JP2857100B2 - Polypropylene fiber and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel polypropylene fiber and a method for producing the same. Specifically, the present invention relates to a polypropylene fiber having high productivity and excellent dyeability of the obtained fiber, and a method for producing the same.

[0002]

2. Description of the Related Art Numerous reports have been made on techniques for improving the dyeability of polypropylene fibers. As one of the methods, there is a method of blending a polar polymer such as nylon, polystyrene, polyvinyl pyridine, and polyglycidyl methacrylate effective for dyeing polypropylene, and some of these methods have already been put to practical use.

[0003] However, polypropylene has poor compatibility with other polymers, and the blend has a so-called sea / island structure depending on the mixing ratio. For example, in the case of a polypropylene fiber having the above-mentioned polar polymer, the added polar polymer generally has an island structure when the amount added to the polypropylene is relatively small. Therefore, when melt-spinning is used as a raw material, yarn breakage tends to occur during production depending on the amount of the polar polymer to be added, and even if melt-spinning is possible, the strength of the obtained fiber is considerably reduced. Was.

[0004] In order to solve the above problem, the present inventor has proposed a method for producing polypropylene fibers having an average particle diameter of 0.1 to 0.1.
It was reported that 0.2 μm fine cross-linked polymer particles of a polar polymer were synthesized in advance, and blended with polypropylene to refine the polar polymer island structure and improve the dyeability of polypropylene fibers (Yukio Mizuta
ni, Bull. Chem. Soc. Jpn., 40, 1519 (1967)).

[0005]

However, in the above-mentioned method, the dispersibility of the crosslinked polymer particles of the polar polymer is not sufficient, and the crosslinked polymer particles have a strong cohesive property and have a good dispersibility in polypropylene. It was not easy to mix in a state. For this reason, it is difficult to sufficiently increase the compounding amount, and there is room for further improvement in dyeing properties. Further, there is a problem that the dyed polypropylene fiber is in a matte state without gloss and does not have a good texture as the fiber.

[0006]

Means for Solving the Problems In view of the above problems, the present inventors have intensively studied to obtain a glossy polypropylene fiber having good dyeability. As a result, by using a polypropylene composition in which crosslinked polymer particles obtained by polymerizing a maleimide monomer having a specific average particle diameter and a crosslinking agent in polypropylene are finely dispersed, yarn breakage occurs during the production of polypropylene fibers. Can be extremely effectively prevented, and the maleimide-based monomer is increased in order to maintain the effect of preventing thread breakage even when the amount of the crosslinked polymer particles in the polypropylene composition is increased. The present inventors have found that a glossy polypropylene fiber having extremely good dyeing properties and strong dyeing properties that does not decolor even by extraction with acetone can be obtained, and the present invention has been completed.

That is, the present invention comprises polypropylene and crosslinked polymer particles obtained by polymerizing a maleimide monomer and a crosslinking agent, and the crosslinked polymer particles have an average particle size of 0.01 to 0.1 in polypropylene. It is a polypropylene fiber composed of a polypropylene composition finely dispersed as particles of 08 μm.

Further, the present invention is characterized in that, as a method for producing the polypropylene fiber, the polypropylene composition obtained by polymerizing a maleimide monomer and a crosslinking agent in a molten polypropylene is melt-spun. The present invention also provides a method for producing the above polypropylene fiber.

In the present invention, the polypropylene composition used as a fiber material has an average particle diameter of 0.01 to 0.08 μm, and preferably 0.01 to 0.08 μm, in the polypropylene.
It is necessary that crosslinked polymer particles obtained by polymerizing a maleimide monomer having a thickness of about 0.07 μm are finely dispersed.
By such finely dispersed crosslinked polymer particles being finely dispersed, the resulting polypropylene fiber contains a sufficient amount of maleimide-based monomer units for dyeing, but the yarn breakage during melt-spinning occurs. There is no generation, and it can be obtained with extremely high productivity. Here, it is preferable that the finely dispersed crosslinked polymer particles are well dispersed in a state in which substantially no aggregate of particles is generated.

The average particle size of the crosslinked polymer particles is 0.08 μm.
If it is larger than m, the formability such as thread breakage during melt spinning becomes poor, and the dyeability is also poor, which is not preferable. On the other hand, when the average particle diameter is smaller than 0.01 μm, it is difficult to produce.

The average particle size of the crosslinked polymer particles can be measured by dyeing a fiber embedded in an epoxy resin with ruthenium tetroxide and observing the entire horizontal section with a transmission electron microscope. The particle diameter refers to the major axis.

In the present invention, the production method of the above-mentioned polypropylene composition is not particularly limited,
Generally, it can be obtained by polymerizing a maleimide monomer and a crosslinking agent in a polypropylene in a molten state. Generally, a maleimide-based polymer obtained by polymerization of a maleimide-based monomer does not have compatibility with polypropylene, so that phase separation occurs. And the crosslinking agent promotes this phase separation. Further, since the diffusion rate of the maleimide-based monomer in the molten polypropylene is low, the maleimide-based monomer is cross-linked and polymerized in a state of being finely dispersed in the molten polypropylene. The coalesced particles are finely dispersed without agglomeration at the fine average particle diameter.

However, in this case, since the polymerization is radical polymerization, in addition to graft polymerization of a maleimide-based monomer onto a polypropylene molecule, it is generally expected that a gel which makes spinning difficult due to cross-linking polymerization will be produced. Is done. However, although it has not been elucidated yet that the formation of the gel has been confirmed, in the present invention, an unpredictable effect that there is no problem in the spinning step was obtained. Also,
The present invention has an effect that, in addition to the effects described above, the polypropylene fibers are glossy despite containing the crosslinked polymer particles. However, at the present time, the mechanism by which the dyed yarn obtained by the present invention has such a fastness that it does not decolor even by extraction with acetone is unknown.

A specific method of polymerizing a maleimide monomer and a crosslinking agent in the above-mentioned molten polypropylene is as follows.
Although not particularly limited, generally, a method is generally used in which a maleimide-based monomer powder, a crosslinking agent, and a polypropylene powder are sufficiently mixed and supplied to an extruder to be polymerized.

The proportion of the cross-linking agent in the composition containing the maleimide monomer and the cross-linking agent or another monomer copolymerizable therewith is not particularly limited, but is generally 1 to 20% by weight. Preferably it is 5 to 15% by weight.

As the polymerization initiator in the above-mentioned polymerization, a known radical polymerization initiator can be used without any limitation. Specifically, azobisisobutyronitrile, benzoyl peroxide, dicumyl peroxide, Di-t-butyl peroxide and the like can be mentioned. The polymerization initiator may be added in advance to the polypropylene,
It may be added simultaneously with the addition of the vinyl monomer or the crosslinking agent.

The amount of the polymerization initiator is not particularly limited, but is generally 0.5 to 8 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the total amount of the maleimide monomer and the crosslinking agent. Parts by weight are appropriate.

Further, the polymerization time varies depending on the blending ratio of the maleimide-based monomer and the crosslinking agent, and cannot be determined unconditionally, but is generally preferably about 0.1 to 5 minutes.

In this manner, crosslinked polymer particles of a maleimide monomer and a crosslinking agent can be formed in the molten polypropylene. Further, the concentration of the maleimide monomer unit contained in the obtained composition is 0.1 to 1.0 meq / g, preferably 0.1 to 0. Preferably, it is in the range of 5 meq / g.

In the present invention, known polypropylenes are used without any particular limitation. For example, a homopolymer of propylene and a copolymer with another monomer copolymerizable with propylene can be exemplified. Specific examples of such other copolymerizable monomers include α-olefins other than propylene, such as ethylene, butene-1, pentene-1, and hexene-1. These other monomers can be used alone or in combination of two or more. The amount of the other monomer used is preferably 30% by weight or less based on propylene. Further, the molecular weight of polypropylene is preferably such that the melt index as an index is in the range of 10 to 50 g / 10 minutes from the viewpoint of melt spinnability of the polypropylene composition.

In the present invention, a known maleimide monomer having a maleimide group can be used.
For example, alkylmaleimides such as maleimide, N-methylmaleimide and N-ethylmaleimide, and arylmaleimides such as N-phenylmaleimide are generally mentioned.
These maleimide monomers may be used alone or in combination of two or more. Further, a copolymerizable monomer such as styrene or vinyltoluene may be used in combination with the maleimide-based monomer. In this case, the amount of the monomer copolymerizable with the maleimide-based monomer is preferably 50% by weight or less based on the maleimide-based monomer.

As the crosslinking agent in the present invention, known crosslinking agents used in radical polymerization can be used without any limitation. For example, a crosslinking agent such as a divinyl compound and a trivinyl compound can be used. More specifically, divinylbenzene, trivinylbenzene, 1,
Examples of the crosslinking agent include 2-distyrylethane and ethylene glycol dimethacrylate.

In the present invention, the melt spinning using the polypropylene composition can be carried out in the molten state after the polypropylene composition is produced by the above-mentioned method. 50 ~
After heating at 100 ° C. to polymerize the unpolymerized maleimide-based monomer that may remain and the crosslinking agent, it is preferable to perform melt spinning. Furthermore, in the drawing at the time of melt spinning or after the spinning, the pellets are decompressed in order to prevent thread breakage, contamination of the working environment, and the like, which may occur due to the maleimide monomer and the crosslinking agent slightly remaining in the polypropylene composition. It is preferable to heat at a temperature of 70 to 150 ° C. below to remove the remaining volatile components.

It is preferable to add a stabilizer to the polypropylene composition. As such compounding agents,
Known hindered phenol-based stabilizers, hindered amine-based stabilizers, phosphite-based stabilizers, sulfur-containing stabilizers, and the like can be suitably used as the polypropylene stabilizer.
The stabilizer may be added in advance when producing the polypropylene composition, but is preferably added after producing the polypropylene composition. That is, it is preferable to re-granulate the pellets of the polypropylene composition obtained after the crosslinking polymerization using a vent together with a stabilizer. In general, the amount of the stabilizer is preferably about 0.1 to 2.0% by weight based on the total amount of the stabilizer and polypropylene.

As the melt spinning method, a known method is employed without any particular limitation. In addition, the polypropylene fiber obtained by melt spinning is drawn as needed. The stretching is suitably performed at a linear magnification of 5 to 10 times, and when the film is stretched at such a stretching ratio, in the present invention, a fiber having good tensile strength can be obtained without trouble such as thread breakage of the fiber.

The polypropylene fiber obtained by the method of the present invention can be dyed by a known method. Usually, a method of dyeing with a disperse dye by a high temperature dyeing method or a carrier dyeing method is generally used. At this time, although the exact mechanism is unknown, an unpredictable result that the dye was not eluted even when the dyed yarn was treated with acetone was obtained. This indicates that the washing fastness is sufficient.

[0027]

As will be understood from the above description, according to the method of the present invention, a polypropylene fiber having good dyeability and gloss can be produced without causing yarn breakage during melt spinning and having high productivity. It is possible to get at.

[0028]

EXAMPLES The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The physical properties of the polypropylene fibers shown in the examples are values measured by the following methods.

Denier (g / 9000 m); length 90
Weight of fiber per 00m.

Elongation (%): Using a tensile tester Autograph 200 manufactured by Shimadzu Corporation, a sample length of 100 mm and a tensile speed of 300% / min.

Breaking strength (g / d); Shimadzu Corporation
The test was carried out at a sample length of 100 mm and a pulling rate of 300% / min using an Autograph 200 manufactured by Toshiba Corporation.

Young's modulus (g / d); Shimadzu Corporation
The test was carried out at a sample length of 100 mm and a pulling rate of 300% / min using an Autograph 200 manufactured by Toshiba Corporation.

Example 1 To 100 parts by weight of a monomer mixture consisting of 95% by weight of N-phenylmaleimide and 5% by weight of divinylbenzene, 1.5 parts by weight of di-t-butyl peroxide was added. The above monomer mixture was mixed with polypropylene powder (melt index 16 g / 10 min, without stabilizer) 100
The mixture was sufficiently mixed in advance at a ratio of 7 parts by weight with respect to the parts by weight, and then heated and melted at a temperature of 170 to 220 ° C. in a twin-screw extruder, polymerized, and then pelletized. The pellet was left overnight at 70 ° C. in N ₂ ,
0.5% by weight of 2,6-di-tert-butyl-
4-Methylphenol was added as a stabilizer and subjected to melt spinning. The melt spinning was performed using a spinning machine at 280 ° C., followed by 6-fold stretching at 130 ° C. As a result, it could be carried out without any problems such as thread breakage and nozzle clogging.

The physical properties of the obtained polypropylene fiber were as follows: denier: 1.1 (g / 9000 m), elongation: 20
(%), Tensile strength: 6.5 (g / d), Young's modulus: 54
(G / d).

The obtained polypropylene fiber is dyed with ruthenium tetroxide, and the entire horizontal section is Hitachi H-8000.
Observation using a transmission electron microscope revealed that N-phenylmaleimide-divinylbenzene crosslinked polymer particles having an average particle size of 0.05 μm were dispersed. The concentration of the imide group was 0.14 meq / g.

The obtained polypropylene fiber was Kayal
on Polyester REDBL-E, Kaya
lon Polyester EBL-E (all trade names, manufactured by Nippon Kayaku Co., Ltd.), Sumikaron Or
angel SE-B (trade name, Sumitomo Chemical Co., Ltd.)
As a result, Carrier dyeing was performed, and glossy and good dyed yarn was obtained. Further, when the dyed yarn was washed with acetone, some coloring was observed in acetone, but the state of dyeing hardly changed.

The pellets of the polypropylene composition before spinning were subjected to Soxhlet extraction using meta-xylene, and as a result, cylindrical filter paper (# 86R) having a pore size of 1 μm was almost completely extracted. This indicates that the polymerized N-phenylmaleimide-divinylbenzene crosslinked copolymer particles are minute.

Example 2 1.5 parts by weight of di-t-butyl peroxide was added to 100 parts by weight of a monomer mixture composed of 80% by weight of N-phenylmaleimide, 10% by weight of styrene, and 10% by weight of divinylbenzene. Was added. The above monomer mixture was mixed with a polypropylene powder (melt index 16 g / 10
, No stabilizer) in a ratio of 7 parts by weight to 100 parts by weight, and thoroughly mixed in advance.
The mixture was heated and melted at a temperature of 70 to 220 ° C., polymerized, and then pelletized. The pellets, in N _2, 70
After left overnight at 0 ° C, 2,6-di-tert-butyl-4-methylphenol was added as a stabilizer at a ratio of 0.5% by weight and subjected to melt spinning. The melt spinning was performed using a spinning machine at 280 ° C., followed by 6-fold stretching at 130 ° C. As a result, it could be carried out without any problems such as thread breakage and nozzle clogging.

The physical properties of the obtained polypropylene fiber were as follows: denier: 1.0 (g / 9000 m), elongation: 18
(%), Tensile strength: 7.1 (g / d), Young's modulus: 60
(G / d).

In the obtained polypropylene fiber, N-phenylmaleimide-styrene-divinylbenzene crosslinked polymer particles having an average particle diameter of 0.04 μm were present in a dispersed state. The concentration of the imide group is 0.11 meq / g.
Met.

The obtained polypropylene fiber was Kayal
on Polyester REDBL-E, Kaya
lon Polyester EBL-E (all trade names, manufactured by Nippon Kayaku Co., Ltd.), Sumikaron Or
angel SE-B (trade name, Sumitomo Chemical Co., Ltd.)
As a result, Carrier dyeing was performed, and glossy and good dyed yarn was obtained. Further, when the dyed yarn was washed with acetone, some coloring was observed in acetone, but the state of dyeing hardly changed.

The pellets of the polypropylene composition before spinning were almost completely extracted as a result of Soxhlet extraction using meta-xylene. This indicates that the polymerized N-phenylmaleimide-styrene-divinylbenzene crosslinked copolymer particles are minute. Example 3 To 100 parts by weight of a monomer mixture comprising 95% by weight of N-ethylmaleimide and 5% by weight of divinylbenzene, di-
1.5 parts by weight of t-butyl peroxide was added. The monomer mixture was sufficiently mixed in advance at a ratio of 7 parts by weight with respect to 100 parts by weight of polypropylene powder (melt index: 16 g / 10 minutes, no stabilizer), and then 170-220 in a twin-screw extruder. The mixture was heated and melted at a temperature of ° C., polymerized, and then pelletized. The pellet was left overnight at 70 ° C. in N ₂ ,
0.5% by weight of 2,6-di-tert-butyl-
4-Methylphenol was added as a stabilizer and subjected to melt spinning. The melt spinning was performed using a spinning machine at 280 ° C., followed by 6-fold stretching at 130 ° C. As a result, it could be carried out without any problems such as thread breakage and nozzle clogging. The physical properties of the obtained polypropylene fiber are as follows:
1.1 (g / 9000 m) elongation: 19 (%), tensile strength: 6.1 (g / d), Young's modulus: 51 (g / d).

In the obtained polypropylene fiber, N-ethylmaleimide-divinylbenzene crosslinked polymer particles having an average particle diameter of 0.06 μm were present in a dispersed state. The imide group concentration was 0.14 meq / g.

The obtained polypropylene fiber was converted to Kayal.
on Polyester REDBL-E, Kaya
lon Polyester EBL-E (all trade names, manufactured by Nippon Kayaku Co., Ltd.), Sumikaron Or
angel SE-B (trade name, Sumitomo Chemical Co., Ltd.)
As a result, Carrier dyeing was performed, and glossy and good dyed yarn was obtained. Further, when the dyed yarn was washed with acetone, some coloring was observed in acetone, but the state of dyeing hardly changed. The pellets of the polypropylene composition before spinning were almost completely extracted as a result of Soxhlet extraction using meta-xylene. This indicates that the polymerized N-ethylmaleimide-divinylbenzene crosslinked copolymer particles are minute.

COMPARATIVE EXAMPLE 1 In 34 L of water, 8 kg of N-phenylmaleimide, 1 kg of styrene, 1 kg of divinylbenzene, 0.5 kg of ethanol
L, 160 g of Na-dodecylsulfonate and di-t-
48 g of butyl peroxide was added and polymerized at 60 ° C. for 4 hours to obtain a fine powder having an average particle diameter of 0.10 μm. The above fine powder is mixed with polypropylene powder (melt index 16 g).
/ 10 min, without stabilizer) Mix well in advance at a ratio of 7 parts by weight to 100 parts by weight, and then heat-melt at 170-220 ° C in a twin-screw extruder to form pellets. did. The pellets are 0.5% by weight of 2,
6-Ditert-butyl-4-methylphenol was added as a stabilizer and subjected to melt spinning. The melt spinning was performed using a spinning machine at 280 ° C., followed by 6-fold stretching at 130 ° C. As a result, there was no clogging of the nozzle, but the frequency of thread breakage was high and the spinnability was poor.

The physical properties of the obtained polypropylene fiber were as follows: denier: 2.0 (g / 9000 m), elongation: 10 (%),
Tensile strength: 6.0 (g / d), Young's modulus: 48 (g / d)
d).

The obtained polypropylene fiber contains N-
The phenylmaleimide-styrene-divinylbenzene crosslinked polymer particles were partially aggregated on the order of several μm. The concentration of the imide group is 0.14 meq / g.
Met.

The obtained polypropylene fiber was converted to Kayal.
on Polyester REDBL-E, Kaya
lon Polyester EBL-E (all trade names, manufactured by Nippon Kayaku Co., Ltd.), Sumikaron Or
angel SE-B (trade name, Sumitomo Chemical Co., Ltd.)
As a result, Carrier dyeing was carried out, and there was no gloss and uneven dyeing. Further, the dyed yarn was washed with acetone, and coloring of the acetone was recognized. The dyeing condition was dull, and the dyeing was uneven and poor.

Claims (2)

(57) [Claims] 1. Polypropylene and crosslinked polymer particles obtained by polymerizing a maleimide monomer and a crosslinking agent, wherein the crosslinked polymer particles have an average particle size of 0.01 in polypropylene.
A polypropylene fiber comprising a polypropylene composition finely dispersed as particles having a size of about 0.08 μm. 2. The polypropylene according to claim 1, wherein the polypropylene composition according to claim 1 obtained by polymerizing a maleimide monomer and a crosslinking agent in a polypropylene in a molten state is melt-spun. Fiber manufacturing method.