JP2007211376A - Core-sheath structure composite fiber containing fluoropolymer in sheath and article having the composite fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conjugate fiber which is obtained by melt-kneading a specific fluorine-containing polymer and then spinning the polymer, and effectively exhibits a liquid-repelling property, even if the fluorine-containing polymer is added in a small amount. <P>SOLUTION: This conjugate fiber has a sheath-core structure comprising (A) a core comprising a thermoplastic resin and (B) a sheath comprising a thermoplastic resin having a melting point of 225°C and a fluorine-containing compound, wherein the fluorine-containing compound is a fluorine-containing polymer having repeating units derived from a fluorine-containing polymerizable compound containing a 1-21C linear or branched fluoroalkyl group or fluoroalkenyl group, or a fluorine-containing urethane compound containing a 1-21C linear or branched fluoroalkyl group or fluoroalkenyl group, and the amount of the fluorine-containing compound is 0.1 to 10.0 wt.% based on the sheath. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a core-sheath structure composite fiber including a fluoropolymer in a sheath part. The composite fiber is characterized in that the fluorine-containing polymer mixed before spinning is unevenly distributed on the fiber surface. The present invention also relates to an article comprising the composite fiber. Applications include articles such as clothing, leisure goods, household goods, wipers, filters, civil engineering materials, building materials, sanitary goods, and medical goods, which are made using this composite fiber fabric. Moreover, it can be used also as a fishing line using this composite fiber, or a nonwoven fabric.

In order to impart water and oil repellency to the fiber surface, a technique for subjecting the surface to fluorine treatment has been conventionally known. However, the method of subjecting the fiber surface to fluorine treatment has a problem in that the water / oil repellent function is not durable and the water / oil repellent function is lowered by repeated use. In order to solve this problem, research has been conducted to impart water and oil repellency by adding a fluorine compound to a resin and melt-kneading the resin before spinning.
For example, in Japanese Patent Application Laid-Open No. 2000-96348, polyethylene terephthalate is used for the core, polyester and nylon are used for the sheath, and a fluoropolymer having a melt viscosity similar to that of the resin is melt-spun, stretched, and scraped off in the sheath. It is described that water repellency, oil repellency, and antifouling properties can be imparted to the surface of the composite fiber by performing heat treatment at 160 to 200 ° C. later.

Japanese Patent Application Laid-Open No. 2000-328866 describes that a fishing line made of a composite monofilament whose core is polyvinylidene fluoride, polyester or polyamide and whose sheath is polyvinylidene fluoride is excellent in water repellency and water repellency. Has been.
In Japanese Patent Application Laid-Open No. 2004-292960, a fishing line made of a composite monofilament composed of a core part made of a polyamide-based resin and a sheath part made of a modified ethylenetetrafluoroethylene copolymer resin having a reactive group has water-repellent performance. It is described that it improves.
Moreover, in Japanese translations of PCT publication No. 2003-520659, in an electret article containing a specific fluorine-containing compound in polypropylene, 95 to 99.5 weight percent polypropylene and 0.5 to 5 weight percent fluorine-containing in the sheath The description relates to a fiber having a core-sheath structure containing a compound. However, since this compound has low compatibility with polypropylene, there is a drawback that bleeding out easily occurs.

  In order to impart liquid repellency to a composite fiber obtained by melt spinning a polymer and a fluorine compound, the fluorine compound must be present on the surface. Even in the known technology, a device for making the fluorine compound easily exist on the surface has been devised, but it is necessary to increase the amount of the fluorine-based polymer or to select a fluorine-based polymer having a limited melt viscosity. Was necessary.

  Therefore, in order to solve these problems, a specific fluorine-containing polymer is melt-kneaded and then spun, and even when a small amount of fluorine compound is added, it effectively segregates on the surface and exhibits liquid repellency. As a result, the present invention has been completed.

The present invention
(A) a core comprising a thermoplastic resin, and (B) a sheath comprising a thermoplastic resin having a melting point of 225 ° C. or less and a fluorine-containing compound, wherein the fluorine-containing compound is a straight chain having 1 to 21 carbon atoms Fluorine-containing polymer having a repeating unit derived from a fluorine-containing polymerizable compound containing a linear or branched fluoroalkyl group or fluoroalkenyl group, or a linear or branched fluoroalkyl group having 1 to 21 carbon atoms Or it is a fluorine-containing urethane compound containing a fluoroalkenyl group, and provides the composite fiber which has a core-sheath structure which consists of a sheath whose quantity of a fluorine-containing compound is 0.1-10.0 weight% with respect to a sheath.
The present invention also relates to articles made from composite fibers, such as fishing lines, non-woven fabrics.

  According to the present invention, a composite fiber excellent in water and oil repellency can be obtained. Since this composite fiber contains a small amount of the fluorine-containing compound, it is relatively inexpensive as a material containing the fluorine-containing compound. Can be used for products such as supplies (eg screen door nets, draining nets, tablecloths, curtains, carpets), wipers, filters, civil engineering supplies, building supplies, sanitary supplies (eg diapers), medical supplies, etc. . It can also be used for fishery products such as fishing lines from composite fibers. Furthermore, it is also possible to create a nonwoven fabric from composite fibers.

BEST MODE FOR CARRYING OUT THE INVENTION

Examples of the thermoplastic resin used for the core include polyamide resin (for example, nylon 6, nylon 12, nylon 66, aromatic nylon, copolymer nylon), polyester resin (for example, polyethylene terephthalate, polybutylene terephthalate), polyolefin resin ( For example, polyethylene, polypropylene, copolymers of ethylene and propylene, copolymers of ethylene or propylene and C _{4 to} C ₂₀ α olefins, terpolymers of ethylene, propylene and C _{4 to} C ₂₀ α olefins, ethylene and vinyl acetate Copolymer, copolymer of propylene and vinyl acetate, copolymer of styrene and α-olefin, polyisobutylene), polyether resin, polyether ester resin, polyacrylate resin, ethylene alkyl Acrylate resins, polydiene resins (e.g., polybutadiene, copolymers of isobutylene and isoprene), and the like polyurethane resins, polyether ether ketone resins, polyether imide resins, polyether sulfone resins, polyphenylene sulfide resins, polycarbonate resins. The melting point of the thermoplastic resin used for the core may be, for example, 80 to 350 ° C.

  Of these, polyamide resin, polyester resin, and polyolefin resin are preferable.

Examples of the thermoplastic resin having a melting point of 225 ° C. or lower, for example, 80 to 180 ° C., used for the sheath are polyamide resin (for example, nylon 6, nylon 12, aromatic nylon, copolymer nylon), polyolefin resin (for example, polyethylene, polypropylene) , Ethylene-propylene random copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, polybutylene, polymethylpentene) and the like.
Polyethylene includes high density polyethylene and low density polyethylene. Polypropylene includes isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, and amorphous polypropylene.

The copolymer nylon is a combination of various raw materials such as nylon 6, nylon 66, nylon 12, and the like, and has different properties, and is selected from commercially available copolymer nylons. It is possible to obtain.
The isotactic polypropylene is a highly crystalline polypropylene mainly composed of isotactic polypropylene produced by a ZIgler-Natta catalyst or a metallocene catalyst, and is generally selected and obtained from commercially available polypropylene. Is possible.
The amorphous polypropylene is propylene having extremely low crystallinity prepared using a metallocene catalyst. Amorphous polypropylene may be a mixture of very low crystallinity polypropylene (eg, at least 50% by weight of the total amount of the mixture) made with a metallocene catalyst and other propylene.
Amorphous polypropylene is available as Sumitomo Chemical's Tough Selenium T-3512, T-3522, and the like.

The fluorine-containing polymer has a repeating unit derived from a fluorine-containing polymerizable compound containing a linear or branched fluoroalkyl group or fluoroalkenyl group having 1 to 21 carbon atoms.
The fluorine-containing polymerizable compound generally has a carbon-carbon double bond in addition to a fluoroalkyl group or a fluoroalkenyl group. Examples of the fluorine-containing polymerizable compound are (meth) acrylic acid ester, epoxy compound, urethane compound, and vinyl ether compound. (Meth) acrylic acid esters are particularly preferred.

The fluoroalkyl group or fluoroalkenyl group is preferably a perfluoroalkyl group or a perfluoroalkenyl group. The upper limit of the number of carbon atoms of the fluoroalkyl group or fluoroalkenyl group is 21, for example 16, preferably 6, especially 5, and especially 4.
Examples of fluoroalkyl _{group, -CF 3, -CF 2 CF 3} , -CF 2 CF 2 CF 3, -CF (CF 3) 2, -CF 2 CF 2 CF 2 CF 3, -CF 2 CF (CF 3 ) ₂ , —C (CF ₃ ) ₃ , — (CF ₂ ) ₄ CF ₃ , — (CF ₂ ) ₂ CF (CF ₃ ) ₂ , —CF ₂ C (CF ₃ ) ₃ , —CF (CF ₃ ) CF ₂ CF ₂ CF ₃ ,-(CF ₂ ) ₅ CF ₃ ,-(CF ₂ ) ₃ CF (CF ₃ ) _2, -(CF ₂ ) ₄ CF (CF ₃ ) ₂ ,-(CF ₂ ) ₇ CF ₃ , _{- (CF 2) 5 CF (} CF 3) 2, - (CF 2) 6 CF (CF 3) 2, - a (CF _{2) 9} CF ₃ and the like. Examples of fluoro-alkenyl _{group, -C (CF (CF 3)} 2) = C (CF 3) (CF 2 CF 2 CF 3), - C (CF (CF 3) 2) = C (CF 3) (CF _{(CF 3) 2), -} C (CF 3) = C (CF (CF 3) 2) it is ₂ or the like.

Among the fluorine-containing polymerizable compounds, as the (meth) acrylic acid ester, for example, the formula:
CH ₂ = C (−X) −C (= O) −A−Rf (I)
[Wherein, X is a hydrogen atom, a methyl group, a linear or branched alkyl group having 2 to 20 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX ¹ X ² group (where X ¹ and X ² are a hydrogen atom, a fluorine atom or a chlorine atom.), A cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted benzyl group, or a substituted or An unsubstituted phenyl group,
A is —O—Y ¹ — (where Y ¹ is an aliphatic group having 1 to 10 carbon atoms, an aromatic group having 6 to 10 carbon atoms or a cyclic aliphatic group, —CH ₂ CH ₂ N (R ¹ ) SO ₂ — (CH ₂ CH ₂ ) _a — group (where R ¹ is an alkyl group having 1 to 4 carbon atoms, a is 0 or 1) or —CH ₂ CH (OR ¹¹ ) CH ₂ — A group (wherein R ¹¹ is a hydrogen atom or an acetyl group)), or —Y ² — [— (CH ₂ ) _m —Z—] _p — (CH ₂ ) _n — (where Y ² is —O— or —NH—; Z is —S— or —SO ₂ —; m is 1 to 10, n is 0 to 10, and p is 0 or 1.
Rf is a linear or branched fluoroalkyl group or fluoroalkenyl group having 1 to 21 carbon atoms. ]
The fluorine-containing (meth) acrylic acid ester shown by these is mentioned.

[式中、Ｒfは炭素数１〜２１のパーフルオロアルキル基
Ｒ¹ は水素または炭素数１〜１０のアルキル基、
Ｒ² は炭素数１〜１０のアルキレン基、
Ｒ³ は、水素原子、塩素原子またはメチル基、
Ａr は置換基を有することもあるアリール基、
n は１〜１０の整数を表わす。]
で示される含フッ素（メタ）アクリル酸エステルを挙げることができる。 Examples of fluorine-containing (meth) acrylic acid have the formula:

[Wherein, Rf is a perfluoroalkyl group having 1 to 21 carbon atoms, R ¹ is hydrogen or an alkyl group having 1 to 10 carbon atoms,
R ² is an alkylene group having 1 to 10 carbon atoms,
R ³ represents a hydrogen atom, a chlorine atom or a methyl group,
Ar is an aryl group which may have a substituent,
n represents an integer of 1 to 10. ]
The fluorine-containing (meth) acrylic acid ester shown by can be mentioned.

Specific examples of fluorine-containing (meth) acrylic acid esters are:
CF ₃ (CF ₂ ) ₃ (CH ₂ ) OCOCH═CH ₂ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) OCOC (CH ₃ ) ═CH ₂ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) OCOCCl═CH ₂ ,
CF ₃ (CF ₂ ) ₃ SO ₂ (CH ₂ ) ₃ OCOCH═CH ₂ ,
CF ₃ (CF ₂ ) ₅ (CH ₂ ) OCOCH═CH ₂ ,
CF ₃ (CF ₂ ) ₅ (CH ₂ ) OCOC (CH ₃ ) ═CH ₂ ,
(CF ₃ ) ₂ CF (CF ₂ ) ₃ (CH ₂ ) ₂ OCOCH═CH ₂ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ OCOC (CH ₃ ) ═CH ₂ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ OCOCH═CH ₂ ,
CF ₃ CF ₂ (CH ₂ ) ₂ OCOCH═CH ₂ ,
CF ₃ (CF ₂ ) ₃ SO ₂ N (CH ₃ ) (CH ₂ ) ₂ OCOCH═CH ₂ ,
_{CF 3 (CF 2) 3 SO} 2 N (C 2 H 5) (CH 2) 2 OCOC (CH 3) = CH 2,
_{(CF 3) 2 CF (CF} 2) 3 CH 2 CH (OCOCH 3) CH 2 OCOC (CH 3) = CH 2,
(CF ₃ ) ₂ CF (CF ₂ ) ₃ CH ₂ CH (OH) CH ₂ OCOCH═CH ₂
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ OCOCH═CH ₂
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ OCOCH═CH ₂
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ OCOC (CH ₃ ) ═CH ₂ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ OCOC (CH ₃ ) ═CH ₂ ,
Can be illustrated.

[式中、Ｒfは炭素数１〜２１のパーフルオロアルキル基、
n は１〜２の整数を表わす。]
で示される含フッ素エポキシ化合物を挙げることができる。 Among the fluorine-containing polymerizable compounds, as the epoxy compound, for example, the formula:

[Wherein Rf is a perfluoroalkyl group having 1 to 21 carbon atoms,
n represents an integer of 1 to 2. ]
The fluorine-containing epoxy compound shown by these can be mentioned.

を例示することができる。 Specific examples of fluorine-containing epoxy compounds are:

Can be illustrated.

Examples of the fluoropolymer obtained by polymerizing the epoxy compound of the formula (II) include the formula:
(−O−CH ₂ CH (CH ₂ Rf) −) m
[Wherein Rf is a perfluoroalkyl group having 1 to 21 carbon atoms,
m represents an integer of 1 or more (for example, 10 to 1000). ]
Having a polyether structure of repeating unit, formula:
(-OCO-Ph-CO-O -CH 2 CH (CH 2 Rf) -) m
[Wherein Rf is a perfluoroalkyl group having 1 to 21 carbon atoms,
Ph is a phenyl group,
m represents an integer of 1 or more (for example, 10 to 1000). ]
And those having the polyester structure as a repeating unit.

Examples of urethane compounds include the formula:
I [-NHC (= O) O-((Rf-A ^1- ) X ¹ O) _a -R ¹ ] _m [-NHC (= O) O-((ClCH _2- ) X ² O) _b -R ² ] _n (III)
[Wherein I is a group obtained by removing an isocyanate group from a polyisocyanate compound,
Rf is a C1-C21 perfluoroalkyl group,
X ¹ and X ² are trivalent linear or branched aliphatic groups having 2 to 5 carbon atoms,
A ¹ is a direct bond or a divalent organic group having ^{1 to} 21 carbon atoms,
R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
a and b are numbers from 1 to 20,
m is a number from 1 to 15,
n is a number from 0 to 14,
The sum of m and n is a number from 2 to 15. ]
The fluorine-containing urethane compound shown by can be mentioned.

In the formula (III), I is a group obtained by removing an isocyanate group from a polyisocyanate compound. A polyisocyanate compound is a compound having at least two isocyanate groups. The polyisocyanate compound may be an aliphatic polyisocyanate, an aromatic polyisocyanate, or a derivative of these polyisocyanates.
Examples of aliphatic polyisocyanates, in particular aliphatic diisocyanates, are hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated dicyclohexylmethane diisocyanate. . Examples of aromatic polyisocyanates, in particular aromatic diisocyanates, are tolylene diisocyanate, diphenylmethane diisocyanate (MDI), tolidine diisocyanate, naphthalene diisocyanate.

The polyisocyanate compound is preferably a diisocyanate, polymeric MDI (diphenylmethane diisocyanate), or a modified isocyanate (particularly a dimer of diisocyanate or an adduct of polyhydric alcohol and diisocyanate). .
Examples of modified isocyanates are urethane-modified diisocyanates, allophanate-modified diisocyanates, biuret-modified diisocyanates, isocyanurate-modified diisocyanates, carbodiimide-modified diisocyanates, uretonimine-modified diisocyanates, and acylurea diisocyanates. is there.

を例示することができる。 Specific examples of the fluorine-containing urethane compound are as follows:

Can be illustrated.

The vinyl ether compound may be, for example, a compound represented by the following formula.
C (−A) (− D) = C (−X) −O−Y− (CH ₂ ) _m −Rf (IV)

[Wherein, A, D and X are a hydrogen atom, a methyl group, a linear or branched alkyl group having 2 to 20 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFL ¹ L ² group (Wherein L ¹ and L ² are a hydrogen atom, a fluorine atom or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted benzyl group, A substituted or unsubstituted phenyl group;
Y is a direct bond, —CH ₂ —CH (—OH) —, or — (CF ₂ CF (—CF ₃ ) O—) _g — (wherein g is 1 to 21);
Rf is a linear or branched fluoroalkyl group or fluoroalkenyl group having 1 to 21 carbon atoms;
m is 0-10. ]
Specific examples of the vinyl ether compound are as follows.
CF ₂ = C (−F) −O−Rf
CF ₂ = C (−F) −O−CH ₂ −Rf
CF ₂ = C (−F) −O−CH ₂ −CH ₂ −Rf
CH ₂ = C (−H) −O−CH ₂ −CH ₂ −Rf
CF ₂ = C (−F) −O−CH ₂ −CH (−OH) −CH ₂ −Rf
CH ₂ = C (-H) -O-CH ₂ -CH (-OH) -CH ₂ -Rf
CH ₂ = C (−H) −O− (CF ₂ −CF (−CF ₃ ) −O) ₂ −Rf
CH ₂ = C (−Cl) −O− (CF ₂ −CF (−CF ₃ ) −O) ₂ −Rf
[Wherein, Rf represents a linear or branched fluoroalkyl group or fluoroalkenyl group having 1 to 21 carbon atoms. ]

  The fluorine-containing polymer is preferably a homopolymer of a fluorine-containing polymerizable compound or a copolymer with a polymerizable compound (particularly a non-fluorine polymerizable compound) copolymerizable with the fluorine-containing polymerizable compound, A compound prepared by a known technique can be used.

There are various types of polymerizable compounds that can be copolymerized.
(1) Acrylic acid and methacrylic acid and their methyl, ethyl, butyl, isobutyl, t-butyl, propyl, 2-ethylhexyl, hexyl, decyl, lauryl, stearyl, isobornyl, β-hydroxyethyl, glycidyl ester, phenyl, benzyl 4-cyanophenyl esters,
(2) Vinyl esters of fatty acids such as acetic acid, propionic acid, caprylic acid, lauric acid, stearic acid,
(3) Styrene compounds such as styrene, α-methylstyrene, p-methylstyrene,
(4) Vinyl halides or vinylidene compounds such as vinyl fluoride, vinyl bromide, vinylidene fluoride,
(5) Aliphatic allyl esters such as allyl heptanoate, allyl caprylate and allyl caproate,
(6) Vinyl alkyl ketones such as vinyl methyl ketone and vinyl ethyl ketone,
(7) acrylamides such as N-methylacrylamide and N-methylolmethacrylamide;
(8) Examples include dienes such as 2,3-dichloro-1,3-butadiene and isoprene.

The copolymerizable polymerizable compound may be a non-fluorine polymerizable compound.
The fluorine-containing polymer may contain a chlorine-containing polymerizable compound as a structural repeating unit. The chlorine-containing polymerizable compound is generally a compound having a chlorine atom and a carbon-carbon double bond. Examples of the chlorine-containing polymerizable compound are vinyl chloride, vinylidene chloride, α-chloroacrylate (for example, alkyl (C1-30) ester) and 3-chloro-2-hydroxypropyl methacrylate.
The non-fluorine polymerizable compound may be, for example, a non-fluorine alkyl (meth) acrylate.

Non-fluorinated alkyl (meth) acrylates generally have the formula:
_{^{X 1 -CX 2 = CH 2 (}} I)
[Wherein, X ¹ is an alkylcarboxylate group (alkyl group having 1 to 18 carbon atoms), and X ² is a hydrogen atom or a methyl group. ]
It is a compound shown by these. The fluorine-containing polymer may not contain non-fluorine alkyl (meth) acrylate.

In the fluorine-containing polymer as a co-weight, the amount of the fluorine-containing polymerizable compound may be 10% by weight or more, for example, 20 to 80% by weight, particularly 25 to 75% by weight, particularly 30 to 70% by weight. . In the fluorine-containing polymer, the amount of the chlorine-containing polymerizable compound may be 50% by weight or less, for example, 0 to 40% by weight, particularly 0.1 to 30% by weight.
The molecular weight of the fluoropolymer may generally be from 1,000 to 1,000,000, for example from 1,500 to 500,000, in particular from 3,000 to 100,000 (for example polystyrene measured by GPC). Conversion).
The amount of the fluoropolymer contained in the sheath may be 0.1 to 10 parts by weight, for example 0.1 to 5 parts by weight, particularly 0.5 to 3 parts by weight, based on 100 parts by weight of the resin mixture.

In the present invention, the ratio of the core and the sheath is preferably such that the core is 50 to 99% by weight of the composite fiber and the sheath is 1 to 50% by weight of the composite fiber. More preferably, the core is 60 to 98% by weight, the sheath is 2 to 40% by weight, still more preferably the core is 70 to 97% by weight, and the sheath is 3 to 30% by weight.
Although the shape of the cross section of a composite fiber is not specifically limited, Generally, it is circular. The thickness (diameter) of the composite fiber may be 5 to 1500 micrometers, in particular 15 to 1200 micrometers. The thickness of the sheath may be 0.5 to 400 micrometers, in particular 1.0 to 300 micrometers. The length of the fiber is determined by the application and is not particularly limited.

  In the present invention, the sheath may be a mixture of two or more thermoplastic resins. In that case, you may use the resin mixture of 1st resin and 2nd resin with low crystallinity or melting | fusing point compared with 1st resin. The second resin may be a mixture of at least two resins. In the resin mixture of the first resin and the second resin, the amount of the second resin is 1 to 60% by weight, for example 2 to 40% by weight, in particular 3 to 30% by weight, especially 5 to 20% by weight. Good.

  When a polyolefin resin is used for the sheath, preferred first resin / second resin combinations are polypropylene / polyethylene, polypropylene / polybutylene, polypropylene / polypropylene, polypropylene / propylene-α-olefin copolymer, polypropylene / ethylene-α-olefin copolymer. . In the polypropylene / polypropylene combination, the first resin is preferably isotactic propylene (crystalline propylene) and the second resin is preferably amorphous propylene. In the resin mixture of the first resin and the second resin, the amount of the second resin is 1 to 60% by weight, for example 2 to 40% by weight, in particular 3 to 30% by weight, especially 5 to 20% by weight. Good.

Crystallinity means the amount of crystallization heat measured by DSC (Differential Scanning Calorimetry). The crystallization heat amount of the second resin may be 5 kJ / kg or more, preferably 10 kJ / kg or more, for example, 15 kJ / kg or more, particularly 20 kJ / kg or more lower than the crystallization heat amount of the first resin.
The melting point can be measured by DSC. The melting point of the second resin may be lower than the melting point of the first resin by 10 ° C. or more, preferably 15 ° C. or more, such as 20 ° C. or more, particularly 25 ° C.

In the conjugate fiber of the present invention, additives (that is, auxiliary agents), for example, dyes, pigments, antistatic agents, antioxidants, light stabilizers, ultraviolet absorbers, neutralizers, nucleating agents are used as necessary. Agents, epoxy stabilizers, lubricants, antibacterial agents, flame retardants, plasticizers and the like. Further, the amount of the fluoropolymer contained in the sheath may be increased in place of the oil used for the purpose of preventing yarn breakage after spinning. Moreover, what mixed beforehand as a masterbatch may be used for the mixed resin of a fluorine-containing compound and a thermoplastic resin, or the mixed resin of a fluorine-containing compound, an additive, and a thermoplastic resin. The amount of the fluorine-containing compound in the master batch may be 1 to 40% by weight, for example 5 to 30% by weight, in particular 10 to 25% by weight.
The composite fiber of the present invention can be prepared by a conventionally known method using a kneaded (for example, melt-kneaded) core thermoplastic resin, a sheath polyolefin resin, and a fluoropolymer. The polyolefin resin in the sheath and the fluoropolymer are compatible in the molten state. About the obtained fiber, you may heat-process in an oven, a drying furnace, etc. after spinning according to a well-known technique. In addition, the fabric, monofilament, and the like made of the composite fiber may be subjected to surface treatment, heat treatment, and the like by a known technique. Particularly when heated at 80 ° C. or higher for 1 minute or longer, the liquid repellency is improved.

The conjugate fiber of the present invention may be a non-woven fabric. The nonwoven fabric can be obtained by a card method, an airlaid method, a papermaking method, a melt blown method or a spun bond method in which a nonwoven fabric is obtained directly from melt extrusion. In melt extrusion, it is preferable to use a temperature that melts both the thermoplastic resin of the sheath and the fluoropolymer. The basis weight of the nonwoven fabric is not particularly limited, but may be 0.1 to 1000 g / m ² . Basis weight of the nonwoven fabric, depending on the nonwoven applications such, 5 to 60 g / m ² in the surface material or the like of the liquid absorbent article, the absorbent in the goods and a wiper such as 10 to 500 g / m ^2, in filter 8～1000G / m ² is preferred. Also about the nonwoven fabric which consists of this composite fiber, you may give surface treatment, heat processing, etc. by a well-known technique. Particularly when heated at 80 ° C. or higher for 1 minute or longer, the liquid repellency is improved.

  Details will be described below with reference to examples, but the present invention is not limited to these examples. In addition, about crystallization calorie | heat amount and melting | fusing point as described in an Example, it analyzed in STG nanotechnology RTG220. Further, the heat of crystallization of the resin was analyzed with a DSC 822e manufactured by METTLER TOLEDO.

Example 1
100 parts by weight of polypropylene (SA3A manufactured by Nippon Polypro Co., Ltd., MFR = 11) as the core, 97 parts by weight of isotactic polypropylene (SA03D manufactured by Nippon Polypro Co., Ltd., MFR = 30, melting point: 167 ° C.) as the thermoplastic resin, fluorine-containing compound C _n F _{2n + 1} CH ₂ CH ₂ OCOCH═CH ₂ (mixture of compounds of n = 6, 8, 10, 12, 14 (average of n is 8)) (fluorinated monomer, hereinafter referred to as “17FA”) and Using a mixed resin of 3 parts by weight of a fluoropolymer having a composition of FA / StMA = 70/30 (weight ratio) which is a fluoropolymer with stearyl methacrylate (hereinafter referred to as “StMA”), the core is extruded After spinning so as to be 70% by weight of the composite yarn at a temperature of 230 ° C and 30% by weight of the composite yarn at an extrusion temperature of 210 ° C, the sheath is drawn and wound at a draw ratio of 5.8. By to give 300 composite monofilament denier (fiber diameter 210 micrometers).
In order to confirm the water repellency of this composite yarn, the following evaluation was performed.

In accordance with yarn strength JIS L 1013, the elongation of the composite monofilament was measured at a test piece length of 300 mm and a tensile speed of 300 mm / min. Five points were measured and the average value was adopted.
A mesh-like woven fabric (hereinafter referred to as “woven fabric”) prepared using the liquid repellent composite yarn was prepared and heat-treated at 105 ° C. for 30 minutes. The woven fabric was dipped in an IPA / water = 70/30 (volume ratio) mixed solution and water for 10 seconds and then pulled up, and the repellency of the liquid at that time was visually evaluated.

Example 2
Isotactic polypropylene (SA03D manufactured by Nippon Polypro Co., Ltd., crystallization heat quantity 109.1 kJ / kg) 87 parts by weight as the first resin in the sheath, amorphous polypropylene (Tufselen T-3512 manufactured by Sumitomo Chemical Co., Ltd.), crystallization as the second resin Heat amount 14.9 kJ / kg) 10 parts by weight, fluorine-containing polymer [fluorine-containing polymer comprising 17FA and stearyl acrylate (hereinafter referred to as “StA”) and having a composition of 17FA / StA = 50/50 (weight ratio)] A composite monofilament was prepared and evaluated in the same manner as in Example 1 except that the mixed resin was 3 parts by weight.

Example 3
Copolymer having a composition of 9FA / StMA = 60/40 (weight ratio) composed of C ₄ F ₉ CH ₂ CH ₂ OCOCH═CH ₂ (fluorinated monomer, hereinafter referred to as “9FA”) and StMA as the fluoropolymer. A composite monofilament was prepared and evaluated in the same manner as in Example 2 except that coalescence was used.

Example 4
Copolymerization having a composition of _{C 4 F 9 CH 2 CH 2} OCOCCl = CH 2 as a fluorine-containing polymer (fluorine-containing monomer, hereinafter referred to as "9FClA") and consists StA 9FClA / StA = 40/60 ( weight ratio) A composite monofilament was prepared and evaluated in the same manner as in Example 2 except that 1 part by weight of the coalescence was used.

Example 5
100 parts by weight of polypropylene (SA3A manufactured by Nippon Polypro Co., Ltd., MFR = 11) in the core, 97 parts by weight of polyamide resin (UBE NYLON 5021T, nylon 6 manufactured by Ube Industries Co., Ltd.) as the sheath, fluoropolymer [9FA and StA A copolymer having a composition of 9FA / StA = 70/30 (weight ratio)] Using a mixed resin of 3 parts by weight, the core is 70 ° C. of the composite yarn at an extrusion temperature of 230 ° C., and the sheath is an extrusion temperature of 250 After spinning at 30 ° C. so as to be 30% by weight of the composite yarn, the composite monofilament of 300 denier (fiber diameter 210 μm) was obtained by drawing and winding at a draw ratio of 4.8. This was evaluated in the same manner as in Example 1.

Comparative Example 1
A composite monofilament was prepared and evaluated in the same manner as in Example 1 except that the sheath was 100 parts by weight of polypropylene (SA03D manufactured by Nippon Polypro Co., Ltd.).
Comparative Example 2
A composite monofilament was prepared and evaluated in the same manner as in Example 1 except that the sheath was 100 parts by weight of a polyamide resin (UBE NYLON 5021T, nylon 6 manufactured by Ube Industries).

  Table 1 shows the components of Examples and Comparative Examples, and Table 2 shows the evaluation results.

ＰＰ ： ポリプロピレン
ｉＰＰ： アイソタクティックプロピレン
ＮＹ６： ナイロン６
表中（ ）内の数値は、芯部、鞘部それぞれの複合モノフィラメント中の重量％を示す。

PP: Polypropylene iPP: Isotactic propylene NY6: Nylon 6
The numerical value in () in the table indicates the weight% in the composite monofilament of each of the core part and the sheath part.

IPA / Water: IPA / Water = 70/30 liquid mixture (volume ratio)
Evaluation of liquid repellency ○: Repels as droplet
Δ: Slightly repels as a droplet
X: It does not repel as a droplet but is wet

From the results shown in Table 2, the composite monofilament containing a fluorine-containing polymer in the sheath is excellent in liquid repellency when added in a small amount without reducing the strength of the fiber itself.

Claims (13)

(A) a core comprising a thermoplastic resin, and (B) a sheath comprising a thermoplastic resin having a melting point of 225 ° C. or less and a fluorine-containing compound, wherein the fluorine-containing compound is a straight chain having 1 to 21 carbon atoms Fluorine-containing polymer having a repeating unit derived from a fluorine-containing polymerizable compound containing a linear or branched fluoroalkyl group or fluoroalkenyl group, or a linear or branched fluoroalkyl group having 1 to 21 carbon atoms Or the composite fiber which is a fluorine-containing urethane compound containing a fluoro alkenyl group, and has the core-sheath structure which consists of a sheath whose quantity of a fluorine-containing compound is 0.1-10.0 weight% with respect to a sheath.   The composite fiber according to claim 1, wherein the thermoplastic resin of the core (A) is polyolefin, polyester or polyamide.   The composite fiber according to claim 1, wherein the thermoplastic resin of the sheath (B) has a melting point of 80 to 180 ° C.   The composite fiber according to claim 1, wherein the thermoplastic resin of the sheath (B) is a polyolefin.   The composite fiber according to claim 1, wherein the thermoplastic resin of the sheath (B) is a mixture of two or more polyolefins.   The composite fiber according to claim 1, wherein the fluorine-containing polymerizable compound is a compound having a fluoroalkyl group or a fluoroalkenyl group and a carbon-carbon double bond.   The composite fiber according to claim 1, wherein the fluorine-containing polymerizable compound is any one of (meth) acrylic acid ester, epoxy compound, and vinyl ether compound. The fluorine-containing polymerizable compound is
formula:
CH ₂ = C (−X) −C (= O) −A−Rf (I)
[Wherein, X is a hydrogen atom, a methyl group, a linear or branched alkyl group having 2 to 20 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX ¹ X ² group (where X ¹ and X ² are a hydrogen atom, a fluorine atom or a chlorine atom.), A cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted benzyl group, or a substituted or An unsubstituted phenyl group,
A is —O—Y ¹ — (where Y ¹ is an aliphatic group having 1 to 10 carbon atoms, an aromatic group having 6 to 10 carbon atoms or a cyclic aliphatic group, —CH ₂ CH ₂ N (R ¹ ) SO ₂ — (CH ₂ CH ₂ ) _a — group (where R ¹ is an alkyl group having 1 to 4 carbon atoms, a is 0 or 1) or —CH ₂ CH (OR ¹¹ ) CH ₂ — A group (wherein R ¹¹ is a hydrogen atom or an acetyl group)), or —Y ² — [— (CH ₂ ) _m —Z—] _p — (CH ₂ ) _n — (where Y ² is —O— or —NH—; Z is —S— or —SO ₂ —; m is 1 to 10, n is 0 to 10, and p is 0 or 1.
Rf is a linear or branched fluoroalkyl group or fluoroalkenyl group having 1 to 21 carbon atoms. ]
The composite fiber according to claim 1, which is a fluorine-containing (meth) acrylic acid ester represented by:   The composite fiber according to claim 8, wherein Rf in the formula (I) is a perfluoroalkyl group having 1 to 5 carbon atoms. In the formula (I), Rf is a group having 1 to 5 carbon atoms, and X is a linear or branched alkyl group having 2 to 20 carbon atoms, fluorine atom, chlorine atom, bromine atom, iodine atom, CFX ¹ X ² group (where X ¹ and X ² are a hydrogen atom, a fluorine atom or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, substituted or non-substituted The composite fiber according to claim 8, which is a substituted benzyl group or a substituted or unsubstituted phenyl group.   A clothing, leisure article, household article, wiper, filter, civil engineering article, building article, sanitary article, or medical article comprising the cloth made from the conjugate fiber according to any one of claims 1 to 10. An article that is.   A fishing line comprising the composite fiber according to any one of claims 1 to 10. A nonwoven fabric comprising the conjugate fiber according to any one of claims 1 to 10.