WATER-DISINTEGRABLE COMPOSITE FIBER AND METHOD FOR PRODUCING THE SAME

• US 20150284879A1
• Filed: 09/12/2013
• Published: 10/08/2015
• Est. Priority Date: 09/14/2012
• Status: Abandoned Application

• Current Assignee: Kureha Corporation
• Original Assignee: Kureha Corporation
• Inventors: Takahashi, Takeo, Yamazaki, Masahiro, Sato, Hiroyuki, Chiba, Yukitoshi
• Application Number:
  US14/421,560
• Publication Number:
  US 20150284879A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C09K 2208/08 Fiber-containing well treatment fluids
• CPC Class Codes: C09K 8/035 Organic additives
• CPC Class Codes: D01D 5/08 Melt spinning methods D01D5/0023 takes precedence
• CPC Class Codes: D01D 5/084 Heating filaments, threads or the like, leaving the spinnerettes
• CPC Class Codes: D01D 5/26 Formation of staple fibres by flash-spinning D01D5/11
• CPC Class Codes: D01F 6/625 derived from hydroxy-carboxylic acids, e.g. lactones
• CPC Class Codes: D01F 8/14 with at least one polyester as constituent
• CPC Class Codes: D10B 2331/041 derived from hydroxy-carboxylic acids, e.g. lactones
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]
• CPC Class Codes: Y10T 428/2931 Fibers or filaments nonconcentric [e.g., side-by-side or eccentric, etc.]

Abstract

A water-disintegrable composite fiber comprising a phase containing a polyglycolic acid resin and a phase containing a polylactic acid resin with a D-lactic acid unit ratio of at least 1.0%; the two phases extending continuously in a lengthwise direction; and the composite fiber having a cross sectional area formed by the phase containing the polyglycolic acid resin having an area ration of at most 50%; and the content of the polyglycolic acid resin being from 2 to 100 parts by mass per 1 part by mass of the D-lactic acid units in the polylactic acid resin.

Claims

1. A water-disintegrable composite fiber comprising a phase containing a polyglycolic acid resin and a phase containing a polylactic acid resin with a D-lactic acid unit ratio of at least 1.0%;

the two phases extending continuously in a lengthwise direction respectively; and

the composite fiber having a cross-sectional area formed by the phase containing the polyglycolic acid resin having an area ratio of at most 50%; and

the content of the polyglycolic acid resin being from 2 to 100 parts by mass per 1 part by mass of the D-lactic acid units in the polylactic acid resin.

2. The water-disintegrable composite fiber according to claim 1, wherein the water-disintegrable composite fiber has a side surface in which a surface area formed by the phase containing the polyglycolic acid resin has an area ratio of at most 50%.

3. The water-disintegrable composite fiber according to claim 1, wherein the water-disintegrable composite fiber has at least one type of structure selected from a core-sheath type, a multicore type, a side-by-side type, a multiple-division type, a multilayer type, and a radial type.

4. The water-disintegrable composite fiber according to claim 1, wherein the fiber is an undrawn fiber.

5. The water-disintegrable composite fiber according to claim 1, wherein the fiber is a drawn fiber.

6. The water-disintegrable composite fiber according to claim 5, wherein a single fiber fineness is 3.0 denier or less.

7. A fiber obtained by removing either the polyglycolic acid resin or the polylactic acid resin from the water-disintegrable composite fiber described in claim 5.

8. A water-disintegrable composite staple fiber obtained by cutting the water-disintegrable composite fiber described in claim 5.

9. The water-disintegrable composite staple fiber according to claim 8, wherein the staple fiber is used as an additive at a time of drilling or sompletion of oil or gas recovery.

10. A method for producing a water-disintegrable composite fiber, the method comprising the steps of:

forming a fibrous composite by continuously discharging a polylactic acid resin having a D-lactic acid unit ratio of at least 1.0% and from 2 to 100 parts by mass of a polyglycolic acid resin per 1 part by mass of D-lactic acid units in the polylactic acid resin from a spinneret for composite fibers, each of the resins being discharged in a molten state; and

cooling the fibrous composite to obtain an undrawn yarn comprising a phase containing the polyglycolic acid resin and a phase containing the polylactic acid resin, the undrawn yarn having a cross section in which an area formed by the phase containing the polyglycolic acid resin has an area ratio of at most 50%.

11. A method for producing a water-disintegrable composite fiber, the method comprising the step of:

drawing an undrawn yarn obtained by the production method described in claim 10 so as to obtain a drawn yarn comprising the phase containing the polyglycolic acid resin and the phase containing the polylactic acid resin, the drawn yarn having a cross section in which an area formed by the phase containing the polyglycolic acid resin has an area ratio of at most 50%, and the drawn yarn containing from 2 to 100 parts by mass of the polyglycolic acid resin per 1 part by mass of the D-lactic acid units in the polylactic acid resin.

12. A method of producing a water-disintegrable composite fiber, the method comprising the step of cutting a drawn yarn obtained by the production method described in claim 11 to obtain a water-disintegrable composite fiber staple fiber.