JP-7856641-B2 - Polycarbonate manufacturing method

Inventors

• 岡添 隆
• 鈴木 将人

Assignees

• ＡＧＣ株式会社
• 国立大学法人 名古屋工業大学

Dates

Publication Date

20260511

Application Date

20220520

Priority Date

20210520

Claims (7)

1. The following dihydroxy component and the following fluorine-containing carbonate component are reacted in the presence of a condensation catalyst such that the molar ratio of the fluorine-containing carbonate component to the dihydroxy component is between 1/1 and 2/1 . A method for producing polycarbonate, comprising heating the obtained prepolymer at a temperature below its melting point and solid-phase polymerizing the prepolymer while discharging the by-product fluorine-containing alcohol from the system. Dihydroxy component: At least one non-aromatic dihydroxy compound selected from the group consisting of alicyclic dihydroxy compounds and linear or branched aliphatic dihydroxy compounds, or a mixture of the non-aromatic dihydroxy compound and the aromatic dihydroxy compound, wherein the alicyclic dihydroxy compound may have some carbon atoms substituted with oxygen atoms, and the linear or branched aliphatic dihydroxy compound may have some carbon atoms substituted with oxygen atoms. Fluorine-containing carbonate component: At least one compound selected from the group consisting of the compound represented by formula (1), the compound represented by formula (2), the compound represented by formula (3), and the compound represented by formula (4). However, R1 is a group represented by CA1B1R4 , and the two R1s may be the same or different. R2 is a group represented by CA2B2R5 , and the two R2s may be the same or different. R3 is a hydrogen atom or a group represented by CA3B3R6 , and the two R3s may be the same or different. A1 to A3 are each independently a hydrogen atom, a fluorine atom, or Rf . B1 to B3 are each independently a hydrogen atom, a fluorine atom, or Rf . R4 to R6 are each independently a fluorine atom, Rf , or ORf . R f is a fluoroalkyl group having 1 to 12 carbon atoms or a fluoroaryl group having 6 to 10 carbon atoms, and in the fluoroalkyl group having 1 to 12 carbon atoms, some of the carbon atoms may be substituted with oxygen atoms. However, R1 is a group represented by CA1B1R4 , R2 is a group represented by CA2B2R5 , R3 is a hydrogen atom or a group represented as CA3B3R6 , R7 is a perfluoroalkylene group having 1 to 5 carbon atoms, and the perfluoroalkylene group having 1 to 5 carbon atoms may have some of its carbon atoms substituted with oxygen atoms. A1 to A3 are each independently a hydrogen atom, a fluorine atom, or Rf . B1 to B3 are each independently a hydrogen atom, a fluorine atom, or Rf . R4 to R6 are each independently a fluorine atom, Rf , or ORf . R f is a fluoroalkyl group having 1 to 12 carbon atoms or a fluoroaryl group having 6 to 10 carbon atoms, and in the fluoroalkyl group having 1 to 12 carbon atoms, some of the carbon atoms may be substituted with oxygen atoms. However, R7 is a perfluoroalkylene group having 1 to 5 carbon atoms, and the two R7s may be the same or different, and the perfluoroalkylene group having 1 to 5 carbon atoms may have some of its carbon atoms substituted with oxygen atoms. However, R9 to R13 are each independently a hydrogen atom, a fluorine atom, or a fluoroalkyl group having 1 to 6 carbon atoms, and the two R9s , two R10s , two R11s , two R12s , and two R13s may be the same or different, and each molecule has at least one fluorine atom, and the fluoroalkyl groups having 1 to 6 carbon atoms may have some carbon atoms substituted with oxygen atoms.
2. The production method according to claim 1, wherein the non-aromatic dihydroxy compound comprises isosorbide.
3. The manufacturing method according to claim 2, wherein the proportion of isosorbide to the total non-aromatic dihydroxy compound is 50 mol% or more.
4. The manufacturing method according to claim 1 , wherein the dihydroxy component is a mixture of the non-aromatic dihydroxy compound and the aromatic dihydroxy compound.
5. The manufacturing method according to claim 1 , wherein the weight-average molecular weight of the prepolymer is 500 to 15,000.
6. The manufacturing method according to claim 1 , wherein the heating temperature when solid-phase polymerization of the prepolymer is 200°C or less.
7. The manufacturing method according to any one of claims 1 to 6, wherein the weight-average molecular weight of the polycarbonate is 10,000 to 100,000.

Description

This invention relates to a method for producing polycarbonate. This application claims priority based on Japanese Patent Application No. 2021-85297, filed in Japan on May 20, 2021, and Japanese Patent Application No. 2021-176302, filed in Japan on October 28, 2021, and the contents thereof are incorporated herein by reference. Polycarbonate is an engineering plastic with excellent heat resistance, impact resistance, and transparency, and is widely used in many fields. Polycarbonate is generally manufactured using raw materials derived from petroleum resources. However, in recent years, concerns have arisen about the depletion of petroleum resources, and there is a growing demand for the use of raw materials derived from biomass resources such as plants. As an example of polycarbonate made from raw materials derived from biomass resources, polycarbonate made from plant-derived isosorbide is well known. A known method for producing polycarbonate using isosorbide involves melt polycondensation of diphenyl carbonate, isosorbide, and, if necessary, other dihydroxy compounds (transesterification method) (Patent Document 1). On the other hand, a method has been proposed for producing aromatic polycarbonates in which a specific fluorine-containing carbonate is reacted with an aromatic dihydroxy compound, and the resulting prepolymer is solid-state polymerized (Patent Document 2). International Publication No. 2012/144573International Publication No. 2014/171367 In this specification, the compound represented by formula (1) will be referred to as compound (1). Compounds represented by other formulas will be referred to similarly. The meanings and definitions of terms used in this invention are as follows: "Etheric oxygen atom" refers to an oxygen atom that forms an ether bond. A "prepolymer" is a solid intermediate product obtained by stopping the condensation reaction between the dihydroxy component and the fluorine-containing carbonate component of the raw materials at an appropriate point. It refers to a polycarbonate with a lower weight-average molecular weight than the high molecular weight polycarbonate obtained by solid-phase polymerization. "Solid-phase polymerization" refers to a polymerization method that obtains high-molecular-weight polycarbonate by polymerizing a prepolymer while maintaining its solid state. The "melting temperature of the prepolymer" refers to the temperature at which the prepolymer melts, becomes liquid, or softens. This temperature is determined by heating the prepolymer to a predetermined temperature and visually observing when it becomes liquid or softens. "Weight-average molecular weight" and "number-average molecular weight" are values converted to standard polystyrene, measured by gel permeation chromatography (GPC). The "glass transition temperature" is the temperature measured by differential scanning calorimetry (DSC) as the intermediate glass transition temperature, in accordance with JIS K 7121:1987. "Crystallization" refers to the process of increasing the crystallinity of a polymer. A "perfluoroalkylene group" refers to an alkylene group in which all hydrogen atoms are replaced by fluorine atoms. "Fluoroalkyl group" refers to a group in which some or all of the hydrogen atoms of an alkyl group are replaced by fluorine atoms. The "~" symbol indicating a numerical range means that the numbers before and after it are included as the lower and upper limits, respectively. A method for producing polycarbonate according to one aspect of the present invention comprises the following steps a and b. Step a: A step of reacting a specific dihydroxy component with a specific fluorine-containing carbonate component in the presence of a condensation catalyst to obtain a prepolymer. Step b: A step of obtaining polycarbonate by solid-phase polymerization of a prepolymer. (Dihydroxy component) The dihydroxy component is at least one non-aromatic dihydroxy compound selected from the group consisting of alicyclic dihydroxy compounds (which may contain an etheric oxygen atom) and linear or branched aliphatic dihydroxy compounds (which may contain an etheric oxygen atom), or a mixture of this non-aromatic dihydroxy compound and an aromatic dihydroxy compound. Examples of alicyclic dihydroxy compounds (which may contain an etheric oxygen atom) include compounds having an alicyclic structure (which may contain an etheric oxygen atom) and two hydroxyl groups directly or via linking groups attached to its ring skeleton. Examples of linking groups include alkylene groups (methylene group, 1,1-dimethylethylene group, 2,2-dimethylpropylene group, etc.). The alicyclic structure may be monocyclic or polycyclic. The rings constituting the alicyclic structure (or, in the case of polycyclic, each of the multiple rings constituting the alicyclic structure) may be, for example, 4- to 7-membered rings. The number of etheric oxygen atoms that the alicyclic structure may contain may be, for example, 1 to 2 pe