JPH08325837A - Method for producing dyeable polypropylene fiber - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a polypropylene fiber with good dyeability and gloss. A polypropylene composition containing crosslinked polymer particles obtained by polymerizing a vinyl monomer having a glycidyl group, for example, glycidyl methacrylate, in a molten polypropylene in the presence of a crosslinking agent, for example, divinylbenzene. Melt spinning.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel method for producing polypropylene fibers. More specifically, the present invention relates to a method for producing a polypropylene fiber having high productivity and good dyeability of the obtained fiber.

[0002]

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

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 the polypropylene fiber having the above polar polymer, the added polar polymer generally has an island structure when the addition amount to the polypropylene is relatively small. Therefore, when melt-spinning this as a raw material, depending on the amount of the polar polymer added, yarn breakage easily occurs during production, and even if melt-spinning is possible, there is a problem that the strength of the fiber obtained is considerably reduced. It was

To solve the above problems, the present inventor has found that the method for producing polypropylene fibers has an average particle size of 0.1 to 0.1.
It was reported that by pre-synthesizing fine cross-linked polymer particles of 0.2 μm in polar polymer and compounding this with polypropylene, the island structure of the polar polymer was miniaturized and the dyeability of polypropylene fiber was improved (Yukio Mizuta
ni, Bull.Chem.Soc.Jpn.40,1519 (1967)).

[0005]

However, in the above-mentioned method, since the cross-linked polymer particles of the polar polymer have a small particle size, the cohesiveness is strong and it is not easy to blend them in polypropylene in a highly dispersed state. . Therefore, it is difficult to sufficiently increase the blending amount, and there is room for further improvement in dyeability. Furthermore, the dyed polypropylene fibers are matte and have no luster,
There was a problem that the texture was not good as a fiber.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have radically polymerized a vinyl monomer having a glycidyl group and a crosslinking agent in polypropylene in a molten state, and finely disperse the crosslinked polymer particles produced by the polymerization in a polypropylene matrix. It is possible to extremely effectively prevent the occurrence of yarn breakage during the production of polypropylene fibers by obtaining a polypropylene composition obtained by the above and further melt-spinning it, and the crosslinked polymer particles in the polypropylene composition. It has been found that the content of glycidyl groups can be increased because the effect of preventing yarn breakage can be maintained even if the compounding amount is increased, and that the dyeability is extremely good and a glossy polypropylene fiber can be obtained. The invention was completed.

That is, the present invention relates to melt spinning a polypropylene composition containing crosslinked polymer particles obtained by polymerizing a vinyl monomer having a glycidyl group in a molten polypropylene in the presence of a crosslinking agent. And a method for producing a polypropylene fiber.

In the present invention, the polypropylene composition to be subjected to melt spinning is
It is extremely important to contain crosslinked polymer particles obtained by polymerizing a vinyl monomer having a glycidyl group in the presence of a crosslinking agent. By including a crosslinked polymer particle of a vinyl monomer having a glycidyl group in polypropylene by such a method, the occurrence of yarn breakage during melt spinning despite the glycidyl group being contained in an amount sufficient for dyeing The fiber can be obtained with extremely high productivity.

Generally, a vinyl polymer obtained by polymerizing a vinyl monomer does not have compatibility with polypropylene, and thus causes phase separation. The crosslinker then promotes this phase separation. Further, since the diffusion rate of the vinyl monomer in the molten polypropylene is small, the vinyl monomer is crosslinked and polymerized in the molten polypropylene in a finely dispersed state, and as a result, the obtained crosslinked polymer particles do not aggregate. Finely dispersed.

In this case, however, since the polymerization is radical polymerization, it is naturally considered that the vinyl monomer is graft-polymerized on the polypropylene molecules, and further, since it is a cross-linking polymerization, the formation of a gel which makes spinning difficult is common. Predicted. However, although it has not been clarified yet about the formation of gel, the present invention has an unpredictable effect that there is no problem in the spinning process. In addition to the effects described above, the present invention also has the effect that the polypropylene fiber is glossy, even though it contains the crosslinked polymer particles.

In the present invention, known polypropylene may be used without particular limitation. For example, a homopolymer of propylene and a copolymer with another monomer copolymerizable with propylene can be mentioned. Specific examples of 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 kinds. The amount of the other monomer used is preferably 30% by weight or less with respect to propylene. Further, the molecular weight of polypropylene is preferably such that the melt index, which is an index thereof, 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, as the vinyl monomer having a glycidyl group, a known vinyl monomer having one or more glycidyl groups is used. For example, glycidyl acrylate and glycidyl methacrylate are generally mentioned. These vinyl monomers having a glycidyl group may be used alone or in combination of two or more. The vinyl monomer having a glycidyl group can be copolymerized with a vinyl monomer having a glycidyl group such as acrylic acid ester, methacrylic acid ester, styrene, vinyltoluene, maleic anhydride, N-phenylmaleimide, and N-alkylmaleimide. A monomer can also be used together. In this case, the amount of the monomer copolymerizable with the vinyl monomer having a glycidyl group is preferably 50% by weight or less based on the vinyl monomer having a glycidyl group.

In the present invention, in order to carry out cross-linking polymerization of a vinyl monomer having a glycidyl group in polypropylene in a molten state, the polypropylene composition comprising the obtained polypropylene and the cross-linked polymer particles has a melt index as a raw material. Lower than polypropylene. However, when the vinyl monomer having a glycidyl group in the present invention is used, the decrease in melt index is smaller than that when a vinyl monomer having no glycidyl group is used. Specifically, the melt index is 33g
When glycidyl methacrylate and divinylbenzene (5%) were polymerized in a raw material polypropylene of / 10 min, the melt index of the polypropylene composition containing the glycidyl methacrylate-divinylbenzene crosslinked polymer was 22 g / 10 min. However, when styrene and divinylbenzene (5%) were polymerized in the same raw material polypropylene to obtain a composition containing a styrene-divinylbenzene cross-linked polymer, the melt index was 3 g / 1.
It will be 0 minutes. A composition having such a too low melt index is difficult to spin.

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 or a trivinyl compound can be used. More specifically, divinylbenzene, trivinylbenzene, 1,
Examples thereof include cross-linking agents such as 2-distyrylethane and ethylene glycol dimethacrylate.

In the present invention, the polymerization of the vinyl monomer having a glycidyl group and the cross-linking agent is not particularly limited as long as it is a method of supplying the vinyl monomer having a glycidyl group and the cross-linking agent into polypropylene in a molten state to perform polymerization. Not done. Generally, a supply port for a vinyl monomer having a glycidyl group and a crosslinking agent is provided at an arbitrary position of the extruder, and the vinyl monomer having a glycidyl group and the crosslinking agent are separately or simultaneously added (including addition in a mixed state). In general, the method of supplying to () and polymerizing is carried out.

The proportion of the cross-linking agent in the total amount of the vinyl monomer having a glycidyl group and the cross-linking agent is not particularly limited, but is generally 1 to 20% by weight, preferably 5
10 to 10% by weight.

As the polymerization initiator in the above-mentioned polymerization, known radical polymerization initiators can be used without any limitation, and specifically, asobisisobutyronitrile, benzoyl peroxide, dicumyl peroxide, diester. Examples thereof include -t-butyl peroxide. The polymerization initiator may be added in advance in polypropylene,
They may be added at the same time when the vinyl monomer having a glycidyl group and the crosslinking agent are added.

The amount of the above-mentioned polymerization initiator to be used is not particularly limited, but is generally 0.1 to 3 parts by weight, preferably 0.1% by weight, based on 100 parts by weight of the total amount of the vinyl monomer having a glycidyl group and the crosslinking agent. 5-2 parts by weight is suitable.

Further, the polymerization time varies depending on the blending ratio of the vinyl monomer having a glycidyl group and the crosslinking agent,
Although it cannot be determined unconditionally, generally about 1 to 5 minutes is suitable.

In this way, crosslinked polymer particles of the vinyl monomer having a glycidyl group and the crosslinking agent are formed in the molten polypropylene. The average particle size of the cross-linked polymer particles is extremely small, and is generally in the range of 0.01 to 0.1 μm.

Further, the concentration of the glycidyl group contained in the obtained composition is 0.1 to obtain good dyeability.
It is preferably in the range of 1.0 meq / g.

In the present invention, the melt spinning using the polypropylene composition may be carried out in the molten state after the polypropylene composition is produced by the above-mentioned method. And 50 ~
After heating at 100 ° C. to polymerize a vinyl monomer having an unpolymerized glycidyl group which may remain and a crosslinking agent, it is preferable to perform melt spinning. Furthermore, during melt spinning or during stretching after spinning, pellets are used to prevent yarn breakage that may occur due to a vinyl monomer having a glycidyl group slightly remaining in the polypropylene composition and a cross-linking agent, and contamination of the working environment. 70 under reduced pressure
It is preferable to heat at a temperature of ˜150 ° C. to remove the remaining volatile components.

Further, it is preferable to add a stabilizer to the polypropylene composition. As such a compounding agent,
Known polypropylene stabilizers such as hindered phenol-based stabilizers, hindered amine-based stabilizers, phosphite-based stabilizers, and sulfur-containing stabilizers can be preferably used.
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 cross-linking polymerization with a stabilizer using a vent. In general, the amount of the stabilizer added is preferably about 0.1 to 2.0% by weight as a proportion of the total amount with the polypropylene.

As the melt spinning method, a known method can be adopted without particular limitation. Further, the polypropylene fiber obtained by melt spinning is stretched if necessary. Stretching is preferably performed at a linear draw ratio of 5 to 10 times, and when stretched at such a draw ratio, in the present invention, there can be obtained a fiber having good tensile strength without causing problems such as fiber breakage.

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 common. At this time, when the dye molecule has a group capable of reacting with an epoxy group such as an amino group or a phenolic hydroxyl group, the dye molecule is completely fixed in the fiber and a sufficient washing fastness is obtained, which is preferable.

Prior to dyeing, ethylenediamine,
Pretreatment with a compound having an amino group such as ethanolamine or triethanolamine allows the obtained fiber to be dyed with an acid dye.

[0027]

As can be understood from the above description, according to the method of the present invention, polypropylene fibers having good dyeability and gloss can be produced with high productivity without causing yarn breakage during melt spinning. Can be obtained at.

[0028]

EXAMPLES Examples will be shown below to more specifically describe the present invention, but the present invention is not limited to these examples.

Example 1 To 100 parts by weight of a monomer mixture containing 95% by weight of glycidyl methacrylate and 5% by weight of divinylbenzene,
Di-t-butyl peroxide was added at a ratio of 1.5 parts by weight. Polypropylene powder (melt index 16 g / 10 min, no stabilizer) was added to the above monomer mixture 1
The mixture was sufficiently mixed in advance at a ratio of 7 parts by weight with respect to 00 parts by weight, and then was heated and melted at a temperature of 170 to 200 ° C. in a twin-screw extruder, polymerized, and then granulated into pellets. . The pellets were allowed to stand overnight at 70 ° C. in N ₂ and then subjected to melt spinning by adding 2,6-ditertiarybutyl-4-methylphenol as a stabilizer at a ratio of 0.5% by weight. The melt spinning was performed using a spinning machine, melt spinning was performed at 280 ° C., and then stretched 6 times at 130 ° C. As a result, there was no problem such as yarn breakage or nozzle clogging.

Glycidyl methacrylate-divinylbenzene crosslinked polymer particles having an average particle diameter of 0.05 μm were dispersed and present in the obtained polypropylene fiber. The concentration of glycidyl group is 0.14 meq / g
Met.

The polypropylene fiber obtained was Kayal.
on Polyester REDBL-E, Kaya
lon Polyester EBL-E (all are trade names, manufactured by Nippon Kayaku Co., Ltd.), Sumi Karon O
range SE-B (trade name, Sumitomo Chemical Co., Ltd.
As a result of carrying out carrier dyeing with a product, a good and glossy dyed yarn was obtained. Further, even if the dyed yarn was washed with acetone, some coloring was observed in the acetone, but the dyeing situation was almost unchanged.

The polypropylene composition pellets before spinning were almost completely extracted as a result of Soxhlet extraction using meta-xylene. This indicates that the polymerized glycidyl methacrylate-divinylbenzene cross-linked copolymer particles are minute.

Example 2 The fiber obtained in Example 1 was treated with an aqueous solution of triethanolamine containing a small amount of a carrier nonionic surfactant (humming) at 100 ° C. for 2 hours, sufficiently dyed, and then Br.
Staining was performed with illiant green. A moderate staining was possible.

Claims (1)

[Claims] 1. A polypropylene composition characterized by melt-spinning a polypropylene composition containing crosslinked polymer particles obtained by polymerizing a vinyl monomer having a glycidyl group in a molten polypropylene in the presence of a crosslinking agent. Fiber manufacturing method.