An ultra-high molecular weight polyethylene fiber having good spinnability, a method for manufacturing the same, and applications thereof

Abstract

The present application relates to a kind of good spinnability ultra-high molecular weight polyethylene fiber, its manufacturing method and its application.The manufacturing method of the ultra-high molecular weight polyethylene fiber of the present application includes the following steps: 1) make ultra-high molecular weight polyethylene with solvent at first temperature first mixing, then second mixing at second temperature higher than the first temperature, prepare spinning solution, 2) the spinning solution is spun into the ultra-high molecular weight polyethylene fiber, wherein the simple supported beam impact strength of the ultra-high molecular weight polyethylene is 30-120kJ / m 2 The present application selects raw material with less entanglement by testing simple supported beam impact strength, and then forms highly uniform spinning solution by two-stage swelling, so that the state of raw material is consistent during disentanglement, achieving good spinnability effect, fiber product linear density is low, and good evenness is good, more suitable for fabric application.

Description

Technical Field

[0001] The present invention relates to the field of high-performance fibers, and in particular to an ultra-high molecular weight polyethylene fiber with good spinnability, a manufacturing method thereof, and applications thereof. Background Art

[0002] The spinnability of ultra-high molecular weight polyethylene (UHMWPE) directly affects the final performance and quality of the fiber. Generally speaking, the narrower the molecular weight distribution, the lower the degree of crosslinking (including physical entanglement), and the better the linearity, the better the spinnability and performance of the raw material. Currently, UHMWPE raw materials are all produced by slurry polymerization using Ziegler-Natta catalysts. Due to the limitations of process conditions, the molecular weight distribution and branching structure cannot achieve a perfect narrow distribution. Current detection methods are insufficient and cannot effectively distinguish the actual molecular structure differences of the raw materials to accurately guide the selection. Therefore, the spinnability during the fiber spinning process is less than ideal, and the fiber performance cannot reach the optimal level.

[0003] In the spinning process of ultra-high molecular weight polyethylene fibers, a one-step feeding method is usually adopted. The moment the raw material particles come into contact with the high-temperature solvent, the surface is easily over-swollen and gelatinized, thereby blocking the channels for the solvent to enter the interior of the particles, resulting in uneven swelling and poor spinnability. Summary of the Invention

[0004] The present invention aims to produce an ultra-high molecular weight polyethylene fiber with excellent spinnability, addressing the limitations of existing technologies, such as the inability to accurately determine the spinnability of raw materials and poor swelling, which prevent high-concentration production. The raw materials undergo a two-stage swelling treatment: first, a cold pre-swelling process to open the capillary channels within the raw material particles, followed by a subsequent swelling process.

[0005] Specifically, the present invention relates to the following aspects.

[0006] 1. A method for producing ultra-high molecular weight polyethylene fiber, comprising the following steps:

[0007] 1) performing a first mixing of the ultra-high molecular weight polyethylene and the solvent at a first temperature, and then performing a second mixing at a second temperature higher than the first temperature (preferably 30-50° C. higher) to prepare a spinning solution,

[0008] 2) spinning the spinning solution into the ultra-high molecular weight polyethylene fiber,

[0009] The ultra-high molecular weight polyethylene has a simple supported beam impact strength of 30-120 kJ / m 2 (Preferably 50-90 kJ / m 2 ).

[0010] 2. The production method according to any one of the preceding or following aspects, wherein in step 1), the amount of the solvent used is 500-1000 parts by weight (preferably 8-20 parts by weight) relative to 100 parts by weight of the ultra-high molecular weight polyethylene.

[0011] 3. The production method according to any one of the preceding or following aspects, wherein in step 1), the solvent is selected from at least one of naphthalene, decalin, tetralin, kerosene, xylene, toluene, petroleum fractions, halogenated hydrocarbons, cycloalkanes, and cycloolefins, preferably decalin.

[0012] 4. The production method according to any one of the preceding or following aspects, wherein in step 1), the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 1 million to 9 million (preferably 3 million to 5 million).

[0013] 5. The manufacturing method according to any of the preceding or following aspects, wherein in step 1), the first temperature is not higher than 50°C (preferably 10-30°C), the first mixing time is 5-40 min (preferably 20-30 min), the second temperature is 55-150°C (preferably 60-100°C), and the second mixing time is 35 min-4 h (preferably 1-3 h).

[0014] 6. The manufacturing method according to any one of the preceding or following aspects, wherein in step 1), the swelling ratio of the swollen particles in the spinning solution is less than 10 (preferably less than 3).

[0015] 7. The manufacturing method according to any one of the preceding or following aspects, wherein in step 2), the spinning comprises the following steps:

[0016] 2-1) extruding the spinning solution to form a spinning stream,

[0017] 2-2) removing at least a portion (e.g., at least 50 wt%, preferably at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt% or at least 97 wt%) of the solvent from the spinning stream to obtain dry filaments,

[0018] 2-3) stretching the dry precursor in one or more stages (such as 1-8 or 2-5 stages) to obtain the ultra-high molecular weight polyethylene fiber.

[0019] 8. The manufacturing method described in any of the above or following aspects, wherein in step 2-1), stretching exists or does not exist, and the extrusion temperature is 150-250°C (preferably 170-190°C); when stretching exists, the stretching ratio is 0-50 (preferably 2-20).

[0020] 9. The manufacturing method according to any one of the preceding or following aspects, wherein in step 2-2), at least a portion of the solvent is removed from the spinning stream by evaporation.

[0021] 10. The manufacturing method described in any of the above or following aspects, wherein the operating conditions of the evaporation include: with or without stretching, the evaporation temperature is 0.5-10°C (preferably 1-5°C) higher than the solvent flash temperature; when stretching is present, the stretching ratio is 1-10 (preferably 2-5).

[0022] 11. The manufacturing method according to any one of the preceding or following aspects, wherein in step 2-2), the spinning stream is cooled to obtain gel filaments, and then at least a portion of the solvent is removed by evaporation and / or extraction.

[0023] 12. The manufacturing method described in any of the above or below aspects, wherein the cooling operating conditions include: with or without stretching, the cooling temperature is -50-100°C (preferably 20-50°C); when stretching is present, the stretching ratio is 1-10 (preferably 2-5).

[0024] 13. The manufacturing method described in any of the above or following aspects, wherein the operating conditions of the evaporation include: with or without stretching, the evaporation temperature is 0.5-10°C (preferably 1-5°C) higher than the solvent flash temperature; when stretching is present, the stretching ratio is 1-10 (preferably 2-5); or, the operating conditions of the extraction include: with or without stretching, the extractant is a volatile hydrocarbon solvent (preferably selected from at least one of xylene and heptane), the extraction temperature is 10-150°C (preferably 40-90°C); when stretching is present, the stretching ratio is 1-10 (preferably 2-5).

[0025] 14. The manufacturing method described in any of the above or following aspects, wherein in step 2-3), the stretching operating conditions include: 1-10 stretching sections (preferably 2-5), a stretching temperature of 90-170°C (preferably 130-150°C), and a stretching ratio of 2-500 (preferably 4-250).

[0026] 15. An ultra-high molecular weight polyethylene fiber obtained by the production method described in any one of the above or below aspects.

[0027] 16. The polyethylene fiber described in any of the preceding or following aspects has a fiber strength greater than 35 cN / dtex (preferably greater than 40 cN / dtex), a modulus greater than 1700 cN / dtex (preferably greater than 1900 cN / dtex), a linear density deviation rate less than 4% (preferably less than 1.5%), a strength cV less than 6% (preferably less than 3%), and a yarn dryness less than 5% (preferably less than 3%).

[0028] 17. A fabric comprising the ultra-high molecular weight polyethylene fiber according to any one of the preceding or following aspects.

[0029] 18. The fabric according to any one of the preceding or following aspects, further comprising at least one other fiber selected from the group consisting of natural plant fibers, natural animal fibers, artificial regenerated fibers, synthetic fibers, and inorganic fibers.

[0030] Technical Effects

[0031] The present invention screens out raw materials with less entanglement by testing the simply supported beam impact strength, and then forms a highly uniform spinning solution through two-stage swelling, so that the raw materials are in a consistent state during the untangling process, achieving good spinnability. The fiber product has a low linear density and good yarn uniformity, making it more suitable for fabric applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a one-step feeding swelling diagram. Figure 1 In the figure, 1 represents over-swollen particles.

[0033] Figure 2 It is a two-step feeding swelling diagram. DETAILED DESCRIPTION

[0034] The specific embodiments of the present invention are described in detail below. However, it should be noted that the protection scope of the present invention is not limited by these specific embodiments, but is determined by the claims in the appendix.

[0035] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In the event of conflict, the definitions in this specification will prevail.

[0036] When this specification uses the prefix "well known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, the objects introduced by the prefix include those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become generally recognized in the art to be suitable for similar purposes.

[0037] In the context of the present invention, all numerical values ​​for parameters (eg, amounts or conditions) are to be understood as being modified in all instances by the term "about," regardless of whether "about" actually appears before the numerical value.

[0038] In the context of the present invention, the measurement method for Charpy impact strength is ISO 11542-2.

[0039] In the context of the present invention, the swelling ratio of swollen particles is measured by microscopic observation, and the maximum diameter is measured 10 times and the average value is taken. The growth ratio before and after swelling is the ratio of the diameter before and after swelling.

[0040] In the context of the present invention, the linear density deviation rate, strength cV and yarn evenness are measured by the capacitance method of GB / T 14343, GB / T 19975 and GB / T 14346.

[0041] In the context of the present invention, the measurement method of fiber strength and modulus is GB / T19975.

[0042] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight and pressure is gauge pressure.

[0043] In the context of the present invention, any two or more embodiments or aspects of the present invention may be arbitrarily combined, and the technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the scope of protection of the present invention.

[0044] According to one embodiment of the present invention, a method for manufacturing ultra-high molecular weight polyethylene fiber comprises the steps of: performing a first mixing of ultra-high molecular weight polyethylene and a solvent at a first temperature, and then performing a second mixing at a second temperature higher than the first temperature (preferably 30-50°C higher) to prepare a spinning solution.

[0045] According to the present invention, the first temperature is a relatively mild temperature, which can make the surface of the ultra-high molecular weight polyethylene particles uniformly wetted, gradually expand, and gradually open the capillary channels leading to the interior of the particles, which is conducive to further swelling at the second temperature. At the same time, the mild swelling at the first temperature, which is relatively low, helps to maintain the swelling consistency of ultra-high molecular weight polyethylene particles of different sizes. The second temperature is higher than the first temperature, which can accelerate the diffusion of the solvent into the interior, expand the swelling, achieve the ideal expansion ratio, and form a stable and uniform suspension, such as Figure 2 If this method is not adopted, or the first swelling temperature is too high, the particle surface will undergo rapid gelatinization and swelling, blocking the capillary channel and preventing the solvent from entering the particle interior, resulting in uneven swelling between the ultra-high molecular weight polyethylene particles, and thus uneven spinning solution. Figure 1 .

[0046] According to one embodiment of the present invention, the ultra-high molecular weight polyethylene has a simple supported beam impact strength of 30-120 kJ / m 2 (Preferably 50-90 kJ / m 2 ).

[0047] According to the present invention, if the simply supported beam impact strength is too high, the molecular chains will be too entangled, and the entanglement cannot be effectively solved during the spinning process, making spinning difficult. If the simply supported beam impact strength is too low, it will have an adverse effect on the mechanical properties of the fiber.

[0048] According to one embodiment of the present invention, in step 1), the amount of the solvent used is 500-1000 parts by weight (preferably 8-20 parts by weight) relative to 100 parts by weight of the ultra-high molecular weight polyethylene.

[0049] According to one embodiment of the present invention, in step 1), the solvent is selected from at least one of naphthalene, decahydronaphthalene, tetrahydronaphthalene, kerosene, xylene, toluene, petroleum fractions, halogenated hydrocarbons, cycloalkanes, and cycloalkenes, preferably decahydronaphthalene.

[0050] According to one embodiment of the present invention, in step 1), the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 1 million to 9 million (preferably 3 million to 5 million).

[0051] According to one embodiment of the present invention, in step 1), the first temperature is not higher than 50°C (preferably 10-30°C), the first mixing time is 5-40 min (preferably 20-30 min), the second temperature is 55-150°C (preferably 60-100°C), and the second mixing time is 35 min-4 h (preferably 1-3 h).

[0052] According to one embodiment of the present invention, in step 1), in the spinning solution, the swelling ratio of the swollen particles is less than 10 (preferably less than 3).

[0053] According to one embodiment of the present invention, the manufacturing method includes step 2): spinning the spinning solution into the ultra-high molecular weight polyethylene fiber.

[0054] According to one embodiment of the present invention, in step 2), the spinning comprises the following steps:

[0055] 2-1) extruding the spinning solution to form a spinning stream,

[0056] 2-2) removing at least a portion (e.g., at least 50 wt%, preferably at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt% or at least 97 wt%) of the solvent from the spinning stream to obtain dry filaments,

[0057] 2-3) stretching the dry precursor in one or more stages (such as 1-8 or 2-5 stages) to obtain the ultra-high molecular weight polyethylene fiber.

[0058] According to one embodiment of the present invention, in step 2-1), with or without stretching, the extrusion temperature is 150-250° C. (preferably 170-190° C.) When stretching is present, the stretching ratio is 0-50 (preferably 2-20).

[0059] According to one embodiment of the present invention, in step 2-2), at least a portion of the solvent is removed from the spinning stream by evaporation.

[0060] According to one embodiment of the present invention, the operating conditions of the evaporation include: with or without stretching, the evaporation temperature is 0.5-10°C (preferably 1-5°C) higher than the solvent flash temperature; when stretching is present, the stretching ratio is 1-10 (preferably 2-5).

[0061] According to one embodiment of the present invention, in step 2-2), the spinning stream is cooled to obtain gel filaments, and then at least a portion of the solvent is removed by evaporation and / or extraction.

[0062] According to one embodiment of the present invention, the cooling operating conditions include: with or without stretching, the cooling temperature is -50-100°C (preferably 20-50°C); when stretching is present, the stretching ratio is 1-10 (preferably 2-5).

[0063] According to one embodiment of the present invention, the evaporation operating conditions include: with or without stretching, the evaporation temperature is 0.5-10°C (preferably 1-5°C) higher than the solvent flash temperature. When stretching is present, the stretching ratio is 1-10 (preferably 2-5).

[0064] According to one embodiment of the present invention, the extraction operating conditions include: with or without stretching, an extraction temperature of 10-150°C (preferably 40-90°C); when stretching is present, a stretch ratio of 1-10 (preferably 2-5). The extraction solvent is a volatile hydrocarbon solvent, preferably at least one selected from xylene and heptane.

[0065] According to one embodiment of the present invention, in step 2-3), the stretching operating conditions include: 1-10 stretching sections (preferably 2-5), a stretching temperature of 90-170°C (preferably 130-150°C), and a stretching ratio of 2-500 (preferably 4-250).

[0066] According to one embodiment of the present invention, an ultra-high molecular weight polyethylene fiber is obtained by the manufacturing method described in any of the preceding or following aspects of this specification. According to the present invention, the ultra-high molecular weight polyethylene fiber has a fiber strength greater than 35 cN / dtex (preferably greater than 40 cN / dtex), a modulus greater than 1700 cN / dtex (preferably greater than 1900 cN / dtex), a linear density deviation rate less than 4% (preferably less than 1.5%), a tenacity cV less than 6% (preferably less than 3%), and an evenness less than 5% (preferably less than 3%).

[0067] According to one embodiment of the present invention, a fabric is also provided, comprising the ultra-high molecular weight polyethylene fiber described in any one of the preceding or following aspects of this specification.

[0068] According to one embodiment of the present invention, the fabric further comprises at least one other fiber selected from natural plant fibers, natural animal fibers, artificial regenerated fibers, synthetic fibers and inorganic fibers.

[0069] Example

[0070] The present invention is further described in detail below using examples and comparative examples, but the present invention is not limited to these examples.

[0071] Example 1

[0072] In this embodiment, an ultra-high molecular weight polyethylene fiber with good spinnability is obtained by the following process:

[0073] Ultra-high molecular weight polyethylene (UHMWPE) with a viscosity average molecular weight of 4.5 million was mixed with decalin at a ratio of 100:1300 and swelled. The charpy impact strength of UHMWPE is 65 kJ / m 2 The mixing and swelling process is carried out in two steps. First, the mixture is mixed at 30°C for 25 minutes, and then at 80°C for 2 hours. The swelling ratio of the swollen particles is 2.8, forming a suspension. The suspension is dissolved by screw shearing and extruded at 180°C and a stretching ratio of 10 to form a spinning stream. At least 98% of the solvent is removed by evaporation. The evaporation temperature is 3°C higher than the solvent flash temperature and the stretching ratio is 3, forming an initial raw yarn. The initial raw yarn is stretched in three stages at a stretching temperature of 145°C and a stretching ratio of 150 to produce a finished yarn.

[0074] The swelling diagram of the feeding in this embodiment is as follows Figure 2 The particles are uniformly swollen, without gelatinization and over-swelling, and the suspension is uniform.

[0075] Example 2

[0076] The same as Example 1, except that the gel was cooled before removing the solvent, the cooling temperature was 300° C., and the stretching ratio was 3.

[0077] Example 3

[0078] The same as Example 1, except that white oil is used as the solvent, the solvent is removed by xylene extraction, the extraction temperature is 80° C., and the stretching ratio is 3.

[0079] Example 4

[0080] Same as Example 1, except that the second temperature is 50°C.

[0081] Example 5

[0082] Same as Example 1, except that the simply supported beam impact strength is 40 kJ / m 2 .

[0083] Example 6

[0084] Same as Example 1, except that the simply supported beam impact strength is 110 kJ / m 2 .

[0085] Example 7

[0086] The same as Example 1, except that the mixing time at the first temperature is 60 minutes.

[0087] Example 8

[0088] The same as Example 1, except that the mixing time at the second temperature is 20 minutes.

[0089] Example 9

[0090] Same as Example 1, except that the first temperature is 45°C and the second temperature is 120°C.

[0091] Example 10

[0092] Same as Example 1, except that the molecular weight of the ultra-high molecular weight polyethylene is 7 million.

[0093] Example 11

[0094] The same as Example 1, except that the initial raw yarn is stretched in 5 stages, the stretching temperature is 135°C, and the stretching ratio is 230.

[0095] Example 12

[0096] The same as Example 1, except that the initial raw yarn is stretched in two stages, the stretching temperature is 150°C, and the stretching ratio is 10.

[0097] Comparative Example 1

[0098] Same as Example 1, except that the first temperature is 55°C.

[0099] Comparative Example 2

[0100] Same as Example 1, except that the first temperature is 55°C and the second temperature is 30°C.

[0101] Comparative Example 3

[0102] Same as Example 1, except that the simply supported beam impact strength is 20 kJ / m 2 .

[0103] Comparative Example 4

[0104] Same as Example 1, except that the simply supported beam impact strength is 140 kJ / m 2 .

[0105] Comparative Example 5

[0106] The same as Example 1, except that the swelling is carried out in one step, and the mixture is directly mixed at 80° C. for 5 h to form a suspension.

[0107] The swelling diagram of the feeding in this embodiment is as follows Figure 1 The particles swell unevenly, there are gelatinization and over-swelling phenomena, and the suspension is uneven.

[0108] Comparative Example 6

[0109] The same as Example 1, except that the first temperature is 60°C and the first mixing time is 1 hour, the second temperature is 155°C and the second mixing time is 5 hours, and the expansion ratio is 20.

[0110] Comparative Example 7

[0111] The same as Example 1, except that the evaporation temperature during solvent removal is 12° C. higher than the solvent flash temperature.

[0112] Comparative Example 8

[0113] The same as Example 1, except that the evaporation temperature during solvent removal is equal to the solvent flash temperature.

[0114]

Claims

1. A method for producing ultra-high molecular weight polyethylene fiber, comprising the following steps: 1) performing a first mixing of ultra-high molecular weight polyethylene and a solvent at a first temperature, and then performing a second mixing at a second temperature 30-50° C. higher than the first temperature to prepare a spinning solution, Wherein, the first temperature is 10-50°C, the first mixing time is 5-40 minutes, the second temperature is 55-100°C, and the second mixing time is 35 minutes to 4 hours. The swelling ratio of the swollen particles in the spinning solution is less than 10, wherein the swelling ratio of the swollen particles is measured by microscopic observation, and the average value is obtained by measuring 10 times at the maximum diameter. The swelling ratio before and after swelling is the ratio of the diameter before and after swelling. 2) spinning the spinning solution into the ultra-high molecular weight polyethylene fiber, The ultra-high molecular weight polyethylene has a simple supported beam impact strength of 30-90 kJ / m 2 .

2. The manufacturing method according to claim 1, wherein the ultra-high molecular weight polyethylene has a simple supported beam impact strength of 50-90 kJ / m 2 .

3. The production method according to claim 1, wherein in step 1), the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is 1 million to 9 million. 4 . The manufacturing method according to claim 1 , wherein in step 1), the first temperature is 10-30° C., the first mixing time is 20-30 min, the second temperature is 60-100° C., and the second mixing time is 1-3 h. The manufacturing method according to claim 1 , wherein in step 1), the swelling ratio of the swollen particles in the spinning solution is less than 3.

6. The manufacturing method according to claim 1, wherein in step 2), the spinning comprises the following steps: 2-1) Extruding the spinning solution to form a spinning stream, 2-2) removing at least 95 wt% of the solvent from the spinning stream to obtain dry raw fibers, 2-3) stretching the dry precursor in 1 to 8 stages to obtain the ultra-high molecular weight polyethylene fiber. 7 . The manufacturing method according to claim 6 , wherein in step 2-3), the dry raw yarn is stretched in 2 to 5 stages.

8. The manufacturing method according to claim 6, wherein in step 2-1), stretching is present or absent, and the extrusion temperature is 150-250°C; when stretching is present, the stretching ratio is 2-50.

9. The manufacturing method according to claim 8, wherein the extrusion temperature is 170-190°C; and when stretching is performed, the stretching ratio is 2-20. 10 . The production method according to claim 6 , wherein in step 2-2), at least a portion of the solvent is removed from the spinning stream by evaporation.

11. The manufacturing method according to claim 10, wherein the operating conditions of the evaporation include: With or without stretching, the evaporation temperature is 0.5-10° C. higher than the flash evaporation temperature of the solvent; when stretching is present, the stretching ratio is 1-10.

12. The manufacturing method according to claim 11, wherein the evaporation temperature is 1-5°C higher than the flash evaporation temperature of the solvent; when stretching is performed, the stretching ratio is 2-5. 13 . The production method according to claim 6 , wherein in step 2-2), the spinning stream is cooled to obtain gel filaments, and then at least a portion of the solvent is removed by evaporation and / or extraction.

14. The manufacturing method according to claim 6, wherein in step 2-3), the operating conditions of the stretching include: The number of stretching sections is 1-10, the stretching temperature is 90-170° C., and the stretching ratio is 2-500.

15. The manufacturing method according to claim 14, wherein in step 2-3), the operating conditions of the stretching include: The number of stretching sections is 2-5, the stretching temperature is 130-150°C, and the stretching ratio is 4-250.

16. An ultra-high molecular weight polyethylene fiber obtained by the manufacturing method according to any one of claims 1 to 15.

17. A fabric comprising the ultra-high molecular weight polyethylene fiber according to claim 16.

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