KR100888621B1 - End-capped polycarbonate resin and method of preparing thereof - Google Patents

Abstract

An end-capped polycarbonate resin is provided to realize efficient end-capping, excellent heat resistance and color stability, to maintain the inherent property of the polycarbonate resin, and to reduce the concentration of a hydroxyl group which is the final end group by applying the existing facilities without the remodeling or change of a reaction process. A method for preparing an end-capped polycarbonate resin comprises a step for performing transesterification of diphenylcarbonate and an aromatic carbonate derivative compound indicated as the chemical formula 1, with divalent phenol; and a step for injecting the aromatic carbonate derivative compound during transesterification. In the chemical formula 1, R1 is a t-butyl group or a p-cumyl group. The divalent phenol has a structure indicated as the following chemical formula 2. In the chemical formula 2, A is a single bond, C1-C5 alkylene, C1-C5 alkylidene, C5-C6 cycloalkylidene, -S- or -SO2-.

Description

End-Capped Polycarbonate Resin and Method of Preparing Thereof}

1 is MALDI-TOF showing the terminal structure change of the polycarbonate resin prepared in Comparative Example 1 and Example 1.

Field of invention

The present invention relates to a polycarbonate resin having a terminal blockage efficiently and a method for producing the same. More specifically, the present invention provides a method for synthesizing polycarbonate by transesterifying diphenyl carbonate and dihydric phenol, wherein a specific hydroxyl carbonate derivative compound is added to the transesterification reaction so that the terminal hydroxyl group is efficiently capped and heat-resistant. And a polycarbonate resin having improved color stability and a method of manufacturing the same.

Background of the Invention

Polycarbonate is excellent in mechanical properties such as impact resistance, and excellent in self-extinguishing, dimensional stability, heat resistance and transparency, the application range of electric and electronic product exterior materials, automotive parts, etc. are increasing day by day.

In general, the polycarbonate is prepared by interfacial polymerization of bivalent phenol salts such as bisphenol A and phosgene in a liquid phase, and diaryl carbonates such as diphenyl carbonate in the above state. There is a method of manufacturing by the exchange method.

The method of preparing polycarbonate by transesterification can eliminate the use of highly toxic substances such as phosgene, do not use organic solvents such as methylene chloride, and do not require cleaning process using a large amount of water. It is an environmentally friendly manufacturing process and the future is a bright manufacturing process.

However, unlike the interfacial reaction which terminates the reaction through the use of monovalent phenolic compounds, the transesterification reaction does not use a reaction terminator. Due to this process difference, polycarbonate resins prepared by transesterification have a higher terminal hydroxyl composition than polycarbonate resins prepared by interfacial reaction, and these terminal hydroxyl groups adversely affect the heat resistance and color tone of the polycarbonate resin. Can be. Therefore, it is preferable to lower the ratio of the terminal hydroxyl group of polycarbonate resin.

EP 360578 describes a method for reducing the concentration of terminal hydroxyl groups by adding an excess of monovalent phenol together with the reaction monomer in the initial stage of the esterification. However, when monohydric phenol is used in a transesterification reaction having a high temperature and low pressure reaction condition, a large amount of monohydric phenol is vaporized. Therefore, the use of excess monohydric phenol is required for efficient terminal blockade, and additional equipment for recovering unreacted monohydric phenols, which is vaporized, has a disadvantage in that the manufacturing cost increases.

US Pat. No. 6,620,902 describes a method for reducing terminal hydroxyl groups by adding low molecular weight aromatic hydroxy compounds to the post-treatment process. The method proceeds under a pressurized condition in order to prevent vaporization of low molecular weight aromatic compounds. In this case, the by-products generated through the reaction are not easily removed, thereby reducing efficiency.

U.S. Patent No. 6,500,914 discloses a method for removing the reactivity of a resin end group using an aromatic carbonate compound having a high boiling point. However, since the method uses phosgene to produce an aromatic compound, there is a high risk, an increase in manufacturing cost, and a problem of deteriorating the physical properties of the polycarbonate resin due to the chlorine-based compound remaining in a small amount.

US Pat. No. 4,310,656 discloses a method for reducing terminal hydroxyl groups using ortho-substituted carbonates or ester derivatives with higher electronegativity than diphenylcarbonate. However, in this case, in order to have a high electronegativity, ortho-substituents are mostly halogen compounds, and these also remain after the reaction, causing problems of deterioration in color stability.

MEANS TO SOLVE THE PROBLEM In order to solve the said problem, in the method of synthesize | combining a polycarbonate by transesterifying diphenyl carbonate and a dihydric phenol, the terminal hydroxyl group is made efficient by injecting a specific aromatic carbonate derivative compound and transesterifying together. The present invention has led to the development of a polycarbonate resin and a method of manufacturing the same, which are capped by and have improved heat resistance and color stability.

An object of the present invention is to provide a polycarbonate resin and a method for producing the end capping efficiently.

Another object of the present invention is to provide an end capped polycarbonate resin having improved heat resistance and color stability, and a method of manufacturing the same.

Still another object of the present invention is to provide an end capped polycarbonate resin capable of maintaining the inherent physical properties of the polycarbonate resin and a method of manufacturing the same.

It is still another object of the present invention to provide an end capped polycarbonate resin and a method for producing the same, which can reduce the concentration of the final terminal hydroxyl group by applying existing equipment without modifying or changing the reaction process.

The above and other objects of the present invention can be achieved by the present invention described below.

Summary of the Invention

The present invention provides a process for producing terminally blocked polycarbonate resin. The method is characterized in that the diphenyl carbonate and the aromatic carbonate derivative compound having a specific structure are transesterified with dihydric phenol.

In an embodiment of the present invention, the aromatic carbonate derivative compound may be added before the start of the transesterification reaction or during the transesterification reaction.

In another embodiment of the present invention, the dihydric phenol is used in a molar ratio of 0.85 to 1.2 with a mixed carbonate monomer composed of the diphenyl carbonate and the aromatic carbonate derivative compound. The mixed carbonate monomer is composed of 60 to 95 mol% of diphenyl carbonate and 5 to 40 mol% of aromatic carbonate derivative compounds.

The transesterification reaction includes hydroxides, oxides, amide compounds, alkoxy compounds of alkali metals and alkaline earth metals; Transition metal oxides; Catalysts selected from nitrogen-containing basic compounds, phosphorus-containing basic compounds or mixtures thereof can be used. The catalyst is a divalent phenol per mole of from about 1 × 10 ^-7 to 1 × 10 ^- can be used in the range of ⁴ mol.

The transesterification reaction may proceed under reduced pressure at 160 to 300 ℃.

Another aspect of the invention provides a terminally blocked polycarbonate resin prepared by the above method. The polycarbonate resin has a concentration of the final terminal hydroxyl group 0 to 10% of the total terminal group.

Hereinafter, the content of the present invention will be described in detail below.

Detailed Description of the Invention

The terminal blocked polycarbonate resin of the present invention is characterized in that the diphenyl carbonate and the aromatic carbonate derivative compound represented by the following formula (1) are transesterified with dihydric phenol.

[Formula 1]

Wherein R ₁ is a t-butyl group or p-cumyl group.

The aromatic carbonate derivative compound may be added before the start of the transesterification reaction or in the transesterification reaction to proceed in situ.

The dihydric phenol may be represented by the following formula (2).

[Formula 2]

(Wherein, A is a cycloalkylidene, -S- or -SO ₂ of a single bond, C ₁ -C ₅ alkylene, C ₁ -C ₅ alkylidene, C ₅ -C ₆ of the - denotes a).

Specific examples of the diphenol of the formula (2) include 4,4'-dihydroxydiphenyl, 2,2-bis- (4-hydroxyphenyl) -propane, 2,4-bis- (4-hydroxyphenyl)- 2-methylbutane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2,2-bis- (3-chloro-4-hydroxyphenyl) -propane, 2,2-bis- (3 , 5-dichloro-4-hydroxyphenyl) -propane and the like. Among them, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane, 1,1-bis- (4- Hydroxyphenyl) -cyclohexane and the like are preferred, and 2,2-bis- (4-hydroxyphenyl) -propane, also referred to as bisphenol-A, is most preferred.

In a specific embodiment of the present invention, the dihydric phenol is used in a molar ratio of 0.85 to 1.2, preferably a molar ratio of 0.85 to 1.2, with a mixed carbonate monomer composed of the diphenyl carbonate and an aromatic carbonate derivative compound. When it uses in the said molar ratio, it is preferable at the molecular weight raise.

The mixed carbonate monomer is composed of 60 to 95 mol% of diphenyl carbonate and 5 to 40 mol% of aromatic carbonate derivative compounds. It is preferable in the reaction rate and the physical property balance in the above range.

In the present invention, it may be carried out in the presence of a catalyst to promote the transesterification reaction. Examples of the catalyst include hydroxides, oxides, amide compounds, alkoxy compounds of alkali metals and alkaline earth metals; Transition metal oxides; Nitrogen-containing basic compounds, phosphorus-containing basic compounds and the like can be used, but are not necessarily limited thereto. These may be used alone or in combination of two or more thereof. In the present invention, each or a combined catalyst can be added to the reaction mixture in the form of a hydrate.

The content of the catalyst can be determined by the amount of dihydric phenol used. In one embodiment of the present invention can be used in the range of 1 × 10 ⁻⁷ to 1 × 10 ⁻⁴ mole per mole of divalent phenol. In the above content range, by-products due to sufficient reactivity and side reactions may be minimized, thereby improving thermal stability and color stability.

In an embodiment of the present invention, the transesterification reaction may proceed under reduced pressure at 160 to 300 ℃, preferably 200 to 300 ℃, more preferably 220 to 260 ℃. It is preferable in the reaction rate and side reaction reduction in the above temperature range.

In addition, the transesterification reaction is preferably performed at least 10 minutes or more, preferably 15 minutes to 24 hours, more preferably 15 minutes to 3 hours under darkening conditions of 1 torr or less for reducing the reaction rate and side reactions.

In one embodiment of the present invention by reacting for about 2 to 3 hours at a reaction temperature of 160 ℃ to 260 ℃ to prepare a terminal blocked polycarbonate resin.

After the polymerization is completed, the polymer is discharged into a water bath and cooled, and then a transparent polymer may be obtained through a drying process. The polymer thus obtained can be pelletized through an extrusion process, and an appropriate additive can be added to this process to obtain a resin composition having improved stability.

The polycarbonate resin according to the present invention may further include an additive. The additives include flame retardants, antibacterial agents, mold release agents, heat stabilizers, antioxidants, light stabilizers, compatibilizers, dyes, inorganic additives, fillers, plasticizers, impact modifiers, admixtures, colorants, stabilizers, lubricants, antistatic agents, pigments, weathering agents, ultraviolet rays. Blocking agents and mixtures thereof.

Another aspect of the invention provides a terminally blocked polycarbonate resin prepared by the above method. The polycarbonate resin has a concentration of the final terminal hydroxyl group 0 to 10% of the total terminal group.

By applying the aromatic carbonate derivative compound, the present invention can dramatically reduce the terminal hydroxyl group of the polycarbonate without modification or addition of existing equipment. Therefore, when the terminally blocked polycarbonate of the present invention is applied, thermal stability and color tone stability can be significantly increased.

The polycarbonate resin may be used in molded products in fields requiring durability, heat resistance, and transparency, such as automobiles, mechanical parts, electrical and electronic parts, office equipment such as computers, and miscellaneous goods. In particular, the present invention can be suitably applied to housings of electrical and electronic products such as televisions, computers, printers, washing machines, cassette players, audio, mobile phones, game machines, toys, and the like. As the molding method, a conventional method may be applied, and for example, extrusion molding, injection molding, vacuum molding, casting molding, extrusion molding, blow molding, calendar molding, or the like may be applied. These are well known by those skilled in the art to which the present invention belongs.

The invention can be better understood by the following examples, which are intended for purposes of illustration of the invention and are not intended to be limited or limited by the appended claims.

Example 1

Mechanical stirrer, 456.6 g (2 mol) of 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 401.0 g (1.872 mol) of diphenyl carbonate and terminal hydroxyl group remover in a 2 L stainless steel reactor with cooling tower 67.9 g (0.208 mol) of di-t-butylphenyl carbonate were added sequentially, followed by removal of oxygen in the reactor using nitrogen. When the mixture in the reactor was completely dissolved by raising the temperature to 160 ° C, the speed of the stirrer was set to 100 rpm, the mixture was stirred to obtain a uniform mixture, and then a KOH aqueous solution, which was a polymerization catalyst, was added. After the reaction temperature was raised to 220 ° C. and reacted for 40 minutes, the reaction temperature was further increased to 260 ° C., and the degree of vacuum was gradually increased to reach a vacuum of 1 torr. After reacting for 20 minutes at 260 degreeC and 1 torr, reaction was complete | finished and the transparent polycarbonate resin melt was manufactured. The prepared polycarbonate resin was analyzed by using a matrix-assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF) analysis machine to analyze the structure of the end group, and the results are shown in FIG. 1.

Example 2

The same procedure as in Example 1 was carried out except that a monomer mixture consisting of 356.5 g (1.664 mol) of diphenyl carbonate and 135.7 g (0.416 mol) of di-t-butylphenyl carbonate was used.

Example 3

The same procedure as in Example 1 was carried out except that a monomer mixture consisting of 311.9 g (1.456 mol) of diphenyl carbonate and 203.6 g (0.624 mol) of di-t-butylphenyl carbonate was used.

Example 4

The same procedure as in Example 1 was carried out except that a monomer mixture consisting of 356.5 g (1.664 mol) of diphenyl carbonate and 187.4 g (0.416 mol) of di-p-cumylphenyl carbonate was used.

Example 5

67.9 g (0.208 mol) of di-t-butylphenyl carbonate, which was an end capping agent, was added in the same manner as in Example 1 except that 107.9 minutes before the end of the reaction.

Comparative Example 1

The same procedure as in Example 1 was carried out except that 445.6 g (2.080 mol) of diphenyl carbonate was used alone. Figure 1 shows the terminal structure change of the polycarbonate resin prepared in Comparative Example 1 as MALDI-TOF.

Comparative Example 2

The same procedure as in Example 1 was carried out except that a monomer mixture consisting of 445.6 g (2.080 mol) of diphenyl carbonate and 62.5 g (0.416 mol) of t-butyl phenol was used.

Comparative Example 3

The same procedure as in Example 2 was carried out except that a monomer mixture consisting of 356.5 g (1.664 mol) of diphenyl carbonate and 62.5 g (0.416 mol) of t-butyl phenol was used.

Comparative Example 4

The same procedure as in Example 5 was carried out except that 356.5 g (1.664 mol) of diphenyl carbonate and 62.5 g (0.416 mol) of t-butyl phenol were used.

The monomer dose, timing and properties of the monomers used in each Example and Comparative Example are shown in Table 1 below.

Analytical Method:

(1) Molecular weight: Measured using GPC (Gel Permeation Chromatography).

(2) Terminal hydroxyl concentration: 20 mg of the polymer was dissolved in 0.5 mL of chloroform substituted with deuterium, and measured using NMR 500 MHz (Bruker).

Terminal OH composition = [phenolic terminal group (6.6 to 6.8 ppm)] / [nonphenolic terminal group (7.3 to 7.5 ppm) + phenolic terminal group (6.6 to 6.8 ppm)] × 100

(3) Terminal structure: MALDI-TOF (Matrix-assisted laser desorption ionization time of flight mass spectroscopy) was analyzed using a device.

From the results of Table 1, the present inventors confirmed that the use of the diaryl carbonate derivative effectively reduces the terminal hydroxyl group without modification of the reaction process, and as a result, the thermal stability and the color stability were improved.

The present invention provides efficient end capping, improved heat resistance and color stability, maintains the inherent physical properties of polycarbonate resins, and reduces the concentration of final terminal hydroxyl groups by applying existing equipment without modifying or changing the reaction process. It has the effect of the invention to provide an end capped polycarbonate resin and a method for producing the same.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (10)

A method for producing a terminally blocked polycarbonate resin, wherein a diphenyl carbonate and an aromatic carbonate derivative compound represented by Formula 1 are transesterified with a dihydric phenol, and the aromatic carbonate derivative compound is added during the transesterification reaction. : [Formula 1]

Wherein R ₁ is a t-butyl group or p-cumyl group. delete The method of claim 1, wherein the dihydric phenol is represented by the following Chemical Formula 2: [Formula 2]

(Wherein, A is a cycloalkylidene, -S- or -SO ₂ of a single bond, C ₁ -C ₅ alkylene, C ₁ -C ₅ alkylidene, C ₅ -C ₆ of the - denotes a). The method for producing a polycarbonate resin according to claim 1, wherein the dihydric phenol is used in a molar ratio of 0.85 to 1.2 with a mixed carbonate monomer composed of the diphenyl carbonate and an aromatic carbonate derivative compound. The method of claim 1, wherein the mixed carbonate monomer is 60 to 95 mol% diphenyl carbonate and 5 to 40 mol% aromatic carbonate derivative compound. The method of claim 1, wherein the transesterification reaction comprises hydroxides, oxides, amide compounds, alkoxy compounds of alkali metals and alkaline earth metals; Transition metal oxides; A process for producing a polycarbonate resin, characterized by using a catalyst selected from a nitrogen-containing basic compound, a phosphorus-containing basic compound or a mixture thereof. The method of claim 6, wherein the catalyst is used in the range of 1 × 10 ⁻⁷ to 1 × 10 ⁻⁴ moles per mole of divalent phenol. The method of claim 1, wherein the transesterification reaction proceeds under reduced pressure at 160 to 300 ℃. A polycarbonate resin prepared by any one of claims 1 and 3 to 8, wherein the concentration of the final terminal hydroxyl group is 0 to 10% of the total terminal groups. The method of claim 9, wherein the polycarbonate resin is flame retardant, antibacterial, mold release agent, heat stabilizer, antioxidant, light stabilizer, compatibilizer, dye, inorganic additive, filler, plasticizer, impact modifier, admixture, colorant, stabilizer, lubricant, The polycarbonate resin further comprises an additive selected from the group consisting of antistatic agents, pigments, weathering agents, sunscreens and mixtures thereof.

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