摘要:
A process for preparing an end-capped polycarbonate comprises melt reacting an aromatic dihydroxy compound, a carbonic acid diester, and optionally a catalyst in a prepolymerization vessel to form a polycarbonate product; transferring the polycarbonate product from the prepolymerization vessel; mixing the polycarbonate product with an end-capping agent under hermetic seal at a pressure of at least about 760 mm Hg; and transferring the polycarbonate product and end-capping agent mixture to a postpolymerization vessel to endcap the polycarbonate product. An apparatus for preparing an end-capped polycarbonate comprises a prepolymerization vessel having and inlet and an outlet; a postpolymerization vessel having an inlet and an outlet; a mixer in fluid communication with the outlet of the prepolymerization vessel and the inlet of the postpolymerization vessel; and a charging port through which an end-capping agent is charged to the mixer, wherein the mixer is hermetically sealed at greater than or equal to 760 mm Hg.
摘要:
Polycarbonate having increased end-cap levels is made by adding an end-capping agent to the polycarbonate, preferably after the polycarbonate has reached a number-average molecular weight of about 2,000 to 15,000 Dalton. The end-capping agent has the formula: wherein R1 is a phenyl, phenoxy, benzyl, or benzyloxy and R2 is selected from the group consisting of C1-C30 alkyl, C1-C30 alkoxy, C6-C30 aryl, C6-C30 aryloxy, C7-C30 aralkyl, and C7-C30 aralkyloxy.
摘要:
Polycarbonate resin containing reduced levels of reaction by-products can be prepared by adding to the polycarbonate a scavenging agent having the formula: wherein R1 is alkoxy, phenoxy, benzyloxy or phenyl, and R2 is a substituted or unsubstituted C1-C30 alkyl group, C6-C30 aryl group, C7-C30 aralkyl group or C6-C30 aryloxy group and processing the resulting mixture at an elevated temperature and for a period of time such that the scavenging agent reacts with linear Fries products to produce capped linear Fries products, and with residual phenols (monohydric or dihydric) to produce capped phenols and ortho-substituted phenols.
摘要:
A process for the production of polycarbonate having increased end-cap levels, the process comprising adding a terminal blocking agent of the formula: wherein R1 is a propoxy or butoxy and R2 is selected from the group consisting of C1-C30 alkyl, C1-C30 alkoxy, C6-C30 aryl, C7-C30 aralkyl, and C6-C30 aryloxy.
摘要:
A process for the production of polycarbonate by melt-polycondensing an aromatic dihydroxy compound and diphenylcarbonate, the process comprising adding the to polycarbonate under melt conditions a compound of the formula (1): wherein R1 and R3 may be the same or different and are selected from the group consisting of alkoxy, phenoxy, benzoxy, aryloxy, phenyl and aryl groups, R2 is selected from the group consisting of alkyl, phenyl, aryl, or aralkyl groups.
摘要:
In various embodiments the present invention comprises 2,4,6-trisubstituted-1,3,5-triazine capping agents comprising one, two, or three leaving groups as substituents with any remaining substituents being essentially inert to reaction with a nucleophilic group on a polymer or monomer, or reactive with a nucleophilic group on a polymer or monomer at a slower rate than any leaving group. The invention also comprises polymers or monomers with nucleophilic groups capped with a triazine moiety. Still other embodiments of the invention comprise processes for capping nucleophilic groups in a polymer or monomer which comprises combining and reacting the polymer or monomer with a triazine-comprising capping agent.
摘要:
In various embodiments the present invention comprises 2,4,6-trisubstituted-1,3,5-triazine capping agents comprising one, two, or three leaving groups as substituents with any remaining substituents being essentially inert to reaction with a nucleophilic group on a polymer or monomer, or reactive with a nucleophilic group on a polymer or monomer at a slower rate than any leaving group. The invention also comprises polymers or monomers with nucleophilic groups capped with a triazine moiety. Still other embodiments of the invention comprise processes for capping nucleophilic groups in a polymer or monomer which comprises combining and reacting the polymer or monomer with a triazine-comprising capping agent.
摘要:
A method for end-capping polycarbonate resins, comprising the step of processing a mixture comprising a polycarbonate having free hydroxyl-end groups and an end-capping reagent in a melt transesterification reaction to produce a polycarbonate resin, wherein the end-capping reagent comprises a mixture of:(a) at least one species of a symmetrical activated aromatic carbonate, and (b) at least one species of a symmetrical non-activated aromatic carbonate, whereby said end-capping reagent reacts with at least some of the free hydroxyl end-groups of the polycarbonate to produce an end-capped polycarbonate resin.
摘要:
A method of making polycarbonate includes the steps of forming polycarbonate by a melt transesterification method using an activated diaryl carbonate, and compounding the polycarbonate with a phosphorus-containing compound that has an abstractable proton or hydrolyzable group. The phosphorus-containing compound is compounded with the polycarbonate in an amount sufficient to result in an improvement in the color properties of the polycarbonate as compared to pellets formed from the same polycarbonate without addition of the phosphorus-containing compound.
摘要:
Alkyl ester end-capped polycarbonates have improved release properties and may be produced by a method comprising the step of combining a polycarbonate having free terminal OH groups with an end-capping reagent comprising a symmetrical activated carbonate and an alkyl ester, whereby the end-capping reagent reacts with at least some of the free hydroxyl end groups of the polycarbonate to produce an end-capped polycarbonate comprising optionally substituted aliphatic ester end groups.