Method of manufacturing transparent resin composition

Patent metadata

Field	Value
Publication number	US-9688001-B2
Application number	US-201615192359-A
Country	US
Kind code	B2
Filing date	Jun 24, 2016
Priority date	Dec 26, 2013
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

In a method of manufacturing a transparent resin composition, a molten resin mixture is produced by supplying polycarbonate resin and acrylic resin continuously to a twin-screw extruder. The molten resin mixture is supplied to a single-screw extruder including a screw in which a shear processing portion is provided. Further, a transparent resin composition is produced continuously by kneading the molten resin mixture in the shear processing portion which rotates at between 500 and 4000 rpm.

First claim

What is claimed is:

1. A method of manufacturing a transparent resin composition containing polycarbonate resin and acrylic resin, the method comprising:
continuously supplying the polycarbonate resin in which an amount supplied per unit time is set to 95 to 60% by weight, and acrylic resin in which an amount supplied per unit time is set to 5 to 40% by weight, to a twin-screw extruder in which two first screws engaging with each other rotate in a same direction at no more than 600 rpm;
producing a molten resin mixture by melting and mixing the polycarbonate resin and the acrylic resin in the twin-screw extruder, and discharging the molten resin mixture continuously from the twin-screw extruder;
continuously supplying the molten resin mixture discharged from the twin-screw extruder to a single-screw extruder, the single-screw extruder comprising a second screw and a cylinder in which the second screw is accommodated, the second screw comprising a feed flight from a base end portion to an apical end portion, and a shear processing portion in an intermediate portion;
producing a transparent resin composition by kneading the molten resin mixture in the shear processing portion which rotates at between 500 and 4000 rpm with the second screw; and
discharging the produced transparent resin composition continuously from the single-screw extruder.

2. The method of claim 1 , wherein
the shear processing portion comprises a backward feed flight which twists in a direction opposite to a direction in which the feed flight twists, and
when the molten resin mixture delivered by the second screw passes through a gap between an inner circumferential wall of the cylinder and an outer circumferential portion of the backward feed flight, the molten resin mixture is kneaded.

3. The method of claim 2 , wherein
a shear action is applied to the molten resin mixture when the molten resin mixture passes through the gap between the inner circumferential wall of the cylinder and the outer circumferential portion of the backward feed flight.

4. The method of claim 1 , wherein
the shear processing portion comprises an annular protrusion which protrudes concentrically in a radial direction of the second screw, the protrusion being formed continuously in a circumferential direction of the second screw, and
when the molten resin mixture delivered by the second screw passes through a gap between an inner circumferential wall of the cylinder and an outer circumferential portion of the protrusion, the molten resin mixture is kneaded.

5. The method of claim 4 , wherein
a shear action is applied to the molten resin mixture when the molten resin mixture passes through the gap between the inner circumferential wall of the cylinder and the outer circumferential portion of the protrusion.

6. The method of claim 1 , wherein
an outer diameter and a root diameter of the feed flight of the single-screw extruder are set constantly, and
the feed flight of the single-screw extruder delivers the molten resin mixture supplied from the twin-screw extruder from a base end portion of the screw to the shear processing portion, and delivers the transparent resin composition produced by the shear processing portion from the shear processing portion to the apical end portion of the screw.

7. The method of claim 1 , wherein
an outer diameter of the second screw is greater than an outer diameter of the first screw, and
the molten resin mixture delivered by the second screw is delivered to the shear processing portion without being filled in intervals of the feed flight of the second screw.

8. The method of claim 2 , wherein
an outer diameter and a root diameter of the feed flight of the single-screw extruder are set constantly, and
the feed flight of the single-screw extruder delivers the molten resin mixture supplied from the twin-screw extruder from a base end portion of the screw to the shear processing portion, and delivers the transparent resin composition produced by the shear processing portion from the shear processing portion to the apical end portion of the screw.

9. The method of claim 3 , wherein
an outer diameter and a root diameter of the feed flight of the single-screw extruder are set constantly, and
the feed flight of the single-screw extruder delivers the molten resin mixture supplied from the twin-screw extruder from a base end portion of the screw to the shear processing portion, and delivers the transparent resin composition produced by the shear processing portion from the shear processing portion to the apical end portion of the screw.

10. The method of claim 4 , wherein
an outer diameter and a root diameter of the feed flight of the single-screw extruder are set constantly, and
the feed flight of the single-screw extruder delivers the molten resin mixture supplied from the twin-screw extruder from a base end portion of the screw to the shear processing portion, and delivers the transparent resin composition produced by the shear processing portion from the shear processing portion to the apical end portion of the screw.

11. The method of claim 5 , wherein
an outer diameter and a root diameter of the feed flight of the single-screw extruder are set constantly, and
the feed flight of the single-screw extruder delivers the molten resin mixture supplied from the twin-screw extruder from a base end portion of the screw to the shear processing portion, and delivers the transparent resin composition produced by the shear processing portion from the shear processing portion to the apical end portion of the screw.

Assignees

• Toshiba Machine Co Ltd
• Hsp Tech Inc

Inventors

• Kobayashi Akiyoshi
• Fujii Shigeyuki
• Sameshima Takafumi
• Shimizu Hiroshi

Classifications

• B29B7/482

  provided with screw parts in addition to other mixing parts, e.g. paddles, gears, discs · CPC title

• C08L33/00

  Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers · CPC title

• B29B7/7485

  with consecutive mixers, e.g. with premixing some of the components · CPC title

• B29B7/487 Primary

  with consecutive casings or screws, e.g. for feeding, discharging, mixing · CPC title

• B29C48/575

  provided with elements of a generally circular cross-section for shearing the melt, i.e. shear-ring elements · CPC title