KR101155077B1 - Hydrophobic polypropylene staple fibers with dielectric properties and method of producing the same, nonwoven made of them - Google Patents

Abstract

The present invention relates to a hydrophobic polypropylene short fiber containing inorganic materials (BaTiO ₃ , TiO ₂ ) having a high dielectric constant, a method for preparing the same, and a nonwoven fabric made thereof, and more specifically, 0.3 to 5 wt% of inorganic material, It maintains the same level of hydrophobic performance as polypropylene short fibers, while significantly reducing the generation of static electricity in the short fiber manufacturing and nonwoven fabric manufacturing stages. Can improve.

Polypropylene, BaTiO3, Thermal Bond Method, Nonwovens

Description

Hydrophobic polypropylene staple fibers with dielectric properties and a method of manufacturing the same, nonwovens made from them {Hydrophobic polypropylene staple fibers with dielectric properties and method of producing the same, nonwoven made of them}

The present invention relates to a short polypropylene fiber and a method for manufacturing the same, and a nonwoven fabric made therefrom, and more particularly, to maintain a hydrophobicity compared to a general hydrophobic polypropylene short fiber, and improve the workability by improving the generation of static fibers and its It relates to a manufacturing method and a nonwoven fabric made therefrom.

In general, the hydrophobic polypropylene fiber has a low melting point, but there is a limit for clothing, but it has been widely used for light sportswear, etc. by using a wicking property, which has an advantage in moisture transfer.

Polypropylene short fibers have the advantages of low melting point, excellent chemical resistance, and relatively low price compared to other materials, so they are processed into various nonwoven fabrics through calender bonding method, needle punching method, etc. It is mainly used for filter of article surface material, air filter, water treatment filter, etc., but its application is very limited due to strong hydrophobicity.

Nonwoven fabrics are fabrics made by gluing or tangling fiber aggregates by mechanical or chemical treatment such as mechanical manipulation or heat bonding, without weaving, weaving, or knitting, needles, spunbond, spunlace, m, etc. Boss films and wet nonwovens are examples of this. By narrowing, it means that the contact of the web (web) overlapped with the random (random) and the fiber is bonded by resin and used as a wick. Such a nonwoven fabric can be produced by various methods, such as needle punching method, chemical bonding method, thermal bonding method, melt blown method, spunlace method, stitch bond method, spunbond method is known.

In Republic of Korea Patent Publication No. 2007-0091065 The production of polypropylene short fibers and nonwovens has been reliant on spinning oils. Lubrication, antistatic properties, and hydrophobicity have been controlled by attaching a certain amount of fluorine, silicone, and alkyl phosphate spinning oils to the fiber surface. However, when the non-woven fabric having a high hydrophobicity due to the strong hydrophobicity and chargeability of the polypropylene itself is produced, process troubles of various forms (such as curling, electrostatic non-spinning, poor uniformity, etc.) occur due to strong friction in the carding process. In particular, due to the rapid production speed of the nonwoven fabric manufacturing process, such troubles are intensifying. When manufacturing polypropylene short fibers and nonwoven fabrics by spinning oil as described above, the hydrophobic performance of the nonwoven fabric is increased by lowering the ratio of the antistatic agent among the oil components, while the processability, nonwoven bacteria, and productivity are improved due to the generation of static electricity during the carding process. Increasing the ratio of the antistatic agent in the emulsion component will result in a decrease in the hydrophobic performance of the nonwoven fabric while improving the fairness, uniformity, and productivity.

Therefore, a technique for developing hydrophobic polypropylene short fibers, which maintains strong hydrophobic performance but has good nonwoven fabric processability, that is, generates little static electricity, is desired.

In order to solve the above problems, an object of the present invention is to provide a polypropylene short fiber manufacturing technology that improves workability by reducing the generation of static electricity while maintaining hydrophobicity, which is an inherent characteristic of polypropylene by adding an inorganic material. .

In addition, an object of the present invention is to provide a manufacturing technique of a nonwoven fabric having high tensile strength and significantly improved generation of static electricity using the short fibers.

In order to achieve the above object, the present invention provides a hydrophobic polypropylene short fiber containing 95 to 99.7% by weight of homopolypropylene and 0.3 to 5% by weight of BaTiO ₃ or rutile TiO ₂ in the fiber. to provide.

The present invention also provides a hydrophobic polypropylene short fiber having a melt index of 4 to 30 g / 10 min, an isotactic index of 90% by weight or more, and a melting point of 160 to 165 ° C. measured by DSC.

In another aspect, the present invention provides a hydrophobic polypropylene short fiber optionally further comprises one or more additives selected from the group consisting of antioxidants, ultraviolet stabilizers, process stabilizers and colorants including white pigments in the hydrophobic polypropylene short fibers.

In addition, the additive in the present invention provides a hydrophobic polypropylene short fiber containing 0.1 to 1.5 parts by weight based on 100 parts by weight of hydrophobic polypropylene short fiber.

In another aspect, the present invention provides a method for producing a short polypropylene fiber, comprising: melting and spinning 95 to 99.7% by weight homopolypropylene and 0.3 to 5% by weight of BaTiO ₃ or rutile TiO ₂ ; Stretching and crimping the stretched unstretched yarn and giving a crimp; Attaching a liquid resin containing a hydrophobic anti-emulsion emulsion to the surface of the crimped stretched yarn; And after heat-setting the stretched yarn, it provides a method for producing polypropylene short fibers comprising the step of cutting into short fibers.

In another aspect, the present invention provides a method for producing a hydrophobic polypropylene short fiber having a melt index of 4 to 30 g / 10 min, an isotactic index of 90% by weight or more, and a melting point of 160 to 165 ℃ measured by DSC. do.

In another aspect, the present invention provides a method for producing a hydrophobic polypropylene short fiber optionally further comprises at least one additive selected from the group consisting of antioxidants, ultraviolet stabilizers, process stabilizers and colorants including white pigments in the hydrophobic polypropylene short fibers. do.

In addition, the additive in the present invention provides a method for producing a hydrophobic polypropylene short fiber comprising 0.1 to 1.5 parts by weight based on 100 parts by weight of the mixture of blended homopolypropylene and BaTiO ₃ or rutile TiO ₂ .

The present invention also provides a hydrophobic polypropylene nonwoven fabric prepared from the hydrophobic polypropylene short fibers.

The short polypropylene produced by the present invention is BaTiO ₃ used in the invention Alternatively, when the powder containing rutile TiO ₂ is blended at the time of homopolypropylene spinning, the fiber contains high dielectric constant (BaTiO ₃ or rutile TiO ₂ ) so that the fiber has inherent hydrophobic properties and occurs in post-processing. Can have the effect of significantly reducing static electricity

In addition, the present invention, unlike the non-woven fabric consisting of a general hydrophobic homopolypropylene short fibers widely used as a sanitary material by preparing a short fiber blended powder containing BaTiO ₃ or rutile TiO ₂ in the homo polypropylene, Has the antistatic effect that homopolypropylene does not have. In addition, the nonwoven fabric made of the polypropylene short fiber of the present invention has an effect of significantly reducing the generation of static electricity when producing a nonwoven fabric compared to the nonwoven fabric made of the conventional hydrophobic homopolypropylene short fiber.

In addition, the polypropylene short fibers of the present invention has the effect of significantly reducing the generation of static electricity in the nonwoven fabric production process is not only suitable for both thermal bonding method, but also nonwoven fabric production method that needs to reduce the generation of static electricity, defects due to static electricity And productivity fall can also be prevented.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that, in the drawings, the same components or parts have the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

The terms " about ", " substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation to or in the numerical value of the manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

The present invention provides a hydrophobic polypropylene short fiber containing 95 to 99.7% by weight of homopolypropylene and 0.3 to 5% by weight of BaTiO ₃ or rutile TiO ₂ in the fiber. When BaTiO ₃ or rutile TiO ₂ is produced within the above range, it is advantageous for radioactivity and effective for preventing static electricity. When blending over the above range, the radioactivity becomes poor, and when blending below the content, the effect is negligible.

The homopolypropylene has a melt index (MI) of 4 to 30 g / 10 min, an isotactic index of 90% by weight or more, and a melting point (Tm) measured by DSC is preferably 160 to 165 ° C. The lower the melt index of the homopolypropylene can impart fiber stiffness, chemical resistance, and lower elongation, but the viscosity decreases, resulting in poor workability. If the melt index is too high, the stiffness of the fiber is lowered, and spinning Since it is difficult to have a melt index of 4 to 30 is most suitable.

One or more additives selected from the group consisting of antioxidants, UV stabilizers, process stabilizers, and colorants including white pigments may be optionally further included in the short polypropylene fibers, and the content of such additives may be 100% hydrophobic polypropylene short fibers. It is preferably included in 3 parts by weight or less with respect to parts by weight, and more preferably contained in 0.1 to 1.5 parts by weight. If the content is exceeded, the physical properties are inhibited.

The polypropylene short fibers are 50 to 100 m / min through spinneret by blending 0.3 to 5.0 wt.% Of powder containing BaTiO ₃ or rutile TiO ₂ when the homopolypropylene resin is melted at a spinning temperature of about 250 ° C. Unstretched yarn is produced by spinning at a spinning speed, and the stretched ratio of the unstretched yarn is appropriately adjusted between 1.5 and 4.0, and stretched to a preheating temperature of 50 to 100 ° C., and then crimped in a crimper. Dipping or spraying the liquid resin containing the hydrophobic spinning emulsion emulsion to attach the spinning emulsion to the fiber surface so that the content of the spinning emulsion is 0.20 to 2.0 wt% based on the total weight of short fibers. . After the stretched yarn is heat-set for about 8 to 12 minutes at a temperature of 100 ℃, the length of the fiber can be cut to 40 to 100 mm through the step of producing a polypropylene short fiber.

As another embodiment of the present invention provides a non-woven fabric produced by the thermal bond method of the short fibers prepared as described above. The thermal bond processing for producing the nonwoven fabric can be made using a calender bonding method.

The calender bonding method may be manufactured by carding short fibers, followed by thermal fusion between fibers while the web laminated on the conveyor passes between two hot rolls set at 140 to 165 ° C.

In the present invention, the thermal bond non-woven fabric was manufactured through a pilot calender bonding facility, and the hot roll temperature of hot roll was the most favorable for the non-woven fabric production speed, the shape of the embossed pattern of the roll, the difference between the roll setting temperature and the surface temperature, and the like. This is a relative result, not an absolute result, as it may vary depending on the production and equipment conditions of the calender bonding method and the fineness of the short fibers used as raw materials.

When the powder containing BaTiO ₃ used in the present invention is blended at the time of homopolypropylene spinning, the fiber contains a high dielectric constant inorganic material (BaTiO ₃ , rutile TiO ₂ ) and the fiber has an inherent hydrophobic characteristic and is post-processed. It has the effect of significantly reducing the static electricity generated in the phase, and shows no radioactivity without trimming or drop in the spinning process.

Hereinafter, embodiments of the present invention will be described in detail. The conditions and test results of each Example and Comparative Examples can be summarized in Table 1 below.

Example  One

When the homopolypropylene resin was melted at a spinning temperature of about 250 ° C., it was blended with 0.3 wt% of powder containing BaTiO ₃ and spun at a spinning speed of 50 m / min through a spinneret to prepare undrawn yarn. The unstretched yarn was properly stretched at a draw ratio between 1.5 and 4.0, and stretched to a preheating temperature of 70 ° C. to impart crimping in the crimper.

As a spinning oil, silicone spinning oil is used. The liquid resin containing a hydrophobic spinning oil emulsion is dipped or sprayed to attach 0.45% by weight of the total short fiber weight to the fiber surface. Then, after heat setting for 10 minutes at 100 ℃ temperature, the length of the fiber was cut to 100 mm to produce a polypropylene short fiber aimed at the final fiber fineness of 6.0 denier, the average elongation of 100 to 400%.

The polypropylene short fibers obtained by the above method were carded at a speed of 100 mpm with a carding machine, a nonwoven web was produced, and passed between two hot rolls to obtain a calender-bonded nonwoven fabric having a basis weight (nonwoven weight) of 20 to 100 gsm. Prepared.

At this time, while the temperature of the hot roll to 140 ~ 165 ℃ to find the optimum temperature of the most excellent tensile strength of the nonwoven fabric to find the thermal fusion temperature (hereinafter referred to as the optimum hot roll temperature) to measure the physical properties.

Example  2 to 4

Work was carried out in the same manner as in Example 1, but was performed by blending the powder at a ratio of 1.0, 3.0, and 5.0% by weight of BaTiO _{3 to} the homopolypropylene resin, respectively.

Example  5

Work was carried out in the same manner as in Example 1, but was carried out by blending rutile TiO ₂ to 1.0% by weight instead of BaTiO ₃ .

Example  6

Operation was carried out in the same manner as in Example 5, but was performed by blending the rutile TiO ₂ to 5.0% by weight of homopolypropylene resin.

Comparative example  One

The operation was carried out in the same manner as in Example 1, but the homopolypropylene alone was performed without blending the powder containing BaTiO ₃ .

Comparative example  2

The operation was performed in the same manner as in Comparative Example 1, but the discharge amount was adjusted to adjust the fineness of the final polypropylene short fibers to 2.0 to 10 deniers.

Comparative example  3

The operation was carried out in the same manner as in Example 1, but was performed by blending 1.0 wt% of powder containing anatase TiO ₂ , which is a mineral having a different dielectric constant.

Comparative example  4

The operation was performed in the same manner as in Comparative Example 3, but the discharge amount was adjusted to adjust the fineness of the final polypropylene short fibers to 2.0 to 10 deniers.

※ Analysis method

1. Melt Index (MI): According to ASTM D 1238

   * Homopolypropylene and random copolymer series: 230 ℃, 2.16kg load

   * PE series such as HDPE, LDPE: 190 ℃, 2.16kg load

2. Isotactic Index (II): ISO 9113: 1986 Plastics-Polypropylene (PP) and propylene-copolymer thermoplastics-Determination of isotactic index: Isotactic component remaining after boiling normal heptane to melt atactic component Is expressed in weight percent and is called isotactic index.

3. Radioactivity: Evaluated by measuring the number of fiber breaks and the number of spin drops generated immediately under the detention of 11,000 to 65,000 holes.

However, trimming or dropping is less than once / hour: ◎

However, trimming or dropping is 1 ~ 3 times / time: ○

Only three times / time of drop or drop: △

No radiation: ×

4. Single fiber fineness: Measure fineness based on ASTM D1577

6. Settling time of short fibers: measured according to ERT (Edana Recommended Test Methods) 10.3-99

7. Non-woven carding property: In the process of passing short card through carding machine, curling or flying phenomenon occurs between card rolls, or if web formation is not good, it is judged as bad.

8. Leveling System: 1 (Poor) ～ 5 (Very Good)

9. Voltage measurement: Measure with a voltmeter on the nonwoven fabric guide bar immediately after calendar roll

10. Non-woven fabric static electricity measurement: 5 layers of non-woven fabric immediately after production is measured using the electrostatic measuring device 'SIMCO's FMX-003'

11. Settling time for nonwovens: measured according to ERT 10.4-02

division
Mineral input Short Fiber Properties Nonwoven Workability Nonwovens Properties Kinds weight% Radioactive Island
(De) Shinto
(%) Settling time Carding Uniformity Voltage measurement
[V] Static [KV] Settling time Example 1 BaTiO ₃ 0.3 ◎ 2.1 364.0 More than 3 hours Good 4 5 0.5 More than 3 hours Example 2 BaTiO ₃ 1.0 ◎ 2.0 362.0 More than 3 hours Good 5 2 0.2 More than 3 hours Example 3 BaTiO ₃ 3.0 ○ 2.0 370.0 More than 3 hours Good 5 One 0.0 More than 3 hours Example 4 BaTiO ₃ 5.0 ○ 1.9 356.0 More than 3 hours Good 4 2 0.1 More than 3 hours Example 5 Rutile TiO ₂ 1.0 ◎ 2.0 362.0 More than 3 hours Good 3 5 0.8 More than 3 hours Example 6 Rutile TiO ₂ 5.0 ○ 2.1 374.0 More than 3 hours Good 4 2 0.2 More than 3 hours Comparative Example 1 - - △ 2.0 360.0 More than 3 hours Bad 2 12 4.5 More than 3 hours Comparative Example 2 - - △ 2.1 360.0 More than 3 hours Bad 2 10 4.3 More than 3 hours Comparative Example 3 Anatase
TiO ₂ 1.0 △ 1.9 362.0 More than 3 hours Bad 2 9 3.0 More than 3 hours Comparative Example 4 Anatase
TiO ₂ 1.0 △ 2.1 367.0 More than 3 hours Bad 2 10 3.2 More than 3 hours

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge of.

Claims (9)

In polypropylene short fibers, 95 to 99.7 wt% of homopolypropylene and 0.3 to 5 wt% of rutile TiO ₂ in the fiber, A hydrophobic polypropylene short fiber having a melt index of 4 to 30 g / 10 min, an isotactic index of 90% by weight or more, and a melting point of 160 to 165 ° C. measured by DSC. delete The method of claim 1, The hydrophobic polypropylene short fiber optionally further includes one or more additives selected from the group consisting of antioxidants, ultraviolet stabilizers, process stabilizers, and colorants including white pigments in the hydrophobic polypropylene short fibers. The method of claim 3, The additive is a hydrophobic polypropylene short fiber containing 0.1 to 1.5 parts by weight based on 100 parts by weight of hydrophobic polypropylene short fiber. In the method for producing polypropylene short fibers, Melting and spinning 95 to 99.7 wt% homopolypropylene and 0.3 to 5 wt% rutile TiO ₂ ; Stretching and crimping the stretched unstretched yarn and giving a crimp; Attaching a liquid resin containing a hydrophobic anti-emulsion emulsion to the surface of the crimped stretched yarn; And After heat-setting the stretched yarn, including the step of cutting into short fibers, The polypropylene short fiber has a melt index of 4 to 30g / 10min, an isotactic index of 90% by weight or more, and a melting point of 160 to 165 ° C as measured by DSC. delete The method of claim 5, The hydrophobic polypropylene short fiber manufacturing method further comprises optionally one or more additives selected from the group consisting of antioxidants, ultraviolet stabilizers, process stabilizers and white pigments in the hydrophobic polypropylene short fibers. The method of claim 7, wherein The additive is a hydrophobic polypropylene short fiber manufacturing method comprising 0.1 to 1.5 parts by weight based on 100 parts by weight of the mixture of blended homopolypropylene and BaTiO ₃ or rutile TiO ₂ . A hydrophobic polypropylene nonwoven made from the hydrophobic polypropylene short fibers according to any one of claims 1, 3 to 5, 7 and 8.