KR20200071559A - Polyethylene-based composition for high modulus fiber - Google Patents

Abstract

The present invention relates to a polyethylene resin composition comprising: 0.01 to 0.7 parts by weight of an anti-oxidant represented by chemical formula 1; and 0.01 to 0.3 parts by weight of a fluorine-based polymer processing additive (PPA) with regard to 100 parts by weight of a polyethylene resin prepared by copolymerizing ethylene and alpha-olefin having 3 to 10 carbon atoms and, more particularly, to a polyethylene resin composition for high modulus fiber, in which the polyethylene resin has a melt flow index (ASTM D1238, 190°C, 2.16kg) of 0.5 to 5.0 g/10 minutes and excellent processibility, has a low single yarn rate due to gel during a high-temperature processing, and has excellent mechanical properties.

Description

Polyethylene-based composition for high modulus fibers

The present invention relates to a high-strength polyethylene-based resin composition for high-strength fibers having excellent processability, low monofilament rate due to gel during high-temperature processing, and excellent mechanical properties.

Polyethylene resins are classified into high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene according to the comonomer content, and are used as engineering plastics and films, and fiber utilization is increasing for clothing and industrial purposes.

Moreover, the recent issue in the textile field is super fibers that exhibit high performance in extreme environments such as aramid fibers, carbon fibers, and polyarylate fibers that require high strength and high elastic modulus, and among them, super fibers based on polyethylene have a molecular weight. There are over millions of ultra high molecular weight polyethylene fibers.

In recent years, further improvement in performance, especially durability, is required for these high-strength polyethylene fibers. For example, mechanical durability over a long period of time or adaptability under severe use conditions. Durability in long-term use is also required in textiles such as sports medical care and fishing threads.

In this regard, in PCT Publication No. WO2014/084470 as a prior art, there is a method of lowering the monoclinicity and increasing the mechanical properties of polyethylene for fibers by using a resin having a low gel as a polyethylene resin, but the strength and There is a problem that the elastic modulus is lowered.

The present invention has been proposed to solve the above problems, it is excellent in processability and suppresses the formation of a gel (gel) when spinning at a high temperature to reduce the single yarn rate, and to increase the draw ratio to provide a high-strength fiber-based polyethylene resin composition.

Aspects of the present invention for solving the above problems,

With respect to 100 parts by weight of a polyethylene resin prepared by copolymerizing ethylene and an alpha-olefin having 3 to 10 carbon atoms,

Antioxidants represented by the formula (1) 0.01 ~ 0.7 parts by weight; And

0.01 to 0.3 parts by weight of a fluorine-based processing additive (PPA); In the polyethylene-based resin composition comprising,

The polyethylene resin is to provide a polyethylene resin composition for fibers having a melt flow index (ASTM D1238, 190° C., 2.16 kg) of 0.5 to 5.0 g/10 min.

<Formula 1>

(Where R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkyl cycloalkyl group having 6 to 12 carbon atoms, or 7 to 12 carbon atoms. An aralkyl group or an aryl group having 6 to 14 carbon atoms,

R ³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms,

X is a single bond, a sulfur atom or -CHR ⁶ -wherein R ⁶ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms,

A is an alkylene group having 2 to 8 carbon atoms or *-COR ⁷ -where R ⁷ is a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond to an oxygen atom,

One of Y and Z is a hydroxy group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms)

The polyethylene-based resin composition for textiles of the present invention has excellent gel reduction effect, and when applied to fiber yarn applications where gel control is important at high temperatures, lowers the monofilament rate by the gel to improve workability. At the same time, it has the effect of improving the mechanical properties of the fiber by increasing the draw ratio.

Hereinafter, the present invention will be described in more detail. However, this is only described specifically to help the understanding of the present invention, and the scope of the present invention is interpreted based on the claims.

The present invention is based on 100 parts by weight of a polyethylene resin prepared by copolymerizing ethylene with an alpha-olefin having 3 to 10 carbon atoms,

Antioxidants represented by the formula (1) 0.01 ~ 0.7 parts by weight; And

0.01 to 0.3 parts by weight of a fluorine-based processing additive (PPA); In the polyethylene-based resin composition comprising,

The polyethylene resin relates to a polyethylene resin composition for fibers having a melt flow index (ASTM D1238, 190° C., 2.16 kg) of 0.5 to 5.0 g/10 min.

<Formula 1>

(Where R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkyl cycloalkyl group having 6 to 12 carbon atoms, or 7 to 12 carbon atoms. An aralkyl group or an aryl group having 6 to 14 carbon atoms,

R ³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms,

X is a single bond, a sulfur atom or -CHR ⁶ -wherein R ⁶ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms,

A is an alkylene group having 2 to 8 carbon atoms or *-COR ⁷ -where R ⁷ is a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond to an oxygen atom,

One of Y and Z is a hydroxy group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms)

The present invention relates to a polyethylene resin composition for fibers comprising an antioxidant and a fluorine-based processing aid, and an excellent gel reduction effect by using an antioxidant and a fluorine-based processing aid.

In one embodiment, the polyethylene resin may be prepared by copolymerizing ethylene and an alpha-olefin having 3 to 10 carbon atoms.

The alpha-olefin having 3 to 10 carbon atoms may be at least one selected from the group consisting of propylene, 1-butene, 1-octene and 1-hexene.

In one embodiment, the polyethylene-based resin composition for fibers of the present invention may include 0.01 to 0.7 parts by weight of the antioxidant represented by Formula 1 with respect to 100 parts by weight of the polyethylene resin.

Since the antioxidant represented by Chemical Formula 1 includes both a phenol-based and a phosphorus-based chemical structure, it performs a radical capture function of a phenolic antioxidant as a primary antioxidant and a peroxide decomposition function of a phosphorus-based antioxidant as a secondary antioxidant. Can be. Therefore, as a general antioxidant, it is possible to exhibit superior properties than using a primary phenol-based (radical inhibitor) and a secondary phosphorus-based (peroxide decomposing agent) antioxidant.

In one embodiment, the antioxidant is contained in 0.01 to 0.7 parts by weight based on 100 parts by weight of the polyethylene resin, preferably 0.05 to 0.3 parts by weight.

When the content of the antioxidant is less than 0.01 parts by weight, the viscosity may increase due to the occurrence of degradation during high-temperature processing, and when it exceeds 0.7 parts by weight, strength and elongation in fiber properties may be inferior.

In one embodiment, the fluorine-based processing aid (polymer processing additive, PPA) may be a fluoroelastomer (fluoroelastomer) or fluoroplastic (fluoroplastic), preferably 0.01 to 0.3 parts by weight based on 100 parts by weight of the polyethylene resin May be included in 0.05 to 0.1 parts by weight.

If the content of the fluorine-based processing aid is less than 0.01 part by weight, the gel may be generated due to high temperature processing, resulting in a lot of yarn trimming, so the continuous winding time may be shortened. If it exceeds 0.3 parts by weight, strength and elongation in fiber properties Can be inferior.

In one embodiment, the polyethylene resin melt flow index (STM D1238, 190 ℃, 2.16kg) may be 0.5 ~ 5.0g / 10 minutes, preferably 0.7 ~ 2.0g / 10 minutes.

If the melt flow index is less than 0.5g/10 minutes, the flow rate decreases, and the processing rate decreases. If it exceeds 5.0g/10 minutes, the low molecular weight increases, so that the strength and elongation among the fiber properties are lowered, so that the draw ratio cannot be increased. have.

In one embodiment, the polyethylene resin may have a density of 0.945 to 0.965 g/cm ³ , and preferably 0.950 to 0.960 g/cm ³ .

When the density is less than 0.945 g/cm ³ , strength and elongation among the properties of the fiber decrease, and when it exceeds 0.965 g/cm ³ , a problem in that the appearance of the fiber may be inferior.

In one embodiment, the polyethylene resin may have a melt flow rate ratio (190°C, MI 21.6kg / MI 2.16kg) of 20 to 50, and when the melt flow rate ratio is less than 20, problems may occur in winding fibers due to deterioration in processability. If it exceeds 50, there is a problem that the strength and elongation of the properties of the fiber is lowered.

If it is out of the above range, the continuous winding time is short, and the strength and elongation of the fiber properties are low, so that the elongation ratio cannot be increased.

In one embodiment, the polyethylene resin can be prepared by polymerization under a Ziegler-Natta catalyst system.

Polyethylene resins polymerized with Ziegler-Natta catalysts have better processability than polymerized with metallocene catalysts.

The polyethylene-based resin composition for fibers of the present invention has a low monoclinic rate due to gel during high-temperature processing and excellent mechanical properties.

Hereinafter, the present invention will be described in more detail through the following examples, but the scope of the present invention is not limited to the examples.

Preparation of catalyst

47.8 g (1.968 mmol) of magnesium and 5.0 g (0.02 mol) of iodine were suspended in 2400 ml of purified heptane in a 5 liter glass reactor equipped with a mechanical stirrer. The temperature of this mixture was raised to 85° C. and 44.9 ml (0.165 mole) of tetratetrabutoxytitanium and 22.8 ml (0.205 mole) of titanium tetrachloride were injected and mixed, and then 318 ml (3.05 mole) of 1-chlorobutane was added over 4 hours. Dropwise. After completion of the injection, an additional reaction was performed for 2 hours, and then washed 4 times with a sufficient amount of hexane. To this, 8.240 ml (0.037 mol) of tetraethoxysilane was injected to further react at 60° C. for 1 hour. The catalyst thus obtained was stored in purified hexane as a slurry.

Preparation of polyethylene resin

0.165 mol of the prepared catalyst, 0.250 mol of the co-catalyst trinormal octyl aluminum (TnOA), polymerization temperature of 90° C., polymerization pressure of 19.5 kgf/cm ² and ethylene of 35 mol% were maintained in a gas phase fluidized bed reactor for 12 hours to polymerize the polyethylene resin. Did.

Example 1

As an additive to the linear low-density polyethylene resin prepared above, it is included in the range of Chemical Formula 1, and has antioxidant properties (Sumitomo, Sumilizer GP) 2000ppm and fluorine-based processing aid (3M, FX5920A, Fluorine 30%). After mixing 700 ppm of ethylene glycol (70%) with a Henschel mixer, it was processed in a twin-screw extruder at 200°C to produce pellets.

Example 2

As an additive, included in the range of Chemical Formula 1, antioxidants having primary and secondary antioxidant functions (Sumitomo, Sumilizer GP) 1500 ppm, secondary antioxidants (Basf, Irgafos-168) 500 ppm and fluorine-based processing aids (3M, FX5920A) , Fluorine 30%, ethylene glycol 70%) was prepared in the same manner as in Example 1, except that 350ppm was added.

Example 3

As an additive, included in the range of Chemical Formula 1, antioxidants having primary and secondary antioxidant functions (Sumitomo, Sumilizer GP) 1500 ppm, primary antioxidants (Songwon Industries, Songnox-1010) 500 ppm, fluorine-based processing aids (3M, FX5920A, Fluorine 30%, ethylene glycol 70%) was prepared in the same manner as in Example 1, except that 350ppm.

Example 4

As an additive, it is included in the range of Chemical Formula 1, and contains 1500 ppm of antioxidants (Sumitomo, Sumilizer GP) having primary and secondary antioxidant functions and 700 ppm of fluorine-based processing aids (3M, FX5920A, Fluorine 30%, ethylene glycol 70%) It was prepared in the same manner as in Example 1 except for one.

Comparative Example 1

It was prepared in the same manner as in Example 1, except that 1000 ppm of the primary antioxidant (Songwon Industry, Songnox-1010) and 500 ppm of the secondary antioxidant (Basf, Irgafos-168) were added as additives.

Comparative Example 2

It was prepared in the same manner as in Example 1, except that only 2000 ppm of the antioxidant (Sumitomo, Sumilizer GP), which is included in the range of Formula 1 as an additive and has a primary and secondary antioxidant function, was added.

Comparative Example 3

As an additive, it is included in the range of Chemical Formula 1, and blends 2000 ppm of antioxidants (Sumitomo, Sumilizer GP) with primary and secondary antioxidant functions and 700 ppm of fluorine-based processing aids (3M, FX5920A, Fluorine 30%, ethylene glycol 70%) It was prepared in the same manner as in Example 1 except for one.

Comparative Example 4

As an additive, included in the range of Chemical Formula 1, antioxidants having primary and secondary antioxidant functions (Sumitomo, Sumilizer GP) 1500 ppm, primary antioxidants (Songwon Industries, Songnox-1010) 500 ppm, fluorine-based processing aids (3M, FX5920A, Fluorine 30%, ethylene glycol 70%) was prepared in the same manner as in Example 1, except that 350ppm.

Comparative Example 5

Additives included in the range of Formula 1, antioxidants having primary and secondary antioxidant functions (Sumitomo, Sumilizer GP) 50 ppm, secondary antioxidants (Basf, Irgafos-168) 40 ppm and fluorine-based processing aids (3M, FX5920A) , Fluorine 30%, ethylene glycol 70%) was prepared in the same manner as in Example 1, except that 350ppm was added.

Comparative Example 6

Additives included in the range of Formula 1, antioxidants having primary and secondary antioxidant functions (Sumitomo, Sumilizer GP) 50ppm, primary antioxidants (Songwon Industries, Songnox-1010) 40ppm, fluorine-based processing aids (3M, FX5920A, Fluorine 30%, ethylene glycol 70%) was prepared in the same manner as in Example 1, except that 350ppm was added.

Comparative Example 7

As an additive, it is included in the range of Chemical Formula 1, and contains 2000 ppm of antioxidants (Sumitomo, Sumilizer GP) having primary and secondary antioxidant functions and 80 ppm of fluorine-based processing aid (3M, FX5920A, Fluorine 30%, ethylene glycol 70%) It was prepared in the same manner as in Example 1 except for one.

Comparative Example 8

As an additive, the primary antioxidant (Songwon Industries, Songnox-1010) 1000ppm, secondary antioxidants (Basf, Irgafos-168) 1000ppm and erucamide (13-cis-dococenamide, Erucamide) 500ppm were mixed in an example It was prepared in the same manner as 1.

Comparative Example 9

As an additive, primary antioxidant (Songwon Industry, Songnox-1010) 1000ppm, secondary antioxidant (Basf, Irgafos-168) 1000ppm and fluorine-based processing aid (3M, FX5920A, Fluorine 30%, ethylene glycol 70%) 350ppm It was prepared in the same manner as in Example 1 except for one.

Cast film manufacturers

Using the polyethylene resin prepared in the above Examples and Comparative Examples, a cast film having a thickness of 40 μm was formed at a temperature of 250° C. with a cast film equipment of OCS.

Method for measuring resin properties

1) Melt flow index (Melt Index, MI)

Measured under a load of 2.16 kg at 190°C according to ASTM D1238.

2) Melt Flow Ratio (MFRR)

MI 21.6 (21.6kg load, melt flow index at 190°C) / MI 2.16 (2.16kg load, melt flow index at 190°C)

3) Density

Measured according to ASTM D1505.

4) Gel measurement

After automatically counting the size and number of the gels using the film surface analyzer FSA-100 of OCS, the produced film is divided by the weight of the film of the measured area to indicate the number of gels per g.

5) Continuous winding time

Calculate the ratio of yarn trimmed by gel to the total yarn produced per hour to calculate the time to continuously wind the fiber.

6) Fineness

In one revolution, the fiber is rotated 90 degrees using a paper tube having a length of 1 m, and the weight is measured by winding a 90-meter thread and converted to 9000 m (denier, de') for evaluation.

7) Strength and elongation

Measured according to ASTM D2256 using a universal testing machine (UTM).

Unit Example 1 Example 2 Example 3 Example 4 Resin properties Melt Index g/10 minutes 0.9 0.8 1.2 2.3 Melt flow rate ratio - 28 31 30 29 density g/cm ³ 0.956 0.955 0.956 0.941 additive A ppm 2000 1500 1500 1500 B ppm - - 500 - C ppm - 500 - - D ppm 700 350 350 700 Gel <200㎛ ea/g 71 92 90 82 > 200㎛ ea/g 12 21 24 18 Textile properties Continuous winding time minute >60 >60 >60 >60 Island de' 400 410 410 410 burglar g/d 15.0 13.8 13.4 12.5 Shinto % 7.0 7.3 7.1 6.9

Unit Comparative example One 2 3 4 5 6 7 8 9 Suzy
Properties Melt Index g/10 minutes 1.0 0.7 6.3 0.1 0.8 0.9 0.9 0.9 0.8 Melt flow rate ratio - 30 31 68 30 31 30 28 29 31 density g/cm ³ 0.956 0.958 0.956 0.956 0.955 0.955 0.956 0.955 0.955 additive A ppm - 2000 2000 1500 50 50 2000 - - B ppm 1000 - - 500 - 40 - 1000 1000 C ppm 500 - - 40 - - 1000 1000 D ppm - - 700 350 350 350 80 - 350 E ppm - - - - - - - 500 - Gel <200㎛ ea/g 698 236 252 662 721 751 158 568 228 > 200㎛ ea/g 164 56 68 185 203 214 32 159 73 fiber
Properties Continuous winding time minute 15 40 20 - 2 2 50 12 30 Island de' 570 500 570 - - - 480 590 530 burglar g/d 15.0 14.8 8.0 - - - 15.1 15.0 14.7 Shinto % 7.6 7.4 2.0 - - - 7.6 7.4 7.5

-Additive A: Sumitomo's Sumilizer GP (including primary and secondary antioxidant functions)

-Additive B: Songnox-1010 from Songwon Industry (phenol-based primary antioxidant _ radical capture)

-Additive C: Irgafos-168 from Basf (phospite-based secondary antioxidant_peroxide decomposition)

-Additive D: 3M's FX5920A (Fluorine 30%, ethylene glycol 70%)

-Additive E: PMC's ARMOSLIP-E erucamide (13-cis-dococenamide, Erucamide)

Here, additives A, B, and C are all antioxidants, additive D is a PPA (polymer processing additive), and additive E is a slip agent erucamide.

As shown in Table 1 and Table 2, Example 1 in which the antioxidant (A) and the fluorine-based processing aid (D) are included together as additives is 200 μm or less and 200 in comparison with Comparative Example 2 containing only the antioxidant (A). Since there are fewer gels of µm or more, there is less yarn trimming by the gel, so the continuous winding time is long.

Example 2, which includes antioxidants (A, C) and fluorine-based processing aids (D) as additives, was found to have excellent fiber properties (strength and elongation), primary antioxidants (phenolic) and secondary antioxidants In Comparative Example 1, each containing only (takeover), the elongation ratio was decreased due to the yarn trimming by the gel, and the fineness was 570 de'.

In addition, although Example 1 and Comparative Example 3 had the same additive type and content, Comparative Example 3 had a MI of 6.3 g/10 min, and the MFRR was 68. Since the time is short, and the fiber properties (strength and elongation) are poor, the elongation ratio cannot be increased, so the island is also large at 570 de'.

Example 3, which includes antioxidants (A, B) and fluorine-based processing aids (D) as additives, was found to have superior fiber properties (strength and elongation) when compared to Comparative Example 4, which had the same additive type and content. In Comparative Example 4, it was difficult to evaluate the physical properties because the melt index was too low to process the fibers. However, although additives A and D were included, Example 4 with low density was found to have poor strength and elongation.

In addition, in Comparative Examples 5 and 6 in which the content of the antioxidant was out, the content of the antioxidant was small, and thus gel was generated due to polymer oxidation during high temperature processing, and fiber processing was difficult. In Comparative Example 7, in which the content of the processing aid was off, the antioxidant A of the same content as in Example 1 was prescribed, but the number of gels was higher, so that the continuous winding time was short and the fineness was 480 de', and included the antioxidant and slip agent. Comparative Example 8, which also does not contain the desired amount of processing aid, has a large number of gels, resulting in a short continuous winding time and a large fineness of 590 de'.

In addition, Comparative Example 9, which contains a primary antioxidant (phenolic) and a secondary antioxidant (phosphorous), respectively, and includes a fluorine-based processing aid, contains an antioxidant A that contains both primary and secondary. As compared with Example 1, there were more gels, so the continuous winding time was short and the fineness was 530de'.

Claims (6)

With respect to 100 parts by weight of a polyethylene resin prepared by copolymerizing ethylene and an alpha-olefin having 3 to 10 carbon atoms,
Antioxidants represented by the formula (1) 0.01 ~ 0.7 parts by weight; And
0.01 to 0.3 parts by weight of a fluorine-based processing additive (PPA); In the polyethylene-based resin composition comprising,
The polyethylene resin melt flow index (ASTM D1238, 190 ℃, 2.16kg) is a polyethylene resin composition for fibers, characterized in that 0.5 ~ 5.0g / 10 minutes.

<Formula 1>

(Where R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkyl cycloalkyl group having 6 to 12 carbon atoms, or 7 to 12 carbon atoms. An aralkyl group or an aryl group having 6 to 14 carbon atoms,
R ³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms,
X is a single bond, a sulfur atom or -CHR ⁶ -wherein R ⁶ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 8 carbon atoms,
A is an alkylene group having 2 to 8 carbon atoms or *-COR ⁷ -wherein R ⁷ is a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond to an oxygen atom,
One of Y and Z is a hydroxy group, an alkoxy group having 1 to 8 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms, and the other is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms)
According to claim 1,
The fluorine-based processing aid (polymer processing additive, PPA) is a fluoroelastomer (fluoroelastomer) or fluoroplastic (fluoroplastic), characterized in that the polyethylene resin composition for fibers.
According to claim 1,
The polyethylene resin has a melt flow rate ratio (190 ℃, MI 21.6kg / MI 2.16kg) is a polyethylene-based resin composition for fibers, characterized in that 20 to 50.
According to claim 1,
The polyethylene resin is a polyethylene resin composition for fibers, characterized in that the density is 0.945 ~ 0.965g / cm ³ .
According to claim 1,
The polyethylene resin is a polyethylene-based resin composition for fibers, characterized in that produced by polymerization under a Ziegler-Natta (Zeigler-Natta) catalyst system.
According to claim 1,
The alpha-olefin is a polyethylene-based resin composition for fibers, characterized in that at least one selected from the group consisting of ethylene, propylene, 1-butene, 1-octene and 1-hexene.