JP2016089317A - Propylene-based resin composition for melt spinning type electrospinning, manufacturing method of propylene-based ultra fine fiber and propylene-based ultra fine fiber manufactured by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an ultra fine fiber by applying a melt spinning type electrospinning method to a propylene-based resin material high in volume resistivity value and hardly applied with the melt spinning type electrospinning method.SOLUTION: There is provided a resin material by heating and melting in a melting cylinder 3 and spinning an ultra fine fiber by conducting continuous extrusion spinning by a melt spinning type electrospinning method and by blending 1 to 50 wt.% of a polymer type antistatic agent with 50 to 99 wt.% of a propylene resin. There is provided a manufacturing method of the propylene-based ultra fine fiber, where the propylene-based resin is a propylene single polymer or a copolymer of propylene and α-olefin (including ethylene) and has MFR (temperature of 230°C and load of 21.2 N) of 50 to 20000 g/10 min. and the heating melting is conducted by a laser heating.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a propylene resin composition for melt spinning electrospinning, a method for producing propylene ultrafine fibers using the same, and a propylene ultrafine fiber produced by the method, and more particularly, melt spinning electrospinning. The propylene-based resin composition for melt spinning type electrospinning capable of spinning ultrafine fibers by performing continuous extrusion spinning in the heated and melted state, and continuous extrusion spinning in the heated and melted state by the melt spinning type electrospinning method. The present invention relates to a method for producing a polypropylene-based ultrafine fiber, which is performed to spin ultrafine fibers, and a polypropylene-based ultrafine fiber spun by the production method and a fiber product thereof.

In recent years, nanotechnology typified by nanocarbon and nanotubes has been developed, and their special functions and applications due to their ultrafine structure have attracted attention, and are being used as a new basic technology along with biotechnology.
In the field of nanotechnology, ultrafine fibers with a diameter of nanometers (about several μm or less), which are generally called nanofibers, have emerged. The ultrafine fibers have a very large surface area and also exhibit unique functions due to their ultrafine structure. Therefore, the use in a very wide variety of technical fields is being developed and used effectively.

As such new applications, various application developments such as battery separators, electromagnetic shielding materials, filters, artificial leather, artificial blood vessels, cell culture substrates, IC chips, organic EL, and solar cells are expected.
In particular, (i) as a high-performance filter unit having high collection performance in the semiconductor industry, pharmaceutical industry, bio-industry, etc., (ii) as a cell culture fiber body in which cells are easy to adhere and proliferate and is easy to handle (iii) ) As a new material to replace and improve the coating material and biological function of the entire surface of biological prosthesis in the medical field, (iv) a separation membrane having excellent ion permeability and charge / discharge characteristics and an electrochemical device using the same (Vi) as an ultrasensitive metal oxide gas sensor, (vi) as a high performance electrochromic display element in electronic paper, and (vii) a dye-sensitized solar cell electrode with high photovoltaic power generation performance, Many important applications have been developed as photoelectric conversion elements that can realize high photoelectric conversion efficiency.

As a manufacturing method in the field of nanofibers, since the fiber diameter is extremely small on the order of nanometers, it is extremely difficult to manufacture by a spinning method for manufacturing a normal fiber. The technical methods that have been developed and manufactured thereby have been extensively studied and various new methods have been presented.
As an electrospinning method, a high voltage of 5 to 100 kV is basically applied so that a polymer solution in which a polymer is dissolved or dispersed in a solvent is dropped from a nozzle toward a target, the nozzle becomes a positive electrode, and the target becomes a negative electrode. Is known (see, for example, Patent Document 1).
However, this electrospinning method is a solution electrospinning method, and the polymer that can be used is limited to a polymer that dissolves in a solvent, and the solvent in which the polymer is dissolved evaporates when electrospinning. When producing nanofibers, the solvent that has evaporated must be recovered, and a huge solvent recovery device is necessary. In addition, there is a problem that a component due to the solvent remains in the obtained fiber, and when the solvent remains in the fiber, there is a possibility that the component due to the solvent oozes out later and causes a problem in the fiber product.

In order to eliminate such drawbacks, a melt electrospinning method in which a thermoplastic resin is heated and melted and electrospun without using a solvent has been researched and developed.
As a basic method for the melt electrospinning method, a thermoplastic resin thread is inserted into a conductive cylindrical nozzle, the tip of the nozzle is heated and melted, the conductive cylindrical nozzle becomes a positive electrode, and the target is negative. A melt electrospinning method and apparatus for applying a high voltage so as to be an electrode are disclosed (see Patent Documents 2 and 3).
However, in the melt electrospinning method described above, heat is applied to reduce the polymer to a viscosity capable of electrospinning, but thermal decomposition may occur due to prolonged heat retention, leading to a decrease in polymer physical properties. there were.

  In order to avoid thermal decomposition of the polymer, an electrospinning method (see Patent Document 4) in which a laser beam is irradiated and melted by heating is presented. Furthermore, an electrospinning method in which the tip of a nozzle is heated with a heat gun, or in a vacuum A method of performing melt electrospinning by using this method has also been proposed.

By the way, in such a melt electrospinning method, a material having a high volume resistivity such as polypropylene is difficult to have a charge even when a voltage is applied and cannot be stretched and stretched efficiently. It is difficult to.
Until now, in order to solve the above-mentioned problems, the present applicant blends an alicyclic hydrocarbon resin and an additive having a specific triazine ring structure in a specific ratio with respect to a polypropylene resin. A composition has been proposed, and attempts have been made to spin ultrafine fibers by the melt electrospinning method (see Patent Documents 5 and 6).
However, none of the conventional ones is sufficiently satisfactory from an industrial point of view or efficiency, and therefore, at present, a resin such as polypropylene that is not suitable for the melt electrospinning method. With regard to, melt electrospinning methods have not been sufficiently studied, and further research and development in this field is required.

JP-T 2008-53860 Publication JP 2007-32246 A JP 2009-150039 A JP 2007-239114 A JP 2012-72514 A JP 2013-44067 A

  In view of the above-mentioned problems of the prior art, the object of the present invention is a melt spinning type capable of spinning ultrafine fibers industrially and efficiently by performing continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method. Propylene-based resin composition for electrospinning, and melt spinning type electrospinning method, spinning by continuous extrusion spinning in a heated and melted state, spinning ultrafine fibers, and spinning by the production method It is to provide a polypropylene-based ultrafine fiber and a fiber product thereof.

  As a result of intensive research to solve the above problems, the present inventors have identified a propylene-based resin that has a high volume resistivity and is difficult to hold a charge even when a voltage is applied, and cannot be efficiently stretched and stretched. It was found that if a propylene-based resin composition blended with a polymer type antistatic agent at a ratio of 5% was used, ultrafine fibers could be produced by the melt spinning type electrospinning method, and the present invention was completed.

  That is, according to the first invention of the present invention, a resin material for spinning ultrafine fibers by performing continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method, and comprising 50 to 99% by weight of a propylene-based resin Further, a propylene-based resin composition for electrospinning is provided, which contains 1 to 50% by weight of a polymer type antistatic agent.

  According to the second invention of the present invention, in the first invention, the propylene-based resin is a propylene homopolymer or a copolymer of propylene and an α-olefin (including ethylene). A propylene-based resin composition for electrospinning spinning is provided.

  According to the third invention of the present invention, in the first or second invention, the propylene-based resin composition further contains another polymer and / or additive, and the electrospinning spinning A propylene-based resin composition is provided.

  According to the fourth invention of the present invention, in any one of the first to third inventions, the MFR (temperature 230 ° C., load 21.2 N) of the propylene-based resin is 50 to 20,000 g / 10 min. A propylene resin composition for electrospinning spinning is provided.

  According to the fifth invention of the present invention, in any one of the first to fourth inventions, 1 to 20% by weight of a polymeric antistatic agent is blended with 80 to 99% by weight of the propylene-based resin. A propylene-based resin composition for electrospinning spinning is provided.

  According to the sixth invention of the present invention, the propylene-based resin composition for electrospinning spinning according to any one of the first to fifth inventions is continuously extruded and spun in a heated and melted state by a melt spinning type electrospinning method. A method for producing a polypropylene-based ultrafine fiber is provided, characterized in that the ultrafine fiber is spun to perform spinning.

  According to a seventh aspect of the present invention, there is provided a method for producing a polypropylene ultrafine fiber according to the sixth aspect, wherein the heat melting is performed by laser heating.

  According to the eighth invention of the present invention, the propylene-based resin composition according to any one of the first to fifth inventions is spun by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method. Thus, there is provided a polypropylene-based ultrafine fiber obtained by doing so.

  According to the ninth aspect of the present invention, there is provided a fiber product manufactured using the ultrafine fiber according to the eighth aspect.

  In the present invention, even in a propylene-based resin having a high volume resistivity, which was not able to produce uniform ultrafine fibers by the melt spinning type electrospinning method in the conventional method, the uniform ultrafine fibers are industrially produced by the melt spinning type electrospinning method. Can be produced efficiently.

It is explanatory drawing of the melt spinning type electrospinning apparatus used for the spinning method of this invention.

  Hereinafter, each component constituting the propylene-based resin composition for melt spinning type electrospinning of the present invention, in particular, a propylene-based resin material and a polymer-type antistatic agent, and a method for producing a propylene-based ultrafine fiber using the same, and The propylene-based ultrafine fibers produced by the method will be described in detail for each item.

(1) Propylene resin material The propylene resin used in the present invention may be either a propylene homopolymer or a copolymer of propylene and another α-olefin, but propylene and α-olefin. Of these, a propylene / α-olefin random copolymer is preferred. The propylene / α-olefin random copolymer preferably used is a random copolymer of propylene and an α-olefin mainly composed of a structural unit derived from propylene. The α-olefin used as a comonomer is preferably ethylene or an α-olefin having 4 to 18 carbon atoms. The comonomer content is preferably 1.0% by weight to 5.0% by weight.

Specific examples of the α-olefin include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4, 4 -Dimethylpentene-1 etc. can be mentioned. Moreover, as an alpha olefin, 1 type individual or 2 or more types of combination may be sufficient.
Specific examples of the propylene / α-olefin random copolymer include propylene / ethylene random copolymer, propylene / 1-butene random copolymer, propylene / 1-hexene random copolymer, propylene / ethylene / 1- Examples include octene random copolymers and propylene / ethylene / 1-butene random copolymers.

Such a propylene polymer is typically produced in the presence of a Ziegler catalyst mainly composed of a solid titanium catalyst and an organometallic compound, or a metallocene catalyst using a metallocene compound as a component of the catalyst. Can be produced by polymerizing or copolymerizing propylene and other α-olefins.
Examples of the polymerization method include a slurry method using an inert solvent in the presence of the catalyst, a solution method, a gas phase method substantially using no solvent, or a bulk polymerization method using a polymerization monomer as a solvent. .

In the propylene resin used in the present invention, the MFR (melt flow rate) measured at a heating temperature of 230 ° C. and a load of 21.2 N is 50 to 20,000 g / 10 min in accordance with JIS K7210. Is preferred. More preferably, it is 1000-20,000 g / 10min. The higher the MFR value, the easier it is to draw when spinning, and the easier it is to produce fine fibers.
If it is less than 50 g / 10 min, the viscosity of the molten resin becomes too high, and ultrafine fibers cannot be obtained, and those exceeding 20,000 g / 10 min are difficult to produce with the current polymerization technology and equipment.

  In order to obtain a desired MFR, the MFR basically depends on the molecular weight. Therefore, the molecular weight may be controlled, and the polymerization temperature, the supply amount of hydrogen gas, the polymerization terminator, or the like may be controlled. You may adjust by superposing | polymerizing a propylene polymer and melt-kneading using an organic peroxide.

(2) Polymer antistatic agent In the propylene resin composition of the present invention, the polymer antistatic agent described below is contained in 50 to 99% by weight of the propylene resin and 1 in the polymer antistatic agent. The main requirement is to blend ~ 50% by weight.
The polymer type antistatic agent is an antistatic agent having at least two or more repeating units. Preferably, for example, any polymer type antistatic agent having a number average molecular weight of 1,000 or more can be used. Even an ionic, cationic or anionic polymer type antistatic agent is not limited.

Of these, nonionic ones are preferred, and polymer antistatic agents having hydrophilic segments and having antistatic properties imparted by the hygroscopicity of the hydrophilic segments are particularly preferred. As such a polymer type antistatic agent, a lipophilic polymer / hydrophilic polymer block copolymer such as a polyether / polyolefin block copolymer is preferably exemplified. In the polyether / polyolefin block copolymer, the polyether block functions as a hydrophilic segment, and the polyolefin block functions as a lipophilic segment. That is, the hydrophilic segment has an effect of lowering the surface resistance of the molded body due to its hygroscopicity, and the lipophilic segment has an effect of enhancing the compatibility with the propylene-based resin as a base material, and thus is particularly excellent. Antistatic agent.
Examples of the polyether constituting the polyether / polyolefin block copolymer include polyether diol, polyether diamine, modified products thereof, and a polyether-containing hydrophilic polymer. The polyether-containing hydrophilic polymer includes a polyether ester amide having a polyether diol segment, a polyether amide imide having a polyether diol segment, a polyether ester having a polyether diol segment, and a polyether diamine segment. And polyether urethanes having polyether diol or polyether diamine segments.

Examples of the oxyalkylene group constituting the polyether include an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group, which are oxyalkylene groups having 2 to 4 carbon atoms of alkylene. The proportion of the oxyethylene group in the oxyalkylene chain constituting the polyether is preferably 5% by mass or more, more preferably 10 to 100% by mass, and still more preferably 60 to 100% by mass from the viewpoint of improving antistatic properties. %. The number average molecular weight of the polyether is preferably 150 to 20,000.
The polyolefin constituting the polyether / polyolefin block copolymer is preferably a polyolefin obtained by polymerizing at least one selected from olefins having 2 to 30 carbon atoms, more preferably by polymerizing at least one of ethylene and propylene. The resulting polyolefin.

The average number of repeating units of the polyether block and the polyolefin block constituting the polyether / polyolefin block copolymer is preferably 2 to 50, more preferably considering the action of imparting antistatic properties. It is 2.3-30, More preferably, it is 2.7-20, Most preferably, it is 3-10. This average number of repetitions can be determined by the method described in Patent Document 3.
The ratio of the polyether constituting the polyether / polyolefin block copolymer is preferably 20 to 90% by mass, more preferably 25 to 80% by mass, and still more preferably based on the total mass of the polyether and polyolefin. 30 to 70% by mass.
The number average molecular weight of the polyether / polyolefin block copolymer is preferably 2,000 to 60,000, more preferably 5,000 to 40,000, and still more preferably 8,000 to 30,000.

  The polymer antistatic agent to be used is preferably used in such a range that the volatile components from the polymer antistatic agent and the elution amount of sodium and potassium ions do not become a problem. By using such a polymer type antistatic agent, the dispersibility with the propylene-based resin is improved, the moldability is excellent, and the antistatic property of the molded body is improved over a long period of time.

The number average molecular weight of the polymer antistatic agent is preferably 1,000 to 100,000, more preferably 2,000 to 60,000, and still more preferably 3,000 to 30,000.
Examples of such a polymer type antistatic agent include “Pelestat” (trade name, manufactured by Sanyo Chemical Industries) and “Statlite” (trade name, manufactured by The Lubrizol Corporation).

  The addition amount of the polymer type antistatic agent is in the range of 1 to 50% by weight. If the addition amount of the polymer antistatic agent is less than 1% by weight, it is not suitable because sufficient conductive performance cannot be obtained. On the other hand, if the addition amount of the polymer type antistatic agent exceeds 50% by weight, the production cost increases, and the properties of the propylene resin material cannot be maintained, and the strength of the obtained fiber itself may be weakened. Therefore, it is unsuitable. The addition amount of the polymer type antistatic agent is preferably in the range of 1 to 20% by weight.

  By blending this specified polymer type antistatic agent, when the resin is subjected to electrospinning by applying a voltage, the volume resistivity of the resin is lowered, and it becomes stronger because it becomes more conductive. Since spinning is performed at high speed by electrostatic force, it is considered that the fiber diameter obtained in the melt electrospinning method is made finer.

  The additive content is defined as 1% by weight as the lower limit. This is because the effect of addition was not observed at 0.5% by weight as described in Comparative Example 2 described later. The upper limit is defined as 50% by weight. This is because it is considered undesirable to add more additives from the viewpoint of cost and the strength of the spun fiber itself.

(3) Composition of propylene-based resin In the propylene-based resin composition material used in the present invention, the composition further includes a composition with another resin or a composition in which various additives are blended. It can also be used.
As other resins to be blended, an olefin polymer, a polyamide polymer, a polyester polymer, or any other polymer mainly containing components other than propylene such as an ethylene polymer or a butene polymer can be used. .
As other various additives, known antioxidants, neutralizers, light stabilizers, UV absorbers are usually used for polyolefins to improve the performance of resin materials or to add other performances. Various additives such as a lubricant, a lubricant, a low molecular weight antistatic agent, and a metal deactivator can be blended within a range not impairing the object of the present invention.

  Examples of antioxidants include phenolic antioxidants, phosphite antioxidants, and thio antioxidants, and examples of neutralizing agents include higher fatty acid salts such as calcium stearate and zinc stearate. Examples of the light stabilizer and the ultraviolet absorber include hindered amines, nickel complex compounds, benzotriazoles, and benzophenones. In addition, examples of the lubricant include higher fatty acid amides such as stearic acid amide, examples of the low molecular weight antistatic agent include fatty acid partial esters such as glycerin fatty acid monoester, and further, as a metal deactivator. Examples thereof include phosphones, epoxies, triazoles, hydrazides, oxamides and the like.

(4) Melt-spinning type electrospinning device As a melt-spinning type electrospinning device, a heat melting and spinning type electrospinning device manufactured by Kato Tech, etc. is used. A cylinder for heating and melting the resin, an electrode for charging the resin, and for resin extrusion It consists of an electrode plate (target) that receives a piston, a nozzle, and ultrafine fibers, and spins by applying a voltage between the nozzle and the target to the molten resin from the nozzle.
The temperature of the cylinder for heating the resin is preferably 160 to 400 ° C, more preferably 220 to 360 ° C. The nozzle diameter is preferably 0.1 to 0.6 mm. Furthermore, the numerical value of the applied voltage is preferably 20 to 100 kV, more preferably 30 to 80 kV.
FIG. 1 is a schematic explanatory view of a hot melt spinning type electrospinning apparatus used in the present invention.
In the spinning step, a voltage is applied to the melted portion of the thermoplastic resin heated and melted by an appropriate heating means, and the extending fibers are collected on the target by electrical attraction. In this step, a voltage is applied to the melted portion of the thermoplastic resin to apply and charge the opposite polarity of the target, thereby causing the molten resin to fly toward the target and stretch or stretch. Electrospinning.

(5) Ultrafine fiber In the present invention, an ultrafine fiber (nanofiber) having a very small fiber diameter is obtained by the melt type electrospinning method (electrospinning). The average fiber diameter of the ultrafine fibers is, for example, 5 μm or less, and preferably about 100 nm to 3 μm. The finest fiber diameter is 1 μm or less.
The fiber length of the fiber is not particularly limited, and may be selected according to the application by adjusting the production conditions.

The ultrafine fiber spun by the present invention can be used as a long fiber or short fiber in a fiber product such as a normal woven fabric or non-woven fabric.
The ultrafine fibers of the present invention are used as new applications due to the special properties of the ultrafine fibers and the performance of the propylene-based resin material, such as battery separators, electromagnetic shielding materials, high performance filters, bioartificial devices, cell culture substrates, and IC chips. Development of various applications represented by organic EL, solar cells, electrochromic display elements, photoelectric conversion elements and the like is expected.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, and the rationality and significance of the configuration of the present invention and the prior art based on the data of each Example and the comparison between each Example and each Comparative Example. Demonstrate excellence against
Various physical properties in Examples and Comparative Examples were measured and evaluated according to the following evaluation methods, and the resins described in Examples and Comparative Examples were used as the resins used.

A) MFR: Measured according to JIS K7210 at a heating temperature of 230 ° C., a load of 21.2 N, and an orifice diameter of 2.0 mm. However, if the MFR exceeds 200, referring to JIS K7210, the heating temperature is 230 ° C, the load is 21.2N, the orifice diameter is 0.5mm, and the measurement result is converted into the value equivalent to the 2.0mm orifice diameter measurement value. Asked.
B) Finest fiber diameter: From the result of observing the diameter of the spun fiber using a scanning electron microscope (SEM) manufactured by Hitachi High-Technologies, and measuring the fiber diameter of 100 arbitrary fibers with image analysis software. The finest fiber diameter was determined.
C) The standard deviation was determined by observing the fiber diameter with SEM in the same manner as in b) and measuring the fiber diameter of 100 arbitrary fibers with image analysis software.

  2) Tm (melting point): The melting peak temperature Tm is a value determined by a differential scanning calorimeter (DSC manufactured by T.A. Instruments Inc.). Specifically, a sample amount of 5.0 mg is taken. It is a value obtained as a melting peak temperature when it is kept at 5 ° C. for 5 minutes, crystallized to 40 ° C. at a temperature lowering speed of 10 ° C./min, and further melted at a temperature rising speed of 10 ° C./min.

E) Molecular weight distribution by GPC The molecular weight distribution Mw / Mn (where Mw is the weight average molecular weight and Mn is the number average molecular weight) was measured by gel permeation chromatography (GPC). The definitions of Mn, Mw, and Mz are described in “Basics of Polymer Chemistry” (Edited by Polymer Society, Tokyo Kagaku Dojin, 1978) and can be calculated from molecular weight distribution curves by GPC.
And the specific measuring method of GPC is as follows.
Apparatus: GPC manufactured by Waters (ALC / GPC 150C)
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: Showa Denko AD806M / S (3 in series)
-Mobile phase solvent: orthodichlorobenzene (ODCB)
・ Measurement temperature: 140 ℃
・ Flow rate: 1.0 ml / min
・ Injection volume: 0.2ml
Sample preparation: Prepare a 1 mg / mL solution using ODCB (containing 0.5 mg / mL BHT) and dissolve it at 140 ° C. for about 1 hour.
Conversion from the retention capacity obtained by GPC measurement to the molecular weight is performed using a calibration curve prepared in advance by standard polystyrene (PS). The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000
A calibration curve is created by injecting 0.2 mL of a solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. The calibration curve uses a cubic equation obtained by approximation by the least square method.
In addition, the following numerical value is used for the viscosity formula [η] = K × M ^α used for conversion to molecular weight.
PS: K = 1.38 × 10 ⁻⁴ , α = 0.7
PP: K = 1.03 × 10 ⁻⁴ , α = 0.78

F) Measurement of ethylene content by ¹³ C-NMR The α-olefin (preferably ethylene) content α [A2] is measured according to the following conditions by the proton complete decoupling method, and the ¹³ C-NMR spectrum is analyzed. By seeking.
Model: GSX-400 manufactured by JEOL Ltd. or equivalent device (carbon nuclear resonance frequency of 100 MHz or more)
Solvent: o-dichlorobenzene / heavy benzene = 4/1 (volume ratio)
Concentration: 100 mg / ml Temperature: 130 ° C
Pulse angle: 90 ° Pulse interval: 15 seconds Integration number: 5,000 times or more The attribution of the spectrum may be performed with reference to, for example, Macromolecules 17 1950 (1984). The spectral attributions measured under the above conditions are shown in Table 1. In the table, symbols such as S _αα follow the notation of Carman et al. (Macromolecules 10 536 (1977)), P represents a methyl carbon, S represents a methylene carbon, and T represents a methine carbon.

Hereinafter, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six types of triads of PPP, PPE, EPE, PEP, PEE, and EEE may exist in the chain. As described in Macromolecules 15 1150 (1982) and the like, the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions (1) to (6).
[PPP] = k × I (T _ββ ) (1)
[PPE] = k × I (T _βδ ) (2)
[EPE] = k × I (T _δδ ) (3)
[PEP] = k × I (S _ββ ) (4)
[PEE] = k × I (S _βδ ) (5)
[EEE] = k × {I (S _δδ ) / 2 + I (S _γδ ) / 4} (6)
Here, [] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads.
Therefore, [PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7)
It is. Further, k is a constant, I indicates the spectral intensity, and for example, I (T _ββ ) means the intensity of the peak at 28.7 ppm attributed to T _ββ .
By using the relational expressions (1) to (7) above, the fraction of each triad is obtained, and the ethylene content is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100
The propylene-α-olefin random copolymer contains a small amount of propylene hetero bonds (2,1-bonds and / or 1,3-bonds), thereby producing the minute peaks shown in Table 2.

  In order to obtain an accurate α-olefin (ethylene) content, it is necessary to include the peaks derived from these different bonds in the calculation, but it is difficult to completely separate and identify the peaks derived from the different bonds. Since the amount of heterogeneous bonds is small, the ethylene content of the present invention has the same relations (1) to (7) as in the analysis of the copolymer produced with a Ziegler-Natta catalyst that does not substantially contain heterogeneous bonds. It is determined using an expression.

[Example 1]
(Example of polymerization)
(1) Preparation of catalyst In a three-necked flask (volume: 1 L), 20 g of a smectite silicate (Benley SL manufactured by Mizusawa Chemical Co., Ltd.), which was sequentially treated with sulfuric acid, and 200 mL of heptane were charged. After the treatment, the slurry was washed with heptane to obtain slurry 1. In another flask (volume 200 mL), heptane 90 mL, (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium 0.3 mmol Then, 1.5 mmol of triisobutylaluminum was added to prepare slurry 2. Slurry 2 was added to the slurry 1 and stirred at room temperature for 60 minutes. Thereafter, 210 mL of heptane was added, and this slurry was introduced into a 1 L autoclave.
After the internal temperature of the autoclave was set to 40 ° C., propylene was fed at a rate of 10 g / hr, and prepolymerization was carried out for 4 hours while maintaining 40 ° C. for 4 hours to obtain 83 g of a prepolymerized catalyst.

(2) Propylene / α-olefin random copolymer production A hexane-diluted solution of liquid propylene, ethylene, hydrogen, and triisobutylaluminum (TIBA) was continuously supplied to a reactor having an internal volume of 270 L, and the internal temperature was 62. Held at 0C. The supply amount of propylene was 38 kg / hr, the supply amount of ethylene was 0.92 kg / hr, the supply amount of hydrogen was 0.25 g / hr, and the supply amount of TIBA was 18 g / hr. The prepolymerized catalyst was slurried with liquid paraffin and fed at 2.35 g / hr. As a result, a 12.2 kg / hr propylene / ethylene random copolymer (PP-0) was obtained.
The obtained propylene / ethylene random copolymer (PP-0) had MFR = 26.0 g / 10 min, ethylene content = 4.5 mol%, Tm = 125 ° C., and Q value = 2.7.

(3) Compounding of additive Propylene resin (PP-0) is used as a resin material, and 1,3-bis (t-butyl-peroxy-isopropyl) benzene, which is an organic peroxide, with respect to 100 parts by weight of the resin. (Trade name: Parkardox 14, Kayaku Akzo Co., Ltd.) 0.34 parts by weight, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4) which is a phenolic antioxidant '-Hydroxyphenyl) propionate] methane (trade name: IRGANOX1010, manufactured by BASF) 0.1 parts by weight, tris (2,4-di-t-butylphenyl) phosphite which is a phosphite antioxidant ( Product name: 0.1 part by weight of IRGAFOS 168 / BASF Co., Ltd., and calcium stearate as a neutralizing agent (Product name: Calcium Stearate, Nippon Oil & Fat Co., Ltd.) (Product made) 0.1 parts by weight blended, mixed at room temperature for 3 minutes with a high-speed stirring mixer (Henschel mixer: trade name), melt-kneaded in an extruder, and MFR = 2500 g / 10 min propylene A resin pellet (PP-1) was obtained.
Furthermore, a propylene resin pellet (PP-1) is used, and a polyether / polyolefin block copolymer (trade name: Pelestat 303 / Sanyo Kasei) is used as a polymer type antistatic agent (component A) with respect to 98% by weight of the resin. 2% by weight) was blended and melt-kneaded with an extruder to obtain propylene-based resin pellets.

(4) Electrospinning spinning In the melt spinning type electrospinning apparatus shown in FIG. 1, 4 g of the obtained propylene-based resin was put into a melting cylinder heated to 260 ° C., held for 5 minutes, and then 0.05 cc by a piston. It was pushed in at a discharge rate of / hr, and a voltage of 40 kV was applied between the nozzle and the target to obtain ultrafine fibers.
The intended uniform nanofiber was obtained as the ultrafine fiber obtained from the propylene-based resin composition satisfying the requirements of the constitution of the present invention.

[Example 2]
An ultrafine fiber was obtained in the same manner as in Example 1 except that 95% by weight of propylene resin (PP-1) and 5% by weight of component A were blended as the resin composition.
The intended uniform nanofiber was obtained as the ultrafine fiber obtained from the propylene-based resin composition satisfying the requirements of the constitution of the present invention.

Example 3
Except that the blending amount was changed to 90% by weight of propylene resin (PP-1) and 10% by weight of (Component A) as the resin composition, the same procedure as in Example 1 was performed to obtain ultrafine fibers.
The intended uniform nanofiber was obtained as the ultrafine fiber obtained from the propylene-based resin composition satisfying the requirements of the constitution of the present invention.

Example 4
A propylene-based resin (PP-0) is used as a resin material, and 1,3-bis (t-butyl-peroxy-isopropyl) benzene (trade name: Perkadox 14) which is an organic peroxide with respect to 100 parts by weight of the resin.・ 1.4 parts by weight of Tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], a phenolic antioxidant, manufactured by Kayaku Akzo Co., Ltd. G] 0.1 parts by weight of methane (trade name: IRGANOX1010 / BASF), tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168 / BASF) which is a phosphite antioxidant 0.1 parts by weight) and 0.1 parts by weight of calcium stearate (trade name: calcium stearate, manufactured by NOF Corporation) as a neutralizing agent Then, after mixing for 3 minutes at room temperature with a high-speed stirring mixer (Henschel mixer: trade name), melt-kneading with an extruder, propylene resin pellets (PP-2) with MFR = 17000 g / 10 min Got.
Except having used propylene-type resin (PP-2) as a resin composition, it implemented similarly to Example 3 and obtained the propylene-type resin pellet of MFR = 13000g / 10min.
In the melt spinning type electrospinning apparatus shown in FIG. 1, 4 g of the obtained propylene-based resin is put into a melting cylinder heated to 260 ° C., held for 5 minutes, and then discharged at a discharge amount of 0.05 cc / hr by a piston. The fine fiber was obtained by pressing and applying a voltage of 40 kV between the nozzle and the target.
The intended uniform nanofiber was obtained as the ultrafine fiber obtained from the propylene-based resin composition satisfying the requirements of the constitution of the present invention.

[Comparative Example 1]
As a resin composition, in the propylene-type resin (PP-1), it carried out similarly to Example 1 except that the polymer type antistatic agent was not blended, and ultrafine fibers were obtained.
As the ultrafine fiber obtained from the propylene-based resin composition that does not satisfy the requirements of the constitution of the present invention, the intended uniform nanofiber is not obtained.

[Comparative Example 2]
Example 1 except that the propylene resin (PP-1) was changed to 99.5% by weight as the resin composition, and the amount of (Component A) was changed to 0.5% by weight as the polymer antistatic agent. In the same manner as above, ultrafine fibers were obtained.
As the ultrafine fiber obtained from the propylene-based resin composition that does not satisfy the requirements of the constitution of the present invention, the intended uniform nanofiber is not obtained.

[Comparative Example 3]
As the resin composition, in the propylene resin (PP-1), as the polymer type antistatic agent, the blending amount of (Component A) is from 2.0% by weight to the glycerin monosulerate which is a low molecular type antistatic agent. The same procedure as in Example 1 was performed except that (trade name: electro stripper, manufactured by Kao Corporation) was changed to 2.0% by weight, and ultrafine fibers were obtained.
As the ultrafine fiber obtained from the propylene-based resin composition that does not satisfy the requirements of the constitution of the present invention, the intended uniform nanofiber is not obtained.

［実施例と比較例の結果の考察］
表３から明らかなように、実施例１〜４は本発明の構成の要件を満たしているので、比較例１〜３と対照して、均一な極細繊維としてのナノファイバーが得られている。
比較例３については、実施例１と同等量の帯電防止剤が配合されているが、低分子型帯電防止剤には本発明のような効果は認められない。高分子型帯電防止剤は添加剤自身が導電性を有するが、低分子型帯電防止剤の改質機構は成形品表面へのブリードアウトによって導電性能を発現する、すなわちエレクトロスピニングでの紡糸時に溶融樹脂の電気特性改質効果が高分子型帯電防止剤にのみ有るためと考えられる。
以上の結果より、本発明の構成の合理性と有意性及び従来技術に対する卓越性が明示されているといえる。

[Consideration of results of Examples and Comparative Examples]
As can be seen from Table 3, Examples 1 to 4 satisfy the requirements of the constitution of the present invention, so that nanofibers as uniform ultrafine fibers are obtained in contrast to Comparative Examples 1 to 3.
In Comparative Example 3, the same amount of antistatic agent as in Example 1 is blended, but the effect of the present invention is not recognized in the low molecular weight antistatic agent. The polymer antistatic agent has conductivity by itself, but the modification mechanism of the low molecular antistatic agent exhibits conductive performance by bleeding out to the surface of the molded product, that is, melts when spinning by electrospinning. It is thought that the electrical property modification effect of the resin is only in the polymer type antistatic agent.
From the above results, it can be said that the rationality and significance of the configuration of the present invention and the superiority over the prior art are clearly shown.

Since the ultrafine fiber obtained by the melt spinning type electrospinning apparatus using the propylene resin composition of the present invention is ultrafine in nano units, it has a large surface area and is excellent in liquid absorbency and filterability.
Therefore, various applications, for example, electronic parts such as separators for insulating materials, industrial materials (oil adsorbents, leather base fabrics, cement compounding agents, rubber compounding materials, various tape base materials, etc.), medical and hygiene materials (Paper diapers, gauze, bandages, medical gowns, etc.), life-related materials (wipers, printed materials, packaging / bag materials, storage materials, air filters, liquid filters, etc.), clothing materials, interior materials (heat insulation materials, sound absorbing materials) Etc.), construction materials, agricultural and horticultural materials, civil engineering materials, bags and shoes.

DESCRIPTION OF SYMBOLS 1; Piston 5; Electrode plate 2; Shielding plate 6; Insulating plate 3; Melting cylinder 7; Table 4;

Claims (9)

A resin material that spins ultrafine fibers by performing continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method,
1. A propylene-based resin composition for electrospinning spinning, characterized in that 1 to 50% by weight of a polymer type antistatic agent is blended with 50 to 99% by weight of a propylene-based resin.   The propylene-based resin composition for electrospinning according to claim 1, wherein the propylene-based resin is a propylene homopolymer or a copolymer of propylene and an α-olefin (including ethylene).   The propylene resin composition for electrospinning according to claim 1 or 2, wherein the propylene resin composition further contains another polymer and / or an additive.   The propylene-based resin composition for electrospinning spinning according to any one of claims 1 to 3, wherein the MFR (temperature 230 ° C, load 21.2 N) of the propylene-based resin is 50 to 20,000 g / 10 min. object.   The propylene-based resin composition for electrospinning according to any one of claims 1 to 4, wherein 80 to 99% by weight of the propylene-based resin is blended with 1 to 200% by weight of a polymer type antistatic agent. .   The propylene-based resin composition for electrospinning spinning according to any one of claims 1 to 5, wherein the ultrafine fiber is spun by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method. A method for producing polypropylene-based ultrafine fibers.   The method for producing a polypropylene-based ultrafine fiber according to claim 6, wherein the heat-melting is performed by laser heating.   The propylene-based resin composition for electrospinning spinning according to any one of claims 1 to 5, obtained by spinning by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method. And polypropylene-based ultrafine fibers.   A fiber product produced using the polypropylene-based ultrafine fiber according to claim 8.

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