UA9236U - Method to obtain complex thread on the basis of ultra-thin polyolefin fiber - Google Patents

Abstract

A method to obtain complex thread on the basis of ultra-thin polyolefin fiber through mixing the fiber-forming polymer, matrix one and compatibilizer in the melt, with formation of composite thread, thermo-orientation stretching thereof and extraction of the matrix polymer. Preliminarily one mixes in the melt the fiber-forming polymer and the compatibilizer, this is a siloxane liquid and is introduced in amount of 0.1û1.5 mass %.

Description

Description of the invention

The useful model refers to the technology of forming ultra-thin synthetic fibers (microfibers) 2 by processing melts of polymer mixtures. It can be used to create consumer goods with a given set of properties: fabrics, knitwear, artificial suede, etc.

There is a known method of obtaining complex threads based on ultra-thin polypropylene (PP) fibers, which consists in mixing fiber-forming, matrix polymers and a compatibilizer in a melt, forming composite threads, their thermal orientation drawing and extraction of the matrix polymer (Chemical fibers, 70 2002, Mo4, p. 25 -31). Mixing of all components of the mixture is carried out simultaneously. The number of compatibilizers is 3-5% by weight. A copolymer of ethylene with vinyl acetate (SEVA) or sodium oleate is used as compatibilizers. Simultaneous mixing of all components in the melt, with a very low content of additives, does not provide the necessary homogeneity. Previously proposed compatibilizers do not have a surface effect. They improve the process of fiber formation, but cannot increase the resistance of threads to abrasion. According to this 79 method, fibers with a non-smooth surface structure are obtained: each microfiber is covered over the entire surface with ultra-thin microfibrils. The presence of the latter reduces the resistance to abrasion of complex threads based on microfibers in comparison with threads formed by traditional technology.

The useful model is based on the task of creating such a method of obtaining complex threads based on ultrafine polyolefin (PO) fibers, in which, by introducing a new operation and choosing a new compatibilizer, it would be ensured to obtain complex threads from ultrathin PO fibers with high resistance to abrasion, thanks to which the expansion would the raw material base of the textile industry and the range of consumer goods.

The problem is solved by the fact that in the method of obtaining complex threads based on ultra-thin polyolefin fibers, in which by mixing fiber-forming, matrix polymers and compatibilizer in the melt, the formation of composite threads, their thermal orientation drawing and in the extraction of the matrix polymer, according to a useful model, pre-mix in the melt fiber-forming polymer with a compatibilizer, which is a siloxane liquid and is introduced in the amount of 0.1-1.5 wt.oo.

The introduction of the operation of mixing the fiber-forming polymer and the additive of siloxane liquid allows to obtain complex threads that can withstand 2.6-10.1 times more cycles before abrasion, as well as to reduce the average diameter of ultrafine fibers in the complex thread, increase their number and uniformity in transverse dimensions, thanks to which the mechanical properties of complex threads made of microfibers and combined yarn are also improved, which expands the raw material base of the textile industry and the range of consumer goods. 3o The essence of the proposed useful model is that due to the introduction of the pre-mixing operation, the siloxane liquid is thinly dispersed and evenly placed in the fiber-forming polymer melt. Due to the fact that siloxane liquids are not compatible with most organic substances, being introduced into the composition even in the amount of 107795, they are pushed to the boundary of the phase separation of fiber-forming and matrix polymers, reduce the surface tension and surface energy at the interfacial surface, thereby contributing to the increase of 70 the degree of dispersion of the dispersed phase polymer and increasing the kinetic stability of the dispersion in the melt. c The latter makes it possible to reduce the average diameter of microfibers, increase their homogeneity in size and :c» reduce the number of other types of structures that impair the mechanical properties of complex threads (short fibers, particles, films). Siloxane liquids have a low surface tension, so they are distributed at the interface. After the matrix polymer is extracted from the composite thread with a solvent that is inert in relation to the fiber-forming polymer and the siloxane liquid, the latter remains on the surface of the microfibers and, as a good lubricant, reduces the coefficient of friction. The latter provides a sharp increase in the abrasion resistance of complex threads formed from mixtures of polymers containing siloxane liquids. In comparison with complex threads made of microfibers of the prototype, threads obtained by this method are characterized by a smaller average diameter and greater uniformity in transverse dimensions. Such a 4) 50 structure leads to improved mechanical properties, and the presence of siloxane liquids on the surface ensures increased abrasion resistance.

The mixing operation is carried out on extrusion equipment using worm-disc or twin-worm extruders. Siloxane liquid is added in the amount of 0.1-1.5 mass.9o. When a compatibilizer additive of less than 0.1 wt.9o is introduced into the polymer mixture, the effect of increasing abrasion resistance is weak, due to

With the difficulty of uniform mixing and its small amount on the surface of the fiber. An increase in the concentration of siloxane liquid above 1.5wt.9o is not accompanied by an increase in thread resistance to abrasion.

From the literature, the use of siloxane liquids to increase the abrasion resistance of complex threads from polyolefin microfibers formed from melts of compatibilized polymer mixtures is unknown.

Thus, according to the proposed method, complex threads based on ultra-thin polyolefin fibers with abrasion resistance 2.6-0.1 times higher than the prototype method are obtained.

The invention is explained by the following examples.

Example 1

The following initial components were used to form the composite thread: polypropylene (PP) - fiber-forming and co-polyamide (SPA) - matrix polymers and polyethylsiloxane brand PES-5 as a compatibilizer. Polypropylene had the following properties: characteristic viscosity in decalin at 13520 - 1.2;

content of atactic fraction - 595; melting point - 16920. Co-polyamide - co-polymer of caprolactam (50965) and hexamethylene adipinate (5095); the content of low molecular weight compounds (LMCs), which are extracted with water, - 2-Zmas.9o.

Polyethylsiloxane (PES-5) with the following characteristics: specific density, g/cm? - 0.86-1.18; mass fraction of silicon,

Cho - 19.6-28.0; boiling point at a residual pressure of 0.13-0.4OmPa, es - 250.

PP granules were mixed with PES-5 in melt on a LHP-25 worm-disc extruder. The initial SPA was pre-dried under vacuum at a temperature of 9022 to a NMSO content of 0.05 wt.9o, and then mixed on the same extruder with the obtained PP granules with the addition of PES-5. A composite monofilament was formed from the resulting composition on an extruder-type spinning machine and drawn at a temperature of 150 2C. Extraction of 70. matrix polymer was carried out with an aqueous solution of ethyl alcohol.

Characteristics of complex threads from polypropylene microfibers formed from mixtures

PP/SPA/PES-5, listed in Table 1. "complex threads of PP microfibers, mass. 90 y 25 sh prot zoolvos 301ya 01

F

30 Example 2. co

Fiber-forming and matrix polymers, which are described in example 1, were used to form the composite thread, with a ratio of PP/SPA/compatibilizer components of 40.0/59.3/0.7. PMO-100 polymethylsiloxane liquid with the following characteristics was used as a compatibilizer: specific density, F) 35 g/cm - 0.91-0.98; mass fraction of silicon, Zo - 36.5-39.0; the boiling point at a residual pressure of 0.13-0.50 mPa, "C not higher than 300. The introduction of PMO-100 into PP, subsequent mixing of the obtained granules with SPA and the formation of a complex thread from PP microfibers were carried out under the conditions described in example 1. tests showed that the complex thread withstood 1210 cycles before wearing out.

Example 3. t

A mixture of fiber-forming, matrix polymers and organosilicon liquid with a composition of 50.0/49.7/0.3w/w was obtained by mixing using a twin-worm extruder brand "/5K-83" of the "Uueteg" company

RIsmdegeg" with two degassing zones. The presence of two degassing zones allows you to exclude the stage of preliminary drying of the initial SPA. As a fiber-forming component of the mixture, high-pressure polyethylene (PEVT) was used with the following properties: melting point 123 C; degree of crystallinity - 8095. Matrix

Component (SPA) and compatibilizer (PES-5), as in example 1. From the granules of the mixture, a composite was formed

Ge) monofilament, the matrix polymer was extracted as described in example 1. After the extraction of the matrix polymer, a complex thread made of polyethylene microfibers with abrasion resistance 5.1 times higher than that of the prototype was obtained. 2) Example 4.

To form a complex thread from PP microfibers, m, polypropylene and a compatibilizer - PES-5 were used as a fiber-forming polymer, the properties of which are described in example 1. The matrix polymer was a copolymer of ethylene with vinyl acetate (SEVA) with a melting point of 859 and a content of vinyl acetate groups of 1296. An organic silicon liquid PES-5 was pre-mixed with PP on the polymer granulation line, and then the obtained granules were mixed with SEVA on the same extruder. The composite monofilament was formed from a mixture of PP/SEVA/LES-5

C 55 of the composition 30.0/69.0/1.0 on the equipment and under the conditions described in example 1. To obtain a complex thread from PP microfibers, the matrix polymer (SEVA) was extracted with benzene. Complex threads made of PP microfibers withstood 1240 thousand cycles before abrasion.

The analysis of the results shows that the proposed method makes it possible to obtain complex threads based on polyolefin microfibers during the processing of melts of polymer mixtures containing (20-50) wt. 10.1) times the abrasion resistance compared to the prototype.

Claims (1)

The formula of the invention b5 The method of obtaining complex threads based on ultra-thin polyolefin fibers by mixing fiber-forming, matrix polymers and a compatibilizer in the melt, forming composite threads, their thermal orientation drawing and extraction of the matrix polymer, which is characterized by the fact that the fiber-forming polymer is pre-mixed in the melt with a compatibilizer, which is a siloxane liquid and is INTRODUCED in the amount of 0.1-1.5 wt. 90. Official Bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2005, M 9, 15.09.2005. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. that 2 (Se) Zo so s (o) . and? se) ime) (95) 4) So 60 b5