Transparent thermoplastic resin pellet manufacturing method

Patent metadata

Field	Value
Publication number	US-9751990-B2
Application number	US-201214371102-A
Country	US
Kind code	B2
Filing date	Dec 21, 2012
Priority date	Jan 10, 2012
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A method for producing a transparent thermoplastic resin pellet comprising a step of kneading a transparent thermoplastic resin with a kneader under a condition under which a damage history calculated according to the following formula is 500 to 2,500:

Damage history={Residence time ( tr )}×{Shear rate (γ)}

Residence time ( tr )=( W×H×L )/ Q

Shear rate (γ)=(π× D×N )/ H

in the formulae, W represents a screw groove width (pitch) [cm]; H represents a screw groove depth [cm]; L represents a screw length [cm]; Q represents a resin supply amount [g/s]; D represents a screw diameter [cm]; and N represents a screw rotation number [rps].

First claim

The invention claimed is:

1. A method for producing a transparent thermoplastic resin pellet, the method comprising
kneading a transparent thermoplastic resin with a kneader under a condition under which a damage history calculated according to the following formula is from 500 to 2,500 cm 3 /g:
Damage history={Residence time ( tr )}×{Shear rate (γ)}

Residence time ( tr )=( W×H×L )/ Q
Shear rate (γ)=(π× D×N )/ H

wherein W represents a screw groove width (pitch) [cm]; H represents a screw groove depth [cm]; L represents a screw length [cm]; Q represents a resin supply amount [g/s]; D represents a screw diameter [cm]; and N represents a screw rotation number [rps].

2. The method of claim 1 , wherein the transparent thermoplastic resin is an aromatic polycarbonate.

3. The method of claim 2 , wherein the aromatic polycarbonate has a viscosity average molecular weight (Mv) of from 11,000 to 23,000.

4. The method of claim 1 , wherein the kneader is a twin-screw kneader.

5. The method of claim 1 , wherein the kneader is equipped with a melt filter for removal of extraneous foreign matter.

6. The method of claim 1 wherein the damage history is from 900 to 2,000 cm 3 /g.

7. The method of claim 1 wherein the transparent thermoplastic resin is selected from the group consisting of a polyarylate resin, a polymethyl methacrylate resin, a polystyrene resin and a polycarbonate resin.

8. The method of claim 1 wherein the transparent thermoplastic resin is a polycarbonate prepared from bisphenol A.

Assignees

• Idemitsu Kosan Co

Inventors

• Tanaka Takayoshi
• Chosa Munehiro
• Yamazaki Yasunobu

Classifications

• B29C48/40

  using two or more parallel screws {or at least two parallel non-intermeshing screws}, e.g. twin screw extruders · CPC title

• B29B9/16

  Auxiliary treatment of granules · CPC title

• C08J3/005 Primary

  Processes for mixing polymers · CPC title

• C08J2369/00

  Characterised by the use of polycarbonates; Derivatives of polycarbonates · CPC title

• B29K2069/00

  Use of PC, i.e. polycarbonates {or derivatives thereof}, as moulding material · CPC title