JP5421034B2 - Method for producing polyester having plant-derived component - Google Patents

Description

  The present invention relates to a method for producing a novel polyester. More specifically, the present invention relates to a method for producing a polyester containing a portion that can be derived from a biogenic material, having a high degree of polymerization, and having good heat resistance.

  Polyester is a polymer obtained by polycondensation (hereinafter sometimes abbreviated as polymerization) of a dicarboxylic acid compound and a diol compound. Among them, polyester (polyethylene terephthalate, hereinafter referred to as “PET”) obtained from terephthalic acid. For example, fibers for clothing and industrial materials, packaging and magnetic tapes, etc., because of its excellent transparency, gas barrier properties, heat resistance and mechanical strength during molding. It is used in many fields such as films and sheets, bottles that are hollow molded products, and other engineering plastic molded products.

に示した４−ヒドロキシ−３−メトキシ安息香酸（本明細書では以下「バニリン酸」と呼称することもある）、
また、下記式（Ｂ）

に示した４−ヒドロキシ−３、５−ジメトキシ安息香酸（本明細書では以下「シリンガ酸」と呼称することもある）が挙げられる。共に木質由来物質であるリグニンから得られ、例えばバニリン酸はリグニンをアルカリ中で酸化分解して得られたバニリンを変換することにより得られる。また、バニリン酸は糖質からの発酵によって得ることも可能である。 Polyester resins are generally manufactured using raw materials obtained from petroleum resources. Currently, there are concerns about the depletion of petroleum resources and global warming due to carbon dioxide, and raw materials obtained from biological materials such as plants are used. There is a need for the polymers used. Various aliphatic biopolymers such as polylactic acid have been studied as such a polymer having a high content of biogenic substances, but their heat resistance and crystallinity are insufficient and their use is limited. Therefore, in order to improve heat resistance and crystallinity, an aromatic biopolymer using an aromatic hydroxycarboxylic acid raw material that can be produced from sugar or wood has been studied. As such an aromatic hydroxycarboxylic acid raw material, for example, the following formula (A)

4-hydroxy-3-methoxybenzoic acid (hereinafter also referred to as “vanillic acid”),
In addition, the following formula (B)

4-hydroxy-3,5-dimethoxybenzoic acid (hereinafter sometimes referred to as “syringic acid”). Both are obtained from lignin, which is a wood-derived substance. For example, vanillic acid is obtained by converting vanillin obtained by oxidative decomposition of lignin in an alkali. Vanillic acid can also be obtained by fermentation from carbohydrates.

So far, among the aromatic hydroxycarboxylic acids containing the above compounds, vanillic acid polymers have been studied. However, a vanillic acid homopolymer has a very high melting point and is difficult to use.
Therefore, in order to lower the melting point, a monomer compound obtained by hydroxyalkyl etherifying a phenolic hydroxyl group of hydroxybenzoic acid such as vanillic acid such as 4- (2-hydroxyethoxy) -3-methoxybenzoic acid was polycondensed. Polyester (hereinafter sometimes referred to as homopolyester) has been studied (see Patent Documents 1, 2, 3, and Non-Patent Document 1). However, since the activity of the known polymerization catalyst is insufficient, a method for producing a polyester having a high degree of polymerization, high heat resistance, and high biogenic substance content has not been established.

Japanese Patent Publication No.34-10793 Japanese Patent Publication No.35-17345 Japanese Patent Publication No. 36-17198

“Holz als Roh-und Werkstoff”, (Germany), Springer-Verlag (Springer Fairlag), 1981, vol. 39, p. 107-112

  An object of the present invention is to provide a method for producing a polyester having a high degree of polymerization and a high biogenic substance content and excellent heat resistance.

  The present inventor has intensively studied in view of the above problems, and specifically exhibits high activity in producing a polyester by polycondensing a monomer compound obtained by hydroxyalkyl etherifying a phenolic hydroxyl group of hydroxybenzoic acid such as vanillic acid. A polymerization catalyst was found and the present invention was completed. The gist of the present invention is shown below.

（式中、Ｒ^０は炭素数２〜３の脂肪族基、Ｒ^１、Ｒ^２はそれぞれＨ、ＯＣＨ_３、ＯＣ_２Ｈ_５のいずれかである。）
の構成単位よりなるポリエステルの製造方法において、
重合触媒として、ジイソプロポキシチタンビス（トリエタノールアミネート）またはチタンジイソプロポキシビス（２、４−ペンタンジオネート）からなる群から選ばれた少なくとも一つの化合物の存在下に、下記式（２）

（式中、Ｒ^０は炭素数２〜３の脂肪族基であり、Ｒ^１、Ｒ^２はＨ、ＯＣＨ_３、ＯＣ_２Ｈ_５のいずれかであり、Ｒ^３はＨ、ＣＨ_３、Ｃ_２Ｈ_５又はＣ_６Ｈ_５（フェニル基）である。）
で表されるモノマー化合物を、常圧で加熱反応させ、次いで減圧下、２００℃〜３００℃の温度で加熱しながら溶融重縮合させることを特徴とする製造方法。
２． 上記１項の式（２）で表されるモノマー化合物が、下記式（３）

で表される４−（２−ヒドロキシエトキシ）−３−メトキシ安息香酸の誘導体である上記１項記載の製造方法。
３． 上記１項の式（２）で表されるモノマー化合物が、下記式（４）

（式中、Ｒ^１、Ｒ^２はそれぞれＨ、ＯＣＨ_３、ＯＣ_２Ｈ_５のいずれかであり、Ｒ^３はＨ、ＣＨ_３、Ｃ_２Ｈ_５又はＣ_６Ｈ_５（フェニル基）である。）
で表されるヒドロキシ安息香酸誘導体と、炭素数２〜３の酸化オレフィンもしくはモノハロゲン化脂肪族アルコール、または下記式（５）

（式中、Ｒ^０は炭素数２〜３の脂肪族基である）
で表される環状炭酸エステルとを、アルカリ性触媒の存在下に加熱反応させたものである上記１項記載の製造方法。
４． 上記３項において、式（４）で表されるヒドロキシ安息香酸誘導体が、下記式（６）

（式中、Ｒ^３はＨ、ＣＨ_３、Ｃ_２Ｈ_５又はＣ_６Ｈ_５（フェニル基）である。）
で表される４−ヒドロキシ−３−メトキシ安息香酸誘導体である製造方法。 1. Following formula (1)

(In the formula, R ⁰ is an aliphatic group having 2 to 3 carbon atoms, and R ¹ and R ² are each H 1 , O ₂ CH ₃ , or OC ₂ H _5. )
In a method for producing a polyester comprising the structural units of:
In the presence of at least one compound selected from the group consisting of diisopropoxy titanium bis (triethanolaminate) or titanium diisopropoxy bis (2,4-pentanedionate) as a polymerization catalyst, the following formula (2)

(In the formula, R ⁰ is an aliphatic group having 2 to 3 carbon atoms, R ¹ and R ² are H , O CH ₃ , or OC ₂ H ₅ , and R ³ is H, CH ₃ , C ₂ H ₅ or _C 6 _{H 5} is (phenyl group).)
The production method is characterized in that the monomer compound represented by the formula (1) is subjected to a heat reaction at normal pressure, followed by melt polycondensation while heating at a temperature of 200 ° C. to 300 ° C. under reduced pressure.
2. The monomer compound represented by the formula (2) in the above item 1 is represented by the following formula (3):

The manufacturing method of said 1 which is a derivative of 4- (2-hydroxyethoxy) -3-methoxybenzoic acid represented by these.
3. The monomer compound represented by the formula (2) in the above item 1 is represented by the following formula (4).

(In the formula, R ¹ and R ² are each H 1 , O ₂ CH ₃ , or OC ₂ H ₅ , and R ³ is H, CH ₃ , C ₂ H _5, or C ₆ H ₅ (phenyl group). .)
A hydroxybenzoic acid derivative represented by formula (2), an olefin oxide having 1 to 3 carbon atoms or a monohalogenated aliphatic alcohol, or the following formula (5):

(In the formula, R ⁰ is an aliphatic group having 2 to 3 carbon atoms)
2. The production method according to 1 above, wherein the cyclic carbonate represented by the formula is heated and reacted in the presence of an alkaline catalyst.
4). In the above item 3, the hydroxybenzoic acid derivative represented by the formula (4) is represented by the following formula (6):

(In the formula, R ³ is H, CH ₃ , C ₂ H ₅ or C ₆ H ₅ (phenyl group).)
The manufacturing method which is 4-hydroxy-3-methoxybenzoic acid derivative represented by these.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of polyester which shows high biogenic substance content rate and was excellent in heat resistance can be provided.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. It goes without saying that other embodiments may also belong to the category of the present invention as long as they meet the gist of the present invention.

The present invention provides a method for producing a polyester comprising the structural unit of the formula (1), from diisopropoxy titanium bis (triethanolaminate) or titanium diisopropoxy bis (2,4-pentanedionate) as a polymerization catalyst. In the presence of at least one compound selected from the group consisting of the above, the monomer compound represented by the formula (2) is heated and reacted at normal pressure, preferably in an inert gas atmosphere such as nitrogen or argon, Next, the present invention relates to a production method characterized by performing melt polycondensation while heating at a temperature of 200 ° C. to 300 ° C. under reduced pressure. As a polymerization catalyst, at least one compound selected from the group consisting of diisopropoxy titanium bis (triethanolaminate) or titanium diisopropoxy bis (2,4-pentandionate) (hereinafter abbreviated as a highly active titanium complex). In some cases, it is possible to produce a polyester having a structural unit of the formula (1) having a high degree of polymerization, which has not been obtained conventionally. The amount of the polymerization catalyst used is preferably 1 × 10 ⁻⁹ to 1 × 10 ⁻³ mol, more preferably 1 × 10 ^{−8 to} 5 × 10 ⁻ to 1 mol of the monomer compound of the formula (2). It is selected in the range of ⁴ moles.

  Moreover, in the manufacturing method of this invention, you may use compounds other than said highly active titanium complex as an auxiliary polymerization catalyst. Examples of such compounds include titanium compounds other than highly active titanium complexes, compounds of metals other than titanium, and nitrogen-containing organic compounds. In some cases, only polyesters with extremely inferior physical properties such as hue can be obtained.

  Titanium compounds (other than highly active titanium complexes) that can be used as the auxiliary polymerization catalyst include tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, and tetra-n-butyl titanate tetramer. , Tetra-t-butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, titanium tetrakis (2-ethyl-1-hexanolate), nano-sized titanium oxide, titanium acetate, titanium oxalate, titanium lactate, titanium acetylacetonate , Titanium potassium oxalate, Sodium titanium oxalate, Potassium titanate, Sodium titanate, Titanate-aluminum hydroxide mixture, Titanium chloride, Titanium chloride-aluminum chloride mixture, Titanium bromide, Titanium fluoride, Examples thereof include potassium titanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, ammonium hexafluorotitanate, and titanium acetylacetonate.

  As a compound of a metal other than titanium, which can be used as the above auxiliary polymerization catalyst, lithium, sodium, potassium, etc. of the periodic table group I, calcium of the periodic table group II, strontium, barium, Molybdenum, nickel, copper, silver, mercury, lead, platinum, palladium, aluminum, gallium, germanium, titanium, zirconium, hafnium, manganese, iron, and cobalt oxides, hydroxides, alkoxides, carboxylates, carbonic acid Examples include compounds containing at least one metal element component selected from the group consisting of salts, oxalates, organic complexes, halides, and the like. Specifically, germanium dioxide, germanium tetroxide, germanium hydroxide , Germanium tetraethoxide, germanium tetrabutoxide, oxalic acid germany , Manganese oxide, manganese hydroxide, manganese methoxide, manganese acetate, manganese benzoate, manganese acetylacetonate, manganese chloride, cobalt formate, cobalt acetate, cobalt stearate, cobalt naphthenate, cobalt benzoate, cobalt acetylacetonate, Cobalt carbonate, cobalt oxalate, cobalt chloride, cobalt bromide, lithium acetate, sodium acetate, potassium acetate, calcium oxide, calcium hydroxide, calcium acetate, calcium carbonate, barium oxide, barium hydroxide, barium acetate, barium carbonate, trioxide Antimony, antimony pentoxide, antimony acetate, methoxyantimony, triphenylantimony, antimony glycolate, zinc acetate, zinc benzoate, zinc methoxide, zinc acetylacetonate, chloride Lead, lead oxide, methyl mercaptide lead, cadmium acetate, and the like.

  Examples of nitrogen-containing organic compounds that can be used as the auxiliary polymerization catalyst include 4-dimethylaminopyridine (DMAP), 2-dimethylaminopyridine, 1-methylimidazole, 2-methylimidazole, 1-ethylimidazole, and 2-ethyl. Imidazole, bipyridine, 4-pyrrolidinopyridine, 1,4-diazabicyclo [2.2.2. ] Octane (DABCO), 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) and the like.

  In the method for producing the polyester of the present invention, it is important that the monomer compound represented by the formula (2) is heated and reacted at normal pressure, and the reaction temperature at that time is preferably 100 to 200 ° C. This is because the oligomerization reaction proceeds, the alcohol, water, phenol (hereinafter abbreviated as by-product alcohols) and the like by-produced during the reaction are reduced in the late stage of the reaction to distill off the unreacted monomer compound. This is to prevent distillation. The normal pressure in the production method of the present invention is a pressure when no conscious pressure or reduced pressure is applied, and is a normal atmospheric pressure of 0.096 to 0.106 MPa.

  In the production method of the present invention, the reaction can be advanced by appropriately removing by-product alcohols from the system (reactor). For this purpose, it is effective to gradually reduce the pressure with the progress of the oligomerization reaction. In order to prevent distillation of the monomer compound, the pressure is gradually reduced to 5 to 150 Torr (0.67 to 20 kPa), and by-product alcohols. It is preferable to reduce the pressure to 1 Torr (0.13 kPa) or less as much as possible. The polymerization reaction temperature is preferably in the range of 200 ° C. to 300 ° C., more preferably in the range of 205 ° C. to 285 ° C., in order to allow the polymerization reaction to proceed appropriately.

  As described above, the reaction is preferably performed under an inert gas. Examples of the inert gas include nitrogen, argon, helium, carbon dioxide and the like. Furthermore, you may add additives, such as antioxidant, as needed.

  The polyester production method of the present invention uses the monomer compound represented by the formula (2) as a raw material, and specifically, as the monomer compound, 4- (2-hydroxyethoxy) benzoic acid, 4- (3-hydroxypropoxy) benzoic acid, 4- (4-hydroxybutoxy) benzoic acid, 4- (5-hydroxyheptoxy) benzoic acid, 4- (6-hydroxyhexoxy) benzoic acid, 4- (2-hydroxy Ethoxy) -3-methoxybenzoic acid, 4- (3-hydroxypropoxy) -3-methoxybenzoic acid, 4- (4-hydroxybutoxy) -3-methoxybenzoic acid, 4- (5-hydroxyheptoxy) -3 -Methoxybenzoic acid, 4- (6-hydroxyhexoxy) -3-methoxybenzoic acid, 4- (2-hydroxyethoxy) -3,5-dimethoxy Benzoic acid, 4- (3-hydroxypropoxy) -3,5-dimethoxybenzoic acid, 4- (4-hydroxybutoxy) -3,5-dimethoxybenzoic acid, 4- (5-hydroxyheptoxy) -3,5 -Dimethoxybenzoic acid, 4- (6-hydroxyhexoxy) -3,5-dimethoxybenzoic acid and its methyl ester, ethyl ester, phenyl ester are mentioned.

  Among the monomer compounds of the formula (2), 4- (2-hydroxyethoxy) -3-methoxybenzoic acid, 4- (2-hydroxyethoxy) -3,5-dimethoxybenzoic acid, and methyl esters thereof, Ethyl ester and phenyl ester are preferred. The reason is that 4-hydroxy-3-methoxybenzoic acid (also referred to as vanillic acid) and 4-hydroxy-3,5-dimethoxybenzoic acid (also referred to as syringic acid), which are raw materials, are derived from saccharides, wood, or glucose. This is because it is easy to obtain as a renewable resource because it can be made by fermentation.

  The monomer compound of the above formula (2) such as 4- (2-hydroxyethoxy) -3-methoxybenzoic acid and its derivatives used in the method for producing a polyester of the present invention is obtained by converting the hydroxybenzoic acid derivative of the above formula (4) to alkaline. In the presence of a catalyst, the hydroxybenzoic acid derivative of the formula (4) is heated and reacted with an olefin oxide having 2 to 8 carbon atoms or a monohalogenated aliphatic alcohol, or the cyclic carbonate of the formula (5). The phenolic hydroxyl group is converted to a hydroxyalkyl ether to obtain the monomer compound of the formula (2).

  In the production of the monomer compound of the formula (2), the charging ratio at the time of the reaction between the hydroxybenzoic acid derivative of the formula (4) and the olefin oxide or the like is either for promoting the reaction or suppressing the side reaction. It is often used in excess, and depending on their reactivity, price, ease of removal and reuse, a molar ratio of 1: 1 to 1: 8 is preferred, and 1: 1 to 1: 5. More preferred.

  In the method for producing the monomer compound of the formula (2), when olefin oxide is used, there is an advantage that it is inexpensive and highly reactive, and when a cyclic carbonate is used, there is an advantage that safety is low and explosiveness is low. preferable.

  Examples of the olefin oxide having 2 to 8 carbon atoms that can be used for the production of the monomer compound of the formula (2) include ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, isobutylene oxide, 1-pentene oxide, 2-pentene oxide, 1-hexene oxide, 1-octene oxide, and the like can be displayed. Among them, ethylene oxide and propylene oxide are preferable, and ethylene oxide is particularly preferable. The said olefin oxide may be used independently and may be used in mixture of 2 or more types.

  Examples of the monohalogenated aliphatic alcohol having 2 to 8 carbon atoms that can be used in the production of the monomer compound of the formula (2) include 2-fluoroethanol, 2-chloroethanol, 2-bromoethanol, 2-iodoethanol, 3-fluoropropanol, 3-chloropropanol, 3-bromopropanol, 3-iodopropanol, 4-fluorobutanol, 4-chlorobutanol, 4-bromobutanol, 4-iodobutanol, 5-fluoropentanol, 5-chloropen Tanol, 5-bromopentanol, 5-iodopentanol, 6-fluorohexanol, 6-chlorohexanol, 6-bromohexanol, 6-iodohexanol, 7-fluoroheptanol, 7-chloroheptanol, 7-bromoheptanol Nord, 7- Doheputanoru, 8-fluoro-octanol, 8-chloro-octanol, 8-bromo-octanol, etc. 8-iodo-octanol and the like, more preferably those of which 2-bromoethanol and 3-bromo-propanol, particularly 2-bromoethanol are preferred. The monohalogen aliphatic alcohols may be used alone or in combination of two or more.

  Examples of the cyclic carbonate of the formula (5) that can be used in the method for producing the monomer compound of the formula (2) include ethylene carbonate (ethylene carbonate), propylene carbonate (propylene carbonate), trimethylene carbonate, tetramethylene carbonate, Examples include pentamethylene carbonate, neopentyl carbonate, hexamethylene carbonate, heptamethylene carbonate, and octamethylene carbonate. Of these, ethylene carbonate, propylene carbonate, and trimethylene carbonate are more preferable, and ethylene carbonate is particularly preferable. These cyclic carbonates can be used alone or in admixture of two or more.

  Examples of the alkaline catalyst used in the production of the monomer compound of the formula (2) include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and cesium hydroxide, alkali metal alcoholates such as sodium methylate and potassium methylate, metals Examples include alkali metal simple substances such as potassium and sodium metal, alkali metal carbonates such as potassium carbonate and sodium carbonate, alkali metal hydrogen carbonates, alkali metal organic carboxylates, and mixtures of two or more thereof. Of these, preferred are alkali metal hydroxides and alkali metal carbonates, and more preferred are sodium hydroxide and potassium carbonate.

  In the production of the monomer compound of the formula (2), the amount of the alkaline catalyst used is an amount such that the alkali metal element is 0.01 mol to 5 mol with respect to 1 mol of the hydroxybenzoic acid derivative of the formula (4). The amount is preferably 0.1 mol to 3 mol, and more preferably 0.1 mol to 2 mol.

  In the production of the monomer compound of the formula (2), it is preferable to use ethylene oxide, ethylene carbonate, 2-bromoethanol or the like as the compound to be reacted with the hydroxybenzoic acid derivative of the formula (4). Ethylene oxide can be produced from renewable resources ethanol that can be produced from plant raw materials, and ethylene carbonate and 2-bromoethanol can be produced from ethylene oxide, so these and plant-derived vanillic acid derivatives Can be used to produce a polyester with a biogenic content of 100%.

（式中、Ｒ^３はＨ、ＣＨ_３、Ｃ_２Ｈ_５又はＣ_６Ｈ_５（フェニル基）である。）
で表される４−ヒドロキシ−３−メトキシ安息香酸誘導体を用い、前記式（５）で表される環状炭酸エステルとしてエチレンカーボネートを用い、アルカリ性触媒としてアルカリ金属炭酸塩を用いるものが好ましい。 In particular, as a method for producing the monomer compound of the formula (2), as a hydroxybenzoic acid derivative, the following formula (6)

(In the formula, R ³ is H, CH ₃ , C ₂ H ₅ or C ₆ H ₅ (phenyl group).)
Are preferably used, wherein ethylene carbonate is used as the cyclic carbonate represented by the formula (5) and an alkali metal carbonate is used as the alkaline catalyst.

  When the polyester is produced by the production method of the present invention, it may be composed of two or more structural units of the above formula (1) within the range not impairing the object of the present invention, and the phenolic hydroxyl group is a hydroxyalkyl group. You may use as a copolymer with the aromatic hydroxycarboxylic acid which is not etherified. Specific examples of such aromatic hydroxycarboxylic acids include p-hydroxybenzoic acid, m-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 4-methoxy-3-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 2,6-dimethoxy-4-hydroxybenzoic acid, 3-methyl-4-hydroxybenzoic acid, 4-methyl-3-hydroxybenzoic acid, 3-phenyl-4-hydroxy Benzoic acid, 4-phenyl-3-hydroxybenzoic acid, 2-phenyl-4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 3,4-dihydroxycinnamic acid (caffeic acid), (E) -3 -(4-Hydroxy-3-methoxy-phenyl) propane-2-enolic acid (ferulic acid), 3- (4-hydroxyphenyl) -2 Propenone acid (coumaric acid) and the like, it may be used in combination be used or two or more of them may be used alone.

The polyester obtained by the production method of the present invention is a polyester comprising the structural unit of the formula (1), and one of R ¹ and R ² in the formula (1) is hydrogen and the other is a methoxy group. Alternatively, it is preferable that both R ¹ and R ² are methoxy groups, and R ⁰ is preferably one or more selected from aliphatic groups having 2 to 4 carbon atoms. As the polyester obtained by the production method of the present invention, it is particularly preferable that one of R ¹ and R ² in the formula (1) is hydrogen, the other is a methoxy group, and R ⁰ is an ethylene group. .

  According to the production method of the present invention, a reduced viscosity at 35 ° C. of a solution obtained by dissolving 0.06 g of a polymer sample in 10 mL of a mixed solution of 1,1,2,2-tetrachloroethane and p-chlorophenol in a mass ratio of 8: 5 is obtained. A polyester composed of the structural unit of the formula (1) at 0.55 dL / g or more can be obtained by a smooth polymerization reaction. As the polyester, the reduced viscosity is more preferably 0.56 dL / g or more, and extremely preferably 0.58 dL / g or more. A reduced viscosity of 0.55 dL / g or more is preferable because the degree of polymerization is sufficiently high and the mechanical strength of the molded product is extremely high. The upper limit of the reduced viscosity is not particularly limited, but if it is higher than 1.00 dL / g, molding becomes difficult and is not preferable, so it is preferably 1.00 dL / g or less, more preferably 0.80 dL / g or less. In the production method of the present invention, the time for heating and polycondensation reaction at 200 to 300 ° C., more preferably 205 to 285 ° C. is 5 hours or less, and the above reduced viscosity is 0.55 dL / g or more, preferably Can obtain a polyester of 0.56 dL / g or more, more preferably 0.58 dL / g or more.

  The polyester obtained by the production method of the present invention has a melting point of 220 ° C to 300 ° C, preferably 250 ° C to 300 ° C, more preferably 270 ° C to 300 ° C. When the melting point is less than 220 ° C., the heat resistance is poor, and when it exceeds 300 ° C., the thermal stability at the time of molding is deteriorated.

  The polyester obtained by the production method of the present invention has a glass transition temperature (Tg) of 60 ° C to 100 ° C, preferably 70 ° C to 100 ° C. When the glass transition temperature is less than 60 ° C., the heat resistance is poor, and when it exceeds 100 ° C., the moldability is deteriorated.

  The polyester obtained by the production method of the present invention has a 5% mass reduction temperature of 350 ° C. or higher, more preferably 380 ° C. or higher. When the 5% mass reduction temperature is less than 350 ° C., the polymer decomposition during melt molding becomes remarkable, and the moldability deteriorates.

  The polyester of the present invention is a polyester composed of the structural unit of the above formula (1), and the biogenic substance content measured according to ASTM D6866 06a is preferably 50 to 100%, and 70% to 100%. More preferably. Particularly preferred is a polyester comprising only the structural unit of the above formula (1).

  In addition, the polyester obtained by the production method of the present invention includes a hydroxy aliphatic carboxylic acid such as glycolic acid and lactic acid, a polycarboxylic acid such as terephthalic acid and adipic acid, and a polyhydric alcohol, as long as the object of the present invention is not impaired. , As well as those obtained by copolymerizing these esterified products or oligomers.

  The polyester obtained by the production method of the present invention may be used alone for various applications, and other thermoplastic polymers (for example, polyalkylene terephthalate, polyarylate, liquid crystalline polyester, as long as the object of the present invention is not impaired). Polyamides, polyimides, polyetherimides, polyurethanes, silicones, polyphenylene ethers, polyphenylene sulfides, polysulfones, polyolefins such as polyethylene and polypropylene), fillers (glass fibers, carbon fibers, natural fibers, organic fibers, ceramic fibers, ceramic beads, Talc, clay and mica), natural polymers (polyhydroxybutyrate (PHB), polyhydroxybutyrate / valerate, polyhydroxyvalylate / hexanoate, polycaprola Ton (PCL), polybutylene succinate (PBS), polybutylene succinate / adipate, polyethylene succinate, polylactic acid resin, polymalic acid, polyglycolic acid, polydioxanone, poly (2-oxetanone), and other aliphatic polyesters; poly Aliphatic aromatic copolyesters such as butylene succinate / terephthalate, polybutylene adipate / terephthalate, polytetramethylene adipate / terephthalate; starch, cellulose, chitin, chitosan, gluten, gelatin, zein, soy protein, collagen, keratin), oxidation Inhibitors (hindered phenol compounds, sulfur-based antioxidants, etc.), flame retardant additives (phosphorus, bromo, etc.), UV absorbers (benzotriazole, benzophenone, cyanoacrylate) DOO system, etc.), flow modifiers, coloring agents, light diffusion agents, infrared absorbing agents, organic pigments, inorganic pigments, release agent, may be obtained by adding a plasticizer.

  The details of the present invention will be described more specifically by the following examples. However, the present invention is not limited to these examples. It goes without saying that other embodiments may belong to the category of the present invention as long as they match the gist of the present invention. The methyl 4-hydroxy-3-methoxybenzoate (methyl vanillate) used in Examples and Comparative Examples was obtained from a biogenic material.

The measuring method of each physical property is shown below.
1) Reduced viscosity η _{sp / C}
0.06 g of a polymer (polyester) sample was dissolved in 10 mL of a mixed solvent of 1,1,2,2-tetrachloroethane and p-chlorophenol in a mass ratio of 8: 5 (polymer concentration is about 0.6 g / dL). It calculated | required by the following formula from the result measured using the Ubbelohde viscometer at the density | concentration of 35 degreeC using the sample solution.
η _{sp / C} [dL / g] = (t / t ₀ −1) /0.6
t: Flow time of sample solution t ₀ : Flow time of solvent only 2) Glass transition temperature, melting point Measured by DSC (model DSC2920) manufactured by TA Instruments at a heating rate of 10 ° C./min and 2nd Run.
3) Biogenic material content rate Based on ASTM D686606, the biogenic material content rate was measured from the biogenic material content rate test by the radiocarbon concentration (percent carbon) (C14).
4) 5% mass reduction temperature Measured by TGA (model TG 8120 Thermo plus) manufactured by Rigaku.

[Reference Example 1] Monomer synthesis 1
70 parts by mass (0.384 mol parts) of methyl 4-hydroxy-3-methoxybenzoate (methyl vanillate) and 136.18 parts by mass (1.536 mol parts) of ethylene carbonate were placed in a reactor, and were constantly in a nitrogen atmosphere. The mixture was melted by heating to 90 ° C. under pressure.
While stirring in a molten state, 53.07 parts by mass (0.384 mol parts) of potassium carbonate was added as a catalyst and reacted for 24 hours. As a result, 51.08 parts by mass of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate (yield 58.8%) as a monomer compound was obtained.

[Reference Example 2] Monomer synthesis 2
70 parts by mass (0.384 mol parts) of methyl 4-hydroxy-3-methoxybenzoate (methyl vanillate) and 405 parts by mass of 2-butanone (methyl ethyl ketone) were placed in a reactor, and the temperature was increased to 90 ° C. under a nitrogen atmosphere at normal pressure. Heated. Under stirring with methyl vanillate dissolved, 79.61 parts by mass (0.576 mol) of potassium carbonate was added as a catalyst, and 52.73 parts by mass (0.422 mol) of bromoethanol / 2-butanone solution. Was allowed to react for 6 hours. As a result, 45.45 parts by mass (yield 52.3%) of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate as a monomer compound was obtained.

[Example 1] Polymer synthesis 50 g (0.221 mol) of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate obtained in Reference Example 2 above was placed in a reactor and diisopropoxy was used as a polymerization catalyst. 0.0306 g of titanium bistriethanolamate (3 × 10 ⁻⁴ mol per 1 mol of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate) was charged and heated to 180 ° C. at normal pressure in a nitrogen atmosphere. And melted.
Under stirring, the methanol produced was distilled off while gradually raising the temperature to 205 ° C. over 60 minutes. In this state, the pressure was gradually reduced to 100 Torr (13.3 kPa) over 1 hour. Was distilled off.
Next, the temperature was gradually raised to 285 ° C., and after reaching 285 ° C., the pressure was further reduced. Finally, the reaction was performed at 0.75 Torr (0.1 kPa) at 285 ° C. for 3 hours. As a result, a polyester having a reduced viscosity of 0.588 dL / g was obtained. This polyester has a biogenic substance content of 77.3%, a melting point of 276 ° C., a glass transition temperature (Tg) of 84 ° C., and a 5% weight loss temperature (Td) of 399 ° C. The thermal stability was good.

[Example 2] Polymer synthesis 50 g (0.221 mol) of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate obtained in the above Reference Example 2 was placed in a reactor and used as a polymerization catalyst. 0.0241 g (3 × 10 ⁻⁴ mol per 1 mol of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate) of isopropoxybis (2,4-pentanedionate) was charged under a nitrogen atmosphere. It was melted by heating to 180 ° C. at normal pressure.
Under stirring, the methanol produced was distilled off while gradually raising the temperature to 205 ° C. over 60 minutes. In this state, the pressure was gradually reduced to 100 Torr (13.3 kPa) over 1 hour. Was distilled off.
Next, the temperature was gradually raised to 285 ° C., and after reaching 285 ° C., the pressure was further reduced. Finally, the reaction was performed at 0.75 Torr (0.1 kPa) at 285 ° C. for 3 hours. As a result, a polyester having a reduced viscosity of 0.565 dL / g was obtained. This polyester has a biogenic substance content of 77.3%, a melting point of 276 ° C., a glass transition temperature (Tg) of 83 ° C., and a 5% weight loss temperature (Td) of 398 ° C. The thermal stability was good.

[Comparative Example 1] Polymer synthesis (Japanese Examined Patent Publication No. 36-17198, supplementary test of Example 1)
50 g (0.221 mol) of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate obtained in Reference Example 2 was placed in a reactor, and 0.025 g of zinc acetate and antimony oxide were used as polymerization catalysts. Was heated to 200 ° C. and melted at normal pressure in a nitrogen atmosphere.
After stirring for 40 minutes at 200 ° C. with stirring, the temperature was raised to 280 ° C. over 50 minutes, followed by heating for 20 minutes to distill off the produced methanol. In this state, the pressure was gradually reduced to 50 Torr (6.7 kPa), and methanol was further distilled off. Finally, the reaction was performed at 0.5 Torr (0.067 kPa) at 280 ° C. for 12 to 15 hours. As a result, a polyester having a reduced viscosity of 0.471 was obtained. This polyester had a biogenic substance content of 77.3%, a melting point of 254 ° C., and a glass transition temperature (Tg) of 79 ° C., which was inferior in heat resistance. The 5% weight loss temperature (Td) was 395 ° C.

[Comparative Example 2] Polymer synthesis (Further Examination of Japanese Patent Publication No. 35-17345)
50 g (0.221 mol) of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate obtained in Reference Example 2 was placed in a reactor, and 0.020 g of 4-methylmercaptide lead (4- (2-hydroxyethoxy) -3-methoxybenzoate methyl component was added at 3 × 10 ⁻⁴ mol) and heated to 180 ° C. under a nitrogen atmosphere at normal pressure to melt.
Under stirring, the methanol produced was distilled off while gradually raising the temperature to 205 ° C. over 60 minutes. In this state, the pressure was gradually reduced to 100 Torr (13.3 kPa) over 1 hour. Was distilled off.
Next, the temperature was gradually raised to 285 ° C., and after reaching 285 ° C., the pressure was further reduced. Finally, the reaction was performed at 0.75 Torr (0.1 kPa) at 285 ° C. for 5 hours. As a result, a polyester having a reduced viscosity of 0.469 dL / g and an insufficient reduced viscosity was obtained. This polyester had a biogenic content of 77.3%, a melting point of 275 ° C., a glass transition temperature (Tg) of 83 ° C., and a 5% weight loss temperature (Td) of 395 ° C. .

Comparative Example 3 Polymer Synthesis 50 g (0.221 mol) of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate obtained in Reference Example 2 above was placed in a reactor, and tetra-n was used as a polymerization catalyst. -0.0225 g of butyl titanate (3 × 10 ⁻⁴ mol per 1 mol of methyl 4- (2-hydroxyethoxy) -3-methoxybenzoate) was charged and heated to 180 ° C. under a nitrogen atmosphere at normal pressure. Melted.
Under stirring, the methanol produced was distilled off while gradually raising the temperature to 205 ° C. over 60 minutes. In this state, the pressure was gradually reduced to 100 Torr (13.3 kPa) over 1 hour. Was distilled off.
Next, the temperature was gradually raised to 285 ° C., and after reaching 285 ° C., the pressure was further reduced. Finally, the reaction was performed at 0.75 Torr (0.1 kPa) at 285 ° C. for 5 hours. As a result, a polyester having a reduced viscosity of 0.512 dL / g was obtained. This polyester had a biogenic content of 77.3%, a melting point of 275 ° C., a glass transition temperature (Tg) of 82 ° C., and a 5% weight loss temperature (Td) of 396 ° C.

  Polyester showing high biogenic substance content obtained by the production method of the present invention has a high degree of polymerization and excellent heat resistance, fibers for clothing and industrial materials, films and sheets for packaging and magnetic tape, It is suitable for use in many fields such as bottles that are hollow molded products and other engineering plastic molded products.

Claims (4)

Following formula (1)

(In the formula, R ⁰ is an aliphatic group having 2 to 3 carbon atoms, and R ¹ and R ² are each H 1 , O ₂ CH ₃ , or OC ₂ H _5. )
In a method for producing a polyester comprising the structural units of:
In the presence of at least one compound selected from the group consisting of diisopropoxy titanium bis (triethanolaminate) or titanium diisopropoxy bis (2,4-pentanedionate) as a polymerization catalyst, the following formula (2)

(In the formula, R ⁰ is an aliphatic group having 2 to 3 carbon atoms, R ¹ and R ² are H , O CH ₃ , or OC ₂ H ₅ , and R ³ is H, CH ₃ , C ₂ H ₅ or _C 6 _{H 5} is (phenyl group).)
The production method is characterized in that the monomer compound represented by the formula (1) is subjected to a heat reaction at normal pressure, followed by melt polycondensation while heating at a temperature of 200 ° C. to 300 ° C. under reduced pressure. The monomer compound represented by the formula (2) of claim 1 is represented by the following formula (3):

The production method according to claim 1, which is a derivative of 4- (2-hydroxyethoxy) -3-methoxybenzoic acid represented by the formula: The monomer compound represented by the formula (2) of claim 1 is represented by the following formula (4):

(In the formula, R ¹ and R ² are each H 1 , O ₂ CH ₃ , or OC ₂ H ₅ , and R ³ is H, CH ₃ , C ₂ H _5, or C ₆ H ₅ (phenyl group). .)
A hydroxybenzoic acid derivative represented by:
Olefin oxide or monohalogenated aliphatic alcohols 2-3 carbon atoms or the following formula (5)

(In the formula, R ⁰ is an aliphatic group having 2 to 3 carbon atoms)
The production method according to claim 1, wherein the cyclic carbonate represented by the formula is heated and reacted in the presence of an alkaline catalyst. In Claim 3, the hydroxybenzoic acid derivative represented by Formula (4) is represented by the following formula (6).

(In the formula, R ³ is H, CH ₃ , C ₂ H ₅ or C ₆ H ₅ (phenyl group).)
The manufacturing method which is 4-hydroxy-3-methoxybenzoic acid derivative represented by these.