JP3469314B2 - Unstretched fiber containing styrene polymer component, method for producing the same, and drawn fiber containing styrene polymer component - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unstretched fiber containing a styrene polymer component, a method for producing the same, and a stretched fiber containing a styrene polymer component.

[0002]

2. Description of the Related Art Fibers containing a styrene-based polymer are, for example, ion-exchange fibers prepared by introducing a sulfone group into the benzene ring because of the high reactivity of the side chain benzene ring.
Alternatively, it has been proposed to utilize the hydrophilicity for applications such as battery separators. However, since the fiber containing the styrene-based polymer is brittle and has no elongation, it is difficult to process it into a fiber sheet or the like in order to adapt it to various applications, and it has poor versatility.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is excellent in processability into a fiber sheet and general versatility, and contains a styrene-based polymer component-containing unstretched film. An object of the present invention is to provide a fiber, a method for producing the fiber, and a drawn fiber containing a styrene polymer component.

[0004]

Styrenic polymer component containing undrawn fiber of the present invention, in order to solve the problems] contains a styrene-based polymer component having a syndiotactic configuration, have a elongation 60 to 200% fineness Melt spinning with 0.5-20 denier
When the content of the styrene-based polymer component having a syndiotactic structure is 20% by weight or more, the characteristics of the styrene-based polymer component can be utilized.

When the unstretched fiber containing the styrene polymer component of the present invention is an unstretched fiber obtained by mixing and spinning a styrene polymer component having a syndiotactic structure and another polymer component, it has excellent strength. Moreover, it is easy to chemically modify the benzene ring of the styrene-based polymer component, and the unstretched fiber obtained by composite spinning of the styrene-based polymer component having a syndiotactic structure and another polymer component is styrene. It is easy to chemically modify the benzene ring of the base polymer component.

The drawn fiber containing a styrene polymer component of the present invention is obtained by drawing the above-mentioned undrawn fiber containing a styrene polymer component and having an elongation of 20 to 150%.

The method for producing an unstretched fiber containing a styrene-based polymer component of the present invention comprises a polymer containing a styrene-based polymer having a syndiotactic structure, and a spinning temperature of 315 to 315.
It is a method of melt spinning at 350 ° C. at a draft ratio, that is, a ratio of the winding speed of spun fibers to the linear velocity of discharge from a spinning nozzle of 20 to 160.

[0008]

The unstretched fiber containing the styrenic polymer component of the present invention (hereinafter sometimes simply referred to as "unstretched fiber") is 6
Since it has an elongation of 0 to 200%, it is a fiber excellent in workability and versatility into a fiber sheet and the like.

The unstretched fiber of the present invention has excellent fiber strength,
It contains a styrene-based polymer component having a syndiotactic structure that is easily formed into fibers (hereinafter, the "styrene-based polymer component" has a syndiotactic structure unless otherwise specified). The syndiotactic structure is a structure having stereoregularity in which benzene rings and substituted benzene rings, which are side chains, are alternately located in opposite directions with respect to the main chain, and the syndiotactic structure has an IR spectrum. It can be easily analyzed by 13 C-NMR spectrum.

The undrawn fiber of the present invention preferably contains a styrenic polymer component having a high syndiotactic structure, and more specifically, 13 C-NMR.
Analyzed by spectrum, 75% or more, more preferably 85% or more in racemic diad, 3 in racemic pentad
Those having a syndiotacticity of 0% or more, more preferably 50% or more are preferable.

The styrenic polymer component of the present invention includes
For example, polystyrene, polyalkylstyrene such as polymethylstyrene, polyethylstyrene and polyisopropylstyrene, polyhalogenated styrene such as polychlorostyrene, polybromostyrene and polyfluorostyrene, and polyhalogenated styrene such as polychloromethylstyrene. Alkyl styrene, polymethoxystyrene, polyalkoxystyrene such as polyethoxystyrene, polyvinyl benzoate, etc.
Those mixed, hydrogenated or copolymerized can be used. Among these, polystyrene, polyalkylstyrene, hydrogenated polystyrene, and copolymers containing these structural units can be preferably used, and among these, polystyrene is most preferable.

The weight average molecular weight of this styrene polymer component is preferably 10,000 to 4,000,000. If it is less than 10,000, the fiber-forming property is inferior, and if it exceeds 4 million, the viscosity is high and the spinnability is inferior.
Most preferably, it is 100,000 to 300,000.

The glass transition temperature of the styrenic polymer component can be adjusted by, for example, adding a plasticizer, copolymerizing another molecule, or introducing another functional group into the side chain. When the temperature is lowered by 5 ° C. or more, the benzene ring of the styrene polymer component is easily chemically modified. On the other hand, if the glass transition temperature is lowered below 30 ° C., the physical properties of the styrene-based polymer component are remarkably lowered, so that the glass transition temperature is preferably lowered to 30 ° C. or lower. More preferably, the temperature is lowered by 5 to 20 ° C. For example, when the styrene-based polymer component is polystyrene having a glass transition temperature of about 100 ° C, polystyrene having a glass transition temperature lowered to 70 to 95 ° C is used, and more preferably 80 to 95.
The polystyrene reduced to ℃.

When the glass transition temperature of the styrene polymer component is lowered in this way, for example, sulfonation can be easily performed with concentrated sulfuric acid, so that the fiber strength is not lowered and the fiber strength is improved efficiently. It can be done enough. More specifically, in the case of sulfonation with concentrated sulfuric acid to sulfonate up to a sulfur concentration of 5 ppm, fibers made of polystyrene having a glass transition temperature of about 100 ° C. and polystyrene having a glass transition temperature of about 90 ° C. are used. With the fiber, the latter can be sulfonated in about half the time of the former. Further, the glass transition temperature is 90
Fibers made of polystyrene at about ℃ have a sulfur concentration of 2 which cannot be obtained by sulfonation with concentrated sulfuric acid.
It can sulphonate up to 70 ppm.

The concentration of sulfur introduced by sulfonation is the concentration of sulfur obtained by analyzing an absorbent obtained by absorbing fibers by an oxygen combustion flask method with an ion chromatography device (2000 i / SP manufactured by DIONEX). Say. Further, the glass transition temperature can be analyzed by differential thermal analysis measurement.

Among the methods of lowering the glass transition temperature described above, the method of adding a plasticizer is a preferable method because the physical properties of the styrene-based polymer component are less likely to deteriorate and the operation is simple. Examples of the plasticizer include ethylene glycol, propylene glycol, trimethylene glycol, alkylene glycols such as 1,4-butanediol and 1,5 pentanediol, hydrobenzoin,
Aromatic glycols such as benzpicol, carbocyclic glycols such as cyclopentane 1,2-diol, cyclohexane 1,2-diol, phthalates such as dimethyl phthalate and diethyl phthalate, and di-2 adipate.
An aliphatic dibasic acid ester such as -ethylhexyl or di-n-decyl adipate, or a phosphoric acid ester such as tributyl phosphate or tri-2-ethylhexyl phosphate can be used. Among these, alkylene glycol has good compatibility with the styrene-based polymer component and has high plasticization efficiency, and thus can be preferably used, and among these, ethylene glycol is most preferably used.

The amount of the plasticizer added is not particularly limited and may be appropriately set so that the glass transition temperature is lowered by 5 to 30 ° C. For example, for polystyrene,
Ethylene glycol is added in an amount of 0.5 to 10% by weight, more preferably 1 to 6% by weight.

The unstretched fiber of the present invention may consist of the styrene polymer component alone, but may be mixed with other polymer components. In this case, the amount of the styrene-based polymer component is preferably 20% by weight or more, and more preferably 40% by weight or more in order to utilize the characteristics of the styrene-based polymer component. When the benzene ring of the styrene-based polymer component is chemically modified, it is preferable that the styrene-based polymer component occupy 40% or more of the surface of the unstretched fiber, and more preferably 70, so as to facilitate the chemical modification. % Or more.

When the unextracted fiber is sulfonated with a polymer component such as a polyolefin type which is difficult to be sulfonated and a styrene type polymer component, the fiber exposed on the fiber surface is excellent in hydrophilicity on the fiber surface. And a portion having poor hydrophilicity can be formed. Therefore, the portion having excellent hydrophilicity has an excellent electrolyte retaining property, and the portion having poor hydrophilicity has excellent gas permeability, and thus can be suitably used as a fiber for a sealed battery separator.

The polymer component other than the styrenic polymer component may be thermoplastic and fiber-forming, and may be appropriately selected depending on the intended use of the unstretched fiber. For example, polyethylene, Polypropylene, polyolefins such as polystyrene having an atactic structure, polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-butene-propylene copolymer, and nylon such as 6-nylon and 66-nylon,
Polyester such as polyethylene terephthalate and polybutylene terephthalate can be used. For example, when used as a separator for an alkaline battery, polyolefin-based polyethylene, polypropylene and polystyrene having an atactic structure, which are excellent in alkali resistance and oxidation resistance, can be preferably used.

The arrangement state of the styrene polymer component and the other polymer component is, for example, a lotus root shape or a three-dimensional network shape obtained by mixing and spinning the styrene polymer and the other polymer. Styrene-based polymer component or other polymer component is arranged, or obtained by composite spinning styrene-based polymer and another polymer, in the fiber cross section, concentric or eccentric core-sheath type, sea island Mold, or Fig. 1 (a)-(d)
(1) A chrysanthemum type in which one component 1 is arranged between other components 2 and a multi-layer type in which one component 1 and another component 2 are alternately laminated in two or more layers as shown in FIG. 1 (e). There is something. The former mixed-spun product has excellent fiber strength and is characterized in that it is easy to chemically modify the styrene-based polymer component, while the latter composite-spun product exposes the styrene-based polymer component on the fiber surface and It has the feature that it is easy to chemically modify the benzene ring of the polymer component. Among the latter composite spun yarns, the concentric or eccentric core-sheath type or sea-island type can be preferably used because the entire fiber surface can be made of the styrene polymer component.

When unstretched fibers having a chrysanthemum-shaped or multi-layered fiber cross-section can be divided, it is divided into fine fibers to obtain a fiber sheet having a large surface area and a more dense structure. Therefore, it can be used more preferably.

Such unstretched fibers can be obtained by melt spinning a polymer component containing a styrene polymer component. The spinning temperature is 315 to 350 ° C. and the draft ratio is 20 to 160. Is characterized by. If the spinning temperature is less than 300 ° C., the elongation of the unstretched fiber obtained will be less than 60%, the processability will be poor, and the spinning temperature will be 400.
When the temperature exceeds ℃, decomposition of the styrene polymer component is remarkable.

Even if the fiber is spun at the above temperature, if the draft ratio is less than 20 or more than 160, the elongation is 60.
The draft ratio is set to 20 to 160 because unstretched fibers having a content of 10% or more cannot be obtained. More preferably, 30-14
It is 0.

It is to be noted that the unstretched fibers should be oriented to 60
It is preferable to cool in order to have an elongation of not less than%. However, if it is cooled immediately after spinning, the elongation is 60%.
Since it is difficult to obtain the above unstretched fibers and the fibers are easily broken and the spinnability deteriorates, it is preferable to cool at a point 3 mm or more from the spinning outlet end of the spinning nozzle.

Spinning conditions other than these conditions are not particularly limited, but, for example, the spinning nozzle diameter is 0.
The thickness is 1 to 0.5 mm, more preferably 0.2 to 0.4 mm.

The unstretched fibers thus obtained are 6
It has an elongation of 0 to 200%. This elongation is 6
This is because if it is less than 0%, the workability deteriorates. A more preferable elongation is 80 to 200%.

The elongation in the present invention is Tensilon (UTO-III-100, manufactured by Toyo Baldwin Co., Ltd.), a 1 kg cell is used, and the measured fiber length is 20 mm and the tensile speed is 20 mm / min. It is obtained by the following formula from the length before pulling and the length at break. In addition,
This measurement is performed at a temperature of 25 ° C.

The unstretched fiber has a fineness of about 0.5 to 20 denier and a fiber length of 3 mm or more. Also,
The fiber cross-sectional shape is not limited to a circular shape, but may be a polygonal shape such as a triangle, a quadrangle, or a hexagon, an elliptical shape, or an oval shape, and is not particularly limited.

The unstretched fibers as described above are stretched to 20 to 20
A stretched fiber containing a styrene-based polymer component (hereinafter sometimes simply referred to as “stretched fiber”) having an elongation of 150% and being excellent in strength can be obtained. If the elongation is less than 20%, it is brittle and the workability into a fiber sheet is poor,
This is because if it exceeds 150%, there is no strength despite stretching. More preferable elongation is 20 to 100
%.

This stretching may be appropriately set so that the stretched fibers fall within the above range, but in general, it is 1.3 to 3.0.
It is preferable to perform double stretching. This is because if it is less than 1.3 times, the strength is not improved so much even though it is stretched, and if it exceeds 3.0 times, the fiber is easily broken and the elongation of the obtained stretched fiber is lost. More preferably, 1.4-2.
5 times. Although this stretching can be performed at room temperature, it can be stably performed under a temperature condition of 80 to 200 ° C. without the fibers sticking.

Since the orientation of the crystal is caused by the stretching, the birefringence is changed, and by measuring this value, it is possible to distinguish between the stretched fiber and the unstretched fiber.

Since the unstretched fibers and the stretched fibers as described above have excellent elongation, they can be used in the fibrous state as they are, and can be woven or knitted by knitting or by a card machine. It has excellent versatility because it can be opened and processed into a fiber web without breaking.

When the benzene ring of the unstretched fiber or the stretched fiber is chemically modified, the fiber sheet may be formed after chemically modifying the unstretched fiber or the stretched fiber. Alternatively, it may be chemically modified after forming a fiber sheet from drawn fibers.

Since the benzene ring of the unstretched fiber or the stretched fiber, for example, sulfonated is excellent in hydrophilicity, it can be applied to various applications such as an air filter, a liquid filter and a battery separator. is there.

Examples of the present invention will be described below, but the invention is not limited to the following examples. The melt viscosity of the polymer is 320 ° C. and the share rate is 10 3 S-1, and the flow tester (manufactured by Shimadzu Corporation, Flow Tester CFT-500C) has a diameter of 1.0 mm and a length of 10.0 m.
Measurement was performed using a m nozzle.

[0037]

EXAMPLES Example 1 Only polystyrene having a syndiotactic structure (made by Idemitsu Petrochemical Co., Ltd.) having a melt viscosity of 430 poise, a weight average molecular weight of 170,000 and a glass transition temperature of 100 ° C. was spun with a diameter of 0.25 mm. From the nozzle, temperature 3
Discharge at 0.14 g / min at 20 ° C., and 10 cm downward from a point 5 mm or more away from the spinning outlet end of the spinning nozzle.
While cooling with air, it was wound at a speed of 210 m / min and a draft ratio of 66, and had a circular cross section with a fineness of 6 denier and an elongation of 1
35% unstretched fiber was obtained.

Next, this unstretched fiber was stretched twice on a heater at 120 ° C. to have a fineness of 3 denier and an elongation of 29%.
The drawn fiber of was obtained.

(Example 2) An unstretched fiber having a circular cross section, a fineness of 9 denier and an elongation of 110% was obtained in exactly the same manner as in Example 1 except that the fiber was wound at a speed of 140 m / min and a draft ratio of 44. It was Next, this unstretched fiber was stretched 1.5 times on a heater at 120 ° C. to obtain a stretched fiber having a fineness of 6 denier and an elongation of 35%.

Example 3 As in Example 1, 50 parts of polystyrene having a syndiotactic structure and 50 parts of polypropylene having a melt viscosity of 160 poise were mixed and melted, and then a spinning nozzle having a diameter of 0.25 mm. From temperature 32
It was discharged at 0 ° C. and 0.14 g / min, and was cooled with air from a point 5 mm or more away from the spinning outlet end of the spinning nozzle to 10 cm below, while the speed was 210 m / min and the draft ratio was 6
Winding at 0, circular cross section, fineness 6 denier, elongation 158
% Unstretched fiber was obtained.

Next, this unstretched fiber was stretched 1.4 times on a heater at 50 ° C. to obtain a fineness of 4.3 denier and an elongation of 5
0% drawn fiber was obtained.

(Example 4) As in Example 3, 50 parts of polystyrene having a syndiotactic structure and 50 parts of polypropylene were separately melted, and then, a core-sheath type cross section was prepared and a diameter of 0.3 mm. , Polypropylene melt from the core of the spinning nozzle, polystyrene melt from the sheath, and temperature 3
After discharging at 20 ° C. and 0.6 g / min to combine these melts, a speed of 5 was applied while cooling with air from a point 5 mm or more away from the spinning outlet end of the spinning nozzle to 10 cm below.
It was wound at 40 m / min at a draft ratio of 52 to obtain a core-sheath type unstretched fiber having a circular cross section, a fineness of 10 denier, an elongation of 123%.

Next, this core-sheath type unstretched fiber is heated to 125 ° C.
Was drawn twice on the heater of No. 2 to obtain a drawn fiber having a fineness of 5 denier and an elongation of 25%.

Example 5 An unstretched fiber having a circular cross section, a fineness of 3 denier and an elongation of 76% was obtained in exactly the same manner as in Example 1 except that the fiber was wound at a speed of 408 m / min and a draft ratio of 132. It was Next, this unstretched fiber was stretched 1.4 times on a heater at 50 ° C. to obtain a stretched fiber having a fineness of 2.2 denier and an elongation of 30%.

Example 6 An unstretched fiber having a circular cross section, a fineness of 12 denier and an elongation of 150% was obtained in the same manner as in Example 1 except that the fiber was wound at a speed of 105 m / min and a draft ratio of 33. It was Next, this unstretched fiber was stretched twice on a heater at 50 ° C. to obtain a fineness of 6 denier and an elongation of 30.
% Stretched fiber was obtained.

Example 7 Polystyrene having the same syndiotactic structure as in Example 1 (made by Idemitsu Petrochemical Co., Ltd.)
With respect to 96 parts, 4 parts of polyethylene glycol was added as a plasticizer, and the glass transition temperature was set to 90 ° C., in exactly the same manner as in Example 1, circular cross section, fineness 6 denier, elongation 110% An unstretched fiber was obtained.

Then, the unstretched fiber is cooled to room temperature (25 ° C.).
Was drawn 1.5 times to obtain a drawn fiber having a fineness of 4 denier and an elongation of 50%. The drawn fiber was immersed in a 97% sulfuric acid solution at 80 ° C. for 20 minutes, washed with water, dried at 60 ° C., and the concentration of sulfur introduced by sulfonation was measured to be 5.0 ppm.

Comparative Example 1 Only polystyrene having an atactic structure (Stylon 666, manufactured by Asahi Kasei Corporation) having a melt viscosity of 130 poise and a glass transition temperature of 100 ° C. was used, and a speed of 210 m / min and a draft ratio. An unstretched fiber having a circular cross section, a fineness of 6 denier and an elongation of 6% was obtained in exactly the same manner as in Example 1 except that the unstretched fiber was wound at 66. Then, this unstretched fiber was tried to be stretched twice on a heater at 120 ° C.
It could not be stably stretched.

(Comparative Example 2) The temperature of the spinning nozzle was 295 ° C.
In addition, the unstretched fiber having a circular cross section, a fineness of 9 denier and an elongation of 56% was obtained in exactly the same manner as in Example 1 except that the fiber was wound up at a speed of 140 m / min and a draft ratio of 44. Next, this unstretched fiber was stretched 1.5 times on a heater at 120 ° C. to obtain a stretched fiber having a fineness of 6 denier and an elongation of 13%.

(Comparative Example 3) An unstretched fiber having a circular cross section, a fineness of 2 denier and an elongation of 45% was obtained in the same manner as in Example 1 except that the fiber was wound at a speed of 630 m / min and a draft ratio of 198. It was Next, this unstretched fiber was tried to be stretched 1.3 times on a heater at 50 ° C., but the fiber broke, and a stretched fiber could not be stably obtained.

(Comparative Example 4) An unstretched fiber having a circular cross section, a fineness of 24 denier and an elongation of 39% was obtained in the same manner as in Example 1 except that the fiber was wound at a speed of 53 m / min and a draft ratio of 17. It was Then, the unstretched fiber was tried to be stretched 1.3 times on a heater at 50 ° C., but the fiber broke,
A stretched fiber could not be obtained stably.

(Workability test) The drawn fibers of Examples 1 to 7 and Comparative Example 2 were bundled so as to have a denier of 10,000 and crimped with a crimper having a nip roll width of 5 mm.
It was cut into a length of mm to obtain a staple fiber. Next, 20 g of this staple fiber was opened with a card machine to form a fiber web. The processability was judged from the weight of the fiber web obtained at this time. In addition, this card machine produces about 18% of fiber web when carding 20 g of normal fiber and forms about 18 g of fiber web.
It was judged that the processability was excellent if a fiber web of 5 g or more could be formed. The results are shown in Table 1.

[0053]

[Table 1]

[0054]

Styrenic polymer component containing undrawn fiber of the present invention according to the present invention contains a styrene-based polymer component having a syndiotactic configuration, have a elongation 60 to 200% fiber
Since it is a melt-spun fiber having a denier of 0.5 to 20 denier, it is a fiber excellent in processability and versatility.

When the styrene-based polymer component-containing undrawn fiber of the present invention contains 20% by weight or more of the styrene-based polymer component having a syndiotactic structure, the characteristics of the styrene-based polymer component can be utilized. .

When the unstretched fiber containing a styrene-based polymer component of the present invention is an unstretched fiber obtained by mixing and spinning a styrene-based polymer component having a syndiotactic structure and another polymer component, fiber strength is improved. An unstretched fiber obtained by composite spinning a styrenic polymer component having a syndiotactic structure and another polymer component, which is excellent and is easy to chemically modify the styrenic polymer component, It is easy to chemically modify the benzene ring of the combined component.

The stretched fiber containing the styrene-based polymer component of the present invention is obtained by stretching the above-mentioned unstretched fiber containing the styrene-based polymer component and has an elongation of 20 to 150%. It also has excellent workability.

The styrene-based polymer component-containing undrawn fiber of the present invention is produced by spinning the polymer component containing the styrene-based polymer component having a syndiotactic structure at a spinning temperature.
This is a method of melt spinning at 315 to 350 ° C. and a draft ratio of 20 to 160, and an unstretched fiber containing a styrene polymer component and having an elongation of 60 to 200% can be obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-1-183516 (JP, A) JP-A-2-53909 (JP, A) JP-A-2-104715 (JP, A) JP-A-5- 71009 (JP, A) JP 3-2247 (JP, A) JP 4-257310 (JP, A) Special table 6-500369 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D01F 6/22 D01F 6/56 D01F 8/10

Claims (6)

(57) [Claims] 1. A styrene-based polymer component having a syndiotactic structure, which has an elongation of 60 to 200%.
And has a fineness of 0.5 to 20 denier.
Melt-spun unstretched fiber containing a styrene polymer component. 2. The unstretched fiber containing a styrene polymer component according to claim 1, wherein the content of the styrene polymer component having a syndiotactic structure is 20% by weight or more. 3. The styrene-based polymer component-free according to claim 1 or 2, wherein a styrene-based polymer component having a syndiotactic structure and another polymer component are mixed and spun. Drawn fiber. 4. The styrene-based polymer component-free according to claim 1 or 2, wherein a styrene-based polymer component having a syndiotactic structure and another polymer component are subjected to composite spinning. Drawn fiber. 5. The unstretched fiber containing the styrene-based polymer component according to claim 1 is stretched to obtain 20 to 150.
% Stretched fiber containing a styrene polymer component. 6. A polymer containing a styrene-based polymer having a syndiotactic structure is produced at a spinning temperature of 315 to 35.
A method for producing an unstretched fiber containing a styrene-based polymer component, which comprises melt spinning at 0 ° C. and a draft ratio of 20 to 160.