KR0160466B1 - Method of manufacturing ultra fine fiber - Google Patents

Abstract

The present invention provides a method for producing ultra-fine fibers by mixing and spun three kinds of polymers having different solubility in a specific organic solvent, wherein a third component of the conventional method for preparing ultra-fine fibers using a mixed spinning method is added. The interfacial tension can be lowered by mixing and spun three kinds of polymers, so it is not necessary to manufacture under high shear rate, thereby reducing die swell in spinning die and improving spinning property. It can be used as a material for high quality artificial leather

Description

Method for producing multicomponent ultrafine fibers by mixed spinning

1 is a cross-sectional view of a fiber made in the prior art.

2 is a cross-sectional view of the fiber produced by the present invention.

* Explanation of symbols for the main parts of the drawings

1: nylon 6 2: polyethylene

3: polypropylene

The present invention relates to a method for producing ultra-fine fibers by mixed spinning three kinds of polymers having different solubility in a specific organic solvent.

Methods for producing ultrafine fibers using two-component polymers that are incompatible with each other and have different solubility in specific organic solvents include mixed spinning and island-in-the-sea composite spinning.

Of these, the ultra-fine fibers produced by the mixed spinning method have a disadvantage in that the physical properties are not uniform when compared with the island-in-the-sea composite spinning method, but the manufacturing cost is low due to the simple spinneret device, and the fibers having extremely small fineness of about 0.0001 to 0.05 denier It has been used as a material of high-grade artificial leather and the spinning method is introduced in Japanese Patent Laid-Open No. 41-18892, Japanese Patent Laid-Open No. 55-90619, US Patent No. 3,099,067, US Patent No. 3,382,305, and the like.

As such, when two different polymer materials are mixed and melt-spun, there is no compatibility between the two polymers, which results in radiation instability, lowered radioactivity, uneven physical properties of the spun fiber, and lowered stretchability.

In particular, the surface tension and solubility parameter values of solids, which are inherent to the polymers that determine the compatibility of the mixed system when polyamide or polyester and polyethylene are mixed and spun, have a large difference. Mixing system with a large difference of is difficult to be in a good mixed state, and even if it is in a good mixed state, it is difficult to maintain the continuous stability of such a state, so that the phase change between the fibril component and the matrix component occurs, There is a problem in that the radioactivity is very unstable, such as trimming occurs.

In addition, when used as a material of artificial leather, fibril fineness is required to exhibit a texture and characteristic similar to that of natural leather.In order to refine the fineness of fibril, the difference in melting viscosity between fibril and matrix components must be increased. There is a problem of spinning at high shear rates.

In other words, in the conventional method as described above, the reason for increasing the melt viscosity difference of the two polymers and spinning at a high shear rate is for the fineness of fibril, which is explained by the following equation (1).

As shown in Equation (1), the method of increasing the shear rate, which is a conventional spinning method, enables the fineness of fibrils, but has a relatively high viscosity fibril particle when the shear rate is higher than a certain level. These fluids lose their fluidity rapidly, and fibril components are deposited around the spinneret. When the spinning is performed for a long time, the amount of fibril particles deposited is significantly increased, and finally, the thread is interrupted by interrupting the flow of the polymer mixture system. Deteriorates spinning workability.

In addition, the method of increasing the melt viscosity difference, that is, reducing the melt viscosity of the matrix compared to the melt viscosity of the fibrill component also makes fibril finer, but lowering the melt viscosity of the matrix component has its limitations. Another method, namely, a method of increasing the melt viscosity of a fibrill component to increase the melt viscosity difference, increases the viscosity of the entire polymer mixture system, and thus reduces the roundness of the fibrill component particles, making fine fineness impossible. As described above, when the viscosity of the mixed system is increased, it becomes impossible to manufacture ultrafine fibers such as a layered structure.

In order to solve this problem, the present inventors studied a method of lowering interfacial tension in a polymer blending system, and in conclusion, developed a method of manufacturing ultra-fine fibers by mixing and spunting three kinds of polymers by adding a third component. Was done.

Hereinafter, the present invention will be described in detail.

The interfacial tension of the mixed system is determined by the surface tension and the constants, which are inherent in the polymers of the components forming the mixed system. The present invention provides an interface of the mixed system by adding a polymer of a third component to improve compatibility. By reducing the tension, fibril fineness is induced.

That is, the fineness of the fibrils was made possible by adding a third component having a median value of the surface tension and the solubility constant of the fibrill component and the matrix component, and having a good spinning ratio, as an example, polypropylene. There is an advantage in that ultrafine fibers can be produced without increasing the shear rate or the difference in melt viscosity between the fibril component and the matrix component.

In the present invention, as the fibrill component, polyamides such as nylon 6 and nylon 66, and polyesters such as polyethylene terephthalate and polybutylene terephthalate are used, and the matrix component has a melt index of 20 to 100. An olefin polymer such as low density polyethylene is applied, and polypropylene is used as a preferred example in which the melt index is 10 to 70 as a third component added to improve compatibility.

In this case, the mixing ratio of polypropylene is 2 to 20% by weight, and if it is less than 2% by weight, there is no effect of improving the compatibility. If it exceeds 20% by weight, the fibril fineness is too small. It remains with the components, causing a problem of deterioration of physical properties.

In addition, the weight combination ratio of the fibril component is 30 to 60% by weight, and the weight combination ratio of the matrix component is 40 to 70% by weight.

In the manufacture of ultra-fine fibers according to the present invention, by adding a third component in addition to the fibrill component and the matrix component, the compatibility between the fibril component and the matrix component is increased to make the mixing state of the mixing system uniform and the uniform mixing thereof. Since the state is very stable, even if the composition of the fibril component is increased, there is an effect of improving radioactivity such that no phase transition occurs.

In addition, as described in Equation (1), the interfacial tension can be lowered, so that the fibril component particles in the mixed system become smaller, and thus, particularly fine microfibers can be manufactured. The die swell is reduced and the radiation is also improved.

In addition, since the mixed state of each polymer of the mixed system is uniform, it has the advantage that it can be used as a material of high-quality artificial leather of good quality after the production of ultra-fine yarn.

Therefore, the production of ultra-fine fibers by the method of the present invention can lead to improved radioactivity and uniformity of the physical properties of the fibers.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

Example 1

The conventional mixed spinning method combines nylon 6 having a relative viscosity of 2.8 to 98% sulfuric acid, low density polyethylene having a melt index 70, and polypropylene having a melt index 45 at a weight ratio of 47.5: 47.5: 5 to obtain a diameter of 0.25 mm at 265 ° C. After spinning through the spinneret with excitation, it was wound up to 1000m / min and calculated as the draw ratio 2.6.

Example 2

It is the same as Example 1 except the weight ratio of nylon 6, low density polyethylene, and polypropylene is 49: 49: 2.

Example 3

Nylon 6 having a relative viscosity of 3.03 to 98% sulfuric acid was used and the same as in Example 1 except that the spinning temperature is 280 ℃.

Example 4

Nylon 6 with a relative viscosity of 3.03 to 98% sulfuric acid was used and the same as in Example 2 except that the spinning temperature is 280 ℃.

Comparative Example 1

The same procedure as in Example 1 was performed except that nylon 6 having a relative viscosity of 98% sulfuric acid and a low density polyethylene having a melt index 70 were adjusted to a weight ratio of 50:50.

Comparative Example 2

It is the same as Comparative Example 1 except that nylon 6 having a relative viscosity of 3.03 to 98% sulfuric acid is used and the spinning temperature is 280 ° C.

As a result of performing as described above, in the case of Comparative Example 2, the production of ultra-fine fibers was impossible due to the impossibility of winding operation, but in the case of Example 3 and Example 4, in which 2 to 5% by weight of polypropylene was added in the same manner as in Comparative Example 2 And stretching was possible.

In the case of Comparative Example 1, although winding and stretching were possible, the distribution of fibril fineness in the matrix had a non-uniform problem as shown in FIG. 1, and thus the physical properties also showed a large difference in a short time. However, in the case of Example 1 or Example 2, the degree of fineness distribution of fibrils in the matrix is very uniform, as shown in FIG. 2, and the fineness of each fibrils has a small advantage compared to Comparative Example 1. In addition, in the case of Comparative Example 1, the 5% strength value is 160-180g, whereas in Examples 1 and 2, it is 200-220g, which is high, indicating that the fiber withstands external deformation. The higher the value, the more advantageous the process for making artificial leather.

Claims (3)

In a method of mixing and spinning a polymer having different solubility in a specific organic solvent as a fibrill component and a matrix component, the method has a roughly intermediate value of the surface tension and the solubility constant of the fibril component and the matrix component and has excellent radioactivity. Method for producing a multicomponent ultra-fine fiber characterized in that the mixture is spun by adding a third component. The method of claim 1, wherein polyamide or polyester is used as the fibrill component, low density polyethylene having a Melt Index of 20 to 100 is used as the matrix component, and the third component that improves compatibility is melt. A method for producing multicomponent ultrafine fibers by mixed spinning, characterized in that polypropylene having an index of 10 to 70 is used. The weight combination ratio of the fibril component is 30 to 60% by weight, the weight combination ratio of the matrix component is 40 to 70% by weight, and the weight combination ratio of the third component is 2 to 20% by weight. A method for producing a multicomponent ultrafine fiber by a mixed spinning method, characterized in that.