduced by immersing and extracting the pelletized polyester in a solvent that has low solubility in the polyester, such as water or acetone, at a temperature of 20°C to less than 100°C.

[0041] The polyester produced by the production method of one embodiment of the present invention may be mixed with a resin other than polyester (PE). Examples of such resins include, but are not limited to, 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.

[0042] In the production method of one embodiment of the present invention, it is preferable to add an antioxidant and a release agent as additives, and, if necessary, other additives. With regard to these additives, the same explanation as in the above section "Production method of polyester carbonate" also applies to this embodiment.

[0043] [Uses of Polyester Carbonate and Polyester] When the polyester carbonate and polyester according to one embodiment of the present invention are made from raw materials derived from biomass resources, they can be easily decomposed by microorganisms in soil, compost, seawater, rivers, lakes, etc., and therefore can be widely used, for example, in cases where recycling is difficult. In addition, because they have excellent moldability, they can be processed into various molded articles such as films, sheets, laminates, fibers, nonwoven fabrics, threads, and laminates.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] [Physical Properties of Polyester Carbonate and Polyester] The polyester carbonate obtained by the production method 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. 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. In this specification, the weight average molecular weight (Mw) means the weight average molecular weight in terms of polystyrene, and can be measured by the method described in the Examples below.

[0048] In one aspect of the present invention, the polyester, including the aspect as a prepolymer in the production of polyester carbonate, preferably has a number average molecular weight (Mn) of more than 1100, more preferably 1150 or more, even more preferably 1200 or more, and particularly preferably 1300 or more. The number average molecular weight (Mn) is preferably 2500 or less, more preferably 2000 or less. In this specification, the number average molecular weight (Mn) means the number average molecular weight in terms of polystyrene, and can be measured by the method described in the Examples below.

[0049] In one embodiment of the present invention, the amount of terminal hydroxyl groups in the polyester, including the polyester as a prepolymer in the production of polyester carbonate, is preferably 3.20% by mass or less, more preferably 3.15% by mass or less, and even more preferably 3.10% by mass or less. In this specification, the amount of terminal hydroxyl groups can be measured by the method described in the Examples below.

[0050] 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.

[0051] <Methods for measuring various physical properties and characteristics> (1) Phosphorus atom concentration in dicarboxylic acid Qualitative analysis of phosphorus ion species was performed using ion chromatography mass spectrometry (IC-MS), and the phosphorus atom concentration was quantified using inductively coupled plasma mass spectrometry (ICP-MS) on the assumption that all phosphorus atoms contained in dicarboxylic acid are derived from phosphate ions. (Qualitative analysis of phosphorus ion species) Equipment (IC-MS): Dionex, manufactured by Thermo Fisher Scientific Co., Ltd. TM ICS-2100 and ISQ TM EC single quadrupole mass spectrometer Column: IonPac AS18 Eluent: KOH 10-90mM (gradient) Column temperature: 40°C Sample volume: 25µL Sample: A 250-fold diluted solution with ultrapure water was used. Phosphorus ion species: PO3 3- , PO4 3- , P2O7 4- (Quantitative determination of phosphorus atoms) Apparatus (ICP-MS): Agilent 8800 triple quadrupole manufactured by Agilent Technologies, Inc. Sample: Dicarboxylic acid was weighed into a quartz container, nitric acid was added, the container was sealed, and the dicarboxylic acid was heated and decomposed by microwave irradiation. The volume was then adjusted to the specified volume with ultrapure water to obtain a test solution. Detection limit: 0.001 ppm as phosphorus atoms

[0052] (2) Concentration of sodium and calcium atoms in dicarboxylic acids: Semi-quantitative analysis was performed by ICP-MS. Apparatus: Agilent 8800 Triple Quadrupole ICP-MS manufactured by Agilent Technologies, Inc. Sample preparation: Succinic acid was weighed into a quartz container, nitric acid was added, the container was sealed, and microwave irradiation was used for thermal decomposition. The volume was then adjusted to the specified volume with ultrapure water to obtain the test solution. Detection limit: 0.001 ppm for sodium and calcium atoms.

[0053] (3) Amount of terminal hydroxyl groups Calculated by NMR analysis. Apparatus: AVNEO500 manufactured by Bruker. Solvent: deuterated chloroform. Analysis method: The amount of terminal hydroxyl groups was calculated using the integral value of σ3.7, which indicates the terminal hydroxyl groups, and the integral value of σ4.2, which indicates the ester bond 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 terminal hydroxyl groups (mass%) = (16 + 1.008) × 2 / M × 100 Note that the smaller the amount of terminal hydroxyl groups, the more the reaction has progressed.

[0054] (4) Polystyrene-equivalent weight-average molecular weight (Mw) and number-average molecular weight (Mn) were analyzed by GPC. Apparatus: Tosoh Corporation's high-speed GPC HLC-8320 GPC Column: Tosoh Corporation's 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] Example 1: A 300 ml glass flask equipped with a stirrer, thermometer, glass tube, and distillate receiver was charged with 49.6066 g of biomass-derived succinic acid (Shandong Lanzhou Co., Ltd., phosphorus atom content = 0.2 ppm), 53.0000 g of 1,4-butanediol (Mitsubishi Chemical Corporation), and 2 mg of Zr(acac)4 (Fujifilm Wako Pure Chemical Industries, Ltd.) as raw materials. The mixture was reacted under a nitrogen atmosphere at 225°C for 1 hour, and water was then drained off. The mixture was then aged for 2 hours and 30 minutes at a reduced pressure of 200-20 hPa to allow the dehydration reaction to proceed. The reduced pressure was gradually increased to a final pressure of 1 hPa or less, and water and 1,4-butanediol were further distilled off. A partial sample was taken after 4 hours of reaction, revealing a number-average molecular weight of 1,300 and a terminal hydroxyl group content of 2.93% by mass. The reaction was terminated after a total reaction time of 4 hours. The polyester obtained had a number average molecular weight of 2,000, a terminal hydroxyl group content of 2.17% by mass, and an acid value of 0.43 KOHmg / g. The physical properties of the polyester obtained are shown in Table 1. The succinic acid used in the above reaction contained, in addition to phosphorus atoms, 0.3 ppm of sodium atoms and 0.2 ppm of calcium atoms, for a total content of 0.5 ppm.

[0056] (Example 2) A polyester was obtained in the same manner as in Example 1, except that 0.11 mg of phosphoric acid was added to 49.6066 g of succinic acid derived from biomass resources as a raw material, so that the phosphorus atom content in the succinic acid was 0.7 ppm. The physical properties of the polyester sampled after 4 hours of reaction are shown in Table 1.

[0057] (Examples 3 and 4) Polyesters were obtained in the same manner as in Example 2, except that phosphoric acid was added to the raw material succinic acid derived from biomass resources, and the phosphorus atom content in the succinic acid was adjusted to the content shown in Table 1. The physical properties of the polyesters sampled after 4 hours of reaction are shown in Table 1.

[0058] Comparative Example 1 Polyesters were obtained in the same manner as in Example 1, except that succinic acid shown in Table 1 was used as the biomass resource-derived succinic acid. The physical properties of the polyesters sampled after 4 hours of reaction are shown in Table 1. The succinic acid used in Comparative Example 1 contained 0.4 ppm of sodium atoms and 0.2 ppm of calcium atoms in addition to phosphorus atoms, for a total content of 0.6 ppm.

[0059] (Comparative Examples 2 and 3) Polyesters were obtained in the same manner as in Example 2, except that phosphoric acid was added to the raw material succinic acid derived from biomass resources, and the phosphorus atom content in the succinic acid was adjusted to the content shown in Table 1. The physical properties of the polyesters sampled after 4 hours of reaction are shown in Table 1.

[0060] (Reference Example 1) Polymerization was carried out in the same manner as in Example 1, except that petroleum-derived succinic acid (manufactured by Nippon Shokubai Co., Ltd., phosphorus atom content = below detection limit) was used as succinic acid. The physical properties of the polyester sampled after 4 hours of reaction are shown in Table 1.

[0061] Example 5: 25 g of the polyester obtained in Example 1 was placed in a 100 ml glass flask equipped with a stirrer, thermometer, glass tube, and distillate receiver, and 3.4834 g of diphenyl carbonate and 1 mg of zinc acetate as a catalyst were added. The pressure was gradually reduced at 225°C, and while distilling off phenol, the pressure was finally reduced to 1 hPa or less, and the reaction was carried out for 4.5 hours. The reduced pressure was released with nitrogen, and the resulting polyester carbonate was a colorless resin that did not gel and had a weight-average molecular weight (Mw) of 206,000.

[0062]

[0063] As shown in Table 1, Examples 1 to 4, in which the total phosphorus atom content in the dicarboxylic acid succinic acid was less than 1.3 ppm by mass, had a smaller amount of hydroxyl groups than Comparative Examples 1 to 3, in which the phosphorus atom content was 1.3 ppm by mass or more, suggesting that the reaction proceeded more efficiently. Furthermore, the polyesters of Examples 1 to 4 had a larger number average molecular weight and higher mechanical strength than Comparative Examples 1 to 3. Thus, by adjusting the phosphorus atom content in the dicarboxylic acid to less than 1.3 mass%, the polymerization reactivity could be controlled.

Claims

1. A method for producing a polyester carbonate containing a diol-derived structural unit (A) and a dicarboxylic acid-derived structural unit (B), comprising: adjusting the phosphorus atom content in the dicarboxylic acid to be less than 1.3 ppm by mass based on the total amount of the dicarboxylic acid.

2. A method for producing a polyester comprising a diol-derived structural unit (A) and a dicarboxylic acid-derived structural unit (B), comprising the steps of: adjusting the phosphorus atom content in the dicarboxylic acid to be less than 1.3 ppm by mass based on the total amount of the dicarboxylic acid.

3. The method according to claim 1 or 2, wherein the phosphorus atom content in the dicarboxylic acid is adjusted to be 0.001 ppm by mass or more and less than 1.3 ppm by mass.

4. The method according to claim 1 or 2, wherein the total content of sodium atoms and calcium atoms in the dicarboxylic acid is 2 ppm by mass or less based on the total amount of the dicarboxylic acid.

5. The method according to claim 1 or 2, wherein a dicarboxylic acid derived from a biomass resource is used.

6. A molded article comprising a polyester carbonate or polyester obtained by the production method according to claim 1 or 2.