WO2008055405A1

WO2008055405A1 - A process for producing fiber of ultra high molecular weight polyethylene

Info

Publication number: WO2008055405A1
Application number: PCT/CN2007/002906
Authority: WO
Inventors: Panpan Hu; Xiulan You; Zhaofeng Liu
Original assignee: Panpan Hu; Xiulan You; Zhaofeng Liu
Priority date: 2006-11-08
Filing date: 2007-10-09
Publication date: 2008-05-15
Also published as: ATE478178T1; EP2080824A1; DE602007008600D1; EP2080824B1; US20100233480A1; EP2080824A4

Abstract

A process for producing fiber of ultra high molecular weight polyethylene, with flat cross-section and high cohesiveness, is disclosed. The process includes: distributing the powder of UHMW-PE into the solvent evenly; preparing an uniform mixed emulsion by properly untangling with a high shear; at the same time adding the polar polymer comprising polar groups, for example a carboxyl group, a carbonyl group, an ether group, or an ester group and so on; evenly distributing the polar polymer together with the polyethylene powder in the solvent to form an uniform mixed emulsion; forming a gel filament with the mixed emulsion by gel spinning method, then extracting, drying, and ultra drafting so as to obtain the said UHMW-PE fiber, with falt cross section, high strength and cohesiveness. By properly untangling, the swellability and dissolubility of the ultra high molecular weight polyethylene can be accelerated, while the polar polymer being evenly distributed therein can significantly improve the adhesive capacity of the fiber. The operations in the production method are easy, and furthermore, time, labor and cost can be saved. The section of the fiber is of a flat rectangle shape and the wall is thin and even, so the path for the solvent in the fiber diffusing out of the gel filament can be significantly shorten, and thus the efficiency of extraction and the uniformity of the fiber can be improved.

Description

Preparation method of ultrahigh molecular weight polyethylene fiber

The invention relates to a method for preparing high molecular weight polyethylene fibers, in particular to a method for preparing ultrahigh molecular weight polyethylene fibers. Background technique

Ultra-high molecular weight polyethylene jelly spinning-super-stretching technology to prepare high-strength, high-modulus polyethylene fiber was patented by DSM in the Netherlands in 1979, and obtained British patent GB2042414 and GB2051667. Subsequently, Allied Company of the United States, Japan and the Netherlands jointly established Toyobo - DSM. Japan's Mitsui has achieved industrial production. In 1982, Allied Corporation of the United States obtained the US4413110 process patent for the production of ultra-high molecular weight polyethylene fibers. China Textile University has also obtained Chinese patents 89107905 and 97106768.

The main steps of ultra-high molecular weight polyethylene jelly spinning are: adding ultra-high molecular weight polyethylene into a suitable solvent and stirring to dissolve into a solution, the solution is extruded by a screw extruder, formed through a spinning hole, and then cooled, extracted, Dry and stretch over and finally obtain the finished fiber. The preparation of ultra-high molecular weight polyethylene uniform solution, the process of extracting a large amount of the first solvent contained in the jelly fiber by the second solvent before the super-stretching of the jelly fiber is the key to obtain high-strength high-modulus fiber.

As the molecular weight of polyethylene increases, its molecular size is large, and there are intertwined macromolecules. The entanglement between macromolecules is beneficial to increase the stretchability of the fiber to obtain high orientation, so that the fiber reaches high strength and high modulus. the amount. However, various viscoelastic effects caused by excessive and strong inter-molecular entanglement in the polymer make the dissolution much more complicated, which is disadvantageous for dissolution processing, and it is necessary to appropriately reduce inter-molecular entanglement. The entanglement state can be changed by heat treatment, solvent treatment, and shear treatment.

The molecular weight difference between the polymer sample and the low molecular solvent is very different. The polymer chain is very long and difficult to move. The interaction between the polymer bonds is large and there is entanglement between the macromolecules. When the polymer is in contact with the low molecular solvent, the polymer does not diffuse into the solvent. If the polymer powder is easily agglomerated or forms a gel block due to incomplete penetration of the solvent by a conventional dissolution method, a uniform solution cannot be obtained. Moreover, the viscoelasticity caused by the inter-molecular entanglement of the ultrahigh molecular weight polyethylene produces a Weissenberg effect (crawling phenomenon) when stirred. As the molecular weight increases, the polymer concentration increases, and the agitation speed increases, the Weissenberg effect becomes more apparent, making it more difficult to make a uniform solution.

For this reason, a number of solutions have been proposed for some patents. For example, the European patent EP0255618 mentions the use of hydrotreated kerosene, followed by rectification to obtain a hydrocarbon mixture having a boiling point of 180 to 250 degrees Celsius free of naphthalene and biphenyl. Further, the ultrahigh molecular weight polyethylene and decalin were stirred at 135 ° C for several hours to obtain a polyethylene solution. The concentration of the polyethylene solution is not more than 50%.

Japanese Patent JP59232123 mentions that the ultrahigh molecular weight polyethylene and a small amount of solvent are mixed for several minutes and then heated, and the solvent is continuously added under stirring to finally obtain a solution.

In the example mentioned in Japanese Patent Publication No. Sho 63-15838, an antioxidant and a polyethylene are added to a solvent prepared by catalytic hydrogenation of a kerosene fractionation portion, and then stirred at 140 ° C for 3 hours and then dissolved to give a weight percentage of 10%. Ultra high molecular weight polyethylene solution. - There are also ways to solve this problem by decomposing the dissolution into two processes of swelling and redissolution. It is mentioned in Chinese Patent No. 970106768 that it is a suspension of ultrahigh molecular weight polyethylene by a moderate swelling of a terpene hydrocarbon solvent under its respective conditions.

Chinese Patent 97101010 proposes a pre-swelling kettle equipped with a new agitator baffle to pre-melt the powdered ultra-high molecular weight polymer to obtain a suspension solution, in order to avoid the phenomenon of climbing of high molecular weight polyethylene during dissolution and agitation.

In the continuous preparation and mixing method of the Chinese patent 20041009607615 ultra-high molecular weight polyethylene solution, it is proposed to continuously prepare the mixed ultra-high molecular weight polyethylene solution by using a static mixer and a short aspect ratio screw. DSM Corporation CN85107352A provides a continuous process for the preparation of homogeneous solutions of high molecular polymers, including the introduction of finely divided polymers and solvents into the screw extruder, while the suspension and solution are formed inside the extruder, operating temperature Maintaining above the dissolution temperature, its mechanical shear rate is about 30~2000 sec ^-1 . This method destroys the molecular chain of the ultrahigh molecular weight polyethylene and lowers the molecular weight.

Although the above patents have been improved in the solvent and dissolution process, there are still problems such as complicated production equipment, unstable process, production safety hazards, and reduced fiber tensile strength.

The jelly fiber contains a large amount of the first solvent. The solvent in the fiber must be extracted by the second solvent and then subjected to ultra-stretching to obtain high-strength high-modulus fibers. The speed of the extraction process is related to the second solvent used and the extraction process. In addition, it is also related to the path of solvent diffusion. The solvent of the outer layer of the fiber preferentially diffuses out of the jelly fiber during the extraction process. The longer the difference in the diffusion speed of the path, the more the existing method is The jelly fiber of the round section of polyethylene has a thicker wall as seen from the cross section of the fiber. The greater the difference, the more the skin core structure is formed. This uneven structure affects the super-stretching of the fiber, which in turn affects the mechanical properties of the finished fiber. At present, the patents for producing high-density polyethylene shaped fiber membranes have been proposed by USP 4145492, USP 5294338, USP 6436319 ZL200510049263, which are all using the melt spinning method, and the patents USP 5569702 and ZL95193838 are thermoplastic hollow fiber membrane modules and manufacturing methods. The above method is costly and the resulting fiber structure uniformity is not ideal.

In addition, at present, ultra-high molecular weight polyethylene jelly spinning has been industrially produced by preparing high-strength, high-modulus polyethylene fibers by ultra-stretching. The polyethylene anti-spinning related patents EP0205960A EP0213208A US4413110, WO01/73173A EP1746187A1, etc. have been improved. In the ultra-high molecular weight polyethylene gel spinning process, it is critical to obtain a uniformly dissolved polymer solution and uniform ultra-stretching. Their uniformity is a prerequisite for the stability of the finished fiber properties.

In addition, polyethylene fiber is widely used in anti-cutting gloves, body armor, bulletproof helmets, cables, etc. due to its excellent properties such as light weight, high strength, high modulus, UV, impact resistance and seawater corrosion resistance. In most cases, it is necessary to use a composite with one or more substrates such as nitrile rubber, polyurethane, and epoxy resin. The surface inertness of the polyethylene fibers results in poor interfacial adhesion between the fibers and the substrate, which has been highly valued by those skilled in the art. In order to improve the interfacial adhesion strength between the polyethylene fiber and the resin matrix, those skilled in the art have employed a series of surface treatment methods such as surface graft modification, chemical agent etching, plasma treatment modification, and corona discharge. Treatment, photo-oxidation surface modification treatment, etc., activate the fiber inert surface layer.

USP 480136 provides a surface silylation grafting reaction of polyethylene fibers during the spinning process, and cross-linking treatment to improve the bonding performance of the fibers, but is not conducive to the subsequent super-stretching The mechanical properties of the fiber are not ideal. In the patents USP5039549 and USP5755913, ZL03115300.3, etc., the adhesion properties of the surface of the polyethylene fiber by plasma, ozone, corona discharge or ultraviolet irradiation are proposed, but the process is It is cumbersome, high equipment investment, and the best process conditions for handling are difficult to master, and it is difficult to achieve industrialization.

Jiang Sheng et al. (Study on the Adhesion Properties of Ultra High Molecular Weight Polyethylene Fibers, FRP/Composite, 2004 (3): 47) proposed the use of strong oxidizing chemicals such as chromic acid and potassium permanganate for polyethylene fibers. Liquid phase oxidation surface treatment, because the fiber is soaked in a strong oxidizing environment for a long time, improving the fiber Dimensional wettability leads to large loss of mechanical properties of the fiber, and the operation is cumbersome, the equipment is strict, and the waste liquid is seriously polluted.

CN163544 proposes a method for extracting a spun polyethylene gel fiber by using a composite extracting agent containing a polar polymer, thereby improving the surface bonding property of the fiber while maximally maintaining the original strength of the fiber, and is simple in operation. There is no need to add any equipment, but the process is effective in the relaxation state of the jelly fiber, and in the actual tensioning extraction process, the polar polymer is difficult to penetrate into the jelly fiber to bond the surface. The performance improvement effect is not obvious. Summary of the invention

The technical problem to be solved by the present invention is to overcome the technical defects of the existing ultrahigh molecular weight polyethylene fiber, solve the problem of obtaining a uniform raw material mixture, and removing the first solvent in the jelly fiber, and provide a simple and efficient operation. A method for preparing a cost-effective high molecular weight polyethylene fiber. The high molecular weight polyethylene fibers prepared by this method have high adhesion.

The technical problem solved by the present invention can be implemented by the following technical solutions:

A method for preparing an ultrahigh molecular weight polyethylene fiber, characterized in that a polyethylene powder having an ultrahigh relative molecular weight of 1 million to 6 million is added to a polar polymer, dispersed in a solvent, and formulated into a uniform mixed emulsion, and frozen In the silk spinning method, the mixed emulsion is quantitatively fed into the screw extruder while stirring to rapidly swell and dissolve to form a transparent and uniform spinning dope, which is extruded through a spinneret, cooled, solidified to form a spinning, and then passed through Extraction, drying, and ultra-stretching to obtain ultra-high molecular weight polyethylene fibers.

In the process of formulating the homogeneous mixed emulsion of the present invention, a polyethylene powder, a polar polymer and a solvent having an ultrahigh relative molecular weight of 1,000,000 million are injected into the unwinding apparatus in proportion to be unwrapped to form a uniform mixed emulsion.

The above homogeneous emulsion has a percentage concentration of 4% to 60%.

The above polar polymer is a polar polymer containing an ester group, a carbonyl group or an ether group. The polar polymer containing an ester group, a carbonyl group or an ether group is an ethylene/ethylene acetate copolymer, a polyacrylate, a polyvinylpyrrolidone/ethylene acetate copolymer having a different K value, and a polyoxyethylene polymer. One or a mixture of two or more.

The polar polymer is added in an amount of from 1 to 10% by weight based on the weight of the ultrahigh molecular weight of 1,000,000 million polyethylene powder. It is preferably 2-8%. In the above unwrapping process, silicone oil or a derivative thereof may be added for unwinding. Or / and adding silicone oil or a derivative thereof during solidification; wherein the amount of the silicone oil or its derivative added is that the ultra-polymer halo polyethylene fiber contains 0.05-5 wt% of the silicone oil or its derivative.

In the above unwrapping process, one or more of an antioxidant, a stabilizer, a dye, and a flame retardant may be added.

In the above method, the unwrapping device can provide a shear rate of at least 1000 seconds. Preferably, the unwinding apparatus may be 1000-5000 sec- ¹ , more preferably 2000-4000 sec. The unwinding apparatus may be one of a high speed disperser, a stirrer, a colloid mill, a homogenizer, a venturi, or a combination thereof.

In the above method, the relative average molecular weight of the ultrahigh molecular weight polyethylene is preferably from ⁴⁰⁰ in case of ⁶⁰⁰ million. More preferably, it is 2 million to 5 million.

In the process of formulating the homogeneous mixed emulsion of the present invention, the solvent used is a solvent which is liquid at normal temperature, and may be a terpene hydrocarbon, a cyclic hydrocarbon, an aromatic hydrocarbon, a derivative of a terpene hydrocarbon, a derivative of a cyclic hydrocarbon, an aromatic hydrocarbon. One of the derivatives and a mixture of two or more.

In the process of formulating a homogeneous solution of the present invention, the nominal concentration of the ultrahigh molecular weight polyethylene and the solvent is from 1 to 50% by weight.

The screw extruder used in the invention is one of a single screw, a twin screw, a triple screw and a four screw extruder, and the screw extrusion temperature is above the dissolution temperature of the ultra high molecular weight polyethylene, such as a screw extruder. Operating temperature 80-250 ° C o

The twin-screw extruder used can be rotated in the opposite direction or in the opposite direction, and the screw has an aspect ratio of 1:30-65.

In the present invention, the residence time of the homogeneous mixed emulsion in the twin-screw extruder is 10-60 minutes, preferably 20-40 minutes, the material temperature is 50-280 ° C, and the solution spinning temperature is controlled during extrusion. 140-280 °C. It is best at 200-260 °C.

In the present invention, the spinneret hole on the spinneret used in the screw extruder is a rectangular hole having an aspect ratio of 4-20, preferably 5-15.

In the present invention, the emulsion-like mixture may be directly fed to a screw extruder or fed to a screw extruder through a stirred storage tank. The storage cylinders used are one or more.

In the super-stretching process of the present invention, the fiber has a stretching temperature of 80 to 130 ° C and a stretching ratio of 20 times or more, preferably 30 to 60 times. Compared with the prior art, the invention has the following advantages:

1. Ultra-high molecular weight polyethylene fiber impregnated PU or nitrile gloves, which are soft, lightweight, corrosion-resistant, aging-resistant and oil-repellent, have become better cut-proof gloves on the market today. However, due to the chemical inertness of polyethylene, it has poor adhesion to PU or nitrile rubber. The invention adopts high-shear unwinding ultrahigh molecular weight polyethylene and simultaneously adds a polar polymer containing an ester group, a carbonyl group and an ether group, and can be dispersed very uniformly in the ultrahigh molecular weight polyethylene to realize high adhesion polymerization. The manufacture of vinyl fiber does not require any equipment and the process is simple.

2. Ultra-high molecular weight polyethylene and a proper amount of polar polymer mixed emulsion are rapidly swelled and completely dissolved in a twin-screw extruder, which is beneficial to reduce the degradation of the polymer and improve the bonding property of the fiber. Does not affect the mechanical properties of the fiber.

3. Adding an appropriate amount of a carbon chain polar polymer containing a polar side group such as a carboxyl group, a carbonyl group or an ester group while the high shear moderately unwrapping the ultrahigh molecular weight polyethylene, without affecting the breaking strength, Effectively improve the bonding properties of polyethylene.

4. The ultrahigh molecular weight polyethylene fiber prepared by the invention has large fracture power and strong energy absorption ability, and the fracture extension is improved as much as possible under the premise of ensuring sufficient fracture strength, that is, the fracture strength has the best match with the fracture extension. Suitable for cut-resistant gloves. The invention realizes rapid swelling and dissolution of the ultrahigh molecular weight polyethylene by moderately unwinding with high shear, and the fracture work can be made above 30030CN, mm/dtex under the premise of ensuring the breaking strength of the fiber is above 30CN/dtex.

5. The fiber for cut-proof gloves is generally used in a single layer. It is required to have good anti-cutting performance, and the gloves are required to be flat and the density is hooked. This puts high requirements on the uniformity of the fibers. At present, the ultra-high molecular weight polyethylene fiber has a CV value of 8-10%, and the present invention is effective in realizing rapid swelling, dissolution, and addition of a surfactant and a flat wire structure in the coagulation liquid. The ultra-high molecular weight polyethylene fiber is controlled to have a fineness and strength CV value between 4 and 6%.

6. The ultra-high molecular weight polyethylene fiber is made into a flat structure, so that the specific surface area of the fiber is increased, which is favorable for uniform solidification, shortens the path of the solvent in the fiber to diffuse out of the jelly fiber, improves the extraction rate, and saves extraction. The second solvent used reduces the cost and thus "improves the uniformity and strength of the fiber.

7. The invention is not only simple to operate, but also saves time and labor, saves cost, and dissolves more uniformly. Detailed ways

In order to make the technical means, the creative features, the achievement of the object and the effect of the present invention easy to understand, the present invention will be further described below in conjunction with the specific embodiments.

Example 1

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million) powder, and 90# solvent white oil were fed into the unwinding kettle at a weight ratio of 1:8 at room temperature, under nitrogen protection, at a shear rate of 2000 seconds. Under the action of shearing for 10 minutes, a uniform emulsion mixture was obtained, and a co-rotating twin-screw extruder with a diameter of 25 mm and an aspect ratio of 36 was fed. The temperature was controlled at 250 ° C, and the screw speed was adjusted to 35 rpm. minute. After the extrudate is filtered and the spinneret is sprayed out of the jelly filament, it is extracted and super-stretched 35 times to obtain ultrahigh molecular weight polyethylene. Example 2

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million) powder, and 90# solvent white oil were separately fed into the unwrapping kettle at a weight ratio of 1:8 at room temperature, and EVA28190 (ethylene-vinyl acetate copolymer, The content of vinyl acetate was 28%, the melt index was 190), the amount of addition was 4 wt% of polyethylene powder, and the shearing rate was 2000 sec under nitrogen protection for 10 minutes to obtain a uniform emulsion mixture. Feeding a co-rotating twin-screw extruder with a diameter of 025 mm and a length to diameter ratio of 36, the temperature is controlled at 250 ° C, and the screw speed is adjusted to 35 rpm. The extrudate is filtered and the spinneret is sprayed out of the gel. After the silk, it was extracted and super-stretched 35 times to obtain a highly adhesive ultrahigh molecular weight polyethylene.

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million) powder, and 90# solvent white oil were separately fed into the unwrapping kettle at a weight ratio of 1:8 at room temperature, and EVA28190 (ethylene-vinyl acetate copolymer, The content of vinyl acetate is 28%, the melt index is 190), the amount is 2wt% of polyethylene powder, and under nitrogen protection, it is sheared for 10 minutes under the action of shearing speed of 2000 seconds to obtain a uniform emulsion mixture. A co-rotating twin-screw extruder having a diameter of Φ25 ηηηι and a length to diameter ratio of 36 was fed, the temperature was controlled at 250 ° C, and the screw speed was adjusted to 35 rpm. After the extrudate is filtered and the spinneret is sprayed out of the jelly filament, it is extracted and super-stretched 35 times to obtain a highly adhesive ultrahigh molecular weight polyethylene. Example 4

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million) powder, and 90# solvent white oil were fed into the unwrapped kettle at a weight ratio of 1:8 at room temperature, and EVA1030 (ethylene-vinyl acetate copolymer, The content of vinyl acetate is 10%, the melt index is 30), and the amount is 4wt% of polyethylene powder. Under nitrogen protection, it is sheared for 10 minutes under the action of shear rate of 2000 sec- ¹ to obtain uniform emulsion mixture. The liquid was fed into a co-rotating twin-screw extruder having a diameter of Φ25 πιηη and a length to diameter ratio of 36, the temperature was controlled at 250 ° C, and the screw speed was adjusted to 35 rpm. After the extrudate is filtered and the spinneret is sprayed out of the jelly filament, it is extracted and super-stretched 35 times to obtain a highly adhesive ultrahigh molecular weight polyethylene. Example 5

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million) powder, and 90# solvent white oil were transferred into the unwrapping kettle at a weight ratio of 1:8 at room temperature, and polyacrylate was added at the same time. 4wt% of the powder, under nitrogen protection, sheared for 10 minutes under the action of shearing speed of 2000 seconds, to obtain a uniform emulsion mixture, feeding the same direction twin screw extrusion with diameter Φ25ιηπι and length to diameter ratio of 36 The temperature is controlled at 250 ° C and the screw speed is adjusted to 35 rpm. After the extrudate is filtered and the spinneret is sprayed out of the jelly filament, it is extracted and super-stretched 35 times to obtain a highly adhesive ultrahigh molecular weight polyethylene. Example ό .

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million) powder, and 90# solvent white oil were respectively transferred into the unwrapping kettle at a weight ratio of 1:8 at room temperature, and polyoxyethylene was added at the same time. 4wt% of the powder, under nitrogen protection, sheared for 10 minutes under the action of shearing speed of 2000 seconds, to obtain a uniform emulsion mixture, feeding a co-rotating twin-screw extrusion with a diameter of 25 mm and a length to diameter ratio of 36. The temperature is controlled at 250 ° C and the screw speed is adjusted to 35 rpm. After the extrudate is filtered and the spinneret is sprayed out of the jelly filament, it is extracted and super-stretched 35 times to obtain a highly adhesive ultrahigh molecular weight polyethylene.

The mechanical properties and bonding properties of the ultrahigh molecular weight polyethylene fibers obtained in the above Examples 2-6 and Example 1 in which the polar polymer was added were as shown in Table 1. Table 1 Mechanical properties and bond strength of the high molecular weight polyethylene fibers produced by the present invention

The method for measuring the bond strength of the polyethylene fiber is as follows: The polyethylene fiber is passed through a capsule with a small hole, the height of the capsule is about 7 mm, and the epoxy resin and the curing agent are uniformly mixed in a ratio of 4:1, and then injected. In the capsule, after curing for 48 hours, the embedding depth L (mm) of the fiber in the capsule was accurately measured, and the bonding property of the fiber and the epoxy resin was measured by a pull-out experiment using a DXLL-20000 type strength meter. The clamping distance is 200 mm and the falling speed is 50 mm/min. The pull-out strength of the fiber is calculated by the following formula: Pulling strength = test strength *7/L. Example 7

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million), solvent white oil (70#), at room temperature, the above polyethylene and white oil are respectively injected into the unpacking kettle at a nominal concentration of 10% by weight, nitrogen protection The lower shear was cut for 5 minutes and the shearing speed was 3000 seconds. The uniform emulsion mixture was input into the storage tank and the mixture was quantitatively fed into the twin-screw extruder while stirring. The extruder has a diameter of 25mm, L/D=45, the temperature is controlled at 250 °C, and the screw extruder rotates at 30 rpm. The extrudate is discharged from the nozzle through the filter tank to the metering pump, and then discharged into the water bath. After 3⁄4, extraction, drying, and ultra-stretching, the total stretching ratio is 40, and the obtained fiber strength reaches 30 cN/dtex, and the modulus is above 1000 cN/dtex. Example 8

Ultra-high molecular weight polyethylene (relative average molecular mass 5 million), solvent white oil (90#), at room temperature, the above polyethylene and white oil are respectively injected into the unpacking kettle at a nominal concentration of 5% by weight, nitrogen protection The lower shearing was carried out for 5 minutes, and the shearing speed was 3000 sec ^-1 . The uniform emulsion-like mixed liquid was input into the storage tank and fed to the twin-screw extruder while stirring. The extruder has a diameter of 25mm, L/D=64, the temperature is controlled at 250 °C, and the screw extruder rotates at 50 rpm. The extrudate is ejected from the spinneret through the filter tank to the metering pump. Then, after being treated in a water bath, it is extracted, dried, and subjected to ultra-stretching, and the total stretching ratio is 40, and the fiber strength is 28 cN/dtex, and the modulus is 900 cN/dtex or more. ₉ Example 9

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million), solvent white oil (90#), the above polyethylene and white oil were respectively injected into the unpacking kettle at a nominal concentration of 5% by weight at room temperature, adding 0.2% (Weight) Antioxidant, sheared under nitrogen for 5 minutes, shear rate 2000 sec ^-1 , and a uniform emulsion mixture was input into the storage tank and fed to the twin-screw extruder while stirring. The extruder has a diameter of 25 mm, LD = (24), temperature control at 240 ° C, and screw extruder speed of 50 rpm. The extrudate is ejected from the filter tank through the filter tank to the metering pump, and then ejected from the nozzle hole after being treated in a water bath, and then subjected to extraction and drying, and the total stretching is 40, and the obtained fiber strength reaches 28 cN/dtex. The amount is above 900 cN/dtex. Example 10

Ultra-high molecular weight polyethylene (relative average molecular mass 5 million), solvent white oil (90#), the above polyethylene and white oil were respectively injected into the unpacking kettle at a nominal concentration of 12% by weight under nitrogen protection. The shearing was carried out for 10 minutes, and the shearing speed was 2000 seconds. The uniform emulsion-like mixed liquid was input into the storage tank and fed to the twin-screw extruder while stirring. The extruder has a diameter of 25 mm, L/D = (24), temperature control at 250 ^Q C, and screw extruder speed of 30 rpm. The extrudate is discharged from the filter tank through the filter tank to the metering pump, and then discharged into the water bath, and then extracted, dried, and subjected to ultra-stretching. The total stretching ratio is 40, and the obtained fiber strength reaches 35 cN/dtex. The modulus is above 1050 cN/dtex. Example 11

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million), solvent white oil (90#), white oil is injected into the unwrapping kettle at a nominal concentration of 10% by weight at room temperature. The concentration of 10% by weight was added to the unwrapped kettle by a screw propeller at a rate of 0.5 kg/min, and the shearing was added under nitrogen protection. The shear rate was 1000 seconds to obtain a uniform emulsion mixture. The input tank was stirred and quantitatively fed. Twin screw extruder. The extruder has a diameter of 25 mm, L/D = (24), and the temperature is controlled at 250 ^Q C. The screw extruder was rotated at 30 rpm. The extrudate is ejected from the spinneret through the filter housing until the metering pump is metered. Then, a 2% polyether-epoxy modified silicone oil was added to the water bath for treatment, extraction, drying, and ultra-stretching, and the total stretching ratio was 40, and the obtained fiber strength reached 30 cN/dtex, and the modulus was above 1000 cN/dtex. Example 12

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million), solvent white oil (70#), the above polyethylene and white oil are respectively injected into the unpacking kettle at a nominal concentration of 10% by weight at room temperature, under nitrogen protection After shearing for 15 minutes and shearing speed for 1000 seconds, a uniform emulsion mixture was introduced into the storage tank, and fed to the twin-screw extruder while stirring. The extruder has a diameter of 25 mm, L D = (24), a temperature of 250 ° C, and a screw extruder speed of 30 rpm. The extrudate is ejected from the filter tank through the filter tank to the metering pump, and then ejected from the spinning hole after being treated in a water bath, and then subjected to extraction and drying, and the total stretching is 40, and the obtained fiber strength reaches 30 cN/dtex. The amount is above 1000 cN/dtex.

Example 13 - Ultrahigh molecular weight polyethylene (relative average molecular mass 4.5 million), solvent white oil (70#), the above polyethylene and white oil were respectively injected into the unpacking kettle at a nominal concentration of 10% by weight at room temperature. At the same time, adding 1% (by weight) epoxy modified silicone oil, shearing under nitrogen protection for 5 minutes, shearing speed of 3000 seconds - ¹ , obtaining a uniform emulsion mixture into the storage tank, and feeding the twin-screw extrusion while stirring Out of the plane. The extruder has a diameter of 25 mm, IJD = (24), a temperature of 250 ° C, and a screw extruder speed of 50 rpm. The extrudate is sprayed from the filter hole through the filter tank to the metering pump, and then sprayed into the water bath, and then subjected to extraction and drying, and the total stretching is 40, and the obtained fiber strength reaches 30 cN/dtex. The amount is above 1000cN/dtex.

Example 14

Ultra-high molecular weight polyethylene (relative average molecular mass 5 million), solvent white oil (90#), the above polyethylene and white oil were respectively injected into the unpacking kettle at a nominal concentration of 12% by weight under nitrogen protection. After shearing for 10 minutes and shearing rate of 2000 seconds, a uniform emulsion mixture was obtained and fed into the storage tank while being quantitatively fed into the twin-screw extruder. The extruder was 25 mm in diameter, L/D = (24), the temperature was controlled at 250 ° C, and the screw extruder was rotated at 30 rpm. The extrudate is ejected from the spinneret through the filter tank to the metering pump after being metered. Then, a 1.5% epoxy modified silicone oil water bath was added, and after treatment, the extraction was ultra-stretched, and the total stretching ratio was 40, and the obtained fiber strength reached 35 cN/dtex, and the modulus was above 1050 cN/dtex. Example 15

Ultra-high molecular weight polyethylene (relative average molecular mass 4.5 million), solvent white oil (90#), the above polyethylene and white oil are respectively injected into the unwrapping kettle at a nominal concentration of 10% by weight at room temperature, ultrahigh molecular weight The polyethylene was added into the unwrapped kettle at a nominal concentration of 10% by weight from a screw propeller at a rate of 0.5 kg/min. The shearing speed was added under a nitrogen atmosphere and the shear rate was 1000 seconds to obtain a uniform emulsion mixture into the storage tank. Quantitatively fed to the twin-screw extruder while stirring. The extruder was 25 mm in diameter, L/D = (24), the temperature was controlled at 250 ° C, and the screw extruder speed was 30 rpm. The extrudate is sprayed from the filter hole through the filter box to the metering pump, and then added to a 2% by weight polyether-epoxy modified silicone oil water bath for treatment, extraction, drying, and ultra-stretching, pulling The total extension is 30, and the obtained fiber strength reaches 30 cN/dte _X and the modulus is above 1000 cN/dtex. Example 16

Ultra-polymer* polyethylene (relative average molecular mass 4.5 million), solvent white oil, formulated into a uniform solution with a concentration of 8%, fed into a twin-screw extruder, extruder diameter 25mm, L/D=(24) The temperature is controlled at 240 ° C and the screw extruder speed is 30 rpm. The extrudate is ejected from the filter box to the metering pump and is ejected from a spinneret having a rectangular orifice, the oblong hole having an aspect ratio of 8. Then, it is extracted into a water bath and then extracted, dried, super-stretched, and the total stretching ratio is 40, and the obtained fiber strength reaches 30 cN/dtex, and the modulus is above 1000 cN/dtex. Example 17

Ultra high molecular weight polyethylene (relative average molecular mass 4.5 million), solvent white oil, formulated into a uniform solution with a concentration of 12%, fed into a twin-screw extruder, extruder diameter 25mm, IJD=(24), temperature control The screw extruder was rotated at 40 rpm at 250 °C. The extrudate is ejected from the filter box to the metering pump and then ejected from a spinneret having a rectangular orifice having an aspect ratio of 12. Then, it is treated in a water bath, extracted, dried, and subjected to ultra-stretching. The total stretching ratio is 40, and the obtained fiber strength reaches 30 cN/dtex, and the modulus is above 1000 cN/dtex. The basic principles, main features, and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited by the foregoing embodiments, and that the present invention is described in the foregoing embodiments and the description of the present invention. Such changes and modifications are intended to fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and their equivalents.

Claims

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A method for preparing an ultrahigh molecular weight polyethylene fiber, characterized in that a polyethylene powder having an ultrahigh relative molecular weight of 1 million to 6 million is added to a polar polymer, dispersed in a solvent, and formulated into a uniform mixed emulsion. Using the frozen silk spinning method, the mixed emulsion is quantitatively fed into the screw extruder while stirring to rapidly swell and dissolve to form a transparent and uniform spinning dope, which is extruded through a spinneret, and is cooled and solidified to form a spinning. Then, ultrahigh molecular weight polyethylene fibers are obtained by extraction, drying, and super-stretching.

2. The method for preparing ultrahigh molecular weight polyethylene fiber according to claim 1, characterized in that in the process of preparing a uniform mixed emulsion, a polyethylene powder having a high relative molecular weight of 16 million and a polar polymer is used. The solvent is injected into the unwinding device in proportion to untwist to form a uniform mixed emulsion.

The method for producing ultrahigh molecular weight polyethylene fibers according to claim 1 or 2, wherein the uniform mixed emulsion has a percentage concentration of 4% to 60%.

The method for producing an ultrahigh molecular weight polyethylene fiber according to claim 1, wherein the polar polymer is a polar polymer containing an ester group, a carbonyl group or an ether group.

The method for producing an ultrahigh molecular weight polyethylene fiber according to claim 1, wherein the polar polymer containing an ester group, a carbonyl group or an ether group is an ethylene/ethylene acetate copolymer, One or a mixture of two or more of polyacrylates, polyvinylpyrrolidone/ethylene acetate copolymers having different K values, and polyoxyethylene polymers.

6. The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein the polar polymer is added in a weight fraction relative to the weight of the ultrahigh molecular weight of 1 million to 6 million polyethylene powder. 1-10%. ·

7. The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein the polar polymer is added in a weight fraction relative to the weight of the ultrahigh molecular weight of 1 million to 6 million polyethylene powder. 2-8%.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 2, wherein in the above unwrapping process, silicone oil or a derivative thereof may be added for unwinding; or/and silicone oil may be added during solidification. Or a derivative thereof; wherein the silicone oil or a derivative thereof is added in an amount of 0.05 to 5% by weight of the ultrahigh molecular weight polyethylene fiber containing the silicone oil or a derivative thereof.

9. The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 8, characterized in that In the above unwrapping process, one or more of an antioxidant, a stabilizer, a coloring agent, and a flame retardant are further added.

The method of producing ultrahigh molecular weight polyethylene fibers according to claim 2, wherein the unwinding device provides a shear rate of at least 1000 seconds.

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11. The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 10, wherein the unwinding device has a shear rate of 1000 to 5000 seconds.

The method for producing ultrahigh molecular weight polyethylene fibers according to claim 10, wherein the unwinding device has a shear rate of 2000 to 4000 seconds.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 2, wherein the unwinding device is a high speed disperser, a stirrer, a colloid mill, a homogenizer, and a venturi tube. Kind or a combination thereof.

The method for producing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein the ultrahigh molecular weight polyethylene has a relative average molecular weight of 4,000,000 to 6 million.

The method for producing an ultrahigh molecular polyethylene fiber according to claim 1, wherein the ultrahigh molecular weight polyethylene has a relative average molecular weight of 2,000,000 to 5,000,000.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein in the process of preparing the homogeneous mixed emulsion, the solvent used is a solvent which is liquid at normal temperature, and is a terpene hydrocarbon or a cycloalkane. One of an aromatic hydrocarbon, a derivative of an alkane, a derivative of a cycloalkane, a derivative of an aromatic hydrocarbon, and a mixture of two or more.

A method of producing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein the nominal concentration of the ultrahigh molecular weight polyethylene and the solvent is from 1 to 50% by weight in the preparation of the homogeneous solution.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein the screw extruder used is one of a single screw, a twin screw, a triple screw, and a four screw extruder, The screw extrusion temperature was 80-250 °C.

19. The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 18, wherein the twin-screw extruder is rotated in the same direction or in the opposite direction, and the length to diameter ratio of the screw is 1:30- 65.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 19, wherein the uniform mixed emulsion has a residence time in the twin-screw extruder of 10 to 60 minutes, preferably 20 to 40. In minutes, the material temperature is 50-280 ° C, and the solution spinning temperature during extrusion is controlled at 140-280 ° C. Most Good at 200-260 °C.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 20, wherein the uniform mixed emulsion has a residence time of 20-40 minutes in a twin-screw extruder, and the solution is spun at the time of extrusion. The wire temperature is controlled at 200-260 °C.

The method for producing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein the spinneret holes on the spinneret used in the screw extruder are rectangular holes having an aspect ratio of 4-20.

A method of producing an ultrahigh molecular weight polyethylene fiber according to claim 1, wherein the aspect ratio is 5-15.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein the emulsion mixture is directly fed to a screw extruder or fed through a screw with a stirred storage barrel. machine.

The method for preparing ultrahigh molecular weight polyethylene fibers according to claim 1, wherein in the super-stretching process, the stretching temperature of the fibers is 80-130 ° C, and the stretching ratio is 20 times or more. .

The method for producing ultrahigh molecular weight polyethylene fibers according to claim 25, wherein the stretching ratio is 30 to 60 times in the super-stretching process.