JPH0881820A - Polyolefin fiber - Google Patents

Abstract

PURPOSE: To obtain a polyolefin fiber excellent in flexibility, elasticity and spinnabillty, and suitably usable for general clothing, medical/hygienic materials, industrial materials, etc. CONSTITUTION: This polyolefin fiber consists of a propylene-based block copolymer 0.5-40g/10min in melt index (or its blend with polypropylene, etc.) composed of 0.01-5wt.% polybutene component, 1-70wt.% polypropylene component and 25-98.99wt.% propylene-ethylene random copolymer component which is made up of 10-40mol% ethylene-based monomer unit and 90-60mol% propylene-based monomer unit. This fiber has been molecularly oriented by drawing in the direction of fiber axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a polyolefin fiber, more specifically a soft polyolefin fiber which is excellent in flexibility and elasticity and can be suitably used for general clothing, sanitary clothing, industrial materials and the like.

[0002]

2. Description of the Related Art Conventionally, for soft fibers such as clothes,
Soft polyurethane and the like have been preferably used. But,
Due to pollution problems such as generation of toxic gas during incineration, flexible polyurethane has been replaced with polyolefin in recent years.

[0003]

Representative examples of soft polyolefin fibers include unstretched polyethylene fibers and unstretched polypropylene fibers. However, these fibers usually have a so-called yield point, which exceeds the limit of elastic deformation when the fiber is pulled and causes a deviation between polymer molecular chains, and therefore is not always suitable for the above-mentioned applications requiring elasticity. Not not. That is, in the above-mentioned applications, the fiber is often used in a stretched state, so that the stress is reduced near the yield point or necking occurs, resulting in a poor appearance.

From the above, it is an object of the present invention to provide a soft polyolefin fiber which does not have a yield point and can be suitably used for the above-mentioned applications.

[0005]

As a result of intensive studies to solve the above problems, the inventors of the present invention satisfy the above problems by using a propylene-based block copolymer having a specific composition. The inventors have found that a soft polyolefin fiber can be obtained, and completed the present invention.

That is, the present invention is a block copolymer containing a polybutene component, a polypropylene component, and a propylene-ethylene random copolymer component, wherein the polybutene component is 0.01 to 5% by weight and the polypropylene component is 1%.
To 70% by weight, the propylene-ethylene random copolymer component is 25 to 98.99% by weight, and the propylene-
The ethylene random copolymer component contains 10 to 40 mol% of ethylene-based monomer units and 90 to 60 mol% of propylene-based monomer units, and has a melt index of 0.5 to 40 g / 10 min. Is a propylene-based block copolymer, and is a polyolefin-based fiber that is molecularly oriented in the fiber axis direction by stretching.

In the present invention, the propylene block copolymer comprises a polybutene component, a polypropylene component, and a propylene-ethylene random copolymer component component. Here, the polybutene component, the polypropylene component, and the propylene-ethylene random copolymer component each have a component ratio of 0.01 to 5% by weight of the polybutene component, 1 to 70% by weight of the polypropylene component, and a propylene-ethylene random copolymer weight. The combined component is 25 to 98.99% by weight.

The above polybutene component is essential for preventing mutual adhesion of particles during the production of the propylene block copolymer of the present invention. When the content of the polybutene component is less than 0.01% by weight, the propylene block copolymer particles of the present invention tend to stick together and the flexibility of the fiber becomes insufficient. On the other hand, when the polybutene component exceeds 5% by weight,
When the propylene-based block copolymer of the present invention is spun into a fibrous form, the moldability and appearance are deteriorated, which is not preferable. The ratio of the polybutene component is 0, considering the ease of handling during the production of the propylene block copolymer, the spinnability and the appearance.
The range of 04 to 3% by weight is preferable. This polybutene component has an isotacticity of 0.90 in order to reduce the adhesion of particles during the production of a propylene-based block copolymer.
The above is preferable. Here, the isotacticity of poly 1-butene is measured by C-NMR,
Polymer Journal (Polymer J.) No. 16
It is a value of mm when attribution is made based on pages 716 to 726 of Volume (1984).

If the propylene component is less than 1% by weight, the strength of the polyolefin fiber of the present invention is lowered. When the proportion of the polypropylene component exceeds 70% by weight, the flexibility of the fiber is lowered and the intended polyolefin fiber cannot be obtained. Considering flexibility and mechanical strength, the polypropylene component is 3 to 60% by weight.
Is preferable, and especially when it is 30% by weight or less, flexibility and spinnability are improved.

Further, the ethylene-propylene random copolymer component is 25 to 98.99% by weight. When the content of the above components is less than 25% by weight, the flexibility is poor, and when it exceeds 98.99% by weight, the strength and heat resistance of the fibers are inferior, which is not preferable. Considering flexibility, mechanical strength and heat resistance, the ethylene-propylene random copolymer component is 40 to 9
It is preferably in the range of 7% by weight.

The content ratio of each of the ethylene-based monomer unit and the propylene-based monomer unit in the propylene-ethylene random copolymer component is 10 to 40 mol%, preferably the ethylene-based monomer unit. Is 15 to 35 mol%, and the monomer unit based on propylene is 90 to 60 mol%, preferably 85 to 65 mol%.
Is. The content ratio of ethylene-based monomer units is 10
When it is less than mol% and the content ratio of the propylene-based monomer unit exceeds 90 mol%, the flexibility of the obtained fiber is not sufficient, which is not preferable. On the other hand, when the content ratio of ethylene-based monomer units exceeds 40 mol% and the content ratio of propylene-based monomer units is less than 60 mol%, the strength and heat resistance of the obtained fiber are insufficient. Not preferable.

In the above propylene block copolymer, one or more of a polybutene component, a polypropylene component and a propylene-ethylene random copolymer component may be used as long as the physical properties of the propylene resin composition are not impaired.
Other α-olefins may be copolymerized and contained in a small amount, for example, in the range of 5 mol% or less.

The propylene block copolymer used in the present invention is a so-called block copolymer molecule in which at least two kinds of polybutene component, polypropylene component and propylene-ethylene random copolymer component are arranged in one molecular chain. It is considered that the chains and the molecular chains consisting of the polybutene component, the polypropylene component, and the propylene-ethylene random copolymer component alone are micro-mixed to an extent that cannot be achieved by mechanical mixing.

In the present invention, the above-mentioned propylene block copolymer has a melt index (hereinafter referred to as MI).
Abbreviated) is 0.5 to 40 g / 10 minutes, preferably 1.
It is necessary to be 0 to 30 g / 10 minutes. If the MI is less than 0.5 g / 10 min, melt fracture at the time of molding is derived, and fiber spinning becomes difficult. If the MI is greater than 40/10 minutes, melt cutting during molding tends to occur, and the spin molding of fibers also becomes difficult.

The propylene-based block copolymer used in the present invention may be obtained by any method. The method that is particularly preferably adopted is as follows.

That is, first, the following components A and B, or
Further C and / or D A. Titanium compound B. Organoaluminum compound C.I. Electron donor D. In the presence of an iodine compound represented by the general formula (i) RI (i) (wherein R is an iodine atom or an alkyl group having 1 to 7 carbon atoms or a phenyl group), 0.1 to 0.1% of propylene is added. 500g polymer / g
-Preliminary polymerization is carried out to obtain a range of Ti compound to obtain a catalyst-containing prepolymer, and then 1-butene is polymerized and propylene is polymerized in the presence of the catalyst-containing prepolymer to obtain a mixture of propylene and ethylene. Random copolymerization of the mixture is sequentially performed to obtain a high molecular weight powder. Such manufacturing method,
It is described in detail in JP-A-5-287035, and in the present invention, the block copolymer is preferably produced according to the method.

Here, the copolymer particles obtained by the above-mentioned polymerization usually have a weight average molecular weight of 600,000 or more, and more generally 800,000 or more. In addition, the copolymer particles are obtained by gel permeation chromatography (hereinafter referred to as "GP
Abbreviated as "C"), the proportion of components having a molecular weight of 10,000 or less is 1.0% by weight or less, preferably 0.
It is preferably 6% by weight or less.

Next, the melt index (hereinafter abbreviated as MI) of the copolymer particles obtained by the above-mentioned method is usually about 0.1 g / 10 minutes at most, so that the copolymer particles are In order to obtain the propylene-based block copolymer used in the present invention, it is usually necessary to further decompose with an organic peroxide and adjust to the desired MI value.

As the organic peroxide to be used, known compounds can be used without any limitation. Typical examples include ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide and cyclohexanone peroxide; diacyl peroxides such as isobutyryl peroxide, lauroyl peroxide and benzoyl peroxide; diisopropylbenzene hydro Hydroperoxides such as peroxides; dicumyl peroxide, 2,5-
Dimethyl-2,5-di- (t-butylperoxy) hexane, 1,3-bis- (t-butylperoxy-isopropyl) -benzene, di-t-butylperoxide,
2,5-Dimethyl-2,5-di- (t-butylperoxy) -hexane-3 and other dialkyl peroxides;
Peroxyketals such as 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane and 2,2-di- (t-butylperoxy) -butane; t-butylperoxy-pivalate, Examples thereof include alkyl peresters such as t-butyl peroxybenzoate; percarbonates such as t-butyl peroxyisopropyl carbonate.

The blending amount of the above-mentioned organic peroxide is not particularly limited, but generally 0.001 to 5 parts by weight, and further 0.002 parts by weight to 100 parts by weight of the block copolymer.
It is preferably in the range of 3 parts by weight.

The propylene block copolymer used in the present invention preferably has a molecular weight distribution narrower than a specific value. Such a block copolymer having a narrow molecular weight distribution can be achieved by adjusting treatment such as decomposition with the organic peroxide. Specifically, it is preferable to use one having a weight average molecular weight (Mw) / number average molecular weight (Mn) measured by GPC of 1.5 to 4, and preferably 1.7 to 3.5. The fibers obtained in this range have the best properties without stickiness of the fibers.

In the present invention, the propylene block copolymers described above can be used alone as a fiber material, but may be used in combination with other synthetic resins if necessary. Polypropylene is particularly suitable as the other synthetic resin. The above propylene-based block copolymer has excellent compatibility with polypropylene as the same propylene-based polymer, and thus, when mixed with polypropylene in this manner, the block copolymer has excellent flexibility and spinnability. Well maintained. Here, as the polypropylene, propylene homopolymer, propylene 90
Mol% or more and an α-olefin other than propylene, for example, ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 4-methyl-1-pentene or the like, 10 mol% or less. Random or block copolymers can generally be used. Also,
This polypropylene has good MI when it is mixed with the above-mentioned propylene-based block copolymer having an MI in the range of 0.5 to 40 g / 10 minutes, and is a polyolefin fiber having more excellent physical properties. It is preferable because it can be obtained.

In the present invention, when the propylene block copolymer and polypropylene are mixed and used as described above, the mixing ratio may be appropriately determined according to the physical properties required for the polyolefin fiber. In order to obtain a fiber having excellent flexibility, it is preferable to use 20% by weight or more of propylene-based block copolymer and 80% by weight or less of polypropylene. Especially flexibility, spin moldability,
In order to improve elasticity, it is preferable that the propylene block copolymer is 40% by weight or more and the polypropylene is 60% by weight or less.

Next, in the present invention, the polyolefin fiber made of the propylene block copolymer is molecularly oriented in the fiber axis direction by stretching. As a result, the fiber has no yield point and no necking or the like. Further, due to the fact that the material is the propylene-based block copolymer having the above-mentioned specific composition, it becomes excellent in elasticity and the like which cannot be achieved by a usual stretched product of polypropylene fiber.

In the present invention, the polyolefin fiber made of the propylene block copolymer may be made into a fiber by any method. Usually, the propylene block copolymer powder or pellets, if necessary sufficiently mixed with polypropylene powder or pellets, melt spinning, further produced by a method of uniaxially stretching in the fiber axial direction preferable. The method for producing a polyolefin fiber made of a propylene block copolymer is as follows: resin temperature 200 to 260 ° C., resin pressure 10 to 2
Good unstretched fibers can be obtained under the conditions of 00 kg / cm ² and a take-up speed of 5 to 100 m / min. The stretching temperature is from 80 to
120 ° C. is preferable, and the stretching ratio varies depending on the use, but in general, the linear stretching ratio is arbitrarily selected within the range of 2 to 15 times.

It is preferable that the polyolefin fiber obtained by drawing is further heat treated under tension, for example, heat set at a temperature not lower than the drawing temperature and not higher than the melting point, and then cooled to room temperature to obtain the desired product. . Further, it is a preferable embodiment to perform surface treatment by corona discharge treatment, hydrophilic treatment or hydrophobic treatment for the purpose of improving adhesiveness.

As described above, the obtained polyolefin fiber of the present invention usually has a tensile elastic modulus of 10 to 10 in the fiber axis direction.
It is 300 kg / mm ² , and is excellent in flexibility and elasticity. The tensile elastic modulus in the fiber axis direction is 20 to 150 kg / mm.
Those of ² are particularly preferred.

Further, this polyolefin fiber does not have a yield point in the fiber axis direction. Therefore, a decrease in stress near the yield point and an appearance defect due to necking do not occur,
It can be preferably used also in applications such as clothing that is often used in a stretched state.

The polyolefin fiber of the present invention is
From the viewpoint of good flexibility, it is particularly preferable that the elongation measured by JIS-L1069 is 10% or more. Those having such elongation have a draft ratio of 7 or less, preferably 1 to 5.5 when the block copolymer is melt-spun.
And is obtained by stretching the obtained fibrous material 3 to 8.5 times.

Here, the draft ratio is the ratio of the take-up speed (V1) of the fibrous material formed by cooling and solidification to the discharged material (V2) passing through the die-slot gold, and is represented by the following formula.

Draft ratio = V1 / V2 Here, V2 is expressed by (extrusion amount / specific gravity of mixed composition before melting) / cross-sectional area of die-slot gold. As is clear from the above equation, if V1 is made faster with respect to a constant V2, the draft ratio becomes larger and melt shear is applied. When the draft ratio is 7 or less as described above, yarn breakage is unlikely to occur during melt spinning, and the fiber productivity is improved.

The average fiber diameter of the polyolefin fiber of the present invention is not particularly limited, but it is generally preferably 20 to 200 μmφ. The length of the fiber is not particularly limited, but it is generally preferably at least 3 mm or more.

The polyolefin fiber of the present invention may optionally contain a light stabilizer, a crystal nucleating agent, an antistatic agent, an antifogging agent, an antiblocking agent, an antioxidant, a weatherproofing agent, and a colorant (pigment). Etc. can be added.

[0034]

FUNCTION AND EFFECT As described above, the polyolefin fiber of the present invention uses a propylene block copolymer having a specific composition as a raw material resin, and has excellent spin moldability, elasticity and flexibility. Have.

Since the polyolefin fiber of the present invention does not have a yield point, it is used in a stretched state of the fiber, especially for general clothing, bandages, surgical gowns, masks, patches, and sterile packaging materials. It can be suitably used for medical hygiene materials such as, and various industrial materials requiring flexibility.

[0036]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

The measuring method used in the following examples will be described.

(1) Number average molecular weight (Mn), weight average molecular weight (Mw) The ratio of molecular weight of 10,000 or less was measured by GPC (gel permeation chromatography) method. Water-based GPC-150C was used at a temperature of 135 ° C. using O-dichlorobenzene as a solvent. The column used was TSK gel GMH6-HT manufactured by Tosoh Corporation, gel size 10
It is 15μ. The calibration curve has a weight average molecular weight of 950, 2900, 10,000, 50,000, 498,000, 27 as a standard sample.
It was prepared by using polystyrene of 0,000 and 6.75 million.

(2) Measurement of Proportion of Monomer Units Based on Ethylene and Monomer Units Based on Propylene in Propylene-Ethylene Random Copolymer Component and Measurement of Proportion of Polybutene Component A C ¹³ -NMR spectrum chart is shown. It was calculated using.
That is, the respective proportions of the ethylene-based monomer unit and the propylene-based monomer unit in the propylene-ethylene random copolymer component are determined by first determining the polymer (P
Polymer, Vol. 29 (1988), p. 1848, to determine the assignment of peaks, and then by the method described in Macromolecules, Vol. 10, (1977), p. 773. The respective proportions of ethylene-based monomer units and propylene-based monomer units were calculated.

Next, the weight and proportion of the polybutene component were calculated from the integrated intensity ratio of the peak derived from methyl carbon in the monomer unit and the peak derived from methyl carbon in the polybutene component based on propylene.

(3) Isotacticity of poly 1-butene Polymer Journal (Polymer J.) No. 16
Volume (1984), pages 716-726, based on C-NM
The measurement was performed by R.

(4) Melt Index (MI) It was measured according to JIS-K7210.

(5) Spin moldability The unstretched fibers were visually and manually touched and observed, and judged according to the following criteria. Good: No unevenness in thickness or surface unevenness. Fairly good; unevenness in thickness or surface unevenness is minute. Poor; uneven thickness and uneven surface.

(6) Tensile Modulus In accordance with JIS-K7113, the elastic modulus was measured by the following method.

A fiber sample having a length of about 200 mm was cut out, and both ends of the sample were measured by a tensile strength measuring device (autograph;
It was fixed with a chuck (made by Shimadzu). In this case, the chuck gap in the lengthwise direction of the sample was adjusted to be 100 mm. A tensile test was performed at a tensile speed of 300 mm / min to create a tensile stress-strain curve.

The tensile modulus was calculated by the following equation using the first linear portion of the tensile stress-strain curve. Em = Δδ / Δε Em: Tensile modulus Δδ: Difference in stress between two points on the straight line due to the original average cross-sectional area of the sample Δε: Difference in strain between the same two points (7) Yield point According to JIS-Z1521 The tensile stress-strain curve of the fiber was prepared in the same manner, and the presence or absence of the yield point was confirmed from the change in the tensile stress near the elastic deformation.

(8) Necking A fiber sample having a length of about 200 mm was cut out, and both ends of the sample were fixed with a chuck of a tensile strength measuring machine (Autograph; Shimadzu). In this case, the chuck gap in the lengthwise direction of the sample was adjusted to be 100 mm. Tensile speed is 300mm / min and tensile test shows that the elongation is 10
It stopped at 0% (chuck gap 200 mm). In this state, the surface state of the fiber was observed to confirm the presence or absence of necking.

(9) Elongation Measured according to JIS-L1069 by the following method.

A fiber sample having a length of about 200 mm was cut out, and both ends of the sample were measured by a tensile strength measuring device (autograph;
It was fixed with a chuck (made by Shimadzu). In this case, the chuck gap in the lengthwise direction of the sample was adjusted to be 100 mm. A tensile test was performed at a tensile speed of 300 mm / min, and the elongation was calculated from the amount of strain when the sample was cut by the following formula.

Elongation = L / L ₀ × 100 (%) L; Strain amount of sample L ₀ ; Length of sample Production Examples 1 and 2 (preliminary polymerization) Autoclave reaction made of glass having an internal volume of 1 liter equipped with a stirrer After thoroughly replacing the vessel with nitrogen gas, 400 ml of heptane was charged. Set the reactor temperature to 2
Keeping at 0 ° C., 0.18 mmol of diethylene glycol dimethyl ether, 22.7 mmol of ethyl iodide, 18.5 mmol of diethyl aluminum chloride, and titanium trichloride (“TOS-1” manufactured by Marubeni Solvay Chemical Co., Ltd.).
7 "), 22.7 mmol was added, and then propylene was continuously introduced into the reactor for 30 minutes such that the amount of propylene was 3 g per 1 g of titanium trichloride. The temperature during this period was kept at 20 ° C. After stopping the supply of propylene, the inside of the reactor was sufficiently replaced with nitrogen gas, and the obtained titanium-containing polypropylene was washed with purified heptane four times. As a result of the analysis, 2.9 g of propylene was polymerized per 1 g of titanium trichloride.

(Main Polymerization) Step 1: Polymerization of 1-butene A stainless steel autoclave reactor having an internal volume of 1 liter and equipped with a stirrer was sufficiently replaced with nitrogen gas, and then 400 ml of heptane was charged. Keeping the temperature inside the reactor at 20 ° C, diethyl aluminum chloride 18.15mmo
1, diethylene glycol dimethyl ether 0.18m
mol, ethyl iodide 22.7 mmol, 22.7 mmol of titanium-containing polypropylene obtained by prepolymerization as titanium trichloride, and then 1-butene was continuously added for 2 hours so that 1 g of titanium trichloride was 15 g. It was introduced into the reactor. The temperature during this period was kept at 20 ° C.
After the supply of 1-butene was stopped, the inside of the reactor was replaced with nitrogen gas to obtain a titanium-containing poly-1-butene polymer. As a result of the analysis, 14 g of 1-butene was polymerized per 1 g of titanium trichloride.

Step 2: Polymerization of Propylene and Copolymerization of Propylene Ethylene 1 liter of liquid propylene and 0.70 mmol of diethylaluminum chloride were added to a 2 liter autoclave subjected to N substitution, and the internal temperature of the autoclave was adjusted to 7
The temperature was raised to 0 ° C. Add 0.087 mmol of titanium-containing poly-1-butene polymer as titanium trichloride, and add 6 at 70 ° C.
Polymerization of propylene was carried out for 0 minutes. During this time, hydrogen was not used. Then, the internal temperature of the autoclave was rapidly increased to 55 ° C.
At the same time as the temperature was lowered to 0.5, a mixed solution of 0.50 mmol of ethyl aluminum sesquiethoxide (EtAl (OEt)) and 0.014 mmol of methyl methacrylate was added, ethylene was supplied, and the ethylene gas concentration in the gas phase was 7.0.
Copolymerization of propylene and ethylene was carried out at 55 ° C. for 120 minutes so that the concentration became mol%. The ethylene gas concentration during this period was 7.0mo while confirming with a gas chromatograph.
1% was retained. During this time, hydrogen was not used. After the polymerization was completed, unreacted monomers were purged to obtain a particulate polymer. No adhesion was observed in the polymerization tank or on the stirring blade. The yield was 140 g, and the polymerization ratio of all polymers was 7
It was 370 g-polymer / g-titanium trichloride.

Further, as a result of separately polymerizing only propylene, titanium trichloride 1 was obtained at 70 ° C. for 60 minutes.
1030 g of propylene was polymerized per g.
As a result, the polybutene component in the block copolymer was 0.
It can be seen that 19% by weight and 14% by weight of polypropylene component. The results are shown in Table 1.

Next, to 30 kg of the obtained polymer, 1,3-bis- (t-butylperoxyisopropyl) benzene was added as an organic peroxide in a ratio shown in Table 2, and an antioxidant was added. Add 0.1 phr and mix for 1 minute with a Henschel mixer, then use a φ65 mm single screw extruder to
Melt-kneading was performed at 0 ° C. to obtain pellets.

Production Example 3 In the polymerization of 1-butene of Production Example 1, the same operation as in Production Example 1 was performed except that the polymerization amount of 1-butene was 3 g and 50 g per 1 g of titanium trichloride. . The results are shown in Table 1. Further, in the same manner as in Production Example 1, melt kneading was carried out with the amounts of organic peroxides shown in Table 2.

Production Examples 4 and 5 In the propylene polymerization of Production Example 1, the same operation as in Production Example 1 was carried out except that propylene was polymerized at 60 ° C. for 10 minutes and 60 ° C. for 30 minutes. In a separate polymerization experiment, the polymerization ratio of propylene at this time was 240 g-P each.
P / g-TiCl and 540 g-PP / g-TiCl. The results are shown in Table 1. Further, in the same manner as in Production Example 1, melt kneading was carried out with the amounts of organic peroxides shown in Table 2.

Comparative Production Example 1 The same operation as in Production Example 1 was performed except that 1-butene was not polymerized in the main polymerization of Production Example 1. The results are shown in Table 1.
It was shown to. Further, in the same manner as in Production Example 1, the amount of organic peroxide shown in Table 2 was melt-kneaded.

Comparative Production Example 2 The same operation as in Production Example 1 was carried out except that in the main polymerization of Production Example 1, the polymerization of 1-butene was changed to 600 g per 1 g of titanium trichloride. The results are shown in Table 1. Production Example 1
In the same manner as above, melt kneading was carried out with the amount of the organic peroxide shown in Table 2.

[0059]

[Table 1]

[0060]

[Table 2]

Examples 1 to 8 The block copolymers obtained in Production Examples 1 to 3 were mixed with polypropylene having a melt index of 2.0 g / 10 min and a crystallinity of 98.4% at the compounding ratio shown in Table 3. . Further, 0.03 part by weight of erucic acid amide, 0.04 part by weight of calcium stearate and 0.1 part by weight of spherical silica having a particle size of 1.5 μ were added and melt-kneaded. The above resin was melt-spun through a fiber nozzle at a draft ratio shown in Table 3 under conditions of a resin temperature of 230 ° C., a resin pressure of 40 kg / cm ² , and a take-up speed of 10 m / min, and two pairs of Nelson having different rotation speeds were used. It was drawn by a roll at the draw ratio shown in Table 3 to obtain a polyolefin fiber having an average fiber diameter of 150 μmφ.

The spin moldability, tensile modulus, yield point, presence or absence of necking, and elongation of these fibers were measured, and the results are shown in Table 3.

Comparative Example 1 Melt index 2.0 g / 10 minutes, crystallinity 98.
Resin which was melt-kneaded by adding 0.03 part by weight of erucic acid amide, 0.04 part by weight of calcium stearate, and 0.1 part by weight of spherical silica having a particle size of 1.5μ to 100 parts by weight of 4% polypropylene (melting point 159 ° C). Example 1 except that
The same procedure as 8 was performed. The results are shown in Table 3.

Comparative Example 2 The procedure of Comparative Example 1 was repeated except that the fibers were not stretched. The results are shown in Table 3.

[0065]

[Table 3]

Comparative Example 3 The procedure of Comparative Example 2 was repeated except that a linear low density polyethylene having a melt index of 6 g / 10 minutes and a density of 0.92 g / cm ³ was used as the resin. The results are shown in Table 4.

Comparative Example 4 The procedure of Comparative Example 2 was repeated except that the resin of Example 1 was used.
The results are shown in Table 4. Examples 9 to 11 The block copolymer of Production Example 4 and polypropylene having a melt index of 2.0 g / 10 minutes and a crystallinity of 98.4% were mixed at the blending ratio shown in Table 4. Furthermore, 0.03 part by weight of erucic acid amide, calcium stearate 0.
04 parts by weight and 0.1 parts by weight of spherical silica having a particle size of 1.5 μ were added and melt-kneaded in the same manner as in Example 1. A polyolefin fiber was obtained from the above resin by the same method as in Example 1.

The spin moldability, tensile modulus, yield point, presence or absence of necking, and elongation of these fibers were measured, and the results are shown in Table 4.

Comparative Examples 5 and 6 Comparative Example 5 was repeated except that the resins of Comparative Production Examples 1 and 2 were used as the block copolymer. The results are shown in Table 4.

[0070]

[Table 4]

Claims (1)

[Claims] 1. A block copolymer comprising a polybutene component, a polypropylene component, and a propylene-ethylene random copolymer component, wherein the polybutene component is 0.01 to
5% by weight, polypropylene component 1 to 70% by weight, propylene-ethylene random copolymer component 25 to 98% by weight.
99% by weight, and the propylene-ethylene random copolymer component contains 10 to 40 monomer units based on ethylene.
90% to 60% by mol of a propylene-based monomer unit and has a melt index of 0.5 to 4
A polyolefin fiber made of a propylene block copolymer having a weight of 0 g / 10 minutes and molecularly oriented in the fiber axis direction by stretching.