KR800000093B1 - Method for modifying polyester fiber - Google Patents

Abstract

P-contg. compds. with the structure (I; R = an alkylene group with 2-10C which was (un) substituted halogen, Ph. alkylene group with 7-10C, cyclo alkylene group with 7-10C, alkenylene group with 3-5C; R' = alkyl, aryl, aralkyl group which was (un) substituted H or halogen; X,X',Y = O or S ; n = 2-3) were used as flame resistant agents for polyesters contg. telephthalic acid, ethylene glycol and lithium acetate. The P-compds. were added with 100-50.000 ppm based on the weight of the polyester.

Description

Modification method of polyester fiber

The present invention relates to a method for producing a flame retardant polyester fiber. Thermoplastic polyesters, which are widely used in fibers, films, and the like, are inherently combustible materials and are burned violently when ignited. As a method of imparting flame retardancy to polyester fibers, phosphorus compounds such as British Patent 1,481,858, United States Patent 3,960,806, Japanese Patent Application Publication No. 49-54,494, or halogen compounds are used, or Japanese Patent Application No. 46-19,758 and Japanese Patent Application No. 50-10,413. Or bonding a metal halide and oxide to the polyester. However, bromine compounds among these flame retardants generate toxic gases such as HBr and Br ₂ during combustion, and are dangerous to the human body. Phosphorous compounds give good flame retardant effect to polyester, but esters of phosphoric acid and phosphorous acid are transesterified with polyester. Not only does it degrade the chemical and physical properties of the polyester, but it also has the drawback that it cannot hold a continuous flame retardant effect.

Examples of the method of applying the flame retardant to the polyester include the flame retardancy of the yarn and the post-processing method. The post-processing method has a defect in that the durability of the flame retardancy is weak and the texture of the fiber is bad.

Therefore, the present inventors have conducted various studies on the flame retardant of polyester yarn, and as a method of not lowering the physical properties of the polyester and impairing the feel of the product, the ring containing phosphorus is high so that the phosphorus content in the flame retardant is high. The use of dog cyclic phosphonate compounds has been paid attention to, and the configuration thereof is as follows.

In the present invention, in order to impart flame retardancy to the polyester, a cyclic phosphonate type phosphorus compound having 2-3 rings containing phosphorus having the following general formula (I) may be used as a flame retardant. Based on the phosphorus content in I), 100ppm-50,000ppm was added to the polyester.

(ppm = parts per millon)

Wherein R is an alkylene group having 2 to 10 carbon atoms that is not halogenated or

A phenyl alkylene group having 7 to 10 carbon atoms, a phenylene group,

A cycloalkylene group having 7 to 10 carbon atoms,

Alkenylene groups having 3-5 carbon atoms

R 'is hydrogen or an alkyl group which is halogenated or not, an aryl group, an aralkyl group

XX'Y: Oxygen or Sulfur

n is an integer of 2-3

The thermoplastic polyesters to be applied to the present invention include polycondensation polyesters having at least 80% or more of polyethylene terephthalate and ethylene terephthalate, poly 1,4-cyclohexane dimethylene terephthalate, polyethylene setamate, polyethylene adipate, poly Tetramethylene terephthalate and the like, and these polyesters are obtained by a conventional production method.

Specific examples of the compound of the general formula (I) used in the present invention are as follows.

The above has only given some possible examples, and practical flame retardants are not limited thereto. These phosphorus compounds are preferably added in an amount of 100 ppm-50,000 ppm, more preferably 5,000 ppm-20,000 ppm, based on the phosphorus content with respect to the polyester. In this case, the timing of adding the compound of the present invention to the polyester is possible at various stages during the manufacturing process of the polyester company. For example, a polyester polymerization process, mixing into a melt of polyester after polymerization, or injecting during spinning or molding is as known. At the time of spinning or molding, an appropriate powder feeder may be provided in the extruder to be mixed with the polyester chip at the same time, or the flame retardant may be injected into the molten polyester by spraying.

When the compound of the present invention is applied to polyester to perform spinning, the compound of the present invention may be complexed by mixing with polyester and other polymers such as polyamide, polyolefin, polycarbonate, polyether, polyesteramide, polyamide ether, and the like.

The polyester obtained by the present invention does not need to impart flame retardancy by post-processing, so that the touch does not decrease due to post-processing, and is suitable for the production of fabrics and knitted fabrics with good touch.

In addition, when the ester of phosphoric acid used as a flame retardant is added to the polyester more than 2%, there is a defect in the polyester to reduce the degree of polymerization of the polyester properties, but in the present invention to prevent such a decrease in the degree of polymerization As a result, the cyclic phosphonate type was considered, and the compound having 2-3 ring containing phosphorus was suitable to increase the phosphorus content of the flame retardant. The results for practical use are excellent in flame retardancy without causing a decrease in intrinsic viscosity, that is, polymerization degree, as shown in the examples.

The method of the present invention imparts flame retardancy by adding these phosphorus compounds to polyester based on the phosphorus content in the phosphorus compound, more preferably 5,000-20,000 ppm during the polyester manufacturing process. The yarn thus obtained can be excellent in flame retardancy and more efficient since the flame retardant is uniformly distributed throughout without being applied unevenly to the flame retardant as in post-processing.

Therefore, when the compound of the present invention is applied to polyester, the solution viscosity of the obtained flame retardant yarn does not drop as compared to that of regular yarns, and the flame retardant effect is small in view of the structure of the cyclic phosphonate having 2-3 phosphorus-containing rings. It is considered that the invention is an innovative invention because the flame retardant can be uniformly distributed in the inside of the forma by adding a flame retardant during the manufacturing process and can effectively impart flame retardancy.

The flame retardant [I] of the present invention is used as an additive to improve the flame retardancy without degrading the physical properties of the polyester by being uniformly dispersed in the polyester, rather than causing chemical reaction with the polyester polymer in the polymerization process.

Therefore, the short-acting agent [I] of the present invention can achieve the desired purpose at any stage before spinning, but it is better to add it to the polymerization process in order to obtain a sufficient mixing effect. Since the physical properties of the polyester can be reduced, such as forming a polymer having a structure, it is more effective to rapidly mix the material after the completion of the polymerization reaction, which is added during the polymerization process of the flame retardant, and to add the same to the spinning process.

In addition, when the flame retardant of the present invention is added to the polymerization process, the difference in physical properties according to the timing of addition is obvious from the other results that the mixing is most ideal after the completion of the polymerization reaction.

(1) When the flame retardant is added at the beginning of the polymerization reaction:

IV 0.9 of the chip, which is brittle and has a lot of pores in the polymer

(2) When the flame retardant is rapidly added after the completion of the polymerization reaction and stirred for 20 minutes:

IV 0.6 of the chip, no pores and no difference from normal polyester.

(IV = intrinsic viscosity)

The method employed to measure the flame retardant effect in the present invention is as follows.

(1) limit oxygen index (LOI):

The oxygen index method described in ASTM D-2, 863-70 was used.

The limit oxygen index indicates the minimum mole fraction of oxygen in the air in which candle flames are maintained, and the oxygen molar fraction on the beach is 0.21.

(2) Coil test method:

The specimen to be measured has a length of 10cm and a weight of 1g, and rolls it into a coil made of stainless steel with a diameter of 10mm and a length of 15cm at a distance of 2mm.

At this time, the coil should be 45 ° with respect to the horizontal and placed in the box so as not to be influenced by the outside.

At this time, the ignition starts from the bottom and the flame is 45mm by the burner using LPG gas so as to touch the bottom of the sample. According to the length of the sample, the ignition is continued until it burns to 9cm, and it is judged that it is flame retardant when the number of ignitions up to this time is three times or more.

In the present invention, solution viscosity measurements of polyester and flame retardant polyester resins were carried out as intrinsic viscosity at 25 ° C. with orthochlorophenol using a cannon ubbelohde: viscometer.

Reference examples and embodiments are also described below to describe the present invention in detail.

[Reference Example l]

1,000 parts of terephthalic acid (TPA), 450 parts of ethylene glycol (EG) and 0.06 parts of sodium acetate are added to fill the reactor.

The reaction mixture is heated to perform esterification over 3 hours while removing the water generated. Finally, the esterification rate is 96% at an internal pressure of 3 kg / cm ² G and an internal temperature of 250 ° C.

Then, 4.32 parts of titanium dioxide (TiO ₂ ) (0.898 mol% with respect to TPA) 0.075 parts of titanium acetate (0.005 mol% with respect to TPA) and 0.024 parts of phosphorous acid (0.005 mol% with respect to TPA) were added, followed by 20 at 250 ° C. under normal pressure. After heating for minutes, the temperature of the reaction system is gradually decreased while gradually decreasing.

Finally, the condensation reaction is carried out at 285 ° C. for 220 minutes under a vacuum of 0.2 mmHg.

Thereafter, nitrogen pressure is applied in a normal manner, and then passed through a slit die to obtain a ribbon-like plate-like polymer, which is cut into pellets having a size of 3 mm x 3 mm x 2 mm.

The intrinsic viscosity of the pellets obtained at this time is 0.652.

The color tone was 62.2 for L and 0.3 for b, which was measured as a handheld color difference meter. The higher the L difference, the higher the brightness. The b value is larger to the + side.

Reference Example 2

Polyethylethylene terephthalate having an intrinsic viscosity of 0.652 was heated to 180 ° C. in a vacuum rotary dryer and dried for 3 hours.

The dried pellets were spun without bubbles in the barrel temperature of the extruder at 285 ° C, spinnering temperature 285 ° C, winding speed 1,350m / min, discharge amount 51.27g / min, and stretch ratio It extended | stretched at 3.4, the roller 65 degreeC, the pin 130 degreeC, the plate 150 degreeC, and the firing speed 500m / min.

The resulting stretched yarn had 112.2 denier, 32.1% elongation, 4.07 g / d strength, 7.2% shrinkage, and 0.5% homogeneity.

Reference Example 3

In the drawn yarn manufactured in Reference Example 2, the spindle speed was 250,000 rpm twist 3,272 tpm, the firing speed 76.4 m / min, and the heater temperature was 215 ° C. × 190 ° C. (first heater x second heater) in a Heberlein machine. Combustion was carried out at 2/13 / -1%.

In the M / C Type KSM circular knitting machine, the ligated yarn was knitted into an interlock structure with a diameter of 30 inches, a feeder 48, and a gauge 22.

Example 1

A chip having an intrinsic viscosity of 0.652 of 3 mm × 3 mm × 2 mm obtained in Reference Example 1 was dried at reduced pressure at 180 ° C. in a rotary vacuum dryer for 3 hours.

92 parts of dried polyethylene terephthalate and flame retardant

Ten parts were radially stretched in the same manner as in Reference Example 2.

The physical properties of the obtained stretched yarn were 115.7 denier, elongation 37.2%, strength 3.98 g / d, shrinkage rate 6.5, and uniformity 0.4%. The intrinsic viscosity of the drawn yarn was 0.650, and the drop in intrinsic viscosity was 0.002. The stretched yarn was combusted and woven by the method of Reference Example 3, and the flame retardancy was measured. As a result, the number of ignitions by LOI 0.30 and the coil test method was 5-6.

Comparative Example 1

A 3 mm x 3 mm x 2 mm intrinsic viscosity 0.652 chip obtained in Reference Example 1 was dried by heating at 180 ° C under reduced pressure for 3 hours in a rotary vacuum dryer.

When 92 parts of dried polyethylene terephthalate and 8 parts of triphenylphosphate were added and spin-drawn under the conditions of Reference Example 2, the fineness was 120 denier, elongation 40.3%, strength 3.5 g / d, shrinkage 8.2%, and uniformity 0.8%. Shinto shrines were obtained, and the intrinsic viscosity of Yeonsinsa was 0.57.

Cut ratio was also shown to increase than normal yarn or Example 1.

Comparative Example 2

A chip having an intrinsic viscosity of 0.652 of 3 mm x 3 mm x 2 mm obtained in Reference Example 1 is dried in a vacuum rotary dryer.

92 parts of dried polyethylene terephthalate and flame retardant

One part was radially stretched by the method of Reference Example 2, and was combusted and woven by the method of Reference Example 3, and the flame resistance was measured by the coil test method.

Example 2

Instead of the flame retardant in Example 1, using the compound shown in [Table 1] spin-stretched by the method of Reference Example 2, and subjected to the LOI and coil test method by combusting and weaving by the method of Reference Example 3 [Table 1 1].

Flame Retardant 1:

Flame Retardant 2:

Flame Retardant 3:

Claims (1)

The cyclic phosphonate-type phosphorus compound having 2-3 rings containing phosphorus represented by the following general formula (I) is 100-50,000 ppm (based on the phosphorus content in the phosphorus compound (I)) parts per million) A method of modifying polyester fiber, characterized in that the melt spinning by addition.

here, R is an alkylene group having 2 to 10 carbon atoms which is not halogenated, a phenyl alkylene group having 7 to 10 carbon atoms, a phenylene group, A cycloalkylene group having 7 to 10 carbon atoms, Alkenylene groups having 3-5 carbon atoms R 'is hydrogen or an alkyl group which is halogenated or not, an aryl group, an aralkyl group. X, X ', Y: oxygen or sulfur n is an integer of 2-3