JP2012072514A - Propylene-based resin composition for melt spinning-type electrospinning and method of melt-spinning ultra fine fiber using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an ultra fine fiber by use of a propylene-based resin material in the melt spinning-type electrospinning method.SOLUTION: A resin material is suitable for spinning an ultra fine fiber by continuously extruding in the heat melted state with the melt spinning-type electrospinning method. The material comprises 0.01 to 2.5 pts.wt. of an additive having a triazine ring structure based on 100 pts.wt. of a propylene-based resin.

Description

  The present invention relates to a propylene-based resin composition for melt spinning type electrospinning and a melt spinning method of ultrafine fibers thereby, and more specifically, by continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method. Propylene-based resin composition to be spun, and polypropylene-based ultrafine fiber produced by continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method, and a polypropylene spun by the production method Related to ultrafine fibers and their textile products.

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, since this electrospinning method is a solution electrospinning method, 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. However, the production of the product requires the recovery of the evaporated solvent, 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, 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 a target becomes a negative electrode. A melt electrostatic spinning method and an apparatus for applying such a high voltage are disclosed (see Patent Documents 2 and 3).
However, in the melt electrospinning method, 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 deterioration of physical properties of the polymer. .
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, 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.
Therefore, at present, regarding the resin such as polypropylene which is not suitable for the melt electrospinning method, there has been little research on the melt electrospinning method.

JP-T 2008-53860 Publication JP 2007-32246 A JP 2009-150039 A JP 2007-239114 A

  As described above in paragraph 0006 of the background art, regarding the resin such as polypropylene which is not suitable for the melt electrospinning method, there has been little research on the melt electrospinning method. In view of the present situation where development of a technique for producing ultrafine fibers is desired by application, the present invention makes it a problem to be solved by the present invention to realize such a process for producing ultrafine fibers.

In order to solve the above-mentioned problems, the inventors of the present invention have prepared the spinning device and spinning conditions of the melt electrospinning method, the physical properties and performance specifications of the propylene-based resin material, and further the modification and composition of the propylene-based resin. As a result, the propylene-based resin, which has a high volume resistivity and is difficult to hold a charge even when a voltage is applied, cannot be efficiently stretched and stretched. The present invention was created by finding that if a propylene resin composition containing an additive having a structure is employed, ultrafine fibers can be produced by melt spinning type electrospinning even in a propylene resin having a high volume resistivity. It came to do.
Here, the specific additive in the present invention is an additive having a triazine ring structure as a chemical structure represented by the general formula (I).

（Ｉ）

(I)

Therefore, the basic invention in the present invention is a resin material for spinning ultrafine fibers by continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method, and the propylene blended with the above additives The amount of the resin composition is defined as 0.01 to 2.5 parts by weight with respect to 100 parts by weight of the propylene resin.
In addition, the rationality and significance of the requirements (specific matters of the invention) of such a configuration in the present invention are verified by Examples and Comparative Examples described later.

As an incidental invention in the present invention, in the above basic invention, the propylene resin is an invention in which the propylene resin is a propylene homopolymer or a copolymer with an α-olefin (including ethylene), and the propylene resin composition The invention further includes another polymer and / or various additives, and the invention in which the propylene resin is a propylene resin composition satisfying the following characteristics: [a) MFR (temperature 230 ° C. The load 21.2N) is 50 to 5,000 g / 10 min. B) The melting peak temperature (Tm) measured by DSC (differential scanning calorimetry) method is 110 to 150 ° C.], this propylene resin A polypropylene-based ultrafine fiber is obtained by spinning a composition by continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method. It is an invention of a method for forming a inventions heating and melting in those methods for producing a polypropylene microfine fibers is performed by laser heating.
Furthermore, it is an invention of a polypropylene-based ultrafine fiber obtained by spinning a propylene-based resin composition by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method, and this ultrafine fiber is used. It is an invention of various fiber products manufactured in this way.

  The present invention has been found for the first time by the above-described inventions that even in a propylene-based resin having a high volume resistivity, ultrafine fibers can be produced industrially and efficiently by the melt spinning type electrospinning method, paragraph 0007 Even if the conventional patent documents including the patent documents described in 1) are scrutinized, the requirements (specific matters of the invention) of the new configuration of the present invention cannot be obtained.

  In the above, since the background of the creation of the present invention and the basic components and features of the present invention have been described in overview, the present invention can be summarized as a unit group of the following invention. The invention of [1] is a basic invention, and the following is an incidental invention or an embodiment invention of the basic invention. The entire invention group is collectively referred to as “the present invention”.

  [1] A resin material that spins ultrafine fibers by continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method, and is represented by the general formula (I) with respect to 100 parts by weight of a propylene-based resin. A propylene-based resin composition for electrospinning spinning, comprising 0.01 to 2.5 parts by weight of an additive having a triazine ring structure.

（Ｉ）

(I)

[2] The propylene resin composition for electrospinning according to [1], wherein the propylene resin is a propylene homopolymer or a copolymer with an α-olefin (including ethylene).
[3] The propylene resin composition for electrospinning according to [2], wherein the propylene resin composition further contains another polymer and / or various additives.
[4] The propylene resin composition for electrospinning spinning according to any one of [1] to [3], wherein the propylene resin satisfies the following characteristics.
a) MFR (temperature 230 ° C., load 21.2 N) is 50 to 5,000 g / 10 min b) melting peak temperature (Tm) measured by DSC (differential scanning calorimetry) method is 110 to 150 ° C. is there

[5] Propylene-based resin composition according to [4] is manufactured by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method to spin ultrafine fibers. Method.
[6] The method for producing a polypropylene-based ultrafine fiber according to [5], wherein the heat-melting is performed by laser heating.

[7] A polypropylene-based ultrafine fiber obtained by spinning the propylene-based resin composition according to [4] by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method.
[8] Various fiber products manufactured using the ultrafine fiber according to [7].

  In the present invention, even in a propylene-based resin having a high volume resistivity, which could not be produced conventionally by the melt spinning type electrospinning method, the ultrafine fiber is industrially produced efficiently by the melt spinning type electrospinning method. Can be manufactured.

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

The present invention, as a basic invention, is a resin material in which ultrafine fibers are spun by continuous extrusion spinning in a heated and melted state by a melt spinning type electrospinning method, with respect to 100 parts by weight of a propylene-based resin. A propylene-based resin composition for electrospinning spinning, characterized in that 0.01 to 2.5 parts by weight of an additive having a triazine ring structure represented by the general formula (I) presented in (1) is blended.
In the following, each requirement of the basic invention will be described specifically and in detail with respect to the invention and the embodiments accompanying the basic invention.

(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.

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. .

(2) Propylene-based resin composition In the propylene-based resin composition of the basic invention in the present invention, 0.01 to 2.5 parts by weight of an additive having a triazine ring structure represented by the general formula (I) is added. The main requirement is preferably 0.1 to 2.0 parts by weight.

（Ｉ）

(I)

  Although it does not specifically limit as an additive which has a triazine ring prescribed | regulated by this invention as a chemical structure, As a typical additive, N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [ N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate (manufactured by BASF; Chimasoap (R) 119FL ( Hereinafter defined as component A))), poly [(6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl) ((2,2 , 6,6-tetramethyl-4-piperidyl) imino) hexamethylene ((2,2,6,6-tetramethyl-4-piperidyl) imino)] (manufactured by BASF; Kimasorb (R) 944LD (hereinafter, component) Defined as B.) , 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5 - ((hexyl) oxy) - phenol (BASF Corp., Tinuvin (R) 1577FF) and the like.

  By blending an additive with this defined triazine ring in the chemical structure, when the resin is electrospun by applying a voltage, the resin is more easily charged and spins at high speed with strong electrostatic force. Therefore, it is considered that the fiber diameter obtained in the melt electrospinning method is made finer.

  The additive content is defined as 0.01 part by weight as the lower limit. This is because the effect of addition was not observed at 0.005 parts by weight, as described in Comparative Example 2 described later. The upper limit is specified as 2.5 parts by weight. Although this is also described in the Examples, it is because the additive effect is the maximum value at 2.5 parts by weight, and it is considered that addition of more additives is not desirable from the viewpoint of cost.

(3) Specification of physical properties of propylene-based resin In the propylene-based resin used in the present invention, MFR (melt flow rate) measured at a heating temperature of 230 ° C. and a load of 21.2 N in accordance with JIS K7210 is It is preferably 50 to 5,000 g / 10 min, more preferably 100 to 4,000 g / 10 min, and most preferably 500 to 3,600 g / 10 min.
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 5,000 g / 10 min are difficult to produce with the current polymerization technology and equipment.

The propylene resin used in the present invention preferably has a melting peak temperature (Tm) measured by a differential scanning calorimeter (DSC) of 110 to 150 ° C, more preferably 120 to 140 ° C. .
When the melting peak temperature is less than 110 ° C., the cooling and solidification rate of the melted propylene resin is slow, and the spun ultrafine fibers are fused with each other. The cooling and solidification rate is too high, and the fibers are solidified without being sufficiently stretched. This is not preferable because ultrafine fibers cannot be obtained.
Here, the specific measurement of Tm is performed using a differential scanning calorimeter (DSC), taking a sample amount of 5 mg, holding at 200 ° C. for 5 minutes, and then crystallizing to 40 ° C. at a rate of temperature decrease of 10 ° C./min. Further, the peak position of the curve drawn when the film is melted at a temperature rising rate of 10 ° C./min is defined as a melting peak temperature Tm (° C.).

(4) Physical property regulation control method In order to obtain a desired MFR, the MFR basically depends on the molecular weight, so the molecular weight may be controlled, such as the polymerization temperature, the supply amount of hydrogen gas, or the polymerization terminator. Control may be performed. You may adjust by superposing | polymerizing a propylene polymer and melt-kneading using an organic peroxide.
The Tm of the propylene homopolymer can be set to a desired Tm by selecting a metallocene catalyst complex. In order to control Tm of the copolymer with α-olefin, it can be easily adjusted by controlling the amount of α-olefin supplied to the polymerization reaction system.

(5) 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, various polymers of propylene and α-olefin, olefin polymers, and other arbitrary polymers 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 an agent, a lubricant, an 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. Examples of the lubricant include higher fatty acid amides such as stearic acid amide, examples of the antistatic agent include fatty acid partial esters such as glycerin fatty acid monoester, and examples of the metal deactivator include phosphine. Examples include phons, epoxies, triazoles, hydrazides, and oxamides.

(6) Melt-spinning type electrospinning device and method for producing ultrafine fiber using the same As the melt-spinning type electrospinning device, a heat melting spinning type electrospinning device manufactured by Kato Tech, etc. is used. It consists of an electrode to be charged, a piston for resin extrusion, a nozzle, and an electrode plate (target) that receives ultrafine fibers. A voltage is applied between the nozzle and the target to spin the molten resin from the nozzle.
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.

(7) 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.

(8) Utilization mode of extra fine fiber The extra fine fiber spun by this invention can be used for textile products, such as a normal woven fabric and a nonwoven fabric, as a long fiber or a short fiber.
And, as described in paragraph 0003, the ultrafine fiber of the present invention has new properties such as a battery separator, an electromagnetic shielding material, a high performance filter, and a bioartificial device. Development of various applications represented by cell culture substrates, IC chips, 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. The rationality and significance of the configuration of the present invention and the prior art will be described based on the data of each Example and the comparison between each Example and each Comparative Example. Demonstrate excellence.
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. and a load of 21.2 N.
B) Melting peak temperature: Using a Seiko DSC, take a sample of 5.0 mg, 20
After maintaining at 0 ° C. for 5 minutes, crystallization was performed at a rate of temperature decrease of 10 ° C./min up to 40 ° C., and the melting peak temperature when melted at a rate of temperature increase of 10 ° C./min was measured.
C) Finest fiber diameter: The diameter of the spun fiber was observed using a scanning electron microscope (SEM) manufactured by Hitachi High-Technologies Corporation, and the finest fiber diameter was measured.

[Example 1]
(Example of polymerization)
(1) Preparation of catalyst In a three-necked flask (volume: 1 L), 20 g of smectite group silicate (Benley SL manufactured by Mizusawa Chemical Co., Ltd.) that 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-1) was obtained.
The resulting propylene / ethylene random copolymer (PP-1) had MFR = 26.0 g / 10 min, ethylene content = 4.5 mol%, Tm = 125 ° C., Q value = 2.7, and T80− T20 was 6.3 ° C. and 0 ° C. soluble content was 0.13% by weight.

(3) Blending of additive Propylene resin (PP-1) is used as the 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: Perkadox 14, manufactured by Kayaku Akzo Co., Ltd.) 0.04 parts by weight, N, N'-bis (3-aminopropyl) ethylenediamine-2,4- as an additive having a triazine ring in the chemical structure Bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate (manufactured by BASF; Chimasorpe (R) 119FL: Component A) 1.0 part by weight, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane which is a phenolic antioxidant (Product : IRGANOX 1010 (manufactured by BASF) 0.1 parts by weight, tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF) 0.1 0.1 parts by weight of calcium stearate (trade name: calcium stearate, manufactured by Nippon Oil & Fats Co., Ltd.), which is a neutralizing agent, and blended with a high-speed stirring mixer (Henschel mixer: trade name) After mixing at room temperature for 3 minutes, the mixture was melt-kneaded with an extruder to obtain propylene-based resin pellets with MFR = 80 g / 10 min.

(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 desired nanofiber was obtained as an ultrafine fiber obtained from the propylene-based resin composition that satisfies the requirements of the constitution of the present invention.

[Example 2]
In the propylene resin (PP-1) as the resin composition, instead of component A, poly [(6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2, 4-diyl) ((2,2,6,6-tetramethyl-4-piperidyl) imino) hexamethylene ((2,2,6,6-tetramethyl-4-piperidyl) imino)] (manufactured by BASF, The same procedure as in Example 1 was conducted, except that 1.0 part by weight of Kimasorb (R) 944LD: Component B) was obtained, and propylene-based resin pellets with MFR = 80 g / 10 min were obtained.
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. Pushing, a voltage of 40 kv was applied between the nozzle and the target to obtain ultrafine fibers.
The desired nanofiber was obtained as an ultrafine fiber obtained from the propylene-based resin composition that satisfies the requirements of the constitution of the present invention.

Example 3
In the propylene-based resin (PP-1) as the resin composition, the same procedure as in Example 2 was performed except that the amount of (Component B) was changed from 1.0 part by weight to 2.0 parts by weight, and MFR = A propylene-based resin pellet of 80 g / 10 min was obtained.
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. Pushing, a voltage of 40 kv was applied between the nozzle and the target to obtain ultrafine fibers.
The desired nanofiber was obtained as an ultrafine fiber obtained from the propylene-based resin composition that satisfies the requirements of the constitution of the present invention.

Example 4
As a resin composition, commercially available polypropylene (WMB3: manufactured by Nippon Polypro Co., Ltd.): (PP-2) and 1,3-bis (t-butyl-peroxy-isopropyl) benzene (trade name) which is an organic peroxide. : 0.04 parts by weight of Perkadox 14 (manufactured by Kayaku Akzo Co., Ltd.), 1.0 part by weight of (Component B) as an additive having a triazine ring in the chemical structure, tetrakis [phenolic antioxidant] Methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (trade name: IRGANOX1010, manufactured by BASF) 0.1 parts by weight, phosphite antioxidant Tris (2,4-di-t-butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF) 0.1 parts by weight, and stearic acid as a neutralizing agent 0.1 part by weight of calcium (trade name: calcium stearate, manufactured by Nippon Oil & Fats Co., Ltd.) was blended, mixed for 3 minutes at room temperature with a high-speed stirring mixer (Henschel mixer: trade name), and then extruded. The resulting mixture was melt kneaded in a machine to obtain propylene-based resin pellets having a melting point of 142 ° C. and MFR = 80 g / 10 min.
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. Pushing, a voltage of 40 kv was applied between the nozzle and the target to obtain ultrafine fibers.
The desired nanofiber was obtained as an ultrafine fiber obtained from the propylene-based resin composition that satisfies the requirements of the constitution of the present invention.

Example 5
(Catalyst production example)
A metallocene polymerization catalyst was prepared based on the method described in Example 1 of JP-A-2002-284808.
(Polymerization example)
After the inside of the stirring autoclave having an internal volume of 200 L was sufficiently substituted with propylene, 45 kg of sufficiently dehydrated liquefied propylene was introduced. To this, 500 ml (0.12 mol) of a triisobutylaluminum / n-heptane solution, 2.03 kg of ethylene, and 20 L of hydrogen (as a standard state volume) were added, and the internal temperature was maintained at 30 ° C. Next, 0.2 g (as a solid catalyst component) of the metallocene polymerization catalyst prepared according to the catalyst production example was injected with argon to initiate the polymerization, the temperature was raised to 62 ° C. over 40 minutes, and the temperature was maintained for 120 minutes. . Here, 100 ml of ethanol was added to stop the reaction. The residual gas was purged to obtain 16.6 kg of a polypropylene polymer (propylene resin (PP-3)). The polypropylene polymer obtained had an MFR of 500 g / 10 min and a melting point of 125.0 ° C.
1,3-bis (t-butyl-peroxy-isopropyl) benzene which is an organic peroxide in a propylene resin (PP-3) as a resin composition (trade name: manufactured by Perkadox 14, Kayaku Akzo Corporation) 0.04 parts by weight, as an additive having a triazine ring in the chemical structure, 1.0 part by weight of (Component B), tetrakis [methylene-3- (3 ′, 5′-di) which is a phenolic antioxidant -T-butyl-4'-hydroxyphenyl) propionate] methane (trade name: IRGANOX1010, manufactured by BASF) 0.1 parts by weight, tris (2,4-di-t-) as a phosphite antioxidant Butylphenyl) phosphite (trade name: IRGAFOS 168, manufactured by BASF) 0.1 parts by weight, and calcium stearate (trade name: calcium stearate) as a neutralizing agent (Made by Nippon Oil & Fat Co., Ltd.) 0.1 parts by weight, mixed for 3 minutes at room temperature with a high-speed stirring mixer (Henschel mixer: trade name), then melt-kneaded with an extruder Propylene-based resin pellets having a melting point of 125 ° C. and MFR = 500 g / 10 min were obtained.
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. Pushing, a voltage of 40 kv was applied between the nozzle and the target to obtain ultrafine fibers.
The desired nanofiber was obtained as an ultrafine fiber obtained from the propylene-based resin composition that satisfies the requirements of the constitution of the present invention.

Example 6
(Polymerization example)
Except for changing the amount of hydrogen to 30 L (as a standard volume), the same operation as in Example 3 was performed. As a result, 12.4 kg of a polypropylene polymer (propylene resin (PP-4)) was obtained. . The resulting polypropylene polymer had an MFR of 3,600 g / 10 min and a melting point of 125.2 ° C.
Except having used propylene resin (PP-4) instead of propylene resin (PP-3) as a resin composition, it implemented similarly to Example 3 and obtained the ultrafine fiber.
The desired nanofiber was obtained as an ultrafine fiber obtained from the propylene-based resin composition that satisfies the requirements of the constitution of the present invention.

Example 7
It implemented similarly to Example 4 except having used commercially available polypropylene (MA1: Nippon Polypro Co., Ltd. product): (PP-5) instead of propylene resin (PP-2) as a resin composition. , Ultrafine fibers were obtained.
The desired nanofiber was obtained as an ultrafine fiber obtained from the propylene-based resin composition that satisfies the requirements of the constitution of the present invention.

[Comparative Example 1]
As a resin composition, in the propylene-based resin (PP-1), an ultrafine fiber was obtained in the same manner as in Example 1 except that an additive having a triazine ring in the chemical structure was not blended.
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 target nanofiber is not obtained.

[Comparative Example 2]
As the resin composition, in the propylene-based resin (PP-1), as an additive having a triazine ring in the chemical structure, the amount of (Component B) was changed from 1.0 part by weight to 0.005 part by weight. In the same manner as in Example 2, 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 target nanofiber is not obtained.

  The measurement results in each of the above examples and comparative examples are collectively shown in Table 1.

[Consideration of results of Examples and Comparative Examples]
As is clear from Table 1, Examples 1 to 7 satisfy the requirements of the constitution of the present invention, so that nanofibers as ultrafine fibers are obtained in contrast to Comparative Examples 1 and 2.
Since Comparative Examples 1 and 2 do not satisfy the requirements of the configuration of the present invention, the finest fiber diameter is inferior in the nanofiber as the ultrafine fiber.
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-based resin material 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 2; Shielding plate 3; Melting cylinder 4; Nozzle 5; Electrode plate 6; Insulating plate 7;

Claims (8)

A triazine ring structure represented by the general formula (I) with respect to 100 parts by weight of a propylene-based resin, which is 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 A propylene-based resin composition for electrospinning spinning, characterized by containing 0.01 to 2.5 parts by weight of an additive having the following.

(I)
The propylene-based resin composition for electrospinning according to claim 1, wherein the propylene-based resin is a propylene homopolymer or a copolymer with an α-olefin (including ethylene). The propylene-based resin composition for electrospinning according to claim 2, wherein the propylene-based resin composition further contains another polymer and / or various additives. The propylene resin composition for electrospinning spinning according to any one of claims 1 to 3, wherein the propylene resin satisfies the following characteristics.
a) MFR (temperature 230 ° C., load 21.2 N) is 50 to 5,000 g / 10 min b) melting peak temperature (Tm) measured by DSC (differential scanning calorimetry) method is 110 to 150 ° C. is there A polypropylene-based ultrafine fiber is produced by spinning the propylene-based resin composition according to claim 4 by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method to spin ultrafine fibers. Method. The method for producing a polypropylene-based ultrafine fiber according to claim 5, wherein the heat-melting is performed by laser heating. A polypropylene-based ultrafine fiber obtained by spinning the propylene-based resin composition described in claim 4 by continuous extrusion spinning in a heat-melted state by a melt spinning type electrospinning method. Various fiber products manufactured using the ultrafine fiber according to claim 7.

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