JP2008001999A - Flame-retardant polyester fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a flame-retardant polyester fiber having sufficient flame retardance, excellent drawability, slight fluffs caused by drawing and excellent processability of weaving or knitting machine, etc. <P>SOLUTION: The flame-retardant polyester fiber is a polyester fiber composed of a mixture of a polyethylene terephthalate (component A) copolymerized with a phosphorus compound and a polyethylene terephthalate (component B) in the mass ratio of the component A to the component B of 4:1-1:1 and has a phosphorus atom content of 3,000-7,000 ppm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flame-retardant polyester having high strength and excellent flame retardancy and suitable for use as a building material.

  Building materials such as safety nets, civil engineering sheets, or mesh sheets need to be flame retardant. Therefore, these building materials that have been formed using polyester fibers that do not have flame retardants are conventionally used as safety nets, civil engineering sheets, etc. After the molding process is performed, flame retardant processing is performed, and mesh sheets and the like are subjected to resin processing using a flame retardant polyvinyl chloride resin, etc., to prevent misalignment and impart flame resistance. Is common.

  However, in recent years, safety nets and civil engineering sheets that have been subjected to flame retardant processing have been problematic in terms of sustainability of flame retardant performance due to long-term use and washing. In addition, mesh sheets, etc. that have been processed with flame-retardant resin are disposed of in landfills because they tend to generate harmful gases when incinerated. The impact on is a problem.

  From such a thing, in recent years, using a flame-retardant polyester fiber containing a phosphorus compound as described in Patent Documents 1 and 2 in a polyester fiber, flame-retardant in a safety net or civil engineering sheet For those that need to prevent misalignment, such as mesh sheets, blend a small amount of low-melting-point heat-sealing fibers to the extent that they do not impair flame retardant performance. After weaving into a mesh sheet, etc., building materials that do not perform flame-retardant processing or resin processing by performing heat treatment at a temperature equal to or higher than the melting point of the heat-fusible fiber and bonding the intersections to prevent misalignment Attention has been paid.

  Polyester terephthalate (hereinafter sometimes referred to as “PET”), which is inexpensive and has excellent weather resistance and dimensional stability, is advantageous in terms of cost. is there.

  And as a method of making a phosphorus compound as mentioned above contain in PET, the thing which added the phosphorus compound and copolymerized so that a phosphorus atom may become predetermined content in PET at the time of superposition | polymerization improves flame retardance It is preferable in terms of However, in order to obtain fibers used for civil engineering materials that require high strength, it is necessary to stretch at a high magnification, but when a phosphorus compound having a phosphorus atomic weight sufficient to satisfy flame retardancy is copolymerized, It becomes inferior in stretchability compared with the PET fiber. In addition, due to this, a lot of stretched fluff is generated, and there are many stops due to the fluff during weaving and weaving, resulting in poor workability.

Therefore, there is a demand for a flame-retardant polyester fiber that has excellent drawability and excellent workability with less stretched fluff even if it contains a phosphorus atom amount sufficient to satisfy flame retardancy.
Japanese Patent Publication No.53-13479 Japanese Patent Publication No. 55-41610

  The present invention provides a flame-retardant polyester fiber that solves the above-described problems, has sufficient flame retardancy, has excellent stretchability, has few stretch fluffs, and has excellent processability such as knitting and weaving. Is a technical issue.

  As a result of intensive studies to solve the above problems, the present inventors have reached the present invention.

  That is, the present invention is a polyester fiber made of a mixture of polyethylene terephthalate (component A) and polyethylene terephthalate (component B) copolymerized with a phosphorus compound, and the mass ratio of component A to component B is 4: 1 to 1. 1: The flame retardant polyester fiber is characterized in that the phosphorus atom content is 3000 to 7000 ppm.

  The flame-retardant polyester fiber of the present invention is excellent in stretchability despite containing a phosphorus atom amount necessary for imparting sufficient flame retardancy to the fiber, and therefore has low stretch fluff and quality. Are better. For this reason, there are few stops by fluff at the time of weaving and weaving, and the workability at the time of weaving and weaving is also good.

  Hereinafter, the present invention will be described in detail.

  Since the flame-retardant polyester fiber of the present invention is mainly used for building materials, it is necessary to have high strength, excellent weather resistance, and low cost. Therefore, as a component constituting the fiber, It is necessary to adopt PET that is inexpensive and excellent in weather resistance.

  And the flame-retardant polyester fiber of this invention needs to use the mixture of PET (A component) and PET (B component) by which the phosphorus compound was copolymerized. The reason is that if the fiber is composed of only the component A, the stretchability becomes inferior as described above. However, by using a mixture of the component A and the component B, the stretchability is improved without impairing the flame retardancy. It is because it can be made.

  Further, the mass ratio of the A component and the B component constituting the fiber needs to be in the range of 4: 1 to 1: 1, and preferably 4: 1 to 3: 2. When the component A exceeds this range, the stretchability becomes poor, and when the component A decreases, the phosphorus compound is not uniformly dispersed and the flame retardancy tends to vary, which is not preferable.

  Next, the type of the phosphorus compound copolymerized with the component A is not particularly limited, but the phosphorus compounds described in Patent Documents 1 and 2 described above can be used. Among these, in terms of flame retardancy and yarn production, a product name manufactured by Clariant Japan Co., Ltd .: Oxa-Phosphoran glycolester (ester of 3-methylphosphinicopropionic acid and ethylene glycol) is preferable.

  Then, in order to copolymerize the phosphorus compound with the component A, the phosphorus compound is added so as to have a target phosphorus atom content before the start of the polycondensation reaction of PET, and the polycondensation reaction is performed to form a chip once. Then, when using for the civil engineering material use for which high intensity | strength is required, it is preferable to solid-phase-polymerize to arbitrary viscosity similarly to normal PET, and to make high viscosity.

  In addition, the phosphorus atom content in the component A is preferably 3750 to 14000 ppm in consideration of the mass ratio of the A component and the B component in the fiber and the phosphorus atom content in the fiber.

  As B component, it is preferable to set it as PET which does not contain a phosphorus atom, and further contains other components and does not copolymerize.

  Next, the intrinsic viscosity [η] of the mixture comprising the A component and the B component constituting the flame-retardant polyester fiber of the present invention is preferably 0.85 to 1.1, and if the intrinsic viscosity is lower than 0.85, the strength is high. Is difficult to obtain, and if it is higher than 1.1, the stretchability becomes inferior, and the cost is not preferable.

  The intrinsic viscosity of the mixture composed of the A component and the B component is determined by the intrinsic viscosity of the A component and the B component used at the time of spinning, and the intrinsic viscosity of the A component and the B component may be the same or different. If the viscosity difference is too large, the difference in viscosity between the single yarns due to the mixed spots and the viscosity spots in the longitudinal direction of the fibers become large, so that the uniformity in terms of performance such as high elongation tends to be inferior. Therefore, the difference in intrinsic viscosity [η] between the A component and the B component is preferably 0.2 or less in terms of quality.

  The mixing and spinning of the component A and the component B are each melted and melted with separate melt extruders, polymerized, set with a metering pump, and spun while kneading with a kneader such as a mixer, Alternatively, it is possible to use a method of spinning while dry blending with a metering mixer or the like generally used when spinning the original fiber.

  Next, the phosphorus atom content in the flame retardant polyester fiber of the present invention is 3000 to 7000 ppm, preferably 3500 to 6500 ppm, more preferably 4000 to 6000 ppm. If the phosphorus atom content is less than 3000 ppm, the flame retardancy is inferior, and if it exceeds 7000 ppm, the phosphorus compound is expensive, which is disadvantageous in terms of cost.

  Since the flame-retardant polyester fiber of the present invention is mainly used for building materials, the cutting strength is preferably 5.5 cN / dtex or more. On the other hand, in consideration of operability such as stretchability, the upper limit is preferably about 7.5 cN / dtex.

  The fineness is preferably 400 to 3000 dtex suitable for ordinary industrial materials, and the single yarn fineness is preferably 2 to 30 dtex.

  Furthermore, the cross-sectional shape of the flame-retardant polyester fiber of the present invention may be any of a round cross-section and an irregular cross-section such as a Y cross-section.

  Further, the flame retardant polyester fiber of the present invention may be added with a color pigment, various additives and the like to the extent that the original performance is not impaired.

  The flame-retardant polyester fiber of the present invention can be produced using a conventional melt spinning and stretching apparatus. In that case, the undrawn yarn can be wound once and then drawn, but the spin draw method in which the undrawn yarn is taken up by continuously drawing and relaxing heat treatment without taking up the undrawn yarn in terms of productivity and cost. preferable.

  The winding speed in the spin draw method is preferably about 2000 to 4000 m / min. If the winding speed is slower than 2000 m / min, the productivity is lowered, and if it is faster than 4000 m / min, the stretchability is lowered or the strength is increased. Things are hard to get.

Next, the present invention will be specifically described with reference to examples. In addition, each physical-property value in an Example was measured with the following method.
(A) Intrinsic viscosity of PET Measurement was performed at a concentration of 0.5 g / dl and a temperature of 20 ° C. using an equal mass mixture of phenol and ethane tetrachloride as a solvent.
(B) Cutting strength and cutting elongation Using an autograph DSS-500 manufactured by Shimadzu Corporation according to JIS L-1013, the sample length was 25 cm and the tensile speed was 30 cm / min.
(C) Stretchability (measurement of the number of fluff)
Five pieces of 10 kg cheese are sampled, and each cheese 80,000 m of fluff is measured at a speed of 500 m / min using an AN type 4 type fully automatic warping machine having a photoelectric tube type fluff detector. The total number of fluffs in a total of 400,000 m of the book was defined as the number of fluffs, and this value was used to evaluate stretchability.
(D) Flame retardancy Measured according to JIS L-1091 8.4D method (flame contact test) at n = 5, and the average value was obtained. In addition, it shows that flame retardance is so high that the numerical value of flame contact number is large.

Example 1
The molar part of terephthalic acid and ethylene glycol was 100: 170, the low molecular weight oligomer obtained by performing esterification reaction at a pressure of 0.3 MPaG and a temperature of 250 ° C. for 4 hours was sent to a polycondensation reaction tank, Phosphorus compound (product name: “Oxa-Phosphoran glycolester”: manufactured by Clariant Japan, esterified product of 3-methylphosphinicopropionic acid and ethylene glycol) was added, antimony trioxide was added as a catalyst, temperature was 280 ° C., A polycondensation reaction was performed for 3 hours at a reduced pressure of 1.3 hPa or less. Then, a PET having an intrinsic viscosity [η] 0.7 and a phosphorus atom content of 7000 ppm was obtained, and then this PET was subjected to solid phase polymerization for 17 hours while stirring at a temperature of 220 ° C. under reduced pressure. η] PET of 1.02 was obtained and used as the A component.
As the component B, PET having an intrinsic viscosity [η] of 1.02 was used.
Then, melt spinning was performed using a metering mixer while metering and mixing such that the mass ratio of the A component and the B component was 3: 2. That is, a melt spinning nozzle having a hole diameter of 0.6 mm and 192 holes is attached to a conventional melt spinning apparatus, spinning at a temperature of 300 ° C., and then passing through a heating cylinder having a length of 30 cm and a temperature of 450 ° C. The product was cooled with a cooling air having a temperature of 20 ° C. and a speed of 0.7 m / sec by a horizontal cooling device having a length of 150 cm, applied with an oil agent, and taken up by an unheated first roller. After the 1.01 times alignment with the second non-heated second roller continuously, 5.6 times with the third roller at a temperature of 220 ° C. while spraying steam at a temperature of 400 ° C. and a pressure of 0.7 MPa on the fiber. Stretching was performed. After that, a relaxation treatment with a relaxation rate of 3% was performed with a fourth roller at a temperature of 190 ° C., wound around a winder with a speed of 3000 m / min, polyester fiber (1111 dtex / 192 filament, phosphorus atom content 4200 ppm, round cross-sectional shape) )

Example 2
Except having changed the mass ratio of A component and B component into 4: 1, it carried out like Example 1 and obtained the polyester fiber whose content of a phosphorus atom is 5600 ppm.

Example 3
The amount of the phosphorus compound added when obtaining the component A was changed to obtain a PET having an intrinsic viscosity [η] of 1.02 and a phosphorus content of 8000 ppm, except that this was used as the component A. A flame-retardant polyester fiber having a phosphorus atom content of 4800 ppm was obtained.

Comparative Example 1
A flame retardant polyester fiber was obtained in the same manner as in Example 1 except that only the PET having an intrinsic viscosity [η] of 1.02 and a phosphorus atom content of 7000 ppm was used without using the B component. It was.

Comparative Example 2
The addition amount of the phosphorus compound in obtaining the A component was changed to obtain PET having an intrinsic viscosity [η] of 1.02 and a phosphorus content of 4900 ppm, which was used as the A component, and the mass ratio with the B component was 6: Except that it was set to 1, it carried out similarly to Example 1, and obtained the flame-retardant polyester fiber whose phosphorus atom content is 4200 ppm.

Comparative Example 3
The amount of the phosphorus compound added when obtaining the A component was changed, the solid phase polymerization time was changed, and an intrinsic viscosity [η] 0.9 and a phosphorus content of 11000 ppm were obtained. Using this as the A component, B A flame retardant polyester fiber having a phosphorus atom content of 4400 ppm was obtained in the same manner as in Example 1 except that the mass ratio with respect to the component was 2: 3.

  Table 1 shows the characteristic values of the fibers obtained in Examples 1 to 3 and Comparative Examples 1 to 3, and the evaluation results of flame retardancy and stretchability.

As is clear from Table 1, the polyester fibers obtained in Examples 1 to 3 have satisfactory performance for building materials in terms of both cutting strength and cutting elongation, are excellent in flame retardancy, and are further stretched. Since the properties were good and there was little stretched fluff, it was excellent in workability such as knitting and weaving.
On the other hand, the polyester fiber of Comparative Example 1 did not contain a B component, and the polyester fiber of Comparative Example 2 had a small amount of the B component. For this reason, it was inferior to workability, such as weaving and weaving. Moreover, since the polyester fiber of the comparative example 3 had too much B component, a phosphorus compound was not disperse | distributed uniformly, the dispersion | variation in a flame retardance produced, and it became inferior to a flame retardance.

Claims (1)

A polyester fiber comprising a mixture of polyethylene terephthalate (component A) and polyethylene terephthalate (component B) copolymerized with a phosphorus compound, the mass ratio of component A and component B being 4: 1 to 1: 1, A flame-retardant polyester fiber having a content of 3000 to 7000 ppm.