JPH02154018A - Covering yarn - Google Patents

Abstract

PURPOSE:To obtain the subject yarn resistant to the lowering of physical properties in wet state and having excellent post-processability, abrasion resistance, etc., by using a conjugate fiber of a non-elastic fiber containing a specific polyester as the core component and a polyamide as the sheath component and winding the conjugate fiber around an elastic fiber. CONSTITUTION:In a covering yarn produced by winding a non-elastic fiber (in multiple layers) around an elastic yarn, a conjugate fiber having a sheath- core conjugate structure containing (A) a core component consisting of a polyester composed mainly of ethylene terephthalate unit and (B) a sheath component consisting of a polyamide is used as the non-elastic fiber of the outermost layer. The ratio of the component A is 30-90wt.%, the core component has an intrinsic viscosity [eta] of >=0.6, a birefringence of 150X10<-3> - 190X10<-3> and a density of >=1.39g/cm<3>, the polyamide sheath component of the component B has a relative viscosity etar of >=2.6 (in sulfuric acid) and a birefringence of >=40X10<-3> and the core component has a highly oriented and highly crystalline fiber structure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a covering yarn formed by winding a thermoplastic synthetic fiber thread around an elastic material such as polyurethane material. More specifically, the present invention relates to a covering yarn that suppresses deterioration of physical properties when wet, has excellent post-processability, and has improved abrasion resistance, dyeing properties, and mechanical strength.

[Prior art] By wrapping inelastic thermoplastic synthetic fibers such as polyamide or polyester in one or multiple layers around a core thread that is an elastic fiber such as polyurethane fiber, it is possible to improve the dyeing properties and mechanical properties that are disadvantageous to elastic fibers. JP-A-53-23 (33
This is shown in Publication No. 35, etc. Such covering yarns have been used in pantyhose, tights, socks, cuffs, tape, lace, inside belts, swimwear,
It has been used for clothing such as ski wear and wet suits.

Further, JP-A-61-119739 discloses the use of nylon 4G as the polyamide of the inelastic fiber.

Furthermore, recently, covering yarns have been used for industrial purposes, such as reinforcing fibers for toothed belts, by taking advantage of their elastic properties and mechanical strength, as shown in Japanese Patent Application Laid-Open No. 19443/1983.

[Problems to be Solved by the Invention] A drawn yarn that is not a flat yarn (through various processing) of polyamide, such as nylon 6, nylon 66, or nylon 6], which is well known as an inelastic fiber of conventional covering yarn. ) or false-twisted yarn, although the vivid color of polyamide can be obtained, there are problems such as poor dimensional stability in wet conditions, resulting in poor uniformity and texture, and furthermore, the so-called sagging phenomenon occurs. . In order to improve this, JP-A-61-119739 discloses the use of nylon 46 as the polyamide.

However, when nylon 46 is used, although there is little change in mechanical strength and elongation when wet and the so-called sagging phenomenon is suppressed, the dimensional stability when wet is not improved, and the uniformity and texture are not improved. It could not be said that the results were good, and on the contrary, properties such as wear resistance deteriorated.

On the other hand, if a flat yarn or false twisted yarn made of polyester fiber such as polyethylene terephthalate or polybutylene ethylene phthalate is used as the covering yarn's inelasticity, deterioration of physical properties when wet is prevented, but the Because high-temperature dyeing is required, the physical properties of the elastic fibers deteriorate, and durability such as abrasion resistance is inferior to that of polyamide, leading to problems such as fluffing, which reduces high-order processability. Ta.

The object of the present invention is to overcome the above problems and provide a covering yarn that suppresses deterioration of physical properties when wet, has excellent post-processability, and has improved abrasion resistance, dyeing properties, and mechanical strength. In particular, as an inelastic fiber for covering yarn, it has improved wet dimensional stability comparable to that of polyester, dyeing properties and durability of polyamide groups, which could not be achieved with conventional technology, and the peeling of the polymer at the core-sheath composite interface. An object of the present invention is to provide a covering yarn using a composite* fiber having sufficient durability against.

[! ! Means and Effects for Solving the Problems In order to achieve the above object, the present invention provides a covering yarn in which inelastic fibers are wound around elastic fibers in one or more layers, in which at least the inelastic fibers in the outermost layer are made of ethylene. A composite fiber having a core-sheath type composite structure in which the core component is polyester containing terephthalate units as a main component and the sheath component is polyamide, wherein the ratio of the polyester core component in the composite fiber is 30 to 90% by weight. %, the intrinsic viscosity [η] of the core component is 0°6 or more, and the birefringence is 150X10-3 ~
190XIO″3 The density is 1.39 g/cm3 or more, the relative sulfuric acid viscosity ηr of the polyamide sheath component is 2.6 or more, the birefringence is 40X10-3 or more, and the core component has a highly oriented, highly crystalline fiber structure. This is achieved by a covering yarn characterized by:

The covering yarn of the present invention has the above-mentioned structure, and in particular, as an inelastic fiber of the covering yarn, which is the object of the present invention, it has an improved wet dimensional stability comparable to that of polyester, which has not been achieved with the prior art, and a polyamide group. Improvements in dyeing properties and durability, as well as peel durability of core-sheath composite interfacial polymers, can be obtained by combining the specified birefringence and density of the polyester and polyamide fiber portions forming the core and sheath, respectively.

The contents and effects of each element constituting the present invention will be explained in detail below.

The elastic fibers used in the present invention are preferably polyurethane elastic fibers, which are generally referred to as spandex fibers.
It may also be a type of elastic fiber.

The form of the inelastic conjugate fibers constituting the covering yarn may be flat yarns, fibers subjected to various post-processing such as false twisting, long fibers or short fibers.

Further, the cross-sectional shape of the composite fiber is not particularly limited, and may be round, three-lobed, multi-lobed with four or more leaves, hollow, or a combination thereof, and may have pores and grooves on the surface and inside of the fiber. It's okay to be lazy.

There is no limit to the fineness of the composite fiber, and it can be used depending on the purpose.

Note that the inelastic fiber in the outermost layer is a single covering yarn (
Single covering yarn) has inelastic fibers, double covering yarn (
(Double Covering Yarn) In a multiple covering yarn, the inelastic fibers are wound on the outermost side.

The polyester serving as the core component of the composite t & sole is preferably a polyester consisting essentially of polyethylene terephthalate units. to an extent that does not substantially reduce the physical and chemical properties of the polyethylene terephthalate polymer, e.g.
It may contain less than 0% copolymer component. The co-components may include dicarboxylic acids such as isophthalic acid, naphthalene dicarboxylic acid and diphenyldicarboxylic acid, and diol components such as ethylene oxide, propylene glycol and butylene glycol. Similarly, polyesters such as polybutylene terephthalate and polyethylene naphthalate may be blended to an extent that does not substantially reduce the physical properties of the fibers of the present invention, for example, less than 10%.

In order to obtain the strength of the composite fiber of 5.0 g/d or more, the core component polyethylene terephthalate fiber has an intrinsic viscosity [η]
has a relatively high viscosity of 0.6 or more, preferably 0.7 or more.

On the other hand, the polyamide sheath components include polycabramide, polyhexamethyleneadipamide, polytetramethyleneadipamide F,
It is made of ordinary polyamides such as polyhexamethylene dodecamide and polyhexamethylene dodecamide, but polyhexamethylene adipamide-based polymers are preferred. It should be noted that, for example, 10% may be added to an extent that does not substantially reduce the physical properties of the fiber of the present invention.
Copolymerization of less than 10% of components such as ε-cabramide, tetramethylene adipamide, hexamethylene dodecamide, hexamethylene dodecamide, etc., or less than 10% of polytetramethylene adipamide, polyhexamethylene adipamide, poly to You may also blend xamethylene dodecamide or the like.

In addition, the polyamide sheath component may include the present invention Wi
Matting agents, pigments, light stabilizers, heat stabilizers, antioxidants, antistatic agents, dyeability improvers, adhesion improvers, etc. can be added to the extent that the physical properties of the fibers are not deteriorated. In particular, copper salts and other organic and inorganic compounds can be added as thermal oxidative deterioration inhibitors. When used for industrial purposes, copper salts such as iodide steel, acetate steel, chloride steel, and stearate steel should be used in an amount of 30 to 500 ppm as copper and alkali metal halides such as potassium iodide, sodium iodide, potassium bromide, etc. 0.01 to 0.5% by weight, and/or organic,
Inorganic phosphorus compound at 0.01 to 0. It is preferable to contain 1% by weight.

The ratio of the polyester core component of the composite fiber is 30 to 90
MfJ%. polyester! If the fraction is less than 30% by weight, a composite fiber that effectively utilizes the wet dimensional stability of the polyester component cannot be obtained, and a preferable covering yarn cannot be obtained. On the other hand, 90% by weight
When the polyester core component occupies more than , it is a composite that effectively utilizes the dyeing properties of the polyamide component! In addition, the covering yarn becomes coarse and hard, making it impossible to obtain a preferable covering yarn.

The composite fiber has a polyester core component that is particularly highly oriented,
It is characterized by being crystallized.

That is, the birefringence of the polyester core component is 150X10-3~
It is 190X 10-3. If it is less than 150X10-', the strength of the composite A fiber is 5.0 g/d or more, and the initial tensile resistance is 6.
It is not possible to achieve 0 g/d or more. On the other hand, 190
If it exceeds X10-3, dimensional stability and durability cannot be improved.

Depending on the novel manufacturing method of the composite fiber described below, the birefringence usually does not exceed 190.times.10@-3.

On the other hand, the birefringence of the polyamide sheath component is 40 x 10-1 or more, usually 45 x 10-'' or more, which is relatively highly oriented.If the birefringence is less than 40 x 10-3, the composite fiber has high strength and high color fastness. I can't get it.

The birefringence of the core-sheath composite fiber can be measured as follows. That is, the core part is measured using a transmission interference microscope as it is, and the core part is measured using a transmission interference microscope after dissolving the polyamide sheath component in formic acid, sulfuric acid, fluorinated alcohol, etc.

The density of the polyester core component is 1.39 g/cm3 or more, and it is highly crystallized. Unless the density is above the above value, the dimensional stability and durability of the composite fiber will not be improved.

The density of the polyester core component was measured by dissolving and removing the polyamide sheath component with formic acid, sulfuric acid, fluorinated alcohol, or the like.

The composite fiber characterized by the above is 5.0g/
It has high strength of d or more and initial tensile resistance of 60 g/d or more. A more preferable composite fiber characteristic is a strength of 6 g/d.
As described above, the initial tensile resistance is 70 g/d or more, which can be achieved by appropriately combining the above conditions.

The composite fiber having the above-mentioned characteristics is manufactured by the novel method shown below.

In order to obtain the polymer physical properties of the polyester core component described above, a polymer consisting essentially of polyethylene terephthalate and having an intrinsic viscosity [η] of 0.65 or more, usually 0.75 or more is used.

The polyamide sheath component polymer has a sulfuric acid relative viscosity of 2°6 or more,
Usually, a polymer with a high polymerization degree of 2.7 or more is used.

It is preferable to use two pressure Melk type spinning machines or an extruder type spinning machine for melt spinning the polymer. The polyester and polyamide polymers melted in each Merck or extruder are introduced into a composite spinning bag, passed through a composite spinning nozzle, and spun into a composite fiber with polyester in the core and polyamide in the sheath.

The spinning speed is 1,500 m/min or more, preferably 2,000 m/min.
m/preparative high speed. When spinning high-viscosity polymers, a heat insulating cylinder, heating cylinder, etc. is placed directly under the spinneret to maintain the temperature at 200°C over a distance of 10 cm or more and 11 cm or less directly below the spinneret.
As described above, spinning is preferably carried out by creating a heating atmosphere of 260° C. or higher, but if the polymer viscosity is relatively low, the heat-insulating tube, heating tube, etc. may be omitted. Thereafter, the spun yarn is quenched and solidified with cold air, then applied with an oil agent and taken off with a take-off roll that controls the spinning speed. The taken-off undrawn yarn may be wound up once, or may be drawn continuously without being wound up.

The birefringence of the undrawn yarn sampled on a take-up roll for the purpose of understanding the physical properties of the undrawn yarn before stretching is 15X10-3 or more for the polyamide sheath, preferably 25XIO-3 or more, and 20X10-3 for the polyester core. As mentioned above, it is highly oriented, preferably 30×10 −3 or more.

Adoption of high-speed spinning brings about the effect of improving the wet dimensional stability and durability of the composite fiber, but surprisingly, the durability of the core-sheath composite interface is significantly improved. Unlike the conventional low-speed spinning method, in which a polyamide component that has undergone moisture absorption and crystallization is combined with an amorphous polyester component, in the high-speed spinning method, oriented crystallization progresses in both the polyamide component and the polyester component. It is thought that the following factors contribute to the durability of the composite interface: the condition of the fiber, the fact that the stretching ratio after spinning is small, and the like.

Next, the undrawn yarn is drawn continuously or sequentially. Stretching conditions vary depending on the application, but one stage of cold stretching is
The temperature may be higher than 180℃, preferably 200℃.
Multi-stage hot stretching of two or more stages may be performed at a high temperature of C or higher. In all cases, the Nobeki magnification is in the range of 1.4 to 3.5 times.

The fiber thus obtained has the characteristics of an inelastic composite fiber for coating the covering yarn of the invention.

The covering method was a generally known method disclosed in, for example, Japanese Patent Application Laid-Open No. 53-236335 or Japanese Patent Publication No. 45-18063.

Next, I will explain based on an example, but zero invention! The fiber properties and measurement methods described in the main text of the book III and the examples are as follows.O Properties of the polyester core fiber A sample was prepared after the polyamide sheath component was dissolved and removed with formic acid.

(a) Intrinsic viscosity [η]: A sample was dissolved in an orthochlorophenol solution and measured at 25°C using an Ostwald viscometer.

(b) Birefringence: The average birefringence observed from the side of the fiber was determined by the interference fringe method using a transmission quantitative interference microscope manufactured by Carl Zeiss Jena (East Germany). 2 l from the surface layer of the fiber towards the center
Measurements were taken at intervals of t, and the average value was determined.

(c) Density: Measured at 25° C. using a density gradient tube prepared using carbon tetrachloride as a heavy liquid and n-heptane as a light liquid.

Characteristics of polyamide sheath fibers (d) Relative viscosity of sulfuric acid ηr: A sample was dissolved in formic acid, and the dissolved portion was reprecipitated by a conventional method, washed, dried, and applied to a measurement sample.

One gram of the sample was dissolved in 25 cc of 98% 5R acid and measured at 25°C using an Ostwald viscometer.

(B) Birefringence: As with the polyester core fiber, only the surface layer polyamide fiber portion was measured from the side using the interference fringe method using a transmission quantitative interference microscope.

Characteristics of O-conjugated fiber: Strength, elongation, and initial tensile resistance; Strength, elongation, and initial tensile resistance were determined according to the definition and measurement method of JIS-L1017. The specific conditions for the tensile test to obtain the SS curve are as follows.

After taking the sample into a shape and leaving it in a temperature and humidity controlled room at 20℃ and 65% RH for more than 24 hours, Tensilon U T
L-4L” type tensile test 81 (manufactured by Orientic@)
The measurement was carried out using a sample length of 25 Cnl and a tensile speed of 30 cm/min.

(G) Dry heat shrinkage rate: Take a sample and leave it in a temperature and humidity controlled room at 20°C and 65% RH for 24 hours or more, then apply a load equivalent to 0.1 g/d of the sample and measure the length. A sample of size L8 is processed in an oven at 150°C for 30 minutes under no tension. The treated sample was air-dried, left in the temperature and humidity control room for 24 hours or more, and the load was applied again, and the measured length L+ was calculated using the following formula.

Dry heat shrinkage rate (%) = (us-L+)/Ls×100 Characteristics of O-coated elastic fibers and knitted fabrics (h) Coverability: Evaluation was made by visual observation using a magnifying glass according to the following criteria.

○: Good △: Slightly poor ×: Poor (S) Uniformity of knitted fabric: The obtained covered elastic fibers were made into a knitted fabric using a normal method, and its evenness was visually inspected using a magnifying glass according to the following criteria. It was evaluated by

O: Good △: Slightly poor ×: Poor (N) Interfacial peeling durability of composite wc Usui: When the above knitted fabric is dyed with ordinary acid dye, for example, Xyle
ne Fast Blue 1. O%owf
(98° C. x 30 minutes), and friction was repeatedly applied to this tubular knitted fabric using a pilling tester (Toyosei [manufactured by 1 Seisakusho]) under the following conditions.

Friction means... Plane wear (rotation) Friction table... 86±3 rpm pressurization...
750 g Frictional contact surface... 4 czeg probe... Nylon filament woven state...
Number of wet frictions: 1000 times If the above friction causes composite interfacial peeling of the coated bullet fibers on the friction surface of the knitted fabric, the color of the knitted fabric turns white.

Visually observe the whitening condition, and if there is no whitening at all, mark it as ○.
: Good, and evaluated based on the following criteria.

O: Good Δ: Slightly poor ×: Poor (ru) Water absorption and elongation rate: A sample of 0.1 g/d was applied to a cage-shaped sample that had been left in a temperature and humidity controlled room at 20°C and 65% RH for 24 hours or more. A sample of length LO measured by
The sample was immersed in water at .degree. C., taken out after 30 minutes, and immediately subjected to the same load as above.The water absorption elongation rate was calculated from the measured length Ll using the following formula.

Water absorption elongation rate (%) = (Ll La) / Le (wa) Abrasion resistance: Among the above peeling durability evaluation methods, the number of times of friction was 1000
The knitted fabric was rubbed in the same manner except that it was rubbed 0 times, and the fluffing state of the coated elastic fibers was evaluated visually using a magnifying glass according to the following criteria.

Q: Good △: Slightly poor ×: Poor [Example 1.2 and Comparative Examples 1 to 3] Intrinsic viscosity [η)
1.05, carboxyl end group concentration 10.5eq/10
8 g of polyethylene terephthalate (PET) and 0.02% by weight of copper iodide and 0.02% by weight of potassium iodide. Hexamethylene adipamide (N66: sulfuric acid relative viscosity η
r3.3) were each melted using a 20 φ spindle type spinning machine, introduced into a composite spinning bag, and spun from a core-sheath composite spinneret into a composite yarn of polyethylene terephthalate in the core and polyamide in the sheath. The proportions of the core and sheath components were varied as shown in Table 1. The cap used had a hole diameter of 0.51φ and seven holes. Polyethylene terephthalate and polyamide were melted at 295°C and 290°C, respectively, and spun at a spinning back temperature of 300°C. A 15cn1 heating cylinder was attached directly below the mouthpiece, and the cylinder was heated to an atmospheric temperature of 290°C. The ambient temperature is the ambient temperature measured at a position 10 cm below the mouth surface and 1 cm away from the outermost thread. An annular chimney with a length of 400 cm was installed under the heating chamber, and cold air was blown perpendicularly to the yarn at 25° C. at a rate of 40 m/min from around the yarn to cool the yarn.

After applying an oil agent, the yarn speed was controlled using a take-up roll rotating at the speed shown in Table 1, and then the yarn was continuously stretched without being wound up. The film was stretched in two stages using three pairs of Nelson type rolls, then subjected to a relaxation heat treatment with 3% relaxation, and then wound up. The stretching conditions were as follows: take-up roll temperature: 60°C; first stretching roll temperature: 120°C; second stretching roll temperature: 120°C;
Stretching was carried out at a stretching roll temperature of 210° C., a tension adjusting roll after stretching without heating, and a first-stage stretching ratio of 70% of the total stretching ratio. The yarn was produced by varying the spinning speed, total draw ratio, etc., and the discharge amount was changed in accordance with the spinning speed and draw ratio so that the fineness of the drawn yarn was 20 denier.

Nylon 66 filament (20D-7F
il) and polyethylene terephthalate filaments (20D-7F i I), including the spinning conditions, obtained drawn yarn properties, and fiber structure parameters are shown in Table 1.

(Margin below) Table 1 Next, a commercially available spandex yarn of 20 denier and 3 filaments was stretched 3.5 times as an elastic fiber, and the composite fiber and comparative yarn were used as inelastic fibers for covering using a normal covering machine. We did double covering. The covering number is 2000.

Evaluations of the coated elastic fibers are shown in Table 2.

Table 2 Note: Among the physical properties of the PET core component, numbers within 0 indicate the PET woven properties, and among the physical properties of the polyamide sheath component, those within 0 indicate the polyamide edge material properties.

1st. As can be seen from the results in Table 2, the covering yarn of the present invention not only has excellent covering properties and uniformity, but also has revolutionary superior peeling durability compared to conventional polyester/nylon core-sheath composite fibers, and is superior to conventional nylon. It has a low water absorption elongation rate that is not found in conventional polyesters, and has abrasion resistance that is not found in conventional polyesters.

[Effects of the invention] The covering yarn of the present invention not only has excellent covering properties and uniformity, but also has revolutionary peeling durability and dyeing properties compared to conventional polyester/nylon core-sheath composite fibers, and has properties not found in conventional nylon. It has dimensional stability when wet and has abrasion resistance not found in conventional polyester. Therefore, when used for clothing such as pantyhose, tights, socks, cuffs, tape, lace, inside belts, swimwear, ski wear, and wet suits, it has an excellent texture and
It can have durability, texture, etc.

Further, by taking advantage of the elastic properties, mechanical strength, dimensional stability, and durability of the covering yarn of the present invention, it can be used for industrial purposes, such as reinforcing fibers for toothed belts.

Claims (2)

[Claims] (1) In a covering yarn in which inelastic fibers are wound singly or multiple times around elastic fibers, at least the outermost layer of inelastic fibers wound around the outer periphery of the elastic fibers is made of polyester whose main component is ethylene terephthalate units. A composite fiber having a core-sheath type composite structure with polyamide as a core component and polyamide as a sheath component, wherein the proportion of the polyester core component in the composite fiber is 30 to 90% by weight.
, the core component has an intrinsic viscosity [η] of 0.6 or more and a birefringence of 1
50 x 10^-^3 ~ 190 x 10^-^3, density is 1
．． 39 g/cm^3 or more, the relative sulfuric acid viscosity ηr of the polyamide sheath component is 2.6 or more, the birefringence is 40 x 10^-^3 or more, and the core component has a highly oriented, highly crystalline fiber structure. Features covering yarn. (2) Claim (1) characterized in that the composite fiber has a strength of 5.0 g/d or more, an initial tensile resistance of 60 g/d or more, and a dry heat shrinkage rate of 7% or less. Covering yarn as described.