A highly dispersed weather-resistant masterbatch for polypropylene fibers and its preparation method

Abstract

This invention discloses a highly dispersed weather-resistant masterbatch for polypropylene fibers, comprising the following components: 65-80 parts of polypropylene resin; 15-25 parts of light stabilizer; 5-10 parts of functional modifier; and 0.2-2 parts of antioxidant. The functional modifier effectively establishes a viscosity gradient between the masterbatch carrier and the additives, promoting uniform dispersion of the weather-resistant additives and effectively reducing the precipitation of additives in the masterbatch. The appropriate combination of triazine hindered amine light stabilizer and HALS 622 improves the compatibility of the light stabilizer system with the polypropylene resin. This masterbatch enables rapid and uniform dispersion in polypropylene products, greatly avoiding process problems such as filament breakage and frequent spinneret cleaning during spinning, significantly improving the weather resistance of polypropylene products, and possessing excellent cost-effectiveness and market application value.

Description

Technical Field

[0001] This invention belongs to the field of polypropylene product processing, specifically relating to a highly dispersed weather-resistant masterbatch for polypropylene fibers and its preparation method. Background Technology

[0002] Polypropylene fiber (also known as polypropylene fiber) is a fiber product made from polypropylene through melt spinning. Due to its many excellent properties, polypropylene fiber is increasingly widely used in the three major fields of decoration, industry, and clothing, and has become the second largest variety of synthetic fiber. Polypropylene fiber is divided into staple fiber, filament, nonwoven fabric (spunbond and meltblown), cigarette tow, and bulked continuous filament (BCF), etc. Its applications include packaging, cigarette filter materials, geotextiles, building materials, clothing, carpets, and hygiene products, demonstrating a very wide range of applications and promising market prospects.

[0003] Polypropylene has poor weather resistance, requiring high-quality weather-resistant auxiliaries. Polypropylene fiber products are mostly composed of polypropylene monofilaments, which have a very high specific surface area and fiber diameters typically ranging from 1-10 μm. When used outdoors, they are prone to photo-oxidative aging. Furthermore, polypropylene manufacturing requires high processing temperatures (250-280℃) and fine spinneret orifices, necessitating uniform melt viscosity to prevent die buildup, which can lead to yarn breakage and frequent spinneret cleaning. Currently, weather-resistant auxiliaries in polypropylene products generally employ high-molecular-weight triazine hindered amine light stabilizers, such as HALS 944, HALS 119, and HALS 2020, prepared as pre-dispersed weather-resistant masterbatches to meet demanding processing and environmental requirements.

[0004] Conventional weather-resistant masterbatch processes fail to achieve the desired high dispersion and weather-resistant application effects. Conventional weather-resistant masterbatch formulations simply homogenize triazine hindered amine light stabilizers with resin and extrude them through a twin-screw extruder. Due to differences in polarity and molecular weight, this often only achieves resin carrier encapsulation of the additives, and the additives are prone to precipitation during subsequent storage. The masterbatch product exhibits poor processing and dispersibility in polypropylene products, preventing the weather-resistant additives from truly and effectively exerting their weather-resistant effects in polypropylene products. Summary of the Invention

[0005] To address the above problems, this invention discloses a highly dispersed weather-resistant masterbatch for polypropylene fibers and its preparation method.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A highly dispersed weather-resistant masterbatch for polypropylene fibers is composed of the following components:

[0008] 65-80 parts of polypropylene resin;

[0009] 15-25 parts light stabilizer;

[0010] Functional regulator 5-10 parts;

[0011] Antioxidant 0.2-2 parts.

[0012] The functional modifier is a PE oligomer or a POE oligomer with a number average molecular weight of 80 million to 300 million.

[0013] Furthermore, the light stabilizer is a compound of triazine hindered amine light stabilizer and HALS 622 in a mass ratio of 2:1 to 5:1.

[0014] Furthermore, the triazine hindered amine light stabilizer is one of HALS 944, HALS 119, HALS 2020, HALS 3346, and HALS 3529.

[0015] Furthermore, the antioxidant is one or two of antioxidant 3114, antioxidant 1010, antioxidant 245, antioxidant 168, and antioxidant 626.

[0016] Furthermore, the polypropylene resin is a powdered polypropylene resin with a melt index of 1-10 g / 10 min.

[0017] This invention also provides a method for preparing the polypropylene fiber highly dispersed weather-resistant masterbatch as described above, comprising the following steps:

[0018] (1) Weigh the polypropylene resin, light stabilizer, functional modifier and antioxidant according to the proportion, put them into the mixer and stir at room temperature for 5-8 minutes;

[0019] (2) The mixed material is fed into the main feed port of the twin-screw extruder. The temperature of the extruder conveying section is 100-180℃, the temperature of the melt mixing section is 180-210℃, the temperature of the metering section is 170-190℃, the main machine speed is 300-400r / min, and the length-to-diameter ratio of the extruder is 48-52.

[0020] (3) After the material strip is extruded from the die, it is cooled in a cooling water tank, air-dried, pelletized, and homogenized to obtain polypropylene fiber high dispersion weather-resistant masterbatch.

[0021] The beneficial effects of this invention are as follows:

[0022] By using PE oligomers or POE oligomers, a suitable viscosity gradient can be established, which can effectively transfer the stress of the screw extruder to the resin and additives, accelerate the uniform dispersion of the two, and avoid the problem of poor plasticization of additives caused by "slippage".

[0023] Using PE oligomers or POE oligomers can effectively reduce the precipitation of additives and promote the dispersion rate of light stabilizers during polypropylene spinning. The polarity difference between polypropylene resin and triazine light stabilizers causes polypropylene to easily undergo directional rearrangement crystallization. With fewer amorphous regions, light stabilizers are prone to aggregation and precipitation.

[0024] HALS 622 can act as a compatibilizer, reducing the polarity difference between the triazine hindered amine light stabilizer and the polypropylene resin. Through multiple experiments, it has been demonstrated that the reasonable combination of the two does not affect the protection efficiency against photo-oxidative aging, and reduces die buildup, filament breakage frequency, and the cost of weather-resistant additives. Detailed Implementation

[0025] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0026] Example 1

[0027] Required additives: HALS 944, HALS 622, antioxidant 3114 and antioxidant 168 are all from Suqian Liansheng Technology Co., Ltd., functional modifier POE 8402 is from Dow Chemical, PE wax SN108D is from Qingdao Sainuo New Materials Co., Ltd., and polypropylene resin is from Nanjing Yangzi Petrochemical Co., Ltd. See Table 1 for the composition.

[0028] Table 1

[0029]

[0030] Preparation process:

[0031] (1) Weigh the polypropylene resin, light stabilizer, functional modifier POE / PE wax and antioxidant according to the proportions in Table 1, and put them into the mixer and stir at room temperature for 8 minutes.

[0032] (2) The mixed material is fed into the main feed port of the twin-screw extruder. The temperature of the extruder conveying section is 100-180℃, the temperature of the melt mixing section is 180-210℃, the temperature of the metering section is 170-190℃, the main machine speed is 300r / min, and the length-to-diameter ratio of the extruder is 48.

[0033] (3) After the material strip is extruded from the die, it is cooled in a cooling water tank, air-dried, pelletized, and homogenized to obtain weather-resistant masterbatch 1.

[0034] Example 2

[0035] The light stabilizer and POE are different from those in Example 1, as shown in Table 1. The preparation process is the same as in Example 1, and weather-resistant masterbatch 2 is obtained.

[0036] Comparative Example 1

[0037] The light stabilizer differs from that in Example 1, but the preparation process is the same as in Example 1, as detailed in Table 1, resulting in weather-resistant masterbatch 3.

[0038] Comparative Example 2

[0039] The light stabilizer differs from that in Example 1, but the preparation process is the same as in Example 1, as detailed in Table 1, resulting in weather-resistant masterbatch 4.

[0040] Comparative Example 3

[0041] PE wax SN 108D was used to replace POE 8402 in Example 1, as detailed in Table 1. The preparation process was the same as in Example 1, resulting in weather-resistant masterbatch 5.

[0042] Comparative Example 4

[0043] The amount of antioxidant used differs from that in Example 1, as detailed in Table 1. The preparation process is the same as in Example 1, resulting in weather-resistant masterbatch 6.

[0044] Performance testing

[0045] The above six groups of weather-resistant masterbatches were added at a rate of 2% to polypropylene filament material (F 401) and melt spinning tests were conducted.

[0046] A) After mixing the two evenly in the mixer for 5 minutes, feed them into the screw extruder for melt extrusion. The temperature settings of the four zones of the screw extruder are as follows: Zone 1: 210℃, Zone 2: 230℃, Zone 3: 245℃, Zone 4: 258℃, the temperature of all melt pipes is 258℃, and the temperature of the spinning box is 256℃.

[0047] B) The melt extruded from the screw extruder is spun through the spinneret of the spinning assembly at a spinning speed of 255 m / min and a winding speed of 997 m / min. The spinneret temperature is maintained at 245℃, the draw ratio is 3.91, the draw roller temperature is 80℃, and heat setting is performed at 135℃ to obtain polypropylene filament. High-strength weather-resistant polypropylene twisted yarn is obtained by twisting.

[0048] C) Ten yarn samples were randomly cut from each group of polypropylene twisted yarns along a length of 100 meters. Five samples were taken before and five after aging for maximum tensile strength testing. Aging test standard: based on GB / T 31899-2015 "Textiles - Weather Resistance Tests - Ultraviolet Exposure" with UVA 340 0.89W / m 2 The nm test was conducted for 500 hours; the results are shown in Table 2.

[0049] The process stability of polypropylene weather-resistant masterbatch in the production of polypropylene fiber was observed by continuously running the above melt spinning process. The results are shown in Table 3.

[0050] Table 2

[0051]

[0052] The aging retention rate reflects the effect of weather-resistant additives on improving the weather resistance of polypropylene products, while the data variance reflects the volatility of weather resistance data, essentially indicating the dispersibility of weather-resistant additives in polypropylene products. Table 2 clearly shows that the use of POE oligomers increases the dispersibility of polypropylene weather-resistant masterbatch in polypropylene fibers. The aging retention rates of polypropylene corresponding to the weather-resistant masterbatches prepared in Examples 1 and 2 are both >70%, and the weather resistance data is stable. However, when using ordinary PE wax, the initial strength and weather resistance data stability of the polypropylene filaments fluctuate significantly. The weather resistance effect of the triazine hindered amine light stabilizer and HALS 622 in this invention is the best, no less than the effect of HALS 944 used alone. The introduction of excessive antioxidants in weather-resistant masterbatch 6 creates a counteracting effect with the hindered amine light stabilizer, leading to a decrease in weather resistance. Furthermore, the polypropylene filament products show obvious reddening after one week of storage.

[0053] Table 3

[0054]

[0055] Table 3 shows that polypropylene weather-resistant masterbatches 1 and 2 exhibit the best process stability and excellent dispersibility in the polypropylene fiber production process, showing a positive correlation with the weather resistance in Table 2. Weather-resistant masterbatch 4 uses pure HALS 944, but due to masterbatch dispersion issues, both weather resistance and process stability have certain problems.

[0056] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A highly dispersed weather-resistant masterbatch for polypropylene fibers, characterized in that, It consists of the following components: 65-80 parts of polypropylene resin; 15-25 parts light stabilizer; Functional regulator 5-10 parts; Antioxidant 0.2-2 parts; The functional modifier mentioned is POE 8402; The light stabilizer is a mixture of HALS 944 and HALS 622 in a mass ratio of 2:1 to 5:

1.

2. The polypropylene fiber highly dispersed weather-resistant masterbatch according to claim 1, characterized in that, The antioxidant is one or two of antioxidants 3114, 1010, 245, 168, and 626.

3. A method for preparing a highly dispersed weather-resistant masterbatch for polypropylene fibers as described in any one of claims 1-2, characterized in that, Includes the following steps: (1) Weigh the polypropylene resin, light stabilizer, functional modifier and antioxidant according to the proportion, put them into the mixer and stir at room temperature for 5-8 minutes; (2) The mixed material is fed into the main feed port of the twin-screw extruder. The temperature of the extruder conveying section is 100-180℃, the temperature of the melt mixing section is 180-210℃, the temperature of the metering section is 170-190℃, the main machine speed is 300-400r / min, and the length-to-diameter ratio of the extruder is 48-52. (3) After the material strip is extruded from the die, it is cooled in a cooling water tank, air-dried, pelletized, and homogenized to obtain polypropylene fiber high dispersion weather-resistant masterbatch.

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