KR20190023414A - Insulating Paper Containing Polyphenylene Sulfide Conjugated Fiber - Google Patents

Abstract

The present invention relates to an insulating paper comprising a polyphenylene sulfide composite fiber with high heat resistance and excellent mechanical properties and, more specifically, to an insulating paper comprising a polyphenylene sulfide composite fiber produced by sheath-core composite spinning. The polyphenylene sulfide composite fiber is a sheath-core composite fiber, a sheath part consists of polyphenylene sulfide resins, and a core part is composed by any one of a polyester-based compound, a polyamide-based compound, a polyolefin-based compound or a vinyl-based compound.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyphenylene sulfide conjugated fiber,

TECHNICAL FIELD The present invention relates to an insulating paper containing polyphenylene sulfide conjugated fiber, more particularly, to an insulating paper including polyphenylene sulfide conjugated fiber having excellent mechanical properties at a high temperature and excellent insulating properties .

Generally, in case of winding transformer, high-efficiency motor, starting motor for automobile, HVT for microwave oven, insulation tape, etc., insulation paper with excellent mechanical strength and excellent electrical properties is used.

Generally, cellulose fibers are used as insulating fibers and have excellent form stability and high mechanical properties. However, due to the influence of heat, oxygen and moisture, cellulose molecules are weakened with time, If it is used for a long time at a temperature of 120 ° C or higher, gas and water may be generated, which may lower the service life of the used equipment.

In particular, insulating paper used for insulating tapes is superior in heat resistance at high temperatures, while securing mechanical properties such as dimensional stability, and is mainly used for industrial equipment, so that the material that is originally made of black is apparently advantageous.

Although the meta-aramid (m-aramid) can be used as the black material, it can be considered that the addition of the black masterbatch (Black M / B) based on polyphenylene sulfide is generally high .

However, polyphenylene sulfide having a simple structure is highly expensive due to a high rate of defective spinning, and it is also difficult to prepare a black master batch to be added to polyphenylene sulfide.

Techniques for improving the processability of polyphenylene sulfide include a technique for producing polyphenylene sulfide multifilaments by applying a high temperature air or an inert gas under a spinneret and then conducting a stretching process DE-A-4006397, Japanese Patent Application Laid-Open No. 1991-168750, which discloses a technique for blowing air flow of 45 占 폚 or more to a radiated PPS fiber followed by heat stretching through a heated region, and polyphenylene sulfide (Polyphenylene sulfide) resin is melted at a temperature of 310 to 340 DEG C and continuously spinned through a hole having a diameter of 0.1 to 0.5 mm in the spinneret to produce a multifilament, which is sealed by a heat insulating tube or a heating tube Japanese Unexamined Patent Publication (Kokai) No. Hei 10-241685 (hereinafter, referred to as Japanese Patent Application Laid-open 1990-219475.

The above techniques have a meaning that the filter characteristics are improved by introducing PPS fiber into a dust filter requiring heat resistance. However, since the cooling and cooling failure when the molten polymer is continuously passed through the spinneret, I have.

On the other hand, as a technique for lowering the manufacturing cost of the PPS fiber, there is a technique of using a polyphenylene sulfide resin as a sheath portion and a relatively low cost polyester resin as a core portion through a composite spinning of a PPS resin Korean Patent Laid-Open Publication No. 10-1992-0012561. However, when it is produced by the above-mentioned technique, the polyester part which is vulnerable to high temperature and high humidity environment easily hydrolyzes and durability of the final product is lowered.

Therefore, there is a need to provide a method of using polyphenylene sulfide fiber as an insulating paper, which can preserve the superior characteristics of polyphenylene sulfide fiber while also having excellent spinnability and thus reducing manufacturing costs. have.

It is an object of the present invention to provide an insulating paper comprising polyphenylene sulfide conjugated fiber having high heat resistance and excellent mechanical properties.

It is another object of the present invention to provide an insulating paper containing polyphenylene sulfide conjugated fiber, which can improve process defects of polyphenylene sulfide singly-spun fibers and reduce manufacturing costs.

In order to solve the above problems, the present invention provides an insulating paper comprising polyphenylene sulfide composite fiber, wherein the polyphenylene sulfide conjugate fiber is a sheath core composite fiber, and the sheath portion is a polyphenylene sulfide resin And the core portion is provided with an insulating paper containing polyphenylene sulfide composite fiber made of a cis-core composite yarn which can be composed of any one of a polyester-based, polyamide-based, polyolefin-based or vinyl-based compound.

In addition, the present invention provides an insulating paper comprising polyphenylene sulfide composite fiber, characterized in that the polyphenylene sulfide composite fiber comprises 50 to 90% by weight of the polyphenylene sulfide composite fiber.

Also, the polyphenylene sulfide composite fiber according to the present invention is characterized in that the polyphenylene sulfide composite fiber has a fineness of 0.3 to 5 denier and a length of 2 mm to 15 mm.

Also, the present invention provides an insulating paper comprising a polyphenylene sulfide composite fiber characterized in that the master batch to be added to the core portion is composed of 0.5 to 5 parts by weight with respect to 100 parts by weight of the core portion.

Also, the present invention provides an insulating paper comprising polyphenylene sulfide composite fibers characterized in that the sheath occupies an area of 50 to 70% of the total cross-sectional area of the composite fibers and 30 to 50% of the total area of the composite fibers do.

The present invention also relates to a polyphenylene sulfide composite characterized in that the compound of the core part has an intrinsic viscosity of 0.40 to 0.80 dl / g and a black master batch (Black M / B) to be added has a carbon content of 10 to 50% Provides insulating paper including fibers.

The present invention is an insulating paper containing polyphenylene sulfide conjugated fiber and has an excellent heat resistance and excellent insulating property.

In addition, polyphenylene sulfide conjugated fiber, which is a constituent of the present invention, is a conjugated fiber using a resin having excellent melt flow index such as polyphenylene sulfide in the sheath portion and polyester in the core portion. This has an excellent effect.

Also, the polyphenylene sulfide composite fiber, which is a constituent of the present invention, has an effect of improving the process defects of the single spun fibers and reducing the manufacturing cost.

Further, the polyphenylene sulfide composite fiber of the present invention is characterized by high gloss properties of cis-polyphenylene sulfide and easiness of coloring using a core part.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

As used herein, the terms "substantially", "substantially", and the like are used herein to refer to a value in or near the numerical value when presenting manufacturing and material tolerances inherent in the meanings mentioned, Absolute numbers are used to prevent unauthorized exploitation by unauthorized intruders of the mentioned disclosure.

The present invention relates to an insulating paper containing polyphenylene sulfide composite fibers.

First, the polyphenylene sulfide conjugated fiber is a sheath core conjugate fiber, and the sheath portion is made of polyphenylene sulfide resin, and the core portion is made of any one of polyester, polyamide, polyolefin, ≪ / RTI >

The core portion may further comprise a black master batch (Black M / B) in any one of a polyester series, a polyamide series, a polyolefin series or a vinyl series compound.

Polyphenylene sulfide may be caused by defective solidification which may occur when the polyphenylene sulfide is spun alone and defective crimp development may occur during the stretching process. Thus, a polyamide-based, polyolefin-based or vinyl-based compound ≪ / RTI > is advantageous in the spinning process.

Any one of the polyester-based, polyamide-based, polyolefin-based or vinyl-based compound used in the core part has an intrinsic viscosity in the range of 0.40 to 0.80 dl / g, preferably in the range of 0.55 to 0.65 dl / g It is good. If the intrinsic viscosity of the core part compound is less than 0.40 dl / g, not only the strength of the fiber is remarkably lowered but also the shrinkage rate is difficult to control. When the intrinsic viscosity is more than 0.80 dl / g, And thus increases the cost of raw materials.

The polyphenylene sulfide resin is a crystalline engineering plastic having the following chemical structure and has high heat resistance and excellent mechanical properties, chemical resistance, electrical characteristics and dimensional stability. Examples of applications include electric and electronic parts, automobile parts, and machine parts.

The polyphenylene sulfide resin may be a linear, crosslinked or semi-crosslinked polymer but preferably linear, having an intrinsic viscosity of 0.1-10 dl / g and a weight average molecular weight (Mw) of 2,000 to 8,000 , And a melt flow index (Melt Flow index) of 20 to 150 g / 10 min.

Also, when the polyphenylene sulfide is used as an insulating paper of an insulating tape using mechanical and thermal durability, which is the above-described characteristic of polyphenylene sulfide, black coloring is advantageous, and when a method of adding a coloring agent before the spinning process is used, Excellent in fastness. The process is mainly used for expressing basic index black, indigo, and brown.

The black masterbatch may be composed of 0.5 to 5 parts by weight with respect to 100 parts by weight of the core part, and the black masterbatch (Black M / B) may have a carbon content of 10 to 50 By weight.

If the amount is less than 0.5 parts by weight based on the weight of the core part, color development may be a problem. If the amount is more than 5 parts by weight, carbon particles may interfere with fiber formation, which may cause problems in spinning processability.

In addition, the polyester in the core part may generate a carboxylic acid due to a hydrolysis reaction in which an ester group contained in the main chain of the polymer reacts with water, and the polymer main chain may be destroyed. The reaction formula is as shown in the following formula (1). This reaction is generated in a chain by the pumped carboxylic acid and causes a decrease in the fiber strength as a whole.

[Chemical Formula 1]

Therefore, in order to prevent the hydrolysis reaction of the core portion, the polyester of the core portion contains hydrolyzable additives in the master batch state. The hydrolysis-resistant additive is a polyester-based carbodiimide-based, phenol-based, or oxazoline-based compound and is contained in a weight ratio of 5 to 20.

The hydrolysis-resistant additive carbodiimide-based compound removes from the ester group of the polyester compound of the core part the carboxylic acid hydrolyzed with the hydrolyzed carboxylic acid in a preferential urea reaction to remove the carboxylic acid causing the chain reaction, and at the same time, And the reaction formula thereof is as shown in the following formula (2).

(2)

Generally, the carbodiimide-based compound is generically referred to as a compound containing a structure represented by the following formula (3) in the molecule.

(3)

 -N = C = N-

The carbodiimide compound preferably has at least 1 to 1000 structures represented by the formula (3), more preferably 1 to 100 structures represented by the formula (3) It is more preferable that the structure includes 1 to 10 structures in the molecule.

In this case, if the number of carbodiimide groups represented by the formula (3) exceeds 1,000 in one molecule, the intrinsic viscosity of the starting material is too large, the molecular weight is excessively large, There arises a problem that the efficiency of a molecule having a carbodiimide group becomes too large to cover a portion showing a functional effect of a molecule having a substantial function.

In the present invention, a specific example of the carbodiimide compound may be a compound represented by the following general formula (4), and in the following general formula (4), the compound wherein n is 4 and m is 11 is benzene, 1,3, Isocyanato-1-methylethyl) -, homopolymer, polyethylene glycol mono-ether-block (benzene, 1-isocyanato- Me-ether-blocked (hereinafter referred to as polymeric carbodiimide compound of formula (4)).

[Chemical Formula 4]

In Formula 4, n is from 1 to 100, and m is from 1 to 100.

Another example of the carbodiimide compound in the present invention is 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide as a compound represented by the following formula (5) carbodiimide or 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide.HCl may be used.

[Chemical Formula 5]

The hydrolysis-resistant compound preferably contains 5 to 20 parts by weight of the core part and more preferably has an intrinsic viscosity in the range of 0.55 to 0.95 dl / g.

The core portion preferably occupies 30 to 50% of the total cross-sectional area of the composite fiber. If the cross-sectional area of the core portion is more than 50%, the core portion may be eccentrically biased to one side on the fiber, or the core portion may protrude to the fiber surface during the spinning process (or post process) Chemical properties are deteriorated,

 If the area is less than 30%, the core part is hardly positioned on the central axis of the fiber during spinning, and thus the radiation processability and the manufacturing cost reduction effect are lowered.

In addition, the thickness of the sheath is important for the external expression using the super bright characteristic of black sheath polyphenylene sulfide in the core part, and when the sheath area is 70% or more, It may not be expressed.

Other types of polymers can be applied to the polyester within the scope of not impairing the effect of the present invention. Examples of the substitutable polymer include a polyamide-based, polyolefin-based, and vinyl-based polymer, and these polymers may also occupy 30 to 50% of the total area of the core.

The complex spinning process conditions for producing the conjugate fiber using the polyphenylene sulfide and polyester of the present invention may be selected from known techniques known to those skilled in the art, but preferably, a distribution plate for supplying the polymer of the core portion It is advisable to use a composite spinneret in the form of a pin or without a pin, and it is preferable to make it into a short fiber form after stretching and heat setting by heating heat treatment. Further, the sheath-core conjugate fiber of the present invention is preferably arranged in a forward sheath-core structure.

The polyphenylene sulfide composite fiber of the present invention has a fineness of 0.3 to 5 deniers and a length of 2 mm to 15 mm.

If the fineness is too low, the spinnability is deteriorated and the defect rate is increased. If the fineness is too high, there is a danger of deterioration, and the fiber length should be a suitable length which is easy to disperse in water.

The method for producing insulating paper according to the present invention is as follows.

50 to 90% by weight of the polyphenylene sulfide-coated fiber is added to a dispersion containing 1 to 3% by weight of a polyethylene oxide or polyacrylamide dispersant, and 10 to 50% Dispersed in individual fibers in water to form a web.

The web produced through the above process is subjected to a web bonding process through at least one method selected from the group consisting of hydrogen bonding, thermal bonding bonding, PVA binder bonding, latex bonding, and spun lace bonding.

Thereafter, calendering is performed at a temperature of 150 to 200 ° C. and a pressure of 1500 to 2500 kg / cm ² for controlling the pore and thickness of the laminating and papermaking to improve the smoothness of the manufactured web, In this process, mutual entanglements can be increased to improve the glossiness. In addition, an additive may be added to adjust appropriate bonding force, smoothness, whiteness and the like, and there is no limitation in the present invention.

Thus, an insulating paper containing the polyphenylene sulfide conjugated fiber according to the present invention can be produced.

Hereinafter, the present invention will be described by way of examples. The following examples are intended only for a better understanding of the present invention and are not intended to limit the scope of protection of the present invention.

Example  One

A sheath portion was formed of polyphenylene sulfide having an intrinsic viscosity of 0.2 dl / g, and a core portion was formed of polyester (PET) having an intrinsic viscosity of 0.64 dl / g. A polyester black master batch (PET Black M / B) having a carbon black content of 25% by weight was prepared by a master batch method with a cross sectional area ratio of the sheath portion and the core portion of 50/50 to the total area of the composite fibers Was added in a proportion of 2 parts by weight based on 100 parts by weight of the core part. The spinning temperature was 290 캜 and the spinning speed was 800 m / min. The unstretched fiber was prepared and the stretching magnification was set at 3.6 to prepare a polyphenylene sulfide composite fiber having a fineness of 1 Da and a fiber length of 6 mm.

50% by weight of the polyphenylene sulfide conjugated fiber and 50% by weight of the natural pulp fiber were mixed and stirred with water using a papermaking method, and the paper was papermaking at an initial stage of 25 x 25 cm based on TAPPI standard pulp paper Dried (110 ° C) using a drum dryer, and then formed into a basis weight of 100 g / m ² .

Example 2

The polyphenylene sulfide composite fiber was prepared by spinning and stretching under the same conditions as in Example 1 to prepare a conjugate fiber, wherein 80 wt% of the polyphenylene sulfide conjugated fiber and 20 wt% of the natural pulp fiber were mixed and stirred in the production of insulating paper, Are the same as those in the first embodiment.

Comparative Example 1

Polyphenylene sulfide having an intrinsic viscosity of 0.2 dl / g was prepared singly to prepare a polyester black master batch (PET Black M / B) having a carbon black content of 25 wt% ) Was added at a ratio of 2 parts by weight based on 100 parts by weight of the fibers. The spinning temperature was 295 캜 and the spinning speed was 800 m / min. The unstretched fiber was prepared and the stretching magnification was set at 3.6 to produce a polyphenylene sulfide single fiber having a fineness of 1 Da 'and a fiber length of 6 mm.

50% by weight of the polyphenylene sulfide sole fiber and 50% by weight of the natural pulp fiber were mixed and stirred in the production of insulating paper.

Comparative Example 2

100% of the natural pulp fiber was stirred and the subsequent process was the same as in Example 1.

In the following Examples and Comparative Examples, physical properties were measured as follows.

*How to measure

1. Radial fairness

The single yarn phenomenon occurring during spinning, that is, yarn breakage, was measured for 24 hours and compared with the number of occurrences per hour. Poor status display due to fairness △ Normal ◎ Good ◎

2. Fiber strength

Measured by KS K 0860 method

3. Strength retention

High Temperature / High Humidity To determine the strength of the fiber under moisture conditions, we compared the strength of the fibers tested at 85 ℃ and 85% relative humidity for 4 weeks and the strength of the initially measured fiber.

4. Colorimetry (brightness: L)

Using a colorimeter. Measurements were made three times each and averaged.

The colorimetric values are shown in the CIE L / a / b colorimetric system

L represents the brightness of the color (White to Black). If the L value is 100, it means pure white. If the L value is 0, it indicates pure black.

5. Tensile strength measurement

Insulating paper was prepared according to the test method for electrical cellulose paper (KS C IEC 60554-2) and measured at a tensile speed of 250 mm / min using a tensile tester specified in KS M ISO 1924-2.

6. Measurement of dielectric strength

The dielectric strength of the insulating paper was measured according to ASTM D149 97A

unit Example 1 Example 2 Comparative Example 1 Comparative Example 2 pps fiber
Properties Radiation fairness ◎ ◎ △ - burglar g / h 5.1 5.1 5.0 - Strength retention rate % 91.2 91.2 99.2 - Insulating paper
Properties Colorimetry 20.2 20.2 18.2 - The tensile strength N / cm 45.1 40.2 38.4 51.2 Dielectric strength kV / mm 24.2 35.2 25.4 9.8

It can be seen from Table 1 that the composite fibers of the present invention including the polyester black masterbatch (PET Black M / B) in particular have excellent mechanical properties as spinning processability and insulating paper material.

Also, in Example 1, the strength and the colorimetric L value are comparable to each other in comparison with the comparative example, so that there is no significant difference.

Further, in Example 2, as the polyphenylene sulfide content is increased, the tensile strength is somewhat reduced, but the dielectric strength is excellent.

In addition, in Comparative Example 1, it can be confirmed that there is a problem in the radiation fairness due to the PPS single spinning.

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 (6)

An insulating paper comprising polyphenylene sulfide composite fibers,
The polyphenylene sulfide conjugate fiber is a sheath core conjugate fiber,
Wherein the sheath portion is composed of a polyphenylene sulfide resin,
Wherein the core portion comprises a polyphenylene sulfide conjugate fiber produced from a cis-core conjugate fiber which can be composed of any one of a polyester-based, polyamide-based, polyolefin-based or vinyl-based compound.
The method according to claim 1,
Wherein the insulating paper including the polyphenylene sulfide composite fiber is characterized in that the polyphenylene sulfide composite fiber accounts for 50 to 90% by weight of the polyphenylene sulfide composite fiber.
3. The method of claim 2,
Wherein the polyphenylene sulfide composite fiber has a fineness of 0.3 to 5 deniers and a length of 2 mm to 15 mm.
The method according to claim 1,
Characterized in that the master batch to be added to the core portion is composed of 0.5 to 5 parts by weight based on 100 parts by weight of the core portion.
The method according to claim 1,
Wherein the sheath portion occupies 50 to 70% of the total cross-sectional area of the composite fiber, and the core portion occupies an area of 30 to 50% of the total area of the composite fiber.
The method according to claim 1,
Wherein the compound of the core part has an intrinsic viscosity of 0.40 to 0.80 dl / g and a black master batch (Black M / B) to be added has a carbon content of 10 to 50 wt% .