# US 10,870,929 B2 · Polypropylene fiber and method for manufacturing polypropylene fiber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,870,929 B2 - Document ID: US10870929B2 - Status: Granted - Kind: B2 - Application number: 15/743,565 - Filed: 2016-07-12 - Published: 2018-07-19 - Granted: 2020-12-22 - Earliest claimed: 2015-07-24 - Assignees: Mitsubishi Chemical Corporation - Applicants: Mitsubishi Chemical Corporation - Inventors: Masaki Fujie; Tomoyoshi Yamashita; Hironobu Ikeda; Junya Imakita - Web page: https://patentgrep.com/patent/US10870929B2 ## CPC - D01F 6/06: from polypropylene - C08L 23/12: Polypropene - D01D 5/16: using rollers, or like mechanical devices, e.g. snubbing pins - D02J 1/22: Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch (stretch spinning D01D5/12) - G01N 25/4866: {by using a differential method} - C08L 2205/16: Fibres; Fibrils - C08L 2205/24: Crystallisation aids - D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS - D02J: FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE (curling or crimping D02G; by treatment with liquids, gases or vapours D06B; finishing other than by liquid treatment, of yarns in warp or sheet form D06C; for chemical matters, see D06L, D06M, D06P, D06Q; treatment during rope-making, apparatus for treating ropes auxiliary to rope-making D07B) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Obtained is a polypropylene fiber that selectively satisfies any of the following requirements: the degree of amorphous orientation being not lower than 85%; the degree of crystalline orientation being not lower than 90%; the degree of crystallinity being 60-75%; the strength being not lower than 7 cN/dtex; the initial elastic modulus being not lower than 100 cN/dtex; the rupture elongation being 10-30%; and the single fiber fineness being 3-20 dtex. This polypropylene fiber, in which a crystalline chain and an amorphous chain are highly oriented and that has high strength and high initial elastic modulus, is produced through a two-stage drawing method and by controlling the drawing tension of the final stage while maintaining production speed. ## Claims ### Claim 1 A polypropylene fiber, having an amorphous orientation degree of 88% or higher, wherein a strength is 7 cN/dtex or more, an initial elastic modulus is 100 cN/dtex or more, and a elongation at break is 10% to 30%. ### Claim 2 (depends on 1) The polypropylene fiber according to claim 1, wherein a single fiber fineness is 3 dtex to 20 dtex. ### Claim 3 (depends on 1) The polypropylene fiber according to claim 1, wherein a total fineness is 90 dtex to 900 dtex. ### Claim 4 (depends on 1) The polypropylene fiber according to claim 1, having an amorphous orientation degree of 90% to 92%. ### Claim 5 A polypropylene fiber, having an amorphous orientation degree of 85% or higher and a crystallinity degree of 60% to 75% as determined by wide angle X-ray diffraction. ### Claim 6 (depends on 5) The polypropylene fiber according to claim 5, having an amorphous orientation degree of 88% to 98%. ### Claim 7 (depends on 5) The polypropylene fiber according to claim 5, wherein a single fiber fineness is 3 dtex to 20 dtex. ### Claim 8 (depends on 5) The polypropylene fiber according to claim 5, wherein a total fineness is 90 dtex to 900 dtex. ### Claim 9 (depends on 5) The polypropylene fiber according to claim 5, wherein a strength is 7 cN/dtex or more, an initial elastic modulus is 100 cN/dtex or more, and a elongation at break is 10% to 30%. ### Claim 10 A polypropylene fiber, having an amorphous orientation degree of 85% or higher and an endothermic melting peak of 85 J/g to 12.0 J/g as determined by differential scanning calorimetry. ### Claim 11 (depends on 10) The polypropylene fiber according to claim 10, having an amorphous orientation degree of 88% to 98%. ### Claim 12 (depends on 10) The polypropylene fiber according to claim 10, wherein a single fiber fineness is 3 dtex to 20 dtex. ### Claim 13 (depends on 10) The polypropylene fiber according to claim 10, wherein a total fineness is 90 dtex to 900 dtex. ### Claim 14 (depends on 10) The polypropylene fiber according to claim 10, wherein a strength is 7 cN/dtex or more, an initial elastic modulus is 100 cN/dtex or more, and a elongation at break is 10% to 30%. ### Claim 15 A polypropylene fiber, having an amorphous orientation degree of 85% or higher and a ratio of a scattering intensity in a meridian direction to a scattering intensity in an equatorial direction of 0.5 to 0.95 as determined by small angle X-ray scattering. ### Claim 16 (depends on 15) The polypropylene fiber according to claim 15, having an amorphous orientation degree of 90% to 98%. ### Claim 17 (depends on 15) The polypropylene fiber according to claim 15, wherein a single fiber fineness is 3 dtex to 20 dtex. ### Claim 18 (depends on 15) The polypropylene fiber according to claim 15, wherein a total fineness is 90 dtex to 900 dtex. ### Claim 19 (depends on 15) The polypropylene fiber according to claim 15, wherein a strength is 7 cN/dtex or more, an initial elastic modulus is 100 cN/dtex or more, and a elongation at break is 10% to 30%.