Melt spinning resin composition, manufacturing method for same, and fiber manufacturing method

Patent metadata

Field	Value
Publication number	US-2024133078-A1
Application number	US-202318535350-A
Country	US
Kind code	A1
Filing date	Dec 11, 2023
Priority date	Dec 2, 2019
Publication date	Apr 25, 2024
Grant date	—

Abstract

The resin composition for melt spinning of the present invention is a filament having a melt viscosity of 250 Pa·s or less at 200° C. and a shear rate of 0.1 s −1 and a tensile strength of 10 MPa or more. The filament can be produced by forming a molten liquid of a resin composition having a melt viscosity of 250 Pa·s or less at 200° C. and a shear rate of 0.1 s −1 into a filament shape to provide a formed material, and conveying and concurrently cooling the formed material. The present invention also provides a resin composition for melt spinning being a filament, and a method for producing fiber using a melt spinning apparatus.

First claim

1 : A method for producing fiber using a melt spinning apparatus,
wherein
the melt spinning apparatus comprises:
a supply port to which a material is supplied;
a heating section which melts the material supplied from the supply port, without application of any kneading force; and
a nozzle which is in direct communication with the heating section and discharges the material in a molten state,

wherein the material for melting spinning is a resin composition, wherein the resin composition is a filament and having a melt viscosity of 250 Pa·s or less at 200° C. and a shear rate of 0.1 s −1 and a tensile strength of 10 MPa or more, the method comprising: supplying the material to the supply port of the melt spinning apparatus; supplying the material from the supply port and concurrently discharging the material in a molten state from the nozzle to be spun.

2 : The method for producing fiber according to claim 1 , wherein
the melt spinning apparatus further comprises a gas flow spraying section which conveys the material discharged from the nozzle by gas flow, and the filament is supplied from the supply port, and concurrently the material in a molten state is discharged from the nozzle to be spun, in a state where the gas flow is sprayed from the gas flow spraying section.

3 : The method for producing fiber according to claim 1 , wherein
the melt spinning apparatus further comprises an electrically charging device which electrically charges the material discharged from the nozzle, and the filament is supplied from the supply port, and concurrently the material in a molten state is discharged from the nozzle into an electrical field to be spun, in a state where the electrical field is formed by the electrically charging device.

4 : The method for producing fiber according to claim 1 , comprising:
forming a molten liquid of the resin composition into a filament shape to provide a formed material; and conveying and concurrently cooling the formed material.

5 : The method for producing fiber according to claim 1 , wherein the filament has a cross-sectional average diameter in a direction perpendicular to a length direction thereof of 1 mm or more and 30 mm or less.

6 : The method for producing fiber according to claim 4 , wherein
a filament producing apparatus is used, the filament producing apparatus comprises an extruding section which extrudes the molten liquid from a discharge port to provide the formed material and a conveying section which conveys the formed material, and a distance between the discharge port and the conveying section is 1 mm or more and 50 mm or less.

7 : The method for producing fiber according to claim 4 , wherein an extruding section which extrudes the molten liquid from a discharge port to provide the formed material, a conveying section which conveys the formed material, and a cooling section which cools the formed material are provided, and
the formed material in a filament shape is cooled by using at least one of air cooling, a cooling roller, a gas tank, and a liquid tank.

8 : The method for producing fiber according to claim 4 , wherein
the method for producing fiber comprises: extruding the molten liquid into a filament shape to provide a formed material; and conveying and concurrently cooling the formed material, and a ratio of a speed of the formed material conveyed (V2) to a speed of the molten liquid extruded (V1), V2/V1, is 1 or more and 50 or less.

9 : The method for producing fiber according to claim 8 , wherein the speed of the formed material conveyed, V2, is 0.2 m/min or more and 200 m/min or less.

10 : The method for producing fiber according to claim 1 , wherein
the resin composition includes a thermoplastic resin at an amount of 95 parts by mass or more based on 100 parts by mass of the resin composition.

11 : The method for producing fiber according to claim 1 , wherein
the resin composition comprises a thermoplastic resin, and the thermoplastic resin comprises a polylactic acid-based resin.

12 : The method for producing fiber according to claim 1 , wherein
the thermoplastic resin comprises one or more selected from a polypropylene resin having a weight-average molecular weight of 150,000 g/mol or less and a polylactic acid-based resin having a weight-average molecular weight of 150,000 g/mol or less.

13 : The method for producing fiber according to claim 1 , wherein
the resin composition comprises a thermoplastic resin,
the thermoplastic resin comprises a polypropylene resin, and
the polypropylene resin has a weight-average molecular weight of 1,000 g/mol or more and 150,000 g/mol or less.

14 : The method for producing fiber according to claim 1 , wherein
the resin comprises a thermoplastic resin, and the thermoplastic resin comprises a polylactic acid-based resin having a weight-average molecular weight of 100,000 g/mol or less.

15 : The method for producing fiber according to claim 1 , wherein
the filament has a cross-sectional average diameter in a direction perpendicular to a length direction thereof of 1 mm or more and 5 mm or less.

16 : The method for producing fiber according to claim 1 , wherein the heating section does not include a screw or a stirring blade.

17 : The method for producing fiber according to claim 1 , wherein
the material comprises a single, continuous filament, the heating section melts a part of the single filament, and the resin composition is continuously supplied from the supply port as the material for melt spinning.

Assignees

• Kao Corp

Inventors

• Hirano Takahiro
• Kobayashi Hideo
• Uematsu Takehiko
• Natsui Shohei

Classifications

• B29K2067/046

  PLA, i.e. polylactic acid or polylactide · CPC title

• D01D5/0023 Primary

  the material being a polymer melt · CPC title

• D01D1/06

  Feeding liquid to the spinning head (constructions of pumps F04) · CPC title

• D01F6/06 Primary

  from polypropylene · CPC title

• D01F6/625

  derived from hydroxy-carboxylic acids, e.g. lactones · CPC title