JP5415685B2 - Polycarbonate having plant-derived components and process for producing the same - Google Patents

Description

  The present invention relates to a polycarbonate having a plant-derived component having a high degree of polymerization and a good hue, and a method for producing the same.

  Polycarbonate resins are excellent in transparency, heat resistance, and impact resistance, and are currently widely used in the optical media field, electrical / electronic / OA field, automobile / industrial equipment field, medical field, and other industrial fields. However, currently used aromatic polycarbonates are produced from raw materials obtained from petroleum resources. Therefore, in recent years when there are concerns about global warming due to carbon dioxide generated by the incineration of waste and waste, incineration of materials with the same physical properties as aromatic polycarbonates, but with less environmental impact. The appearance is awaited.

  Under such circumstances, dianhydrohexitols (such as isomannide, isoidide, and isosorbide, which may be referred to as ether diols hereinafter), which are anhydrous sugar alcohols, are derived from plant-derived raw materials such as mannitol, ididol, and sorbitol. Renewable resources for the production of polymers, especially polyesters and polycarbonates (unlike natural resources such as petroleum and coal, such as forest resources, biomass, wind power, small scale hydropower, etc.) It is considered as a resource that itself has regenerative capacity. In particular, studies have been actively conducted on polymers using isosorbide, which is made from inexpensive starch as a starting material, and has a use as a pharmaceutical raw material and is easily commercially available (for example, Patent Documents 1 to 3).

  Further, studies have been made on carbonates obtained by copolymerizing glycols used in polyester raw materials together with isosorbide as diol components (for example, Patent Documents 4 to 5). This is because a polycarbonate having a diol component only of isosorbide has problems such as extremely high melt viscosity and difficulty in molding because of its rigid structure. Further, dianhydrohexitols are quite expensive as a polymer raw material, and there is a problem of cost. That is, copolymerizing inexpensive glycols within a range in which necessary polymer physical properties can be maintained also has an advantage of reducing the cost of raw materials.

  As a method for producing a polycarbonate resin having plant-derived components as described above, a transesterification reaction (melt polycondensation method) between a diol compound and a carbonic acid diester is a method in which phosgene is directly reacted with a dihydroxy compound (interfacial polycondensation). In comparison, there is no problem in using a toxic phosgene or a halogen compound such as methylene chloride as a solvent.

  However, until now, when anhydrous sugar alcohol is used as a raw material for polycarbonate, the polymer is likely to be colored, and the degree of polymerization may not increase to a value sufficient to withstand practical use, which hinders practical use and application development. There was a case. Many studies have been made on catalysts particularly for improving the degree of polymerization in the production of polycarbonate (for example, Patent Documents 6 to 8), and these are all studies on aromatic polycarbonates, which are aliphatic and alicyclic, and further derived from plants. Such a study has not been made on polycarbonate having components.

British Patent No. 1079686 International Publication No. 1999/054119 Pamphlet International Publication No. 2007/013463 Pamphlet International Publication No. 2004/111106 Pamphlet JP 2003-292603 A Japanese Patent Application Laid-Open No. 1991-203928 Japanese Patent Laid-Open No. 1995-165904 Japanese Patent Laid-Open No. 1995-228681

  An object of the present invention is to solve these problems of the prior art and to provide a process for producing a polycarbonate having plant-derived components having a high degree of polymerization and a good hue.

（Ｒ_１〜Ｒ_４はそれぞれ独立に水素原子、アルキル基、シクロアルキル基またはアリール基から選ばれる基であり、Ｒ_５は炭素数が２から１２である脂肪族炭化水素基であり、またｎは０．４≦ｎ≦１．０である）
で表されるポリカーボネートを製造するにおいて、
Ｎａ、Ｃａ、Ｆｅ含有量合計が２質量ｐｐｍ以下である、下記式（２）で表されるジオールと、

（Ｒ_１〜Ｒ_４はそれぞれ独立に水素原子、アルキル基、シクロアルキル基またはアリール基から選ばれる基である）、
Ｎａ、Ｃａ、Ｆｅ含有量合計が２質量ｐｐｍ以下である、下記式（３）で表されるジオールとをジオール成分として用い、

（Ｒ_５は炭素数が２から１２である脂肪族炭化水素基）
Ｎａ、Ｃａ、Ｆｅ含有量合計が２質量ｐｐｍ以下である、下記式（４）

（Ｒ_６およびＲ_７は、アルキル基、シクロアルキル基またはアリール基から選ばれる基であり、Ｒ_６とＲ_７は同じ基であっても異なる基であってもよい）
で表される炭酸ジエステルを炭酸成分として用い、重縮合触媒としてバリウム化合物の存在下に溶融重縮合させることを特徴とするポリカーボネートの製造法。
２．前記１項記載の製造法によって得られる、ポリマー中のＮａ、Ｃａ、Ｆｅ含量が１０質量ｐｐｍ以下であり、かつＣｏｌ−ｂ値が５以下であるポリカーボネート。 That is, the gist of the present invention is as follows.
1. Following formula (1)

(R _{1 to} R ₄ are each independently a group selected from a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, R ₅ is an aliphatic hydrocarbon group having 2 to 12 carbon atoms, and n Is 0.4 ≦ n ≦ 1.0)
In producing a polycarbonate represented by
A diol represented by the following formula (2), wherein the total content of Na, Ca and Fe is 2 mass ppm or less;

(R _{1 to} R ₄ are each independently a group selected from a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group),
A diol represented by the following formula (3) having a total Na, Ca, Fe content of 2 mass ppm or less is used as a diol component.

(R ₅ is an aliphatic hydrocarbon group having 2 to 12 carbon atoms)
Na, Ca, Fe content total is 2 mass ppm or less, following formula (4)

(R ₆ and R ₇ are groups selected from an alkyl group, a cycloalkyl group or an aryl group, and R ₆ and R ₇ may be the same group or different groups)
A process for producing a polycarbonate, characterized in that a carbonic acid diester represented by the formula (1) is used as a carbonic acid component and melt polycondensed in the presence of a barium compound as a polycondensation catalyst.
2. A polycarbonate having a Na, Ca, Fe content of 10 ppm by mass or less and a Col-b value of 5 or less, obtained by the production method according to 1 above.

  According to the present invention, it is possible to provide a polycarbonate having a plant-derived component having a high degree of polymerization and a good hue, and a method for producing the polycarbonate.

Hereinafter, embodiments for carrying out the present invention will be described in detail.
The polycarbonate obtained by the production method of the present invention is represented by the above formula (1), and the molar ratio of the ether diol residues derived from the raw material of the above formula (2) in the total diol residues (the above formula (1) N) in the range of 0.4 to 1. When the molar ratio of the ether diol residue is smaller than this range, the glass transition temperature of the resulting resin is lowered, and the heat resistance is deteriorated. In addition, when n = 1, that is, when the diol residues are all ether diol residues, the melt viscosity is high, so that it may be difficult to produce or process a polymer having a high degree of polymerization. A more preferable range of the molar ratio n of ether diol residues in all diol residues is 0.6 or more and 0.9 or less, and a particularly preferable range is 0.65 or more and 0.85 or less.

  The plant-derived ether diol component used in the present invention is represented by the above formula (2), specifically, dianhydrohexitols. Examples of dianhydrohexitols include 1,4: 3,6-dianhydro-D-mannitol (hereinafter sometimes abbreviated as isomannide), 1,4: 3,6-dianhydro-L- Iditol (hereinafter, sometimes abbreviated as isoidide) and 1,4: 3,6-dianhydro-D-sorbitol (hereinafter, sometimes abbreviated as isosorbide) (respectively). (Following formula (5), (6), (7)).

  These dianhydrohexitols are substances obtained from natural biomass and are one of so-called renewable resources. Isosorbide is obtained by hydrogenating D-glucose obtained from starch and then dehydrating it. Other dianhydrohexitols can be obtained by the same reaction except for the starting material. Isosorbide is a diol that can be easily made from starch and the like, and can be obtained in abundant resources. In addition, isosorbide is superior in ease of manufacture compared to isomannide and isoidide.

  The diol component to be copolymerized is represented by the above formula (3) (hereinafter, the diol of formula (3) may be abbreviated as glycols), ethylene glycol, propylene glycol, 1,3-propanediol, 1 , 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1, Examples include 12-dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol. Among these, 1,3-propanediol (hereinafter sometimes abbreviated as 1,3-PDO), 1, which has high polymerizability in polymer synthesis and also exhibits a high glass transition point in the physical properties of the polymer, 4-butanediol and 1,6-hexanediol are preferable, and 1,3-propanediol is particularly preferable in that it can be obtained from plant raw materials and has a large effect of improving melt fluidity by copolymerization. . Moreover, you may combine at least 2 or more types of these diol components of Formula (3).

The method for purifying the diol used in the present invention is not particularly limited. Preferably, it may be purified by either simple distillation, rectification or recrystallization, or a combination of these techniques. However, commercial products of the diol may contain stabilizers and deteriorated products generated during storage, which may adversely affect the polymer quality. This is particularly noticeable in plant-derived diols of formula (2). When the diol is used to obtain a polymer, it is preferable that the polymer is purified again and used immediately in the polymerization reaction. When it is unavoidably stored and used for a while after purification, it is preferably used after being dried, stored at a low temperature of 40 ° C. or lower, light-shielded and in an inert atmosphere.
In the diol components of the formulas (2) and (3) used in the present invention, the total content of Na, Fe and Ca is 2 mass ppm or less, and preferably 1 mass ppm or less.

  The carbonic acid diester used in the present invention is represented by the above formula (4). For example, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, bis (ethylphenyl) carbonate, bis (methoxyphenyl) carbonate, bis (ethoxyphenyl) Aromatic carbonic acid diesters such as carbonate, dinaphthyl carbonate, and bis (biphenyl) carbonate, and aliphatic carbonic acid diesters such as dimethyl carbonate, diethyl carbonate, and dibutyl carbonate are exemplified. Of these compounds, aromatic carbonic acid diesters are preferably used in terms of reactivity and cost, and diphenyl carbonate is more preferably used.

The method for purifying the carbonic acid diester used in the present invention is not particularly limited. Preferably, it may be purified by either simple distillation, rectification or recrystallization, or a combination of these techniques.
In the carbonic acid diester used in the present invention, the total content of Na, Fe and Ca is 2 mass ppm or less, preferably 1 mass ppm or less.

  Known methods for producing polycarbonate resins include a phosgene method in which an alkaline aqueous solution of a dihydroxy compound and phosgene are reacted in the presence of an organic solvent, or a melt weight of a dihydroxy compound and a carbonic acid diester in the presence of a transesterification catalyst at high temperature and high vacuum. Examples thereof include a melt polycondensation method in which a condensation reaction is performed. Among them, the melt polycondensation method is a process that requires a transesterification catalyst and a high temperature / high vacuum, but is more economical than the phosgene method, and can further obtain a polycarbonate resin substantially free of chlorine atoms. There are advantages. In the present invention, the polycarbonate is produced by a melt polycondensation method.

  Further, in the production method of the present invention, the above formula (2) and preferably the above formula (2) and preferably the above formula (2) by the melt polycondensation method using the diol represented by (3) and the carbonic acid diester represented by the above formula (4) as raw materials. The polycarbonate of 1) is produced.

  In the melt polycondensation method of the polycarbonate production method of the present invention, it is preferable to use a carbonic acid diester in an amount of 0.90 to 1.30 mol, based on 1 mol of the diol component, and 0.98 to 1.05 mol. More preferably, it is used in an amount of.

  In the present invention, a barium compound is used as the catalyst. Impurities and additives that reduce the catalytic activity when barium compounds are used as catalysts compared to the most common sodium compounds, the ultimate reduced viscosity under the same polycondensation conditions, that is, the polymerization rate is significantly higher Even if there is, there is a feature that it is not easily affected.

  Examples of the barium compound include barium hydroxide, barium carbonate, barium bicarbonate, barium acetate, and barium stearate. Among them, it is preferable to use a basic barium compound such as barium hydroxide, barium carbonate, and barium acetate in terms of reactivity and cost, and it is relatively stable and relatively weak even when it comes into contact with the body. In terms of safety, barium carbonate and barium acetate are particularly preferred.

  These barium compounds may be used alone or in a plurality of types, and these barium compounds may be used in combination with (i) a nitrogen-containing basic compound and (ii) a metal compound other than barium. . Among these, it is particularly preferable to use in combination with (i), and it is more preferable to use tetramethylammonium hydroxide for (i). Examples of the catalyst that can be used as the catalyst of (ii) include alkoxides or phenoxides of alkali metals, alkoxides or phenoxides of alkaline earth metals other than barium, nitrogen-containing basic compounds, quaternary ammonium salts, Alkali metal or alkaline earth metal organic acid salts, boron compounds, aluminum compounds, zinc compounds, boron compounds, silicon compounds, titanium compounds, organotin compounds, lead compounds, osmium compounds, antimony Examples thereof include compounds having catalytic ability for transesterification reaction or esterification reaction such as compounds, zirconium compounds and manganese compounds.

The nitrogen basic compound (i) is used in such a ratio that the basic nitrogen atom is 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol per mol of the total of all diol compounds or carbonate. The ratio is preferably 2 × 10 ⁻⁵ to 8 × 10 ⁻⁴ mol.
Regarding the catalyst (ii), the total amount of addition with the barium compound is in the range of 1 × 10 ⁻⁷ to 1 × 10 ⁻⁵ mol per 1 mol of either the total diol compound or the carbonate ester. Preferably, it is in the range of 1 × 10 ^{−7 to} 5 × 10 ⁻⁶ mol.

  In the production method of the present invention, preferably, the raw material diol and carbonic acid diester are heated at normal pressure in the presence of a polycondensation catalyst, pre-reacted, and then stirred while heating at a temperature of 280 ° C. or lower under reduced pressure. Then, the resulting phenols or alcohols are distilled off. The reaction system is preferably maintained in an atmosphere of a gas inert to the raw material such as nitrogen and the reaction mixture. Examples of inert gases other than nitrogen include argon.

  It is preferable to carry out the heating reaction at normal pressure at the beginning of the reaction. This is because the oligomerization reaction proceeds, and when the phenols or alcohols are distilled off at a later stage of the reaction to distill off the phenols or alcohols, unreacted monomers are distilled out to prevent the molar balance from being lost and the polymerization degree from being lowered. . In the production method according to the present invention, the reaction can be advanced by appropriately removing phenols or alcohols from the system (reactor). For that purpose, it is effective and preferable to reduce the pressure.

  In the production method of the present invention, a low temperature condition is preferable as much as possible in order to suppress decomposition of the diol and obtain a highly viscous resin with little coloring, but the polymerization temperature is 180 ° C. or higher and 280 ° C. in order to proceed the polymerization reaction appropriately. The following range is preferable, and more preferable is the condition where the highest polymerization temperature is in the range of 230 to 260 ° C.

  The polycarbonate produced by the present invention has a total content of Na, Ca and Fe of 10 ppm by mass or less, more preferably 7 ppm by mass or less, and particularly preferably 3 ppm by mass or less. If the total content of Na, Ca and Fe exceeds this range, coloring becomes remarkable, and there are problems such as deterioration in melt stability and hydrolysis resistance, which is not preferable. In addition, Na, Ca, and Fe are inorganic in the polymer because they are easily contaminated from materials such as production equipment and the outside air, and the amount of diol of the formula (2) contained in the commercial product is large. It accounts for the majority of impurities. In order to make the total content of Na, Ca, and Fe within the above range, there are methods such as using a raw material with a low content, or manufacturing with an apparatus made of a material that hardly dissolves the components. The smaller the total content of Na, Ca, and Fe in the polymer, the better. However, if it is attempted to make it 0 ppm by mass, there is a risk that a significant increase in cost and a decrease in production efficiency may occur for the purpose of preventing contamination. The lower limit of the total content of Na, Ca, and Fe in the polymer that can be reached while maintaining productivity is about 3 ppm by mass. The total content of Na, Ca and Fe in the polymer is preferably quantified by an ICP (inductively coupled plasma) emission spectrometer or ICP mass spectrometer from the viewpoint of accuracy and simplicity.

The polycarbonate of the present invention is a polycarbonate having a Col-b value of 5 or less, preferably 3 or less.
In addition, the polycarbonate produced by the present invention preferably has a reduced viscosity in the range of 0.5 to 1.0 dL / g, more preferably in the range of 0.6 to 0.8 dL / g. Is.

  The polycarbonate produced by the present invention may be used alone for molding and the like, and other thermoplastic resins (for example, polyalkylene terephthalate resin, polyarylate resin, liquid crystalline polyester resin within the range not impairing the object of the present invention). , Polyamide resin, polyimide resin, polyetherimide resin, polyurethane resin, silicone resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polyolefin resin such as polyethylene and polypropylene), filler (glass fiber, carbon fiber, natural fiber) Organic fibers, ceramic fibers, ceramic beads, talc, clay and mica), antioxidants (hindered phenol compounds, sulfur antioxidants, etc.), flame retardant additives (phosphorous, bromo, etc.) ), UV absorbers (benzotriazole, benzophenone, cyanoacrylate, etc.), flow modifiers, colorants, light diffusing agents, infrared absorbers, organic pigments, inorganic pigments, mold release agents, plasticizers, etc. can do.

  The polycarbonate produced by the present invention was processed by various molding and film forming methods such as injection molding, compression molding, injection compression molding, extrusion molding, blow molding, solvent casting method, melt extrusion method, and calendar method. Later, it can be widely used in various applications including optical media applications, electrical / electronic / OA applications, automobile / industrial equipment applications, medical / security applications, sheet / film / packaging applications, and miscellaneous goods applications. Specifically, DVDs, CD-ROMs, CD-Rs, mini-discs for optical media applications, mobile phones, personal computer housings, battery pack cases, liquid crystal parts, connectors, automobiles, industrial equipment for electrical / electronic / OA applications Applications include headlamps, inner lenses, door handles, bumpers, fenders, roof rails, springs, clusters, console boxes, cameras, electric tools, nameplates, carports, diffusion / reflection films for liquid crystals, drinking water tanks, for medical and security applications. Examples of miscellaneous goods include pachinko parts and fire extinguisher cases.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
The reduced viscosity of the polycarbonate resin composition and the molded product is the viscosity of a solution obtained by dissolving 120 mg of the polycarbonate resin composition in 10 mL of a mixed solvent of phenol / tetrachloroethane (volume ratio 50/50) at 35 ° C. (DL / g unit).
The glass transition temperature was measured using a DSC2920 manufactured by TA Instruments.

  The contents of Na, Ca, and Fe in the raw material isosorbide and polycarbonate resin composition were measured accurately in a platinum dish, ashed by adding concentrated sulfuric acid, and then the ash was melted with potassium hydrogen sulfate. It evaluated by melt | dissolving in nitric acid and performing an ICP emission analysis (VISTA MP-X (multi-type) by a Varian company).

  Regarding the hue of the polymer, the Col-b value was measured using UV-VIS RECORDING SPECTROTOPOMETER (manufactured by Shimadzu Corporation) according to JIS Z 8722. The measurement was performed by adding 4 ml of methylene chloride to 0.935 g of the polymer and dissolving it under the conditions of a wavelength of 780 to 380 nm, illumination: C, and visual field: 2 °, and the Col-b value was measured.

[Example 1]
Isosorbide (Rocket) (61.38 g, 0.42 mol), 1,3-propanediol (14.38 g, 0.19 mol) and diphenyl carbonate (128.53 g, 0.6 mol) subjected to simple distillation once Was added to a three-necked flask, and barium carbonate (0.0592 mg, 3 × 10 ⁻⁷ mol) and tetramethylammonium hydroxide (5.47 mg, 6.0 × 10 ⁻⁵ mol) were added as a polycondensation catalyst under a nitrogen atmosphere. Melted at ℃. Under stirring, the pressure in the reaction vessel was reduced to 100 mmHg (13.33 kPa), and the reaction was allowed to proceed for about 20 minutes while distilling off the produced phenol. Next, after heating up to 200 degreeC, it pressure-reduced to 30 mmHg (4.00 kPa), distilling phenol off. Furthermore, the pressure was reduced and the temperature was raised, and the reaction was finally performed under the conditions of 250 ° C. and 0.8 mmHg (0.11 kPa). The time when the temperature reached 250 ° C. and 0.8 mmHg (0.11 kPa) was set to time 0 minutes, and sampling was performed 10 minutes later to measure the reduced viscosity, the content of inorganic impurities, and the Col-b value.

[Example 2]
The same operation as in Example 1 was performed except that barium hydroxide octahydrate (0.0946 mg, 3 × 10 ⁻⁷ mol) was used instead of the polycondensation catalyst barium carbonate. The results are shown in Table 1.

[Comparative Example 1]
The same operation as in Example 1 was performed except that sodium hydroxide (0.012 mg, 3 × 10 ⁻⁷ mol) was used instead of the polycondensation catalyst barium carbonate. The results are shown in Table 1.

[Comparative Example 2]
Rocket isosorbide was not purified by distillation, and 2,2-bis (4-hydroxyphenyl) propane disodium salt (0.04 mg, 1.5 × 10 ⁻ ) was used instead of the polycondensation catalyst barium carbonate. ^{The same} operation as in Example 1 was carried out except that ⁷ mol (abbreviated as BPA · 2Na in Table 1) was used. The results are shown in Table 1.

[Comparative Example 3]
Instead of isosorbide that was subjected to simple distillation once (manufactured by Rocket), isosorbide manufactured by Sanko Chemical Co., Ltd. was used without pretreatment such as distillation purification, and instead of barium carbonate as a polycondensation catalyst, 2,2- The same procedure as in Example 1 was performed except that bis (4-hydroxyphenyl) propane disodium salt (0.04 mg, 1.5 × 10 ⁻⁷ mol, abbreviated as BPA · 2Na in Table 1) was used. It was. The results are shown in Table 1.

[Comparative Example 4]
Instead of isosorbide (manufactured by Rocket) once subjected to simple distillation, isosorbide manufactured by Sanko Chemical Co., Ltd. was used without pretreatment such as distillation purification, and instead of barium carbonate as a polycondensation catalyst, barium hydroxide 8 The same operation as in Example 1 was performed except that hydrate (0.0946 mg, 3 × 10 ⁻⁷ mol) was used. The results are shown in Table 1.

Claims (2)

Following formula (1)

(R _{1 to} R ₄ are each independently a group selected from a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, R ₅ is an aliphatic hydrocarbon group having 2 to 12 carbon atoms, and n Is 0.4 ≦ n ≦ 1.0)
In producing a polycarbonate represented by
A diol represented by the following formula (2), wherein the total content of Na, Ca and Fe is 2 mass ppm or less;

(R _{1 to} R ₄ are each independently a group selected from a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group),
A diol represented by the following formula (3) having a total Na, Ca, Fe content of 2 mass ppm or less is used as a diol component.

(R ₅ is an aliphatic hydrocarbon group having 2 to 12 carbon atoms)
Na, Ca, Fe content total is 2 mass ppm or less, following formula (4)

(R ₆ and R ₇ are groups selected from an alkyl group, a cycloalkyl group or an aryl group, and R ₆ and R ₇ may be the same group or different groups)
A process for producing a polycarbonate, characterized in that a carbonic acid diester represented by the formula (1) is used as a carbonic acid component and melt polycondensed in the presence of a barium compound as a polycondensation catalyst.   A polycarbonate obtained by the production method according to claim 1, wherein the content of Na, Ca and Fe in the polymer is 10 ppm by mass or less and the Col-b value is 5 or less.