Patent Description:
Terminally reactive polycarbonates include polycarbonates having a vinyl end group or a conjugated double bond (Patent documents <NUM> and <NUM>). These polycarbonates have an ultraviolet absorbing capacity but are highly reactive. Therefore, they have a drawback in that they are even reactive and polymerized by ultraviolet light outside, whereby they lose their activity and function as a UV absorber. Moreover, a polycarbonate having a triazole or benzophenone-based UV absorber bound to its end is known (Patent document <NUM>). Such UV absorber shows excellent weatherability but has low activity as a reactive group and thus is not suitable to be used as a raw material for producing a block copolymer with other resin or as a reactive resin modifier.

As terminally modified polycarbonate resins, a terminally modified polycarbonate oligomer terminated with a chalcone derivative (Patent document <NUM>), a polycarbonate resin having an end group with a specific structure including a benzotriazole ring (Patent document <NUM>), and the like are known but further development of terminally modified polycarbonate resins is desired.

Development of a novel terminally modified polycarbonate resin having an excellent UV absorbing capacity is desired.

The present inventors have gone through extensive studies and as a result of which developed a novel terminally modified polycarbonate resin having an excellent UV absorbing capacity, thereby accomplishing the present invention.

Thus, the present invention comprises the following embodiments.

The present invention can provide a novel terminally modified polycarbonate resin having an excellent UV absorbing capacity.

The present invention provides a terminally modified polycarbonate resin comprising a structure represented by General formula (A) and a structural unit derived from a dihydric phenol:
<CHM>
(in General formula (A) above, R<NUM> represents a hydrogen atom or a C1-C6 alkyl group, R<NUM> represents a C1-C6 alkylene group, R<NUM> represents a hydrogen atom or a methyl group, R<NUM> represents a hydrogen atom or a halogen atom, and * represents the position of the bond to the main chain of the polycarbonate resin.

The terminally modified polycarbonate resin of the present invention may be a terminally modified polycarbonate resin having a structural unit represented by General formula (<NUM>) below which has an end group represented by General formula (A). <CHM>
<CHM>.

In one embodiment of the present invention, X of the structural unit represented by General formula (<NUM>) above may be a divalent group represented by General formula (<NUM>).

In one embodiment of the present invention, the dihydric phenol may be a bisphenol compound. According to the present invention, examples of the bisphenol compound used as the dihydric phenol include, but not limited to, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>,<NUM>-dibromophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>,<NUM>-dichlorophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-bromophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-chlorophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-methylphenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>,<NUM>-dimethylphenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-phenylethane, bis(<NUM>-hydroxyphenyl)diphenylmethane, α,ω-bis[<NUM>-(O-hydroxyphenyl)propyl]polydimethylsiloxane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane (bisphenol A; BPA), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-phenylethane (bisphenol AP), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)butane (bisphenol B; BPB), bis(<NUM>-hydroxyphenyl)diphenylmethane (bisphenol BP), bisphenol CD, <NUM>,<NUM>-bis(<NUM>-methyl-<NUM>-hydroxyphenyl)propane (bisphenol C), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)ethane (bisphenol E), bis(<NUM>-hydroxyphenyl)methane (bisphenol F), <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-isopropylphenyl)propane (bisphenol G), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-ethylhexane (bisphenol IOTD), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-methylpropane (bisphenol IBTD), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-methylpentane (bisphenol MIBK), <NUM>,<NUM>'-(<NUM>-methylethylidene)-bis[<NUM>,<NUM>'-(bisphenyl)-<NUM>-ol]propane (bisphenol PH), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>,<NUM>,<NUM>-trimethylcyclohexane (bisphenol TMC) and <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)cyclohexane (bisphenol Z; BPZ). In a preferred embodiment of the present invention, the bisphenol compound may be selected from the group consisting of bisphenol A, bisphenol AP, bisphenol Z, bisphenol CD, bisphenol C, bisphenol IOTD, bisphenol IBTD and bisphenol MIBK. In one embodiment of the present invention, a single kind of dihydric phenol mentioned above may be used alone or two or more kinds of them may be used in combination.

A monohydric phenol (also referred to as "Terminating agent A"), which is a precursor of the structure represented by General formula (A) above is commercially available as a UV absorber. In one embodiment of the present invention, a single kind of monohydric phenol mentioned above may be used alone or two or more kinds of them may be used in combination.

In a preferred embodiment of the present invention, the end structure represented by General formula (A) above may be a structure represented by Formula (<NUM>) below. <CHM>
(in General formula (<NUM>), *represents the position of the bond to the main chain of the polycarbonate resin.

In one embodiment of the present invention, the end structure represented by General formula (A) above may be contained in an amount of preferably <NUM>%-<NUM>% by mass relative to the above-described structural unit derived from a dihydric phenol. The end structure represented by General formula (A) above may be contained in an amount of more preferably <NUM>%-<NUM>% by mass, still more preferably <NUM>%-<NUM>% by mass, and particularly preferably <NUM>%-<NUM>% by mass relative to the above-described structural unit derived from a dihydric phenol.

In one embodiment of the present invention, the terminally modified polycarbonate resin may comprise any of a random copolymer structure, a block copolymer structure or an alternating copolymer structure.

In one embodiment of the present invention, the terminally modified polycarbonate resin can be blended with other resin to give a terminally modified polycarbonate resin composition. Examples of other resin include, but not limited to, polyamide, polyacetal, polycarbonate, a modified polyphenylene ether, polyethylene terephthalate and polybutylene terephthalate.

In one embodiment of the present invention, the terminally modified polycarbonate resin may be added with an antioxidant and a mold release agent as an additive to give a terminally modified polycarbonate resin composition.

Examples of the antioxidant include triethylene glycol-bis[<NUM>-(<NUM>-tert-butyl-<NUM>-methyl-<NUM>-hydroxyphenyl)propionate], <NUM>,<NUM>-hexanediol-bis[<NUM>-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)propionate], pentaerythritol-tetrakis[<NUM>-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)propionate], octadecyl-<NUM>-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)propionate, <NUM>,<NUM>,<NUM>-trimethyl-<NUM>,<NUM>,<NUM>-tris(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzyl)benzene, N,N-hexamethylenebis(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxy-hydrocinnamide), <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxy-benzylphosphonate-diethylester, tris(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzyl)isocyanurate and <NUM>,<NUM>-bis{<NUM>,<NUM>-dimethyl-<NUM>-[β-(<NUM>-tert-butyl-<NUM>-hydroxy-<NUM>-methylphenyl)propionyloxy]ethyl}-<NUM>,<NUM>,<NUM>,<NUM>-tetraoxaspiro (<NUM>,<NUM>)undecane.

The content of the above-described antioxidant in the terminally modified polycarbonate resin composition is preferably <NUM>% or less by mass, more preferably <NUM>%-<NUM>% by mass, and particularly preferably <NUM>%-<NUM>% by mass.

The mold release agent is preferably one that contains an ester resulting from an alcohol and a fatty acid in an amount of <NUM>% or more by mass. Examples of the ester resulting from an alcohol and a fatty acid specifically include an ester resulting from a monohydric alcohol and a fatty acid, and a partial or whole ester resulting from a polyhydric alcohol and a fatty acid. The ester resulting from a monohydric alcohol and a fatty acid described above is preferably an ester resulting from a monohydric alcohol having <NUM>-<NUM> carbon atoms and a saturated fatty acid having <NUM>-<NUM> carbon atoms. Moreover, a partial or whole ester resulting from a polyhydric alcohol and a fatty acid is preferably a partial or whole ester resulting from a polyhydric alcohol having <NUM>-<NUM> carbon atoms and a saturated fatty acid having <NUM>-<NUM> carbon atoms.

Examples of the ester resulting from a monohydric alcohol and a saturated fatty acid specifically include stearyl stearate, palmityl palmitate, butyl stearate, methyl laurate and isopropyl palmitate. Examples of the partial or whole ester resulting from a polyhydric alcohol and a saturated fatty acid include glycerol monostearate, glycerol monostearate, glycerol distearate, glycerol tristearate, sorbitan monostearate, glycerol monobehenate, glycerol monocaprylate, glycerol monolaurate, pentaerythritol monostearate, pentaerythritol tetrastearate, pentaerythritol tetrapelargonate, propylene glycol monostearate, biphenyl biphenate, sorbitan monostearate, <NUM>-ethylhexyl stearate, and partial or whole esters of dipentaerythritol such as dipentaerythritol hexastearate.

The content of the above-described mold release agent in the terminally modified polycarbonate resin composition is preferably <NUM>% or less by mass, more preferably <NUM>%-<NUM>% by mass, and particularly preferably <NUM>%-<NUM>% by mass.

Furthermore, the terminally modified polycarbonate resin composition of the present invention may be added with other additive(s) such as a processing stabilizer, a UV absorber, a fluidity modifier, a crystal nucleating agent, a reinforcing agent, a dye, an antistatic agent, a bluing agent, an antibacterial agent or the like.

In one embodiment of the present invention, the terminally modified polycarbonate resin can be produced by a method employed for producing conventional polycarbonate resins except that a terminating agent is used.

Specifically, in a case of an interfacial polymerization method, a dihydric phenol-based compound and phosgene are allowed to react with each other in the presence of an inert organic solvent and an aqueous alkaline solution, and then a terminating agent and a polymerization catalyst such as a tertiary amine or a quaternary ammonium salt are added to allow polymerization. In a case of a pyridine method, a dihydric phenol-based compound and a terminating agent are dissolved in pyridine or a mixed solution of pyridine and an inert solvent, into which phosgene is blown to directly obtain a polycarbonate oligomer. According to the interfacial polymerization method, the above-described terminating agent may be added upon reaction between the dihydric phenol-based compound and phosgene.

In one embodiment of the present invention, the viscosity-average molecular weight (Mv) of the terminally modified polycarbonate resin may preferably be <NUM>,<NUM>-<NUM>,<NUM>. The viscosity-average molecular weight (Mv) of the terminally modified polycarbonate is more preferably <NUM>,<NUM>-<NUM>,<NUM>, still more preferably <NUM>,<NUM>-<NUM>,<NUM>, yet still more preferably <NUM>,<NUM>-<NUM>,<NUM>, and particularly preferably <NUM>,<NUM>-<NUM>,<NUM>. As far as the viscosity-average molecular weight (Mv) of the polycarbonate lies within the aforementioned range, the molded body can be prevented from becoming brittle, the melt viscosity can be prevented from becoming too high so that the produced resin can be taken out easily, and the fluidity can be improved to facilitate injection molding in a molten state.

The viscosity-average molecular weight (Mv) was calculated by the following equation: <MAT> where the intrinsic viscosity [η] (deciliters/gram) was determined under the following measurement conditions at a Huggins constant of <NUM>:.

In one embodiment of the present invention, the transmittance at <NUM> of the terminally modified polycarbonate resin may be <NUM>% or less. The transmittance at <NUM> of the terminally modified polycarbonate resin of the present invention may be preferably <NUM>% or less, and more preferably <NUM>% or less. As far as the transmittance at <NUM> lies within the above-mentioned range, the terminally modified polycarbonate resin can be put to practical use as a polycarbonate resin excellent in both UV absorbing capacity and photostability.

The transmittance at <NUM> was obtained by conducting zero adjustment at <NUM> with a dichloromethane solvent, and then measuring transmittance of the resin solution under the following conditions:.

Absorptions of C=N stretching and N=N stretching originating from Terminating agent A were confirmed at <NUM>-<NUM> and <NUM>-<NUM> in the IR spectrum, confirming incorporation of the terminating agent at the end of the polycarbonate resin.

The IR spectrum was obtained by conducting measurement in the measured wavenumber range of <NUM>-<NUM>-<NUM> by a film technique using FT/IR-<NUM>+ manufactured by JASCO Corporation. The film was prepared by a solution-cast film technique by dissolving the polycarbonate resin in dichloromethane.

Hereinafter, the present invention will be described by way of examples. These examples are not intended to limit the present invention.

Terminally modified polycarbonate resins were produced by the following methods to analyze the viscosity-average molecular weight (Mv), the transmittance at <NUM> and the infrared absorption (IR) spectrum of each of the resulting resins.

To <NUM> of a <NUM>% (w/w) aqueous sodium hydroxide solution and <NUM> of pure water, <NUM> of bisphenol A (BPA) manufactured by NIPPON STEEL Chemical and Material Co. and <NUM> hydrosulfite were added to be dissolved therein. To this, <NUM> of dichloromethane was added, and <NUM> of phosgene was blown into the resultant by spending <NUM> minutes while stirring and keeping the solution temperature within a range of <NUM>-<NUM>.

After the end of phosgene blowing, <NUM> of a <NUM>% (w/w) aqueous sodium hydroxide solution, <NUM> of dichloromethane and <NUM> of RUVA-<NUM> manufactured by Otsuka Chemical Co. (Terminating agent A) dissolved in <NUM> of dichloromethane were added and vigorously stirred to emulsify, followed by addition of <NUM> of triethylamine (TEA) as a polymerization catalyst to allow polymerization for about <NUM> minutes. <CHM>
<CHM>.

The polymerization solution was separated into an aqueous phase and an organic phase. The organic phase was neutralized with phosphoric acid and repeatedly washed with pure water until pH of the rinsing liquid was neutral. The organic solvent was evaporated and distilled away from the resulting polycarbonate resin solution, thereby obtaining polycarbonate resin powder.

Mv was <NUM>,<NUM>, and transmittance at <NUM> was <NUM>%. Furthermore, absorptions of C=N stretching and N=N stretching originating from Terminating agent A were confirmed at <NUM>-<NUM> and <NUM>-<NUM> in the IR spectrum, confirming incorporation of the terminating agent at the end of the polycarbonate resin.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that BPA was changed to <NUM> of bisphenol AP manufactured by Honshu Chemical Industry Co. , and the amount of Terminating agent A was changed to <NUM>.

Mv was <NUM>,<NUM>, and transmittance at <NUM> was <NUM>%. As with Example <NUM>, incorporation of the terminating agent at the end of the polycarbonate resin was confirmed in the IR spectrum.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that BPA was changed to <NUM> of bisphenol Z manufactured by Honshu Chemical Industry Co. , and the amount of Terminating agent A was changed to <NUM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that BPA was changed to <NUM> of bisphenol cyclododecane (bisphenol CD) manufactured by Honshu Chemical Industry Co. , and the amount of Terminating agent A was changed to <NUM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that <NUM> of bisphenol C manufactured by Honshu Chemical Industry Co. was used in addition to <NUM> of BPA, and the amount of Terminating agent A was changed to <NUM>. <CHM>
<CHM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that BPA was changed to <NUM> of bisphenol MIBK manufactured by Honshu Chemical Industry Co. , and the amount of Terminating agent A was changed to <NUM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that BPA was changed to <NUM> of bisphenol IOTD manufactured by Honshu Chemical Industry Co. , and the amount of Terminating agent A was changed to <NUM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that BPA was changed to <NUM> of bisphenol IBTD manufactured by Honshu Chemical Industry Co. , and the amount of Terminating agent A was changed to <NUM>. <CHM>
<CHM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that BPA was changed to <NUM> of bisphenol CD manufactured by Honshu Chemical Industry Co. and <NUM> bisphenol MIBK manufactured by Honshu Chemical Industry Co. , and the amount of Terminating agent A was changed to <NUM>. <CHM>
<CHM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that the amount of Terminating agent A was changed to <NUM>.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that Terminating agent A was changed to <NUM> of p-tert-butylphenol (PTBP).

Mv was <NUM>,<NUM>, and transmittance at <NUM> was <NUM>%. Absorptions at <NUM>-<NUM> and <NUM>-<NUM> were not confirmed in the IR spectrum.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that Terminating agent A was changed to <NUM> of MILEX PM (Terminating agent B) manufactured by Mitsui Chemicals, Inc.

A polycarbonate resin was synthesized in the same manner as Example <NUM> except that Terminating agent A was changed to <NUM> of p-tert-butylphenol.

The results of analyses described above are summarized in Table <NUM> below.

Claim 1:
A terminally modified polycarbonate resin comprising a structure represented by General formula (A) and a structural unit derived from a dihydric phenol:
<CHM>
(in General formula (A) above, R<NUM> represents a hydrogen atom or a C1-C6 alkyl group, R<NUM> represents a C1-C6 alkylene group, R<NUM> represents a hydrogen atom or a methyl group, R<NUM> represents a hydrogen atom or a halogen atom, and * represents the position of the bond to the main chain of the polycarbonate resin.)