KR101306240B1 - Dope for spinning lyocell, lyocell filament fiber, and tire cord using the same - Google Patents

Abstract

The present invention is a lyocell spinning dope, lyocell filament fibers and tires comprising cellulose, silicone oil having a predetermined repeat structure, N-methylmorpholine-N-oxide (NMMO) and water It's about the code.

Since the lyocell spinning dope of the present invention includes silicone oil having a predetermined repeating structure, the lyocell spinning dope enables the provision of a lyocell filament fiber having high physical properties and a tire cord for high-speed driving.

Tire cord, lyocell, silicone oil

Description

DELOP FOR SPINNING LYOCELL, LYOCELL FILAMENT FIBER, AND TIRE CORD USING THE SAME

The present invention relates to lyocell spinning dope, lyocell filament fibers and tire cords comprising the same.

Generally used tire cord material is nylon, polyester, rayon and the like. These materials are limited in size and use, etc. of the tires used due to their advantages and disadvantages.

Nylon fiber has high tensile elongation and high strength, and is mainly used for tires used on curved roads such as heavy trucks and unpaved roads. However, the nylon fiber is not suitable for a tire for a passenger car in which concentrated heat accumulation occurs inside the tire, and a low modulus is used to travel at high speed or require a ride comfort.

Polyester fiber has better shape stability and price competitiveness than nylon, and strength and adhesion are improved due to continuous research, and its usage is increasing in the tire cord field. However, it is not suitable for high-speed running tires because of limitations in heat resistance and adhesive strength.

Rayon fiber, a regenerated cellulose fiber, exhibits excellent strength retention and shape stability at high temperatures. Therefore, rayon fiber is known as an optimal tire cord material. However, due to the strong deterioration due to moisture, thorough water management is required during tire manufacturing, and due to non-uniformity in yarn manufacturing, the rate of defective products is high. Above all, its price / performance ratio is very low compared to other materials, and it is mainly applied only to high speed or expensive tires.

Korean Unexamined Patent Publication No. 2002-0085188 discloses a tire cord using lyocell fibers having better health, wet strength and modulus than rayon fibers. However, the lyocell fiber has a disadvantage in that the strength decreases due to repeated fatigue due to a higher modulus and a lower cutting elongation than the conventional rayon fiber, and the life of the tire is reduced.

This requires the development of lyocell fibers with improved properties such as strength or elongation.

The present invention is to provide a lyocell spinning dope that can improve the spinning properties of lyocell filament fibers.

The present invention is also to provide a lyocell filament fiber having improved spinning properties and more improved physical properties.

The present invention also provides a tire cord including the lyocell filament fiber.

The present invention provides a lyocell spinning dope comprising cellulose, a lubricant, N-methylmorpholine-N-oxide (NMMO) and water.

The lubricant may be a silicone oil having a repeating structure of Formula 1 below:

[Formula 1]

-[SiR ₁ R ₂ -O]-

In Formula 1, R ₁ and R ₂ each independently represent alkyl having 1 to 5 carbon atoms, aryl having 6 to 20 carbon atoms, arylalkyl or alkylaryl.

The present invention also provides lyocell filament fibers comprising a lubricant in the fiber structure.

Such lyocell filament fibers can be made from the lyocell spinning dope.

In addition, the present invention comprises the steps of extrusion spinning the lyocell spinning dope through a spinning nozzle; Solidifying the extruded spun lyocell spinning dope to produce a multifilament; Washing the multifilament with water; And it provides a method for producing a lyocell filament fiber comprising the step of drying the washed multi-filament.

The present invention also provides a tire cord comprising the lyocell filament fibers.

Hereinafter, the present invention will be described in more detail.

The lyocell spinning dope according to the present invention includes cellulose, a lubricant, N-methylmorpholine-N-oxide (NMMO) and water.

The cellulose may be conventional in the art to which the present invention pertains, but in order to improve the physical properties of the fiber, an alpha-cellulose (α-cellulose) content may be used that is 96% by weight or more. In particular, Southern pine pulp with an alpha-cellulose content of 96% by weight can be used.

The lyocell spinning dope of the present invention may include 5 to 35% by weight of cellulose in consideration of spinning properties, and may also be included as 7 to 18% by weight.

As the lubricant, a silicone oil having a repeating structure of Chemical Formula 1 may be used, and the lubricant may improve spinning characteristics. Therefore, in the process of manufacturing a multi-filament by spinning a lyocell spinning dope comprising the same, to improve the spinning speed and to suppress the generation of waste in the spinning nozzle, the defect or breaking on the multi-filament You can prevent it. As a result, physical properties such as strength or elongation of the lyocell filament fibers manufactured using the lyocell spinning dope can be improved.

More specifically, as the lubricant, for example, a silane-based oil having a hydrophobic substituent may be used, and polydimethylsilane may be preferably used. Such silicone oils can improve spinning properties.

In addition, the silicone oil may have a weight average molecular weight of 150 to 50000. As the silicone oil has such a weight average molecular weight, it is possible to further improve the spinning speed of the lyocell spinning dope and to more effectively suppress the generation of waste in the spinning nozzle.

The lyocell spinning dope according to the present invention may further contain the lubricant in an amount of 0.05% by weight or more to further improve physical properties such as strength or elongation of the lyocell filament fibers to be manufactured, and further, 5 weights for maintaining the weaving properties. It may contain up to%.

In addition, the solvent included in the spinning dope of the present invention is a mixed solvent containing N-methylmorpholine-N-oxide (NMMO): water, the weight ratio of NMMO and water in the mixed solvent is the melting point of the solvent is raised or the manufacturing temperature The weight ratio of NMMO and water may be 93: 7 to 85:15 to prevent excessively high and at the same time to ensure the minimum solubility and swelling of the cellulose.

The spinning dope of the present invention is swelled after adding silicone oil and cellulose to a mixed solvent containing N-methylmorpholine-N-oxide (NMMO): water in a weight ratio of 90:10 to 50:50, followed by swelling. Prepared according to the process of removing water such that the weight ratio of Pauline-N-oxide (NMMO): water is 93: 7 to 85:15 and the final content of cellulose is 5 to 35% by weight, more preferably 7 to 18% by weight. Can be.

The lyocell filament fiber of the present invention comprises the steps of extrusion spinning the spinning dope through a spinning nozzle; Solidifying the extruded spun lyocell spinning dope to produce a multifilament; Washing the multifilament with water; And it can be prepared according to the manufacturing method comprising the step of drying the washed multifilament. In this manufacturing process, as the spinning dope includes the silicone oil described above, the generation of waste generated in the spinning nozzle is suppressed and the spinning speed is improved. Accordingly, since defects or breaks may be prevented from occurring on the multifilament, the lyocell filament fiber manufactured through the above manufacturing method may exhibit improved properties such as strength or elongation.

In the above manufacturing method, the extrusion spinning temperature can be maintained at 70 to 130 ℃.

Solidification of the spun filament is carried out in a coagulation bath, the coagulation temperature may be 45 ℃ or less. This means that the solidification temperature is 45 ° C. or lower so that the temperature is not too high than necessary so that the solidification rate is properly maintained. Here, the coagulation bath is not particularly limited because it can be prepared and used in a conventional composition in the art.

Subsequently, the prepared multifilament is washed with water and dried.

According to the present invention, in consideration of the ease of recovery and reuse of the solvent after washing, the washing temperature in the step of washing and drying may be 35 ℃ or less, the drying temperature may be 100 ℃ to 200 ℃. Here, the water washing and drying may use the usual conditions in the technical field to which the present invention belongs, and are not particularly limited by the above conditions.

On the other hand, the present invention provides a lyocell filament fiber comprising a lubricant in the fiber structure. Such lyocell filament fibers may be prepared from the spinning dope described above and may comprise, for example, a lubricant in an amount of 5 to 500 ppm. The lyocell filament fibers may exhibit physical properties such as improved strength or elongation.

The present invention also provides a tire cord comprising the lyocell filament fibers.

An example of the manufacturing method of the tire cord is as follows. After the lyocell filament fibers prepared by the method described above are twisted with a twister to produce raw cords, weaving them with a weaving machine to immerse them in a dipping solution to produce tire cords. Can be. The manufacturing method of the tire cord is not limited to the above-described method, in addition, it may be manufactured using a manufacturing method commonly known in the art to which the present invention belongs.

The lyocell spinning dope of the present invention can improve the spinning speed of the lyocell filament fibers and suppress the occurrence of defects of the yarns, so that the lyocell filament fibers can exhibit improved properties such as strength or elongation.

Hereinafter, the configuration and effects of the present invention will be described in more detail with reference to specific examples and comparative examples in order to help understanding of the present invention. However, the following examples are only intended to more clearly understand the present invention, and are not limited to the following examples of the present invention.

 [ Example  And Comparative example ]

Example  One

The cellulose sheet (buckeye V-81) was put into a grinder equipped with a 100 mesh filter to prepare a cellulose powder having a diameter of 1700 μm or less.

The cellulose powder and polydimethylsilane (weight average molecular weight 400) were swollen in a 50 wt% NMMO aqueous solution. In this case, the content of cellulose in the NMMO aqueous solution was 6.5% by weight, and the content of polydimethylsilane was 3% by weight.

The swelled cellulose slurry was maintained at an internal temperature of 90 ° C. and injected into a kneader maintained at an absolute pressure of 50 mmHg at a rate of 16 kg / hour using a rotary valve pump, while 50% by weight of NMMO aqueous solution was 89% by weight of NMMO aqueous solution. After completely dissolving cellulose while removing excess moisture, the spinning dope was discharged through the discharge screw. At this time, the cellulose content of the discharged spinning dope was 11% by weight, the content of polydimethylsilane was 5% by weight, it was confirmed that the homogeneous state does not contain undissolved cellulose particles.

The cellulose dope was adjusted so that the final filament total fineness was 1,650 denier, and was spun using a nozzle having 1000 nozzles and a nozzle cross-sectional area of 0.047 mm 2. At this time, an air layer was placed between the nozzle and the coagulation bath.

The multifilament yarns discharged and solidified were completely removed with NMMO by washing water, and dried on a drying roll to obtain lyocell filament fibers. At this time, the temperature of each drying roll was adjusted to 100 degreeC, 130 degreeC, and 150 degreeC.

Example  2

A lyocell filament fiber was prepared in the same manner as in Example 1 except that a spinning dope was used so that the content of the final polydimethylsilane (weight average molecular weight 1000) was 3% by weight.

Example  3

A lyocell filament fiber was manufactured in the same manner as in Example 1, except that spinning dope was used so that the content of the final polydimethylsilane (weight average molecular weight 10000) was 1% by weight.

Example  4

A lyocell filament fiber was prepared in the same manner as in Example 1 except that spinning dope was used so that the content of the final polydimethylsilane (weight average molecular weight 50000) was 0.05% by weight.

Comparative example  One

The lyocell filament fibers were prepared in the same manner as in Example 1 except that no polydimethylsilane was added at the time of dope preparation.

The lyocell filament fibers manufactured by the process of Examples 1 to 4 have a good lubrication property in the spinneret when the dope is manufactured, so that there is little scratch or damage on the surface of the yarn, and no trimming occurs. The lyocell filament fiber produced by the process according to Example 1 was found to have some trimming in the spinneret and to damage the surface of the fiber produced.

The lyocell spinning dope according to the present invention improves the spinning speed and decreases the defective rate of lyocell filament fibers, and enables the production of lyocell filament fibers with improved strength and elongation, thereby enabling high-speed running tire cords. It is a useful technique to make it.

Claims (10)

Lyocell spinning dope comprising cellulose, silicone oil including a silicone polymer having a repeating structure of Formula 1, a lubricant, N-methylmorpholine-N-oxide (NMMO) and water : [Formula 1] -[SiR ₁ R ₂ -O]- In Formula 1, R ₁ and R ₂ each independently represent alkyl having 1 to 5 carbon atoms, aryl having 6 to 20 carbon atoms, arylalkyl or alkylaryl. delete The method of claim 1, The silicone oil is a lyocell spinning dope having a weight average molecular weight of 150 to 50000. The method of claim 1, 5 to 35% by weight of the cellulose, 0.05 to 5 weight percent of the lubricant, and Residual amount of NMMO solution containing the NMMO and water in a weight ratio of 93: 7 to 85:15 The lyocell spinning dope comprising a. The lyocell spinning dope of claim 1, wherein the cellulose comprises at least 96% by weight of alpha-cellulose. A lyocell filament fiber comprising in the fiber structure a lubricant of a silicone oil comprising a silicone polymer having a repeating structure of formula (I):  [Formula 1] -[SiR ₁ R ₂ -O]- In Formula 1, R ₁ and R ₂ each independently represent alkyl having 1 to 5 carbon atoms, aryl having 6 to 20 carbon atoms, arylalkyl or alkylaryl. The lyocell filament fiber of claim 6, wherein the lubricant has a content of 5 to 500 ppm. delete Extruding the lyocell spinning dope according to claim 1 through a spinning nozzle; Solidifying the extruded spun lyocell spinning dope to produce a multifilament; Washing the multifilament with water; And Method for producing a lyocell filament fiber comprising the step of drying the washed multi-filament. A tire cord comprising lyocell filament fibers according to claim 6.