JP2009079306A - Polypropylene fiber rope - Google Patents

Abstract

An object of the present invention is to make a polypropylene fiber excellent in heat resistance and strength, and in which fibers forming a rope are closely twisted together and there is no separation between the fibers, and excellent in elongation resistance, set resistance, shape retention, etc. Provision of rope structures.
SOLUTION: DSC characteristics with fiber strength of 7cN / dtex or more and (i) a single shape with an endothermic peak shape by DSC having a half-value width of 10 ° C or less and a change in melting enthalpy (ΔH) of 125 J / g And (ii) an average interval of 6.5 to 20 μm and an average height of 0.35 to 0.35, wherein the single fiber fineness is 0.1 to 3 dtex and the surface has a large-diameter raised portion and a small-diameter non-raised portion alternately along the fiber axis. A rope structure formed using polypropylene fiber having one or both of the uneven characteristics of having 1 μm unevenness.
[Selection] Figure 5

Description

The present invention relates to a rope structure formed using polypropylene fibers.
More specifically, the present invention is excellent in heat resistance and strength, and the fibers forming the rope structure are closely twisted together so that there is no separation between the fibers. The present invention also relates to a polypropylene fiber rope structure having excellent shape retention.

Textile ropes have a great many uses, and are widely used, for example, in land / shipping, fishing, agriculture, construction sites and the like. Both natural fibers and synthetic fibers are used as fiber materials for fiber ropes, but in recent years, synthetic fiber ropes have become the mainstream, and synthetic fiber ropes include nylon fibers, vinylon fibers, Examples include ropes formed from polyester fibers, polypropylene fibers, polyethylene fibers, polyvinyl chloride fibers, and the like. Among them, polypropylene fiber ropes have the advantages of being excellent in chemical resistance and light weight, being easily meltable and excellent in recyclability, and generating no harmful gases such as halogen gas even when incinerated. Conventionally, various proposals have been made for ropes using polypropylene fibers, and methods for producing polypropylene fibers used for ropes (see, for example, cited references 1 and 2).
However, polypropylene fibers are not sufficiently heat-resistant among synthetic fibers, so ropes formed using polypropylene fibers are exposed to high temperatures, and due to frictional heat generated during friction and abrasion. There is a need for improvement in heat resistance due to melting of polypropylene fibers forming the wire, fusing of the rope associated therewith, etc., and physical properties such as strength tend to be lowered, and the elongation of the rope at high temperatures is large.

As a conventional technique for improving the heat resistance of polypropylene fiber, the isotactic pentad fraction is 96% or more and less than 98.5%, and the melt flow rate (230 ° C., 2.16 kg load) is 0.1. A polypropylene fiber having a heat shrinkage rate of 10% or less at 170 ° C. for 10 minutes and a melting peak temperature of 178 ° C. or more produced by stretching a homopolypropylene resin of ˜30 g / 10 minutes after melt molding is known. (See Patent Document 3).
However, this polypropylene fiber has a broad double end shape or a broad single endothermic shape, non-uniform crystals, and heat resistance is not yet sufficiently high. For this reason, even if a rope is formed using this polypropylene fiber, fusing and physical properties are liable to occur due to frictional heat and the like, and elongation at high temperatures tends to increase.

In addition, as with other synthetic fiber ropes, even in polypropylene fiber ropes, when twisted together, there is no slip between the fibers and the fiber bundles (strands), and the fibers and the fiber bundles (strands) are Engagement and strong twisting are important from the viewpoints of preventing breakage between fibers forming the rope and between strands, and improving strength, elongation resistance, sag resistance, and shape retention.
However, in the conventional rope made of polypropylene fiber, the slip between the polypropylene fibers and the slide between the polypropylene fiber bundles (strands) are large, and the twisting is sufficiently strong and difficult to be performed closely.

  As a method for reducing slippage between polypropylene fibers and slippage between polypropylene fiber bundles (strands), it is conceivable to provide irregularities on the surface of the polypropylene fibers or to roughen the surface of the polypropylene fibers. However, in the conventionally known polypropylene fiber having irregularities formed on the surface and the polypropylene fiber having a roughened surface, the irregularities (roughening) are insufficient or there are restrictions on the formation of irregularities. Even if a rope is formed using polypropylene fibers, the polypropylene fibers (polypropylene yarns, strands) are not easily tightly and firmly twisted, and have excellent strength, elongation resistance, set resistance, shape retention, etc. A fiber rope cannot be obtained.

For example, a reinforcing fiber for a hydraulic material in which irregularities are formed on the surface by irradiating ionizing radiation to the polypropylene fiber (see Patent Document 4), and the melt-spun polypropylene fiber is embossed and stretched on the surface. Polypropylene fibers for cement blending with irregularities formed (see Patent Document 5), irregularities on the surface produced by applying a stretching treatment after changing the take-up speed of the polypropylene fiber melt-extruded by an extruder and then applying a stretching treatment Polypropylene fibers for cement blending (see Cited Document 6) and the like are known, but even if these polypropylene fibers blended for hydraulic substances (cement) are diverted to the manufacture of ropes, mechanical properties and resistance to sag Polypropylene fiber ropes that are excellent in properties and shape retention cannot be obtained.
Specifically, in the case of polypropylene fibers obtained by the method for forming irregularities described in Patent Documents 4 to 6 and Patent Document 4 (particularly, fine fiber polypropylene fibers having a single fiber fineness of 10 dtex or less), the occurrence of damage is significant. Therefore, even if a rope is formed using the polypropylene fiber, a rope made of polypropylene fiber having excellent strength cannot be obtained.

Further, a concrete having a single yarn strength of 9 cN / dtex or more, produced by drawing an undrawn polypropylene yarn in a hot air tank at 125 to 155 ° C., and having a streaky rough surface structure along the curved surface of the fiber surface. A reinforcing polypropylene fiber is known (Patent Document 7). However, in this polypropylene fiber, since the spacing and height of the streaky rough surface structure existing on the fiber surface are both small, the anti-slip effect between the fibers is not good. Even if diverted to the manufacture of the rope, the twisting is not performed tightly and firmly, and a rope excellent in mechanical characteristics, resistance to stickiness, resistance to cracking, shape retention, etc. cannot be obtained.
Further, a polypropylene undrawn yarn is drawn in one step with pressurized saturated steam of 3.0 to 5.0 kg / cm ² (temperature 133 to 151 ° C.) to produce a drawn yarn having an optically bright part and a dark part. (Patent Document 8), the polypropylene drawn yarn (polypropylene fiber) obtained by this method has insufficient formation of unevenness on the fiber surface, and the interval and height of the unevenness are small. Insufficient anti-slipping effect between fibers, even when used in rope production, twisting is not performed densely and firmly, and excellent in mechanical properties, resistance to stickiness, resistance to cracking, shape retention, etc. A rope cannot be obtained.

Japanese Unexamined Patent Publication No. 7-90785 JP 2002-20926 A JP 2002-302825 A Japanese Examined Patent Publication No. 61-26510 JP-A-56-9268 Japanese Patent Publication No.61-301 JP 2003-293216 A Japanese Patent No. 3130288 “Macromolecules”, Vol. 6, 1973, p925 "Macromolecules", Vol. 8, 1975, p687

  The object of the present invention is high strength, excellent heat resistance, and there is no melting, fusing, or deterioration in physical properties of polypropylene fibers forming a rope even when exposed to high temperatures, or subjected to friction or abrasion. As a result, the rope is not easily cut or stretched at high temperatures, and the slip between the fibers forming the rope or between the fiber bundles (strands) is small, so that the fibers and the fiber bundles (strands) An object is to provide a rope structure made of polypropylene fiber that is tightly and strongly twisted and is excellent in strength, elongation resistance, settling resistance, shape retention, and the like.

The inventor has intensively studied in order to achieve the above-described object. And after melt spinning using a polypropylene having a specific isotactic pentad fraction (IPF) and cooling and solidifying to produce a polypropylene unstretched fiber, the resulting polypropylene unstretched fiber is subjected to a specific condition. By pre-stretching and post-stretching, it exhibits specific endothermic / melting characteristics in scanning differential calorimetry (DSC), has a uniform crystal structure, excellent heat resistance, and excellent strength. No polypropylene fibers could be obtained.
Furthermore, the present inventor employs the specific method described above to produce polypropylene fibers having a single fiber fineness of 3 dtex or less, particularly 0.1 to 3 dtex, so that a large-diameter raised portion and a small-diameter portion are formed on the fiber surface. Polypropylene fibers having non-protruding portions with irregularities with predetermined average intervals and average heights alternately present along the fiber axis, excellent slip resistance, and excellent strength could be obtained. In addition, by making the endothermic / melting characteristics of the polypropylene fiber specific by scanning differential calorimetry (DSC), the crystal structure is uniform, and is resistant to slip and high strength as well as heat resistance. Excellent polypropylene fibers could be obtained.

  Then, this inventor tried to manufacture a rope using the polypropylene fiber obtained above. As a result, when a rope is formed using the polypropylene fiber obtained above, the rope has a high strength and is excellent in heat resistance, and can be formed even when exposed to high temperatures or subjected to friction or abrasion. Polypropylene fibers that are not melted, melted, or deteriorated in physical properties are less prone to breakage of the rope, and the rope is less stretched at high temperatures. It has been found that the slip between the strands is small and the fibers and fiber bundles (strands) are tightly and strongly twisted together to obtain a rope having excellent strength, elongation resistance, settling resistance, shape retention, etc. The present invention has been completed.

That is, the present invention
(1) A half of polypropylene having an isotactic pentad fraction (IPF) of 94% or more, a fiber strength of 7 cN / dtex or more, and an endothermic peak shape by scanning differential calorimetry (DSC) of 10 ° C. or less. A rope structure formed by using a polypropylene fiber having a single shape having a valence width and a melting enthalpy variation (ΔH) of 125 J / g or more;
(2) An uplift with a large diameter on the surface, made of polypropylene having an isotactic pentad fraction (IPF) of 94% or more, a fiber strength of 7 cN / dtex or more and a single fiber fineness of 0.1 to 3 dtex Rope structure formed by using polypropylene fibers having irregularities with an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm, in which portions and small-diameter non-raised portions are alternately present along the fiber axis Body; and
(3) Scanning differential calorimetry (DSC) made of polypropylene having an isotactic pentad fraction (IPF) of 94% or more, a fiber strength of 7 cN / dtex or more, and a single fiber fineness of 0.1 to 3 dtex. The endothermic peak shape by the single shape has a half width of 10 ° C. or less, the amount of change in melting enthalpy (ΔH) is 125 J / g or more, and a large-diameter raised portion and a small-diameter non-raised portion on the surface are fiber axes. A rope structure formed by using polypropylene fibers having irregularities with an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm alternately present along
It is.

  The polypropylene fiber forming the rope structure of the present invention made of polypropylene having an isotactic pentad fraction (IPF) of 94% or more has an endothermic peak shape of 10 ° C. or less in scanning differential calorimetry (DSC). Because it has a unique DSC characteristic that the amount of change in melting enthalpy (ΔH) is 125 J / g or more in a single shape having a half width, it has a high crystallinity and a uniform crystal structure, It is extremely excellent in heat resistance and can maintain good fiber shape and fiber strength without easily melting even when exposed to high temperatures. Therefore, the rope structure of the present invention formed using the polypropylene fiber has high strength and excellent heat resistance, and the rope structure can be used even when exposed to high temperatures or subjected to friction or abrasion. Because there is no melting, cutting, fusing, or deterioration in physical properties of the polypropylene fiber that is formed, the rope structure is less likely to be cut or damaged, has low elongation at high temperatures, and maintains mechanical properties such as strength over a long period of time. It has excellent durability.

Furthermore, the rope structure of the present invention has a high fiber strength of 7 cN / dtex or more, and a large-diameter raised portion and a small-diameter non-raised portion are alternately positioned along the fiber axis on the surface of the fiber. It is formed using polypropylene fibers having specific irregularities with an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm, and the polypropylene fibers have no slip due to having the specific irregularities described above. Since the fibers and the fiber bundles (strands) are tightly and tightly twisted in a state in which the polypropylene fibers are engaged and the polypropylene fiber bundles (strands) are engaged, the strength, elongation resistance, and resistance to sag Excellent shape retention.
In particular, the single fiber fineness is 0.1 to 3 dtex, the fiber strength is 7 cN / dtex or more, the endothermic peak shape by scanning differential calorimetry (DSC) is a single shape having a half width of 10 ° C. or less, and the amount of change in melting enthalpy ( ΔH) is 125 J / g or more, and the rope structure of the present invention formed by using high-heat-resistant, high-strength and low-slip polypropylene fibers having the above-described specific unevenness characteristics on the surface, High strength, excellent heat resistance, and the fibers and fiber bundles (strands) forming the rope structure are tightly and tightly twisted together to provide strength, elongation resistance, set resistance, and shape retention. It is more excellent in properties.

The present invention is described in detail below.
The rope structure of the present invention is formed using a specific polypropylene fiber.
Here, the “rope structure” of the present invention is a rope, cable, cord, string, or the like formed by twisting together a fiber bundle (strand), yarn (yarn) and / or fiber. It is a general term.

The polypropylene fiber forming the rope structure of the present invention is a polypropylene fiber made of polypropylene having an isotactic pentad fraction (IPF) (hereinafter sometimes simply referred to as “IPF”) of 94% or more. Is preferably composed of 95 to 99% polypropylene, and more preferably composed of 96 to 99% polypropylene.
When the IPF of polypropylene is less than 94%, it becomes difficult to form a uniform crystal structure on the polypropylene fiber, and the polypropylene fiber used in the rope structure of the present invention having sufficient strength and heat resistance cannot be obtained. On the other hand, polypropylene having an IPF of over 99% is difficult to industrially mass-produce, and therefore has low practicality in terms of cost.

The polypropylene fiber forming the rope structure of the present invention may be formed from one type of propylene homopolymer or other than propylene and the other as long as the IPF satisfies the above-mentioned values as polypropylene. It may be formed from a propylene copolymer composed of the above copolymerizable monomer. Alternatively, if the IPF of the entire mixture satisfies the above-mentioned values, a mixture of two or more propylene homopolymers, one or two or more propylene homopolymers and one or two or more propylene copolymers. You may form from the mixture of a polymer, or the mixture of two or more types of propylene copolymers.
In addition, the polypropylene fiber forming the rope structure of the present invention has two or more types of propylene homopolymers as long as the IPF in the entire propylene polymer constituting the polypropylene fiber satisfies the above-described value. It may be a composite spun fiber or a mixed spun fiber having a composite form or mixed form such as a core-sheath type, a sea-island type, or a side-by-side type formed using a propylene copolymer.

IPF in polypropylene is an index representing the stereoregularity, and affects the crystallinity when polypropylene is made into a fiber. In general, the higher the IPF, the higher the stereoregularity. The IPF in polypropylene can be determined from ¹³ C-NMR signals, and the IPF value of polypropylene in this specification refers to the value determined by the method described in the following examples.

  The polypropylene fiber used in the present invention is JIS-compliant because the melt spinnability and stretchability when producing the polypropylene fiber are improved and the polypropylene fiber having the above-mentioned specific physical properties used in the present invention can be obtained smoothly. It is formed from polypropylene having a melt flow rate (MFR) of 5 to 70 g, more preferably 10 to 50 g, particularly 15 to 40 g when measured under conditions of a temperature of 230 ° C., a load of 2.16 kg and a time of 10 minutes in accordance with K 7210. It is preferable.

The polypropylene fiber forming the rope structure of the present invention has a fiber strength of 7 cN / dtex or more, and preferably has a fiber strength of 9 to 13 cN / dtex.
Here, the fiber strength (single fiber fineness strength) of the polypropylene fiber in this specification refers to the fiber strength measured by the method described in the following examples.
The rope structure of the present invention has high strength because it is formed using the polypropylene fiber having the fiber strength described above. When a rope structure is formed using polypropylene fibers having a fiber strength smaller than that described above, the strength of the rope structure may be insufficient. On the other hand, a polypropylene fiber having a fiber strength exceeding 13 cN / dtex is difficult in practical use because it is necessary to adopt conditions with low mass productivity in the production.

Among the polypropylene fibers forming the rope structure of the present invention, together with the above fiber strength of 7 cN / dtex or more, the endothermic peak by “scanning differential calorimetry (DSC) (hereinafter sometimes simply referred to as“ DSC measurement ”). Polypropylene fiber having a specific DSC characteristic that the shape is a single shape having a half width of 10 ° C. or less and the amount of change in melting enthalpy (ΔH) is 125 J / g or more ”has such characteristics. Therefore, it has excellent heat resistance.
Using a polypropylene fiber having a narrow (sharp) single shape with a half-value width of 10 ° C. or less as measured by DSC and having a melting enthalpy change (ΔH) of 125 J / g or more. When the rope structure of the present invention is formed, the polypropylene fiber is excellent in heat resistance, so that it is difficult to cause fusing and deterioration of physical properties even when exposed to high temperatures. A durable and durable rope structure that is resistant to fusing and damage, and associated cutting and damage of the rope structure is obtained.
Here, the above-mentioned “endothermic peak shape” and “melting enthalpy change amount (ΔH)” by DSC measurement in the present invention are the endothermic peak shape and melting enthalpy change by DSC measurement performed by the method described in the following examples. The amount (ΔH).

In DSC measurement of isotactic polypropylene fiber, the endothermic peak observed at 160 ° C. or higher is generally derived from melting of α-crystal. Polypropylene fibers having an endothermic peak temperature of 160 ° C. or higher, and in some cases 175 ° C. or higher are conventionally known (see Patent Document 8), but such conventional polypropylene fibers are still sufficiently crystallized. Since it is not performed, the shape of the endothermic peak is a double peak shape or a wide (broad) single peak shape, and the crystal structure as a whole lacks uniformity.
On the other hand, the rope structure of the present invention is “a single shape having an endothermic peak shape by DSC measurement having a half width of 10 ° C. or less, and the amount of change in melting enthalpy (ΔH) is 125 J / g or more. Polypropylene fiber having a DSC characteristic of “there is an endothermic peak shape by DSC measurement has a narrow (sharp) single shape with a half-value width of 10 ° C. or less, and a change in melting enthalpy (Δ When H) is 125 J / g or more, crystallinity is high, a uniform crystal structure is formed, and heat resistance is excellent.

Here, “endothermic peak shape by DSC measurement” and “half-value width” in this specification will be described.
First, FIG. 1 is a diagram schematically showing an endothermic peak shape by DSC measurement in polypropylene fiber.
In FIG. 1, (a) has a single endothermic peak (single peak), the single peak is sharp and has a large peak, and has a large change in melting enthalpy (ΔH). The typical example of the endothermic peak curve of the polypropylene fiber of the invention is shown.
On the other hand, in FIG. 1, (b) is an example of an endothermic peak curve of a conventional polypropylene fiber, which has two endothermic peaks (double peak), a large peak width (half-value width), and a change in melting enthalpy. The amount (ΔH) is small.
Further, in FIG. 1, (c) is another example of the endothermic peak curve of the conventional polypropylene fiber. Although the endothermic peak is one (single peak), the amount of change in melting enthalpy (ΔH) is small.
Next, FIG. 2 is a diagram showing how to find the half width at the endothermic peak by DSC measurement of the polypropylene fiber used in the present invention, taking as an example the case where the peak shape is a single peak in the DSC curve.
In FIG. 2, when the intersection of the perpendicular line extending from the apex X of the endothermic peak (single peak) to the temperature axis and the base line of the endothermic peak is Y, the point that bisects the line segment XY is represented by M. And the length (temperature width) of the line segment N1-N2 is “half-value width (in this specification) where N1 and N2 are the intersection points of the straight line passing through M and parallel to the temperature axis and the endothermic curve, respectively. ° C) ”.

When the endothermic peak curve of the polypropylene fiber is a double peak having two endothermic peaks as shown in FIG. 1B, or when it has three or more endothermic peaks, the peak of the highest endothermic peak is X. , Y is the intersection of the perpendicular from the vertex X to the temperature axis and the baseline of the endothermic peak, M is the point that bisects the line segment XY, and a straight line passing through M and parallel to the temperature axis When the intersection having the lowest temperature is N1 and the intersection having the highest temperature is N2, the length (temperature width) of the line segment N1-N2 is referred to as “half” in this specification. It corresponds to “value width (° C.)”. In this case, the half width (° C.) is generally wide.
In the endothermic peak curve, the base line of the endothermic peak (see FIG. 2) and the area of the portion surrounded by the endothermic peak curve above the baseline are represented by the “melting enthalpy change amount (Δ H) ".

If the crystal formation in the polypropylene fiber is insufficient, an endothermic peak or an exothermic peak may newly appear due to the rearrangement of the crystal at the time of DSC measurement, resulting in a complicated DSC curve. Furthermore, if the crystal formation in the polypropylene fiber is insufficient, the endothermic peak curve changes due to the occurrence or disappearance of the endothermic peak or the exothermic peak even in the same sample due to the difference in the heating rate during DSC measurement. Sometimes.
On the other hand, among the polypropylene fibers used for forming the rope structure of the present invention, “the endothermic peak shape by DSC measurement is a single shape having a half width of 10 ° C. or less, and the amount of change in melting enthalpy (ΔH) is 125 J. Polypropylene fiber having a DSC characteristic of “/ g or more” has a DSC characteristic, so that the temperature rising rate is different in the temperature rising rate range of 1 to 50 ° C./min during DSC measurement. However, the endothermic peak curve has only one endothermic peak, has a sharp and large single peak shape, and has a high amount of change in melting enthalpy (ΔH). That is, among the polypropylene fibers used for forming the rope structure of the present invention, the polypropylene fibers having the DSC characteristics described above have uniform and high crystallinity, and as a result, have high heat resistance. Is backed up.

When the amount of change in melting enthalpy (ΔH) of the polypropylene fiber is less than 125 J / g, the heat resistance may be insufficient.
However, it is a polypropylene fiber that does not have the requirement that “the endothermic peak shape by DSC measurement is a single shape having a half width of 10 ° C. or less and the amount of change in melting enthalpy (ΔH) is 125 J / g or more”. "It is made of polypropylene having an IPF of 94% or more, the single fiber fineness is 0.1 to 3 dtex, the fiber strength is 7 cN / dtex or more, and a large-diameter raised portion and a small-diameter non-raised portion are along the fiber axis on the surface. In the case where the rope structure is formed using polypropylene fibers having the characteristics of having an unevenness with an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm alternately present, Since the fibers have the above-described specific irregularities on the fiber surface, slippage between the fibers and between the fiber bundles (strands) is small, so that the fibers and the fiber bundles (straight) A rope structure in which the ropes are tightly and tightly twisted together is formed, so that a rope having excellent tensile strength, elongation resistance, settling resistance, shape retention, and the like can be obtained.

The higher the amount of change in melting enthalpy (ΔH) of the polypropylene fiber, the higher the heat resistance. However, polypropylene fibers exceeding 165 J / g are difficult to produce unless the production rate is significantly reduced, and the IPF is 100%. Therefore, it is industrially ineffective.
From this point, the polypropylene fiber forming the rope structure of the present invention preferably has a change in melting enthalpy (ΔH) of 125 to 165 J / g, more preferably 130 to 165 J / g. It is more preferable that it is 135-165 J / g, and it is still more preferable that it is 140-165 J / g.

The fineness (single fiber fineness) of the polypropylene fiber forming the rope structure of the present invention is not particularly limited, but is easy to produce (especially easy to stretch) when producing polypropylene fiber, and applied to the rope. From the viewpoint of properties, durability, etc., the fineness (single fiber fineness) of the polypropylene fiber is generally preferably 0.01 to 500 dtex, more preferably 0.05 to 50 dtex, More preferably, it is 5 dtex.
If the fineness (single fiber fineness) of the polypropylene fiber is too small, the rope structure is melted and the yarn is broken after the rope structure is formed, and the strength of the rope structure is reduced. On the other hand, if it is too large, the stretched physical properties for obtaining polypropylene fibers may be lowered, and high strength and highly crystallized polypropylene fibers may not be obtained.

The present invention has a fiber strength of 7 cN / dtex or more, or a fiber strength of 7 cN / dtex or more and the DSC characteristics defined in the present invention [single shape having an endothermic peak shape by DSC measurement of 10 ° C. or less. And the characteristic that the melting enthalpy change amount (ΔH) is 125 J / g or more] and “the single fiber fineness is 0.1 to 3 dtex, and the surface has a large-diameter bulge and a small-diameter non-bulge on the fiber axis. And a rope structure formed by using polypropylene fibers having the characteristics of having an unevenness with an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm.
When using a polypropylene fiber having the above-mentioned specific unevenness characteristics together with a fiber strength of 7 cN / dtex or higher, or a fiber strength of 7 cN / dtex or higher and the above-mentioned specific DSC characteristics, the polypropylene fiber having the uneven characteristics is smooth. In order to manufacture the fiber, the single fiber fineness of the polypropylene fiber is preferably 0.1 to 3 dtex, more preferably 0.2 to 2.5 dtex, and further preferably 0.3 to 2.4 dtex. preferable.

Here, “the polypropylene fiber has irregularities in which the large-diameter raised portions and the small-diameter non-raised portions are alternately located along the fiber axis” on the surface is a schematic diagram of FIG. As shown in FIG. 3, the polypropylene fiber does not have a uniform diameter along the length direction, and has a large bulge (convex portion) (A1, A2, A3, A4,... In FIG. 3). And non-protruding portions (concave portions) having a smaller diameter (B1, B2, B3, B4,... In FIG. 3) are alternately formed along the fiber axis (fiber length direction). This means that the fiber surface is uneven.
In the present specification, the “average interval” refers to an interval between two adjacent ridges (projections) among a large number of projections and depressions (bumps and non-bumps) formed along the fiber axis. Meaning (distance) (the length of A1-A2, A2-A3, A3-A4,... In FIG. 3).
The “average height” is an imaginary straight line that connects the minimum diameter portions of two adjacent non-protruding portions (concave portions) among a large number of irregularities (protruding portions and non-protruding portions) formed along the fiber axis. (A straight line connecting B1 and B2 in FIG. 3, a straight line connecting B2 and B3, a straight line connecting B3 and B4,...) Between the two adjacent non-protruding parts (concave portions) ( It means the average value of the lengths of the vertical lines (h1, h2, h3, h4,... In FIG. 3) from the apex of the convex portion.
The average interval and the average height of the irregularities formed along the fiber axis of the polypropylene fiber can be determined from a photograph of the polypropylene fiber taken using a scanning electron microscope or the like, and the average of the irregularities in the present specification The interval and the average height are values obtained by the method described in the following examples.

If the fineness of the polypropylene fiber is less than 0.1 dtex in the above-described polypropylene fiber having the unevenness characteristics, spinning is performed using a die having an extremely large number of spinning holes in order to maintain mass productivity, and accordingly, the die In order to ensure sufficient space between the spinning holes at the center, it is necessary to make significant improvements to the equipment, such as increasing the scale of the spinning device, and because the fineness is small, yarn drawing troubles and fluff are likely to occur during the drawing process. Become. On the other hand, when the fineness of the polypropylene fiber exceeds 3 dtex, it becomes difficult to express the above-mentioned specific unevenness on the outer periphery of the fiber, and since the specific surface area of the fiber becomes small, it becomes impossible to secure sufficient water retention, and further the drawability is lowered. Thus, it becomes difficult to obtain sufficient fiber strength.
In the polypropylene fiber having the specific unevenness characteristics described above, the fineness (single fiber fineness) is preferably 0.2 to 2.5 dtex, and more preferably 0.3 to 2.4 dtex.

When the polypropylene fiber having the above-described unevenness characteristics is used as the polypropylene fiber, the unevenness having an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm is formed on the surface of the polypropylene fiber. When the rope structure is formed using the polypropylene fiber, the slippage on the fiber surface is reduced while the meshing action due to the unevenness is exhibited. , Tight and strong twisting is carried out by the meshing action between the fibers forming the rope structure and / or between the fiber bundles (strands), and the tensile strength, elongation resistance, sag resistance, shape retention, etc. A rope with excellent resistance can be obtained. In the polypropylene fiber having irregularities on the surface, if the average interval of the irregularities is less than 6.5 μm and / or if the average height is less than 0.35 μm, the irregularities on the fiber surface become too fine, The meshing action due to unevenness is reduced. On the other hand, a polypropylene fiber having an average interval of unevenness exceeding 20 μm and / or an average height exceeding 1 μm cannot be produced unless the production speed of the polypropylene fiber is significantly reduced, and a polypropylene having an IPF close to 100%. Since it needs to be used, it is not practical.
When the rope structure of the present invention is formed using polypropylene fibers having the above-described unevenness characteristics, the average interval of the unevenness formed along the fiber axis direction is 6.6 to 20 μm, particularly 6.8 to 20 μm. Thus, it is preferable to use polypropylene fibers having an average height of 0.40 to 1 μm, particularly 0.45 to 1 μm.

  The shape (transverse cross-sectional shape) of the polypropylene fiber used for forming the rope structure of the present invention is not particularly limited, and may be a solid circular cross-sectional shape or any other irregular cross-sectional shape. Good. Specific examples of the case where the cross section of the fiber has an irregular cross section include a flat shape, a cross shape, a Y shape, a T shape, a V shape, a star shape, a multi-leaf shape, an array shape, and a hollow shape. .

As long as the object of the present invention is not hindered, the polypropylene fiber forming the rope structure of the present invention is, for example, one kind of heat stabilizer, ultraviolet absorber, antioxidant, colorant, filler, antistatic agent and the like. Or you may contain 2 or more types. Polypropylene fiber is generally smaller in specific gravity than water and floats in water as it is, so depending on the use of the rope structure, if necessary, in polypropylene fiber, calcium carbonate, barium sulfate, Specific gravity can be appropriately adjusted by containing titanium oxide, zinc oxide, alumina, silica, potassium methacrylate and the like.
The polypropylene fiber forming the rope structure of the present invention may not be subjected to surface treatment, or may be surface-treated with an appropriate surface treatment agent depending on the use of the rope structure unit.

  The rope structure of the present invention may be formed from long-fiber polypropylene fibers (filaments), or may be formed from spun yarn produced using polypropylene short fibers. From the viewpoint of ease of production, strength of the rope structure, etc., it is preferably formed from long-fiber polypropylene fibers.

The production method of the polypropylene fiber used for forming the rope structure of the present invention is not particularly limited, and the fiber strength is 7 cN / dtex or more and the above-mentioned DSC characteristics [endothermic peak shape by DSC measurement has a half-value width of 10 ° C. or less. Polypropylene fiber having a single shape having a characteristic that the amount of change in melting enthalpy (ΔH) is 125 J / g or more], the above-described DSC characteristics, and the above-mentioned single fiber fineness and unevenness characteristics (single fiber) The fineness is 0.1 to 3 dtex, the average distance between the large-diameter bulges and the small-diameter non-bulges along the fiber axis is 6.5 to 20 μm, and the average height is 0.35. Polypropylene fiber having 1 μm unevenness) or polypropylene fiber having fiber strength, DSC characteristics and unevenness characteristics as described above Any method may be used as long as it can produce fibers.
Among them, the polypropylene fiber used for forming the rope structure of the present invention is produced by melt spinning a polypropylene having an IPF of 94% or more to produce a polypropylene unstretched fiber (unstretched yarn), and cooling and solidifying it. The unstretched polypropylene fiber that has been cooled and solidified can be smoothly produced by the method described below, which is pre-stretched and post-stretched under specific conditions.

First, in producing polypropylene unstretched fibers by melt spinning polypropylene, a method of cooling and solidifying a polypropylene having an IPF of 94% or more at a spinning speed of 200 to 3500 m / min, particularly 300 to 2000 m / min. Is preferably employed.
The melt spinning of polypropylene and the cooling and solidification of the melt-spun polypropylene fiber can be performed by a usual method. Generally, after polypropylene is melt-kneaded at 200 to 300 ° C., it is melted from a spinneret at 220 to 280 ° C. A method of cooling and solidifying by blowing a cooling gas (air or the like) at 5 to 50 ° C. is used.
The single fiber fineness of the unstretched polypropylene fiber is not particularly limited and can be determined according to the draw ratio in the stretching step, the use of the finally obtained polypropylene fiber, etc., but generally 0.3 to 90 dtex, In particular, it is preferably 1 to 60 dtex from the viewpoint of easiness of stretching and strength.

In the production of the polypropylene fiber used for forming the rope structure of the present invention, when melt spinning is carried out at a low spinning speed (generally when the spinning speed is about 200 to 1000 m / min), it is cooled and solidified after melt spinning. The polypropylene unstretched fiber (unstretched yarn) obtained in this manner is stretched at a high magnification in the next stretching step (generally, a total stretch ratio of 5 to 20 times), in particular, a polypropylene fiber having high strength and high heat resistance, particularly Smoothly a polypropylene fiber having a fiber strength of 7 cN / dtex or more, an endothermic peak shape by DSC measurement having a half width of 10 ° C. or less, and a change in melting enthalpy (ΔH) of 125 J / g or more Can be manufactured.
On the other hand, when melt spinning is performed at a high spinning speed (generally when the spinning speed is about 1000 to 3500 m / min), polypropylene unstretched fibers (unstretched yarn) obtained by cooling and solidifying after melt spinning are stretched. Even when the draw ratio at that time is low (generally, the total draw ratio is 3.9 to 7 times), the orientation at the stage of cooling and solidifying the melt-spun fiber is high, and as a result, the fiber strength is 7 cN / dtex or more and As a result, it is possible to smoothly produce a polypropylene fiber having the same DS characteristics and excellent strength and heat resistance.

In the production of polypropylene fiber, the cooled and solidified polypropylene unstretched fiber (unstretched yarn) may be subjected to a stretching process without being wound, or may be subjected to a subsequent stretching process while being unwound and then unwound. Among them, it is preferable to perform the next stretching treatment while winding after winding once, because it is easy to control and manage the stretching conditions.
The polypropylene fiber used for the formation of the rope structure of the present invention is a solidified polypropylene unstretched fiber (unstretched yarn) with a total stretch ratio (total stretch ratio of pre-stretch and post-stretch) of 3.9 to 20 times. Thus, after pre-stretching at a temperature of 120 to 150 ° C. and a stretching ratio of 3 to 10 times, at a temperature of 170 to 190 ° C., a deformation rate of 1.5 to 15 times and a stretching tension of 1.0 to 2.5 cN / dtex. It can be manufactured smoothly by post-drawing at a draw ratio of 1.2 to 3.0 times under the above conditions.

The above-described pre-stretching and post-stretching are preferably performed using a hot air furnace or a hot plate from the viewpoint that the stretching process is performed smoothly. Both pre-stretching and post-stretching may be performed using a hot air furnace, both pre-stretching and post-stretching may be performed using a hot plate, or pre-stretching is performed using a hot air furnace, and post-stretching. A hot plate may be performed, or pre-stretching may be performed using a hot plate, and post-stretching may be performed using a hot air furnace.
When pre-stretching and / or post-stretching is performed using a hot air furnace, the above temperature at the time of pre-stretching and the above temperature at the time of post-stretching refer to the atmospheric temperature of the hot air furnace, and the pre-stretching and / or post-stretching is performed on a hot plate. When performing using, the said temperature at the time of pre-stretching and the said temperature at the time of back stretching say the temperature of a hot plate.

Pre-stretching of the polypropylene unstretched fiber (unstretched yarn) formed by cooling and solidification may be performed in one stage or in multiple stages, and is generally preferably performed in one to three stages. .
In addition, the post-drawing of the drawn polypropylene fiber (drawn yarn) that has been pre-drawn may be performed in one stage or may be performed in multiple stages, and is generally preferably performed in one to five stages.
In performing the stretching treatment, a method may be employed in which a polypropylene stretched fiber (stretched yarn) obtained by pre-stretching is continuously wound without being wound, or after-stretching, or a polypropylene stretched fiber obtained by pre-stretching. A method may be employed in which the (drawn yarn) is cooled (generally at about room temperature) and wound up and then unwound again and then drawn. Among them, the latter method in which the polypropylene stretched fiber (drawn yarn) obtained by pre-drawing is once wound up and then rewound and then stretched is provided with the above-described characteristics used for forming the rope structure of the present invention. Is preferable because it can be obtained more smoothly.

In the pre-drawing, polypropylene undrawn fiber (undrawn yarn) formed by cooling and solidification is introduced into a hot air oven having a temperature (atmospheric temperature) of 120 to 150 ° C, particularly 125 to 140 ° C, or a temperature of 120 to 150. It is preferably carried out in contact with a heat plate at 125 [deg.] C., particularly 125-140 [deg.] C., in a single stage or multiple stages at a stretching ratio of 3 to 10 times, particularly 3 to 5 times.
In addition, the post-stretching is a polypropylene stretched fiber (drawn yarn) obtained by pre-stretching under the above-described conditions, and the temperature (atmosphere temperature) is 170 to 190 ° C, more preferably 170 to 185 ° C, particularly 170 to 180 ° C. It is introduced into a hot stove or brought into contact with a hot plate having a temperature of 170 to 190 ° C., further 170 to 185 ° C., particularly 170 to 180 ° C., and a draw ratio of 1.2 to 3.0 times in one or more stages. In particular, it is preferably performed at 1.3 to 2.5 times.
When post-stretching is performed using a hot air furnace or a stretching plate, the atmospheric temperature of the hot air furnace or the stretching plate temperature is set to a temperature higher than the endothermic start temperature + 10 ° C. in the DSC curve of the polypropylene fiber immediately before the post-stretching treatment. It is preferable to perform post-stretching.
The total draw ratio of pre-stretching and post-stretching is preferably 3.9 to 20 times, more preferably 4.5 to 11 times, and still more preferably 4.7 to 10.5 times.
Further, the melt spinning speed for producing polypropylene unstretched fibers (unstretched yarn) was A (m / min), and the total stretch ratio after the above-described pre-stretching and post-stretching was defined as B (times). Sometimes, the value of A × B is in the range of 3000 to 17000 (m · times / min), especially 3500 to 15000 (m · times / min), and the polypropylene is melt-spun and the above-mentioned pre-stretching and When the post-drawing is performed, the target polypropylene fiber can be produced smoothly.

Here, the above-mentioned draw ratio in the pre-drawing is obtained by dividing the length of the fiber (yarn) immediately after being discharged from the pre-drawing step by the length of the undrawn fiber (undrawn yarn) introduced in the pre-drawing step. The drawing ratio in the post-drawing is the value obtained by dividing the length of the fiber (yarn) immediately after being discharged from the post-drawing step by the length of the fiber (yarn) introduced in the post-drawing step. Say.
The total draw ratio of the above-mentioned pre-drawing and post-drawing is the length of the undrawn fiber (undrawn yarn) introduced into the pre-drawing step by the length of the fiber (yarn) immediately after being discharged from the post-drawing step. The value divided by the above.

The post-stretching employs the above-described temperature (170 to 190 ° C.) and stretch ratio (1.2 to 3.0 times), a deformation rate of 1.5 to 15 times / min, and a stretching tension of 1.0 to 2. Adopting the condition of 5 cN / dtex. By adopting such post-drawing conditions, it is possible to obtain a polypropylene fiber having the above-described characteristics used in the present invention.
The deformation rate at the time of post-drawing is preferably 1.6 to 12 times / min, and more preferably 1.7 to 10 times / min.
The stretching tension during post-stretching is preferably 1.1 to 2.5 cN / dtex, more preferably 1.3 to 2.5 cN / dtex.

Here, the above-described deformation rate in post-stretching is the time (minutes) required for post-stretching the draw ratio (times) in post-stretching [in the case of post-stretching in a hot air furnace, the fiber (yarn) is in the hot air path. When the film was post-stretched with the stretching plate for the existing time, the value divided by the time when the fiber (yarn) was in contact with the stretching plate], and when post-stretching was performed in multiple stages, the final post-stretching A value obtained by dividing the stretching ratio (total stretching ratio) by the total stretching time required for post-stretching.
The drawing tension in the post-drawing is measured by using a tensiometer for the yarn tension immediately after the final drawing in the post-drawing.

  Moreover, after extending | stretching a polypropylene fiber on the above-mentioned conditions, you may give a heat setting or a shrinking process. The treatment temperature and shrinkage rate at that time are not particularly limited as long as the properties of the polypropylene fiber used in the present invention are not impaired.

  The above-described method for producing a polypropylene fiber by pre-stretching a polypropylene unstretched fiber obtained by melt-spinning polypropylene having an IPF of 94% or more and then solidifying by cooling, under the above-described conditions, and then post-stretching under the above-described conditions. The polypropylene fiber excellent in heat resistance and strength, in particular, the endothermic peak shape by DSC measurement is a single shape having a half width of 10 ° C. or less, the amount of change in melting enthalpy (ΔH) is 125 J / g or more, and A polypropylene fiber having a fiber strength of 7 cN / dtex or more and excellent in heat resistance and strength can be produced smoothly.

  Furthermore, when polypropylene polypropylene having an IPF of 94% or more is melt-spun and then cooled and solidified, the polypropylene unstretched fiber is pre-stretched under the above-described conditions and then further stretched under the above-described conditions to produce a polypropylene fiber. In addition, by adjusting the single fiber fineness of the polypropylene unstretched fiber to be supplied to the pre-drawing step, the draw ratio in the pre-drawing and / or post-drawing, etc., the single fiber fineness is finally 3 dtex or less, particularly 0.1-3 dtex. The above-mentioned fiber strength of 7 cN / dtex or more and the above-mentioned specific DSC characteristics [the endothermic peak shape by DSC is a single shape having a half width of 10 ° C. or less, and the melting enthalpy Characteristic that the amount of change (ΔH) is 125 J / g or more] and a large-diameter raised portion on the surface A polypropylene fiber having a specific concavo-convex structure, “small bulges having small diameters are alternately present along the fiber axis, and have an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm”. Obtainable. This polypropylene fiber is excellent in heat resistance and strength, and has a meshing action by having the above-mentioned specific irregularities on the surface, and the rope in which the twisting between the fibers and between the fiber bundles (strands) is made tight and strong. Form a structure.

The type, structure, shape and the like of the rope structure of the present invention are not particularly limited, and any rope structure formed using the polypropylene fibers having the specific physical properties described above may be used.
The rope structure of the present invention may be formed using only the above-described polypropylene fiber having the specific physical property, or one of other fibers and linear members together with the polypropylene fiber having the specific physical property. You may form using 2 or more types.
In order to obtain a rope structure made of polypropylene fiber that fully utilizes the properties (strength, heat resistance, meshing action due to surface irregularities, etc.) of polypropylene fibers having the above specific properties, polypropylene having the above specific properties The proportion of the fiber (mass proportion) is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 70 to 100% by mass based on the mass of the rope structure. preferable.

Although not limited, as a representative example of the rope structure of the present invention,
(I) Collecting fibers and twisting them to make a yarn, collecting 2 to several tens of yarns (preferably 2 to 100 yarns) and twisting them together to form a strand (reverted yarn) ) A plurality of ropes (preferably 3 to 4) twisted together;
(Ii) Collecting the fibers and twisting them to make a yarn, collecting 2 to several tens of yarns (preferably 2 to 30 yarns) and twisting them together to form the first strand (reverted yarn), Two to several tens (preferably 2 to 50) strands of 1 strand (reverse yarn) are collected and twisted to form a second strand (reverted yarn), and a plurality of the second strands (reverted yarn) A rope structure formed by twisting (preferably 3 to 4);
(Iii) Collecting and twisting fibers to form a yarn, collecting 2 to several tens of yarns (preferably 2 to 100 yarns) and twisting them into strands (reverted yarns); A rope structure formed by twisting together a plurality of (preferably 3 to 4) wires in a state of surrounding the core material using other fibers and linear bodies as the core material;
(Iv) Collecting the fibers and twisting them to make a yarn, collecting 2 to several tens of yarns (preferably 2 to 100 yarns) and twisting them together to form a strand (reverted yarn). ) And one or more strands (reverted yarns) and / or linear bodies (for example, metal wires, linear plastics, strings, tapes, etc.) made of other fibers. Rope structure;
And so on.

The rope structures of the above (i) and (ii) may be formed using only the polypropylene fibers having the specific physical properties described above, or using the polypropylene fibers and other fibers having the specific physical properties. It may be formed.
The rope structures (iii) and (iv) are formed by using other fibers and / or linear bodies together with the polypropylene fibers having the specific physical properties described above.
When forming the rope structure of the above (i) using only the polypropylene fiber having the specific physical properties described above, the fineness of the yarn made by collecting and twisting the fibers is about 10 to 5000 dtex, particularly about 100 to 3000 dtex. Thus, the fineness of the strand (reverted yarn) formed by collecting and twisting the yarn is preferably 20 to 500,000 dtex, particularly 200 to 300,000 dtex, from the viewpoint of handleability and practicality.
Moreover, when forming the rope structure of said (ii) using only the polypropylene fiber which has the above-mentioned specific physical property, the fineness of the yarn made by collecting and twisting the fibers is 10 to 5000 dtex, especially 100 The fineness of the first strand (reverted yarn) formed by collecting and twisting the yarn is about ˜3000 dtex, and is formed by twisting the first strand (reverted yarn) with a fineness of 20-150,000 dtex, especially 200-90000 dtex. The fineness of the second strand (reverted yarn) is preferably from 40 to 7500000 dtex, particularly from 400 to 4500000 dtex from the viewpoints of handleability and practicality.
Moreover, when forming a rope structure using another fiber and a linear body with the polypropylene fiber which has the said specific physical property, it is preferable to employ | adopt the fineness according to the above.

  When the rope structure of the present invention is formed using one or more of other fibers and linear bodies together with the polypropylene fiber having the specific physical properties described above, as other fibers, for example, Synthetic fibers such as polypropylene fibers other than polypropylene fibers having the above specific properties, nylon fibers, vinylon fibers, polyethylene fibers, polyester fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, aramid fibers, polyarylate fibers, rayon fibers, etc. And semi-synthetic fibers, natural fibers such as hemp, cotton and wool, metal fibers and carbon fibers. Examples of other linear bodies include metal wires, linear plastics, plastic tapes, cloth tapes, strings produced by knitting and weaving using synthetic fibers and / or natural fibers, and split yarns.

  When the rope structure of the present invention is formed using one or more of other fibers and linear bodies together with the polypropylene fibers having the specific physical properties described above, for example, the rope structure is configured. In the above-described strand (reverse yarn), the polypropylene fiber and other fibers and / or linear bodies may be in a mixed state (mixed), or a strand (reverted yarn) made of only the polypropylene fiber. Strands (reverted yarns) and / or linear bodies made of other fibers may be twisted [for example, in the category of the rope structure of (d) above], or other in the center of the rope structure. The strands (reverted yarns) made only of polypropylene fibers may be twisted around the core, and the strands and the linear body may be twisted [for example, the rope structure of (c) above] Those of category].

The thickness of the rope structure of the present invention is not particularly limited, and can be determined according to the use of the rope structure, the form of use, the handleability, and the like. In general, the diameter of the rope structure of the present invention is preferably about 0.1 to 100 mm, particularly 0.2 to 50 mm, from the viewpoint of ease of manufacture of the rope structure, handling properties, and the like.
Moreover, the rope structure of the present invention may be subjected to heat treatment and / or resin processing as necessary after the twisting step (steel making step).
The production method of the rope structure of the present invention is not particularly limited, and the same method and apparatus conventionally used for producing a rope structure using synthetic fiber or synthetic fiber and other materials are used. Can be manufactured.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. In the following examples, etc., the isotactic pentad fraction (IPF) of polypropylene, the stretching tension at the time of stretching, the DSC characteristics of the polypropylene fiber, the single fiber fineness, the fiber strength, the average spacing and the average height of the irregularities on the fiber surface The Young's modulus of polypropylene yarn (yarn prepared by twisting and twisting polypropylene drawn yarn) and the number of times of rope grinder twist wear cutting were measured or calculated by the methods described below.

(1) Isotactic pentad fraction (IPF) of polypropylene:
Using a superconducting nuclear magnetic resonance apparatus (“Lambda500” manufactured by JEOL Ltd.), the IPF of polypropylene was determined according to “ ¹³ C-NMR spectrum method” described in Non-Patent Document 1. Specifically, the content ratio (fraction) of propylene units (isotactic pentad units) in which five propylene monomer units are continuously isotactically bonded in a ¹³ C-NMR spectrum in polypropylene (%) ) To obtain IPF. At that time, the peak assignment in the ¹³ C-NMR spectrum was determined according to the method described in Non-Patent Document 2.

(2) Stretch tension during stretching:
Using a load tension measuring instrument ("DTMX-5B" manufactured by Nidec Simpo Co., Ltd.), measure the tension of the yarn immediately after coming out of the drawing furnace (hot air furnace) or just after leaving the drawing plate. It was set as the stretching tension (cN / dtex).

(3) DSC measurement of polypropylene fiber:
Polypropylene fibers were allowed to stand for 5 days in an atmosphere at a temperature of 20 ° C. and a relative humidity of 65%, and then the humidity was adjusted. Then, the polypropylene fibers were cut to a length of 1 mm, and 5 mg was weighed to obtain an aluminum pan (capacity 100 μL) (made by METTTLER TOLEDO No. 51119872), sealed using an aluminum pan cover (Meteller Toledo "No. 51119871"), and in a nitrogen atmosphere using a scanning differential calorimeter (TA Instruments "DSC2010"). From the 1 st run DSC curve measured at a heating rate of 10 ° C./min, the half-value width (° C.) of the endothermic peak and the amount of change in melting enthalpy (ΔH) (J / g) are shown in FIG. 1 and FIG. In particular, it was determined by the method described above with reference to FIG.

(4) Fineness of polypropylene fiber (single fiber fineness):
The polypropylene fiber was left to stand for 5 days in an atmosphere at a temperature of 20 ° C. and a relative humidity of 65%, and then the humidity was adjusted. Then, a fixed length (900 mm) of the conditioned polypropylene fiber (monofilament) was taken and its mass was measured. The fineness was calculated. About the same humidity control polypropylene fiber, the same measurement operation as the above was performed 10 times, and the average value was taken as the fineness (single fiber fineness) of the polypropylene fiber. In addition, when the fineness was not able to be measured by mass measurement of a fixed length because the fiber was thin, the fineness was measured using the fineness measuring device (“VIBROMAT M” manufactured by Texttechno) for the same humidity control fiber.

(5) Fiber strength of polypropylene fiber:
The polypropylene fiber is left to stand for 5 days in an atmosphere of a temperature of 20 ° C. and a relative humidity of 65%, and then the humidity is adjusted. Then, the polypropylene fiber (single fiber) is cut to a length of 60 mm to obtain a sample. A single fiber is gripped at both ends (gripping from both ends to 10 mm), and using a fiber strength measuring device (“FAFEGRAPH M” manufactured by Texttechno) under an environment of a temperature of 20 ° C. and a relative humidity of 65%, a tensile speed of 60 mm The tensile strength at the time of cutting was measured, and the fiber strength (cN / dtex) was determined by dividing the value by the fineness of the polypropylene single fiber. In addition, the same operation was performed 10 times about the same polypropylene fiber, fiber strength was calculated | required, the average value was taken, and it was set as the fiber strength of polypropylene fiber (polypropylene single fiber).

(6) Average spacing and average height of the irregularities on the fiber surface of the polypropylene fiber:
Using a scanning electron microscope ("S-510" manufactured by HITACHI), polypropylene fibers (single fibers) were photographed at a magnification of 1000 times from the direction perpendicular to the fiber axis. According to the method described above based on No. 3, the average spacing and average height of the irregularities on the fiber surface were determined. In calculating the average interval and the average height, for ten polypropylene fibers (single fibers), five locations (interval of 10 cm between each measurement location) were selected for each fiber, and the uneven spacing at each location and The height was measured (total of 50 locations), and the average value thereof was taken as the average interval (μm) and the average height (μm).

(7) Young's modulus of polypropylene yarn:
A polypropylene yarn obtained by combining polypropylene fibers (polypropylene drawn yarn) to 2000 dtex, twisted at 70 T / m, is quasi-twisted to JIS L 1013, in an atmosphere at a temperature of 20 ° C. and a relative humidity of 65%. For 3 days, the sample was collected for a predetermined length, and both ends of the sample were gripped so that the length between the gripping devices (test length) was 200 mm. Using the graph AG5000-B ”, the tensile stress P (N) at an elongation of 1% was measured at an atmospheric temperature of 120 ° C. and a tensile speed of 100 mm / min. Young's modulus (cN / dtex) was determined.
The same operation was performed 10 times for the same yarn to determine the Young's modulus, and the average value was taken as the Young's modulus at 120 ° C. of the polypropylene yarn per unit dtex.

Young's modulus of yarn (cN / dtex) = P × 10000 / Td (1)

In the formula, P = tensile stress when elongation is 1% (N)
Td = total fineness of polypropylene yarn before stretching = 2000 dtex

(8) Number of times of rope grinder twist wear cutting:
After immersing the sample (rope) in water at 20 ° C. for 24 hours, as shown in FIG. 4, the rope was twisted at 45 rpm with a 10 kg load applied, and the rope did not dry. While pouring water, rotate the grinder (made of carbon, diameter = 100 mm, particle size # 46) at a rotation speed of 45 rotations / minute to wear the rope, and read the rotation speed of the grinder when the rope breaks, The number of grinder twist wear cuts (times).

<< Production Example 1 >> [Production of Polypropylene Fiber (a-1)]
(1) Polypropylene [“Y2000GV” manufactured by Prime Polymer Co., Ltd., IPF = 97%, MFR = 18 g / 10 min (230 ° C., load 2.16 kg)] is put into an extruder of a melt spinning apparatus and melt kneaded at 240 ° C. Then, from a spinneret attached to the spinning head at a temperature of 245 ° C. [24 holes (circular holes), hole diameter 0.2 mm], 22.3 g / min is discharged and polypropylene is unstretched at a take-up speed of 800 m / min. A yarn was produced, wound on a bobbin, and stored at room temperature (total fineness of polypropylene undrawn yarn = 288 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 128 ° C., and pre-drawn 4.6 times in two stages to obtain a polypropylene pre-drawn yarn. It was manufactured, wound on a bobbin and stored at room temperature (total fineness of polypropylene predrawn yarn = 63 dtex / 24 filament, endothermic onset temperature = 153.5 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above was unwound from a bobbin and introduced into a hot air oven at a temperature of 172 ° C., and the deformation rate was 1.7 times / minute and the draw tension was 1.18 cN / dtex. Under the conditions, polypropylene stretch yarn (total fineness = 48 dtex / 24 filament) [polypropylene fiber (a-1)] having a total draw ratio of 6.0 times was produced by post-drawing in 1.3 stages in three stages. .
(4) About the polypropylene drawn yarn [polypropylene fiber (a-1)] obtained in the above (3), DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.
Moreover, when the polypropylene drawn yarn [polypropylene fiber (a-1)] obtained in the above (3) was photographed using a scanning electron microscope (“S-510” manufactured by HITACHI) (magnification 1000 times). As shown in FIG.

<< Production Example 2 >> [Production of polypropylene fiber (a-2)]
(1) A polypropylene undrawn yarn was produced in the same manner as in (1) of Production Example 1 except that the undrawn yarn take-up speed was changed to 3000 m / min in Production Example 1 (1), and a bobbin was produced. And wound at room temperature (total fineness of polypropylene undrawn yarn = 214 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in (1) above is unwound from a bobbin, introduced into a hot air oven at a temperature of 128 ° C., pre-drawn 3.1 times in two steps, and a polypropylene pre-drawn yarn Was wound around a bobbin and stored at room temperature (total fineness of polypropylene predrawn yarn = 69 dtex / 24 filament, endothermic onset temperature = 155.3 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above was unwound from a bobbin and introduced into a hot air oven at a temperature of 172 ° C., and the deformation rate was 1.8 times / min and the draw tension was 1.34 cN / dtex. Under the conditions, a polypropylene drawn yarn (total fineness = 46 dtex / 24 filament) [polypropylene fiber (a-2)] having a total draw ratio of 4.7 times was produced by post-drawing in three stages to 1.5 times. .
(4) For the polypropylene drawn yarn [polypropylene fiber (a-2)] obtained in (3) above, DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)], and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 3 >> [Production of Polypropylene Fiber (a-3)]
(1) The same polypropylene used in (1) of Production Example 1 was put into an extruder of a melt spinning apparatus, melted and kneaded at 240 ° C., and a spinneret with a temperature of 245 ° C. attached to the spinning head [number of holes 48 Each piece (cross-shaped hole) was discharged at a rate of 20.2 g / min from a hole diameter of 0.2 mm], and undrawn polypropylene yarn was produced at a take-up speed of 800 m / min, wound on a bobbin and stored at room temperature (polypropylene). Total fineness of undrawn yarn = 436 dtex / 48 filament).
(2) The polypropylene undrawn yarn obtained in (1) above is unwound from a bobbin, introduced into a hot air oven at a temperature of 138 ° C., pre-drawn 3.9 times in two stages, and a polypropylene pre-drawn yarn Was wound around a bobbin and stored at room temperature (total fineness of polypropylene pre-drawn yarn = 112 dtex / 48 filament, endothermic temperature = 155.2 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above was unwound from a bobbin and introduced into a hot air oven at a temperature of 172 ° C., and the deformation rate was 2.1 times / minute and the draw tension was 1.12 cN / dtex. Under the conditions, a polypropylene drawn yarn (total fineness = 86 dtex / 48 filament) [polypropylene fiber (a-3)] having a total draw ratio of 5.1 times was produced by post-drawing 1.3 times in one stage. .
(4) About the polypropylene drawn yarn [polypropylene fiber (a-3)] obtained in the above (3), DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 4 >> [Production of Polypropylene Fiber (a-4)]
(1) Using the same polypropylene as used in (1) of Production Example 1 and employing the same conditions as in (1) of Production Example 1, a polypropylene unstretched yarn was produced and wound on a bobbin.
(2) Unwinding the polypropylene unstretched yarn obtained in (1) above from the bobbin, pre-stretching using the same conditions as (2) of Production Example 1 to produce a polypropylene pre-stretched yarn, I wound it on a bobbin.
(3) The polypropylene pre-drawn yarn obtained in (2) above was unwound from a bobbin and introduced into a hot air oven at a temperature of 180 ° C., and the deformation rate was 1.7 times / min and the drawing tension was 1.06 cN / dtex. Under the conditions, polypropylene stretched yarn (total fineness = 50 dtex / 24 filament) [polypropylene fiber (a-4)] having a total draw ratio of 6.0 times was produced by post-drawing by 1.3 times in three stages. .
(4) DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber for the drawn polypropylene yarn [polypropylene fiber (a-4)] obtained in (3) above The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 5 >> [Production of polypropylene fiber (a-5)]
(1) The same melt spinning conditions as (1) of Production Example 1 using polypropylene [“ZS1337A” manufactured by Prime Polymer Co., Ltd., IPF = 96%, MFR = 20 g / 10 min (230 ° C., load 2.16 kg)] Was used to produce a polypropylene undrawn yarn and wound around a bobbin (total fineness of polypropylene undrawn yarn = 288 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 135 ° C., pre-drawn 4.8 times in two stages, and a polypropylene pre-drawn yarn Was wound around a bobbin and stored at room temperature (total fineness of polypropylene predrawn yarn = 60 dtex / 24 filament, endothermic onset temperature = 152.0 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above is unwound from a bobbin and introduced into a hot air oven at a temperature of 172 ° C., and the deformation rate is 1.6 times / minute and the drawing tension is 1.33 cN / dtex. Under the conditions, it was post-stretched by 1.8 times in three stages to produce a polypropylene drawn yarn (total fineness = 50 dtex / 24 filament) [polypropylene fiber (a-5)] having a total draw ratio of 8.6 times. .
(4) DSC measurement [measurement of endothermic peak shape, half-value width, amount of change in melting enthalpy (ΔH)] and fiber for the drawn polypropylene yarn [polypropylene fiber (a-5)] obtained in the above (3) The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 6 >> [Production of Polypropylene Fiber (a-6)]
(1) Using polypropylene [IPF = 98%, MFR = 16 g / 10 min (230 ° C., load 2.16 kg)], adopting the same melt spinning conditions as in (1) of Production Example 1 and unstretched polypropylene A yarn was produced and wound on a bobbin (total fineness of undrawn yarn = 293 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 128 ° C., and pre-drawn 4.6 times in two stages to obtain a polypropylene pre-drawn yarn. It was manufactured and wound on a bobbin and stored at room temperature (total fineness of polypropylene predrawn yarn = 64 dtex / 24 filament, endothermic onset temperature = 156.4 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above was unwound from a bobbin and introduced into a hot air oven at a temperature of 178 ° C., and the deformation rate was 2.8 times / min and the drawing tension was 1.54 cN / dtex. Under the conditions, it was post-drawn 2.2 times in 4 stages to produce a polypropylene drawn yarn (total fineness = 29 dtex / 24 filament) [polypropylene fiber (a-6)] having a total draw ratio of 10.1 times. .
(4) DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber for the drawn polypropylene yarn [polypropylene fiber (a-6)] obtained in (3) above The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 7 >> [Production of Polypropylene Fiber (a-7)]
(1) Polypropylene [IPF = 98%, MFR = 16 g / 10 min (230 ° C., load 2.16 kg)] and polypropylene [“Y3002G” manufactured by Prime Polymer, IPF = 93%, MFR = 30 g / 10 min (230 C., load 2.16 kg)] in a mass ratio of 1: 1 (IPF of the mixture = 95.5%), using the same melt spinning conditions as in Production Example 1 (1), A polypropylene undrawn yarn was produced and wound on a bobbin (total fineness of polypropylene undrawn yarn = 288 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 128 ° C., and pre-drawn 4.6 times in two stages, and the polypropylene pre-drawn yarn Was wound around a bobbin and stored at room temperature (total fineness of polypropylene predrawn yarn = 63 dtex / 24 filament, endothermic onset temperature = 152.5 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above was unwound from a bobbin and introduced into a hot air oven at a temperature of 172 ° C., and the deformation rate was 1.7 times / min and the draw tension was 1.20 cN / dtex. Under the conditions, polypropylene stretched yarn (total fineness = 48 dtex / 24 filament) [polypropylene fiber (a-7)] having a total draw ratio of 6.0 times was produced by post-drawing in 1.3 stages in three stages. .
(4) About the polypropylene drawn yarn [polypropylene fiber (a-7)] obtained in (3) above, DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 8 >> [Production of Polypropylene Fiber (a-8)]
(1) A spinneret [24 holes (circular holes), hole diameter 0.2 mm] for producing core-sheath composite fibers is attached to a spinning head of a melt spinning apparatus, and polypropylene ("Y3002G" manufactured by Prime Polymer Co., IPF = 93%) using a core component and polypropylene [IPF = 98%, MFR = 16 g / 10 min (230 ° C., load 2.16 kg)] as a sheath component, and a mass ratio of core component: sheath component = 1: 2. , Melt-kneaded at 240 ° C., discharged from the spinneret (die temperature: 245 ° C.) at an amount of 22.3 g / min, and wound on a bobbin at a take-up speed of 800 m / min to produce a core-sheath type polypropylene undrawn yarn And stored at room temperature (total fineness of polypropylene undrawn yarn = 287 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 128 ° C., and pre-drawn 4.6 times in two stages to obtain a polypropylene pre-drawn yarn. It was manufactured and wound on a bobbin and stored at room temperature (total fineness of polypropylene predrawn yarn = 62 dtex / 24 filament, endothermic onset temperature = 152.2 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above was unwound from a bobbin and introduced into a hot air oven at a temperature of 172 ° C., and the deformation rate was 1.7 times / min and the draw tension was 1.25 cN / dtex. Under the conditions, it was post-stretched 1.3 times in three stages to produce a polypropylene drawn yarn (total fineness = 48 dtex / 24 filament) [polypropylene fiber (a-8)] having a total draw ratio of 6.0 times. .
(4) About the drawn polypropylene yarn [polypropylene fiber (a-8)] obtained in (3) above, DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)], and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 9 >> [Production of Polypropylene Fiber (a-9)]
(1) Using the same polypropylene as used in (1) of Production Example 1 and employing the same conditions as in (1) of Production Example 1, a polypropylene unstretched yarn was produced and wound on a bobbin.
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 128 ° C., pre-drawn 4.6 times in one stage, and a polypropylene pre-drawn yarn Was wound around a bobbin and stored at room temperature (total fineness of polypropylene pre-drawn yarn = 63 dtex / 24 filament).
(3) The polypropylene pre-drawn yarn obtained in (2) above is unwound from a bobbin and brought into contact with a hot plate at a temperature of 172 ° C., with a deformation rate of 13.8 times / min and a draw tension of 1.43 cN / dtex. Under the conditions, polypropylene stretch yarn (total fineness = 39 dtex / 24 filament) having a total draw ratio of 7.4 times after post-stretching 1.6 times in one stage (contact time to the heat plate = 15 seconds) [ Polypropylene fiber (a-9)] was produced.
(4) About the drawn polypropylene yarn [polypropylene fiber (a-9)] obtained in (3) above, DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 10 >> [Production of Polypropylene Fiber (a-10)]
(1) Using the same polypropylene as used in (1) of Production Example 1 and employing the same conditions as in (1) of Production Example 1, a polypropylene unstretched yarn was produced and wound on a bobbin.
(2) Unwinding the polypropylene unstretched yarn obtained in (1) above from the bobbin, pre-stretching using the same conditions as (2) of Production Example 1 to produce a polypropylene pre-stretched yarn, I wound it on a bobbin.
(3) The polypropylene pre-drawn yarn obtained in (2) was unwound from the bobbin, and the same conditions as in Production Example 1 (3) were adopted to produce a polypropylene drawn yarn, which was wound around the bobbin.
(4) The polypropylene drawn yarn obtained in the above (3) is unwound from a bobbin, introduced into a hot air oven at a temperature of 168 ° C., and contracted by 2% to produce a polypropylene yarn [polypropylene fiber (a-10)]. did.
(5) DSC measurement [measurement of endothermic peak shape, half-value width, amount of change in melting enthalpy (ΔH)] and fiber strength for the polypropylene yarn [polypropylene fiber (a-10)] obtained in (4) above. When the measurement of the anti-friction property, surface irregularity size (average interval and average height of irregularities) and water retention was carried out by the methods described above, the results were as shown in Table 1 below.

<< Production Example 11 >> [Production of Polypropylene Fiber (b-1)]
(1) Using polypropylene (“Y3002G” manufactured by Prime Polymer Co., Ltd., IPF = 93%), the same melt spinning conditions as in (1) of Production Example 1 were adopted to produce a polypropylene undrawn yarn and wound on a bobbin And stored at room temperature (total fineness of polypropylene undrawn yarn = 288 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 128 ° C., and pre-drawn 4.6 times in two stages, and the polypropylene pre-drawn yarn Was wound around a bobbin and stored at room temperature (total fineness of polypropylene predrawn yarn = 68 dtex / 24 filament, endothermic onset temperature = 151.8 ° C.).
(3) The polypropylene predrawn yarn obtained in the above (2) is unwound from a bobbin and introduced into a hot air furnace having a temperature of 172 ° C., and the deformation rate is 1.7 times / min and the draw tension is 0.96 cN / dtex ( (Note: Please consider) Polypropylene drawn yarn (total fineness = 48 dtex / 24 filaments) [polypropylene fiber (b -1)] was produced.
(4) About the polypropylene drawn yarn [polypropylene fiber (b-1)] obtained in the above (3), DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber The strength, friction fusibility and water retention were measured by the methods described above, and the results were as shown in Table 1 below. In addition, the polypropylene fiber obtained by this manufacture example 11 did not have an unevenness | corrugation on the surface.

<< Production Example 12 >> [Production of Polypropylene Fiber (b-2)]
(1) The same operation as (1) and (2) of Production Example 1 was performed to produce a polypropylene pre-drawn yarn [polypropylene fiber (b-2)].
(2) About the polypropylene predrawn yarn [polypropylene fiber (b-2)] obtained in the above (1), DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)], and The fiber strength, friction resistance and water retention were measured by the methods described above, and the results were as shown in Table 1 below. In addition, the polypropylene fiber obtained by this manufacture example 12 did not have an unevenness | corrugation on the surface.

<< Production Example 13 >> [Production of Polypropylene Fiber (b-3)]
(1) Using the same polypropylene (“Y2000GV” manufactured by Prime Polymer Co., Ltd., IPF = 97%) as used in (1) of Production Example 1, the same melt spinning conditions as in (1) of Production Example 1 were adopted. A polypropylene undrawn yarn was produced and wound on a bobbin.
(2) The polypropylene undrawn yarn obtained in (1) above is unwound from a bobbin, introduced into a hot air oven at a temperature of 143 ° C., drawn 6.9 times in one stage, and drawn polypropylene yarn (total Fineness = 42 dtex / 24 filament) [polypropylene fiber (b-3)] was produced.
(3) About the polypropylene drawn yarn [polypropylene fiber (b-3)] obtained in the above (2), DSC measurement [measurement of endothermic peak shape, half-value width, change in melting enthalpy (ΔH)], and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 14 >> [Production of Polypropylene Fiber (b-4)]
(1) Using the same polypropylene (“Y2000GV” manufactured by Prime Polymer Co., Ltd., IPF = 97%) as used in (1) of Production Example 1, the same melt spinning conditions as in (1) of Production Example 1 were adopted. A polypropylene undrawn yarn was produced and wound on a bobbin.
(2) After unwinding the polypropylene unstretched yarn obtained in (1) above from the bobbin, introducing it into a hot water tank at a temperature of 90 ° C., and pre-stretching 3.7 times in one step, without winding Subsequently, it was introduced into a hot air oven at a temperature of 138 ° C. and post-drawn to 1.2 times, and a drawn yarn having a total draw ratio of 4.4 times (total fineness = 65 dtex / 24 filament) [polypropylene fiber (b-4) ] Was manufactured.
(3) About the polypropylene drawn yarn [polypropylene fiber (b-4)] obtained in (2) above, DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)], and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 15 >> [Production of Polypropylene Fiber (b-5)]
(1) The same polypropylene (“Y2000GV” manufactured by Prime Polymer Co., Ltd., IPF = 97%) used in (1) of Production Example 1 is put into an extruder of a melt spinning apparatus, melt-kneaded at 270 ° C., and spun. From the spinneret attached to the head at a temperature of 295 ° C. [24 holes (circular holes), hole diameter 0.2 mm], discharge at an amount of 9.5 g / min and take it up at 1500 m / min to produce a polypropylene undrawn yarn. And wound around a bobbin and stored at room temperature (total fineness of polypropylene undrawn yarn = 65 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin, introduced into a hot air oven at a temperature of 130 ° C., drawn 1.5 times in one stage, and drawn polypropylene yarn (total Fineness = 44 dtex / 24 filament) [polypropylene fiber (b-5)] was produced.
(3) About the polypropylene drawn yarn [polypropylene fiber (b-5)] obtained in (2) above, DSC measurement [measurement of endothermic peak shape, half-value width, amount of change in melting enthalpy (ΔH)], and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 16 >> [Production of Polypropylene Fiber (b-6)]
(1) The same polypropylene (“Y2000GV” manufactured by Prime Polymer Co., IPF = 97%) used in (1) of Production Example 1 is put into an extruder of a melt spinning apparatus, melt kneaded at 230 ° C., and spun. From the spinneret attached to the head at a temperature of 300 ° C. [number of holes 30 (circular holes), hole diameter 0.8 mm], discharge at an amount of 20 g / min, and take up at 300 m / min to produce polypropylene undrawn yarn, bobbin And wound up at room temperature (total fineness of polypropylene undrawn yarn = 535 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in (1) above is unwound from a bobbin and drawn 3.7 times in a single stage with a heat roller at a temperature of 110 ° C. to obtain a polypropylene drawn yarn (total fineness = 145 dtex). / 24 filament).
(3) After fixing both ends of the polypropylene drawn yarn obtained in (2) above, heat treatment was carried out in a gear oven at 165 ° C. for 30 minutes, and heat treated polypropylene drawn yarn [polypropylene fiber (b-6)] Got.
(4) About the polypropylene drawn yarn [polypropylene fiber (b-6)] obtained in (3) above, DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)], and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 17 >> [Production of Polypropylene Fiber (b-7)]
(1) Polypropylene [“ZS1337A” manufactured by Prime Polymer Co., Ltd., IPF = 96%, MFR = 20 g / 10 min (230 ° C., load 2.16 kg)] is charged into an extruder of a melt spinning apparatus and melt kneaded at 300 ° C. Then, from the spinneret attached to the spinning head at a temperature of 320 ° C. [24 holes (circular holes), hole diameter 0.2 mm], 22.3 g / min is discharged and polypropylene is unstretched at a take-up speed of 600 m / min. A yarn was produced, wound on a bobbin, and stored at room temperature (“total fineness of polypropylene undrawn yarn = 304 dtex / 24 filament).
(2) The polypropylene unstretched yarn obtained in (1) above is unwound from the bobbin, pre-stretched 1.5 times in a single step with a heating roll at a temperature of 90 ° C., wound on the bobbin and stored at room temperature. (Total fineness of polypropylene pre-drawn yarn = 203 dtex / 24 filament, endothermic start temperature = 150.8 ° C.).
(3) The polypropylene pre-drawn yarn obtained in (2) above is unwound from a bobbin, introduced into a hot air oven at a temperature of 138 ° C., and post-drawn in a single step to 4.9 times, and the total draw ratio is A 7.4 times drawn polypropylene yarn (total fineness = 40.8 dtex / 24 filament) [polypropylene fiber (b-7)] was produced.
(4) DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)] and fiber for the drawn polypropylene yarn [polypropylene fiber (b-7)] obtained in (3) above The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Production Example 18 >> [Production of Polypropylene Fiber (b-8)]
(1) Melt spinning of the same polypropylene used in (1) of Production Example 1 [“Y2000Gv” manufactured by Prime Polymer Co., Ltd., IPF = 97%, MFR = 18 g / 10 min (230 ° C., load 2.16 kg)] The amount is 35.4 g / min from a spinneret (24 holes (circular holes), hole diameter 0.2 mm) having a temperature of 260 ° C. attached to the spinning head and charged into an extruder of the apparatus at 255 ° C. The polypropylene undrawn yarn was produced at a take-off speed of 600 m / min, wound on a bobbin and stored at room temperature (“total fineness of polypropylene undrawn yarn = 635 dtex / 24 filament).
(2) The polypropylene undrawn yarn obtained in the above (1) is unwound from a bobbin and drawn 11.5 times in a single stage by a steam tank at a temperature of 145 ° C. to obtain a polypropylene drawn yarn (total fineness = 55. 2 dtex / 24 filament) [polypropylene fiber (b-8)].
(3) About the polypropylene drawn yarn [polypropylene fiber (b-8)] obtained in the above (2), DSC measurement [measurement of endothermic peak shape, half width, amount of change in melting enthalpy (ΔH)], and fiber The measurement of strength, friction-fusibility, surface unevenness dimensions (average interval and average height of unevenness) and water retention rate were carried out by the methods described above. The results were as shown in Table 1 below.

<< Examples 1-10 and Comparative Examples 1-8 >>
(1) Production of polypropylene fiber rope:
After combining each of the polypropylene fibers (a-1) to (a-10) and (b-1) to (b-8) (polypropylene drawn yarn) obtained in Production Examples 1 to 18 to 1500 dtex , Twist the yarn at 80 T / m to make the first strand (reverse yarn), and twist the four first strands (reverse yarn) under the condition of 60 T / m to make the second strand (reverse yarn) , 25 second strands (reverse yarn) are twisted under the condition of 40 T / m to form a third strand (reverted yarn), and then 3 third strands (reverse yarn) are made under the condition of 30 T / m A rope made of polypropylene fiber was produced by twisting together.
When the number of times of grinder twist wear cutting of the polypropylene fiber rope thus obtained was measured by the method described above, it was as shown in Table 2 below.
(2) Measurement of Young's modulus of polypropylene yarn:
Each of the polypropylene fibers (a-1) to (a-10) and (b-1) to (b-8) (polypropylene drawn yarns) obtained in Production Examples 1 to 18 was combined to obtain 2000 dtex. Was twisted at 70 T / m to produce a polypropylene yarn, and the Young's modulus at 120 ° C. of this polypropylene yarn was determined by the method described above, and as shown in Table 2 below.

As seen in Table 2 above, in Examples 1 to 10, the fiber strength is 7 cN / dtex or more, which is made of polypropylene having an IPF of 94% or more, and the DSC characteristics satisfy the requirements defined in the present invention, or single fiber The fineness and the unevenness characteristics of the fiber surface satisfy the requirements specified in the present invention, or the DSC characteristics, the single fiber fineness and the unevenness characteristics of the fiber surface satisfy the requirements specified in the present invention, and have high heat resistance, and the predetermined unevenness As a result of producing the rope using any one of the polypropylene fibers (a-1) to (a-10) having the above, the ropes obtained in Examples 1 to 10 had 1152-1305 grinder twist wear cutting times. The rope is not easily cut by friction heat due to friction and is excellent in heat resistance.
On the other hand, in Comparative Examples 1-8, a rope using any of the polypropylene fibers (b-1) to (b-8) in which both the DSC characteristics and the unevenness characteristics on the fiber surface are out of the definition of the present invention. The ropes obtained in Comparative Examples 1 to 8 have a number of grinder twist wear cuts of 792 to 984, and the number of grinder twist wear cuts is about 60 to 85 of Examples 1 to 10. %, It was inferior in heat resistance as compared with the ropes of Examples 1 to 10, and was cut early by frictional heat.

Furthermore, as seen in Table 2 above, in Examples 1 to 10, whether the fiber strength is 7 cN / dtex or more and the DSC characteristics satisfy the requirements defined in the present invention, which is made of polypropylene having an IPF of 94% or more, The single fiber fineness and the unevenness characteristics of the fiber surface satisfy the requirements specified in the present invention, or the DSC characteristics, the single fiber fineness and the unevenness characteristics of the fiber surface satisfy the requirements specified in the present invention, and the heat resistance is high, and the predetermined Polypropylene yarns (strands) formed at the initial stage of the rope manufacturing process by using any of the polypropylene fibers (a-1) to (a-10) having the unevenness of Young's modulus is as high as 41-68 cN / dtex, elongation at high temperature is small, tightly twisted, excellent mechanical properties such as elongation resistance and set resistance, and It has excellent heat resistance.
On the other hand, in Comparative Examples 1 to 8, any one of the polypropylene fibers (b-1) to (b-8) in which both the DSC characteristics and the unevenness characteristics on the fiber surface are out of the definition of the present invention is used. Thus, the polypropylene yarn (strand) formed at the initial stage of the rope manufacturing process has a Young's modulus at 120 ° C. of 8 to 26 cN / dtex, which is significantly higher than that of Examples 1 to 10. Is low, has high elongation at high temperatures, is inferior in mechanical properties such as elongation resistance and sag resistance, and inferior in heat resistance.

  The rope structure of the present invention is formed using polypropylene fibers having high crystallinity, a uniform crystal structure, extremely excellent heat resistance, high fiber strength, and specific irregularities on the surface. Therefore, it is excellent in heat resistance and strength, and the fibers forming the rope are twisted closely together, and there is no flaking between the fibers, and it is excellent in elongation resistance, settling resistance and shape retention. It is excellent and can be used effectively in various applications by taking advantage of these characteristics.

It is the figure which showed typically the endothermic peak shape by DSC measurement in a polypropylene fiber. It is the figure which showed how to obtain | require the half value width in the endothermic peak by DSC measurement of a polypropylene fiber. It is the figure explaining how to obtain | require the average space | interval and average height of an unevenness | corrugation while showing typically the uneven | corrugated shape of the polypropylene fiber used for formation of the rope structure of this invention. It is the figure which showed the measuring method of the grinder twist abrasion cutting | disconnection number of a rope. 2 is a photograph taken with a scanning electron microscope of the polypropylene fiber obtained in Production Example 1. FIG.

Claims (3)

  A half-value width consisting of polypropylene having an isotactic pentad fraction (IPF) of 94% or more, a fiber strength of 7 cN / dtex or more, and an endothermic peak shape by scanning differential calorimetry (DSC) of 10 ° C. or less. A rope structure formed by using a polypropylene fiber having a single shape and a change in melting enthalpy (ΔH) of 125 J / g or more.   It is made of polypropylene with an isotactic pentad fraction (IPF) of 94% or more, the fiber strength is 7 cN / dtex or more, the single fiber fineness is 0.1 to 3 dtex, the surface has a large diameter bulge and a small diameter A rope structure formed using polypropylene fibers having irregularities with an average interval of 6.5 to 20 μm and an average height of 0.35 to 1 μm.   An endothermic peak measured by scanning differential calorimetry (DSC) with polypropylene having an isotactic pentad fraction (IPF) of 94% or more, a fiber strength of 7 cN / dtex or more, and a single fiber fineness of 0.1 to 3 dtex. The shape is a single shape having a half width of 10 ° C. or less, the amount of change in melting enthalpy (ΔH) is 125 J / g or more, and a large-diameter raised portion and a small-diameter non-raised portion are along the fiber axis on the surface. The rope structure formed using the polypropylene fiber which has the unevenness | corrugation with an average space | interval of 6.5-20 micrometers which exists alternately, and an average height of 0.35-1 micrometer.