KR930007830B1 - Producing process of high-intensity polyester monofilament - Google Patents

Abstract

35-95 wt.% of polyethylene terephthalate, whose intrinsic viscosity measured at 20 deg.C by using the mixed solvent of 50:50 of phenol and tetrachloroethane is 0.4-1.2 dl/g; 3-30 wt.% of polyolefin, that is, low density polyethylene, linear low density polyethylene, high density polyethylene or polypropylene, whose melt indices measured by the ASTM D 1238 method are 0.01-30g/10cm, 0.1-30g/10cm, 0.01-30g/10cm and 0.3-60g/10cm respectively; 1-20 wt.% of the fusing agent which is 20,000-50,000 g/mol molecular weight of polyethylene, substituted by alkyl carboxylic group; and 1- 15 wt.% of the chain extender which is 7,000-8,500 g/mol of polycarbodiimide or 1,1',6,6'-(tetra isopropyl) diphenyl carbodiimide.

Description

Process for producing high strength polyester monofilament with excellent processability

The present invention relates to a method for producing a high-strength polyester monofilament, and more particularly, by adding a low melting point polyolefin, a compatibilizer, and a chain extender to the polyester has a high strength and improves workability and has chemical resistance A method for producing a polyester monofilament.

In general, polyester is used in many industries because of its excellent dimensional stability and rigidity. However, such polyester monofilament should be processed by physical force and heating to have a certain shape in the processing process by using a molding machine such as a zipper molding machine or a canvas drying coil forming machine for papermaking. There is a problem that the breakage of the monofilament occurs in the molding process and the molding process is significantly worn.

In order to solve the problem of processing of polyester monofilament, German Patent No. 2,331,101 proposed a method of using an oil for fiber such as polymethylsiloxane or mineral oil in the process of producing monofilament from nylon. This effect was difficult because of its temporary effect, and Japanese Patent Publication No. 51-136,923 suggested a method of adding 0.1-40% by weight of polyolefin having a low melting point to polyethylene terephthalate, but this may improve processability. Since terephthalate and polyolefin are incompatible in a mixed state, mechanical properties, that is, strength are significantly reduced.

Accordingly, an object of the present invention is to provide a method for producing a polyester monofilament having high strength, processability, and chemical resistance by adding a compatibilizer and a chain extender to a mixture of polyester and polyolefin.

Hereinafter, the present invention will be described in detail.

In the present invention, in the production of polyester monofilament from polyethylene terephthalate, 35 to 95% by weight of polyethylene terephthalate, 3 to 30% by weight of polyolefin, 1 to 20% by weight of compatibilizer, and carbide-based chain extender It is characterized by manufacturing by adding 1 to 15% by weight.

Referring to the present invention in more detail as follows.

In the present invention, polyethylene terephthalate is used as the intrinsic viscosity measured at 20 ℃ using a solvent in which phenol and tetragloethane are mixed in a weight ratio of 50:50 using 0.4 to 1.2 dl / g.

In addition, in the present invention, in order to improve the processability of the polyester monofilament, the melt viscosity index (Melt index) value measured by the method of ASTM D 1238 is 0.01 ~ 30g / 10cm, the melting point measured by the method of ASTM D 1238 Linear low density polystyrene with a melt index value of 0.1-30 g / 10 cm, high density polyethylene with a melt index value of 0.01-30 g / 10 cm, measured by the method of ASTM D 1238. 3 to 30% by weight of polyolefin such as polypropylene having a melt index value of 0.3 to 60 g / 10 cm measured by the method was added. When the addition amount is less than 3% by weight, the radial drawing workability is good, but the monofilament When the workability of the resin is lowered, and if it exceeds 30% by weight, the thermal drawing becomes poor, so that the heat deformation of the monofilament is severe.

On the other hand, in order to improve the mechanical properties of the molded article of the incompatible polymer mixture and to have a uniform dispersion form of the dispersion region, it is necessary to improve the dispersibility.

Therefore, when a small amount of compatibilizer (or surfactant) is added to the incompatible mixture, each component of the copolymer is a block copolymer or a graft copolymer having the same or similar chemical composition as the polymer. Ideally, it is effective to reduce the interfacial energy between two incompatible phases, to uniformly disperse the dispersed phase in the kneading process, to suppress macroscopic phase separation and to improve the interfacial adhesion.

In the present invention, since the mixture of the polyester polymer and the polyolefin polymer is incompatible with each other, the mixture is incompatible with each other and has a molecular weight of 20,000 to 50,000 g / mol grafted with fumaric acid having a density of 0.9 and substituted with an alkylcarboxyl group to improve their affinity. Polyethylene is used as a compatibilizer.

When 1 to 20% by weight of such a compatibilizer is added, if the amount is less than 1% by weight, the compatibility may not be improved. If the content exceeds 20% by weight, there is a problem that trimming occurs during the spinning process.

And 1 to 15 polycarbodiimide or 1,1 ', 6,6'-(tetraisopropyl) diphenylcarbodiimide having a molecular weight of 7000 to 8,500 g / mol mainly containing carbodiimide as a chain extender. When added by weight%, such a chain extender acts on the free terminal carboxyl group of the polyester to impart chemical resistance.

Here, if the addition amount is less than 1% by weight, the chain extending action of the polymer hardly occurs, and when the amount exceeds 15% by weight, thermal decomposition of the chain extender itself occurs to cause coloration of the polyester.

In addition, in the present invention, as necessary, pigments such as phthalocyanine blue, benzimidazolone, and carbon black may be added to the color during the reaction process.

To prepare a monofilament using a known method with the composition as described above, for example, polyethylene terephthalate having an intrinsic viscosity of 0.64 ~ 1.0dl / g crystallized at a temperature of 100 ~ 140 ℃ 5-10 hours at 160 ~ 180 ℃ After drying, the moisture content was adjusted to 0.003% or less, followed by melt spinning. At this time, the melt spinning operation transfers the polyethylene terephthalate pellets dried above to the hopper of the spinning device, and performs spinning temperature at 280 ~ 300 ℃, and uses spinnerets having a diameter of 2.2mm and 45 holes. After the monofilament injected into the spinneret is sufficiently solidified by passing through a 60 ~ 90 ℃ cooling tank, the unstretched yarn is stretched by setting the draw ratio 3 ~ 6 and the heat treatment temperature 80 ~ 200 ℃ in the stretching apparatus and the heat treatment apparatus. A final product having a circular cross section with a polyester monofilament diameter of 0.7 mm, a diameter deviation of up to 2.0%, a fineness of about 4780 denier and a roundness of 98% or more can be obtained.

The polyester monofilament produced by the present invention is manufactured in a composition different from the conventional one, and thus has high strength, excellent processability, and chemical resistance, so that the zipper can be used for clothes, bags, tents, etc. It is very useful for industrial materials such as drying.

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

[Production example]

Preparation of Monofilament

Polyethylene terephthalate having an intrinsic viscosity of 0.6 dl / g obtained by a conventional manufacturing method was crystallized at a temperature of 100 to 140 ° C., and then dried at 100 to 180 ° C. for 5 to 10 hours to obtain a moisture content of 0.003% or less, followed by melt spinning. Used.

At this time, the spinning operation was carried out at 280 to 320 ℃ by transferring the dried polyethylene terephthalate pellets to the hopper of the spinning apparatus, using a separate automatic dosing machine using a prepared polyolefin and a compatibilizer or a chain extender The melt spinning was performed by mixing at a constant mixing ratio in the melt extruder.

Here, the spinneret used was a circular mold having a diameter of 2.2 mm and a hole number of 45. The molten monofilament injected into the spinneret was sufficiently hardened by passing through a cooling tank maintained at 60 to 90 ° C. You get a monofilament. The unstretched monofilament is stretched and heat treated stepwise to produce a finished product by winding up the finished polyester monofilament.

At this time, the stretching ratio is carried out in about 3 to 6 and the heat treatment temperature is carried out step by step from 80 to 200 ℃. The polyester monofilament obtained in this way has a diameter of 0.7 mm and a maximum diameter deviation of ± 2.0%. At this time, the fineness has about 4780 denier and a round cross section with a roundness of 98% or more is obtained.

How to evaluate machinability of monofilament

When the obtained monofilament was molded in a zipper molding machine and a canvas forming machine for papermaking drying, molding processability and molding temperature were measured to evaluate workability. At this time, the product which can express the shape having the required dimension at the processing temperature 100 ~ 120 ℃ can be processed in the range of the above processing temperature, and the product having the error range of 0.2 ~ 5% is required. The product can be processed in the above processing temperature range, and the product with the required error range within 6 ~ 10% can be processed at the temperature above 120 ℃ outside the above processing temperature, and the required dimension is 11%. A product having the above error range was determined to be defective.

Example 1

77 wt% of polyethylene terephthalate having an intrinsic viscosity of 0.64 dl / g measured at 20 ° C. using a solvent in which a phenol and tetrachloroethane were mixed at a weight ratio of 50:50 as a viscosity measuring solvent, and the method of ASTM D-1238. Melt index (Melt index) value measured by 13.0g / 10cm, density of 0.965g / cc measured by the method of ASTM D 1505, 20 weight of high density polyethylene having a melting point of 131 ℃ measured by the method of ASTM D 2117 %, 3% by weight of polyethylene substituted with an alkylcarboxyl group as a compatibilizer was carried out by a conventional method for producing polyester monofilament.

Example 2

It carried out similarly to Example 1 except having used 75 weight% of polyethylene terephthalates, and 5 weight% of compatibilizers.

Example 3

It carried out similarly to Example 1 except having used 70 weight% of polyethylene terephthalates, and 10 weight% of compatibilizers.

Example 4

It carried out similarly to Example 2 except having used low density polyethylene instead of high density polyethylene as polyolefin.

Example 5

The polyolefin was carried out in the same manner as in Example 2 except that linear low density polyethylene was used instead of high density polyethylene.

Example 6

It carried out similarly to Example 2 except having used polypropylene instead of high density polyethylene as a polyolefin.

Example 7

77 wt% of polyethylene terephthalate having an intrinsic viscosity of 0.64 dl / g measured at 20 ° C. using a solvent in which a phenol and tetrachloroethane were mixed at a weight ratio of 50:50 as a viscosity measuring solvent, and by the method of ASTM D 1238. 15% by weight of a high density polyethylene having a melt index value of 13.0 g / 10 cm, a density of 0.965 g / cc measured by the method of ASTM D 1505 and a melting point of 131 ° C. measured by the method of ASTM D 2117 5% by weight of polyethylene substituted with an alkylcarboxyl group, a compatibilizer, and a polycarbide having a molecular weight of 7000-8500 g / mol as a chain extender were used to prepare a polyester monofilament.

Example 8

It carried out similarly to Example 7 except having used low density polyethylene instead of high density polyethylene as a polyolefin.

Example 9

The same procedure as in Example 7 was carried out except that linear low density polyethylene was used instead of high density polyethylene as the polyolefin.

Example 10

It carried out similarly to Example 7 except having used polypropylene instead of high density polyethylene as a polyolefin.

Example 11

90% by weight of polyethylene terephthalate, 5% by weight of high density polyethylene as a polyolefin, and 5% by weight of polyethylene substituted with an alkylcarboxyl group as a compatibilizer were carried out in the same manner as in Example 1.

Example 12

80% by weight of polyethylene terephthalate, 15% by weight of high density polyethylene as a polyolefin, and 5% by weight of polyethylene substituted with an alkylcarboxyl group as a compatibilizer were carried out in the same manner as in Example 1.

Example 13

70% by weight of polyethylene terephthalate, 25% by weight of high density polyethylene as polyolefin, and 5% by weight of polyethylene substituted with alkylcarboxyl group as compatibilizers were carried out in the same manner as in Example 1.

Example 14

Except for adding 0.03% by weight of cyanine blue to the polymer as an organic pigment was carried out in the same manner as in Example 1.

Comparative Example 1

It carried out similarly to Example 1 except having used 79.9 weight% of polyethylene terephthalates, 20 weight% of high density polyethylene as a polyolefin, and 0.1 weight% of compatibilizers.

Comparative Example 2

It carried out similarly to Example 1 except having used 50 weight% of polyethylene terephthalates, 20 weight% of high density polyethylene as a polyolefin, and 30 weight% of compatibilizers.

Comparative Example 3

It carried out similarly to Example 7 except having used 79.5 weight% of polyethylene terephthalates, 15 weight% of high density polyethylene as a polyolefin, 5 weight% of compatibilizing agents, and 0.5 weight% of chain extenders.

[Comparative Example 4]

It carried out similarly to Example 7 except having used 60 weight% of polyethylene terephthalates, 15 weight% of high density polyethylene as a polyolefin, 5 weight% of compatibilizers, and 20 weight% of chain extenders.

[Comparative Example 5]

It carried out similarly to the said Comparative Example 3 except having used polypropylene instead of high density polyethylene as a polyolefin.

Comparative Example 6

It carried out similarly to the said Comparative Example 4 except having used polypropylene instead of high density polyethylene as a polyolefin.

Comparative Example 7

It carried out similarly to Example 1 except having used 50 weight% of polyethylene terephthalates, 45 weight% of high density polyethylene as a polyolefin, and 5 weight% of compatibilizers.

Comparative Example 8

It carried out similarly to Example 1 except having used 40 weight% of polyethylene terephthalates, 55 weight% of high density polyethylene as a polyolefin, and 5 weight% of compatibilizers.

Comparative Example 9

Polyester monofilaments were prepared using only polyethylene terephthalate.

Comparative Example 10

Polyester monofilaments were prepared using 80 wt% polyethylene terephthalate and 20 wt% high density polyethylene as polyolefin.

Fiber properties and processability of the polyester monofilament prepared in Examples and Comparative Examples are shown in Tables 1 and 2 below.

TABLE 1

TABLE 2

Claims (5)

In preparing polyester monofilament from polyethylene terephthalate, 35 to 95 weight percent polyethylene terephthalate, 3 to 30 weight percent polyolefin, 1 to 20 weight percent compatibilizer, and chain extenders 1 to 1 based on carbodiimide A method for producing a polyester monofilament, characterized by adding 15% by weight. [Claim 2] The polyester according to claim 1, wherein the polyethylene terephthalate has an intrinsic viscosity of 0.4 to 1.2 dl / g measured at 20 DEG C using a solvent in which phenol and tetrachloroethane are mixed at a weight ratio of 50:50. Method for producing monofilament. The method of claim 1, wherein the polyolefin is a low density polyethylene (Melt index) value of 0.01 ~ 30g / 10cm measured by the method of ASTM D 1238, Melt index (Melt index) measured by the method of ASTM D 1238 Linear low density polyethylene with a value of 0.1-30 g / 10 cm, melt viscosity measured by the method of ASTM D 1238 or high viscosity polyethylene having a value of 0.01-30 g / 10 cm or melt viscosity measured by the method of ASTM D 1238 ( Melt index) A method for producing a polyester monofilament, characterized in that using a polypropylene having a value of 0.3 ~ 60g / 10cm. The method for producing a polyester monofilament according to claim 1, wherein a polyethylene having a molecular weight of 20,000 to 50,000 g / mol substituted with an alkylcarboxyl group grafted with fumaric acid is used as the compatibilizer. The method according to claim 1, wherein as the chain extender, polycarbodiimide having a molecular weight of 7,000 to 8,500 g / mol or 1,1 ', 6,6'-(tetraisopropyl) diphenylcarbodiimide is used. Process for producing polyester monofilament.