Ultra-high molecular weight polyethylene fiber with good spinnability as well as preparation method and application of ultra-high molecular weight polyethylene fiber

Abstract

The invention relates to an ultra-high molecular weight polyethylene fiber with good spinnability as well as a preparation method and application of the ultra-high molecular weight polyethylene fiber. The manufacturing method of the ultra-high molecular weight polyethylene fiber comprises the following steps: 1) carrying out first mixing on ultra-high molecular weight polyethylene and a solvent at a first temperature, and then carrying out second mixing at a second temperature higher than the first temperature to prepare a spinning solution, and 2) spinning the spinning solution into the ultra-high molecular weight polyethylene fiber, wherein the simply supported beam impact strength of the ultra-high molecular weight polyethylene is 30-120kJ / m < 2 >. According to the method, the impact strength of the simply supported beam is tested, the raw materials with less entanglement are screened out, and the highly uniform spinning solution is formed through two-stage swelling, so that the state of the raw materials is consistent in the unentanglement process, a good spinnability effect is achieved, and a fiber product is low in linear density, good in yarn evenness and more suitable for being applied to fabric.

Description

Technical Field

[0001] The 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 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 of the raw material and the better the performance. At present, ultra-high molecular weight polyethylene raw materials are all made 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. The current detection methods are lacking and cannot well distinguish the actual molecular structure differences of the raw materials and accurately guide the selection. Therefore, the spinnability is not ideal during the fiber spinning process 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 passage for the solvent to enter the interior of the particles, resulting in uneven swelling, and thus leading to poor spinnability. Summary of the invention

[0004] The purpose of the present invention is to manufacture an ultra-high molecular weight polyethylene fiber with good spinnability in view of the shortcomings of the prior art that the spinnability of raw materials cannot be accurately determined and the swelling is poor, and high-concentration production cannot be achieved. The raw materials are subjected to two-stage swelling treatment, firstly cold pre-swelling is performed to open the capillary channels inside the raw material particles, and then swelling treatment is performed.

[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 described in any of the above or below 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 described in any 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 manufacturing method described in any of the above or the 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 described in 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 5-40min (preferably 20-30min), the second temperature is 55-150°C (preferably 60-100°C), and the second mixing time is 35min-4h (preferably 1-3h).

[0014] 6. The manufacturing method described in any of the above or below aspects, wherein in step 1), in the spinning solution, the swelling ratio of the swollen particles 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 fine 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 raw fibers,

[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 the 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 the 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 the following 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 the 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 below 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 preceding or following 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 described in any one of the preceding or following aspects.

[0029] 18. The fabric described in any one of the preceding or following aspects further comprises at least one other fiber selected from 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 a good spinnability effect. The fiber product has a low linear density and good yarn uniformity, and is 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, but it should be pointed out 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 conventionally understood by those skilled in the art. In the event of a conflict, the definitions in this specification shall 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, etc., the objects introduced by the prefix cover 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 recognized in the art as being 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 of the 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, measuring the maximum diameter 10 times and taking the average value, and the growth ratio before and after swelling is the ratio of the diameters before and after swelling.

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

[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 protection scope 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 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 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 infiltrated, 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 relative to the low temperature 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 an ideal swelling 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, making it difficult for the solvent to enter the particles well, 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 simply 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 are too entangled, and the entanglements cannot be effectively resolved during the spinning process, making it difficult to spin. 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 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, decalin, tetralin, kerosene, xylene, toluene, petroleum fractions, halogenated hydrocarbons, cycloalkanes, and cycloolefins, preferably decalin.

[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 5-40min (preferably 20-30min), the second temperature is 55-150°C (preferably 60-100°C), and the second mixing time is 35min-4h (preferably 1-3h).

[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 comprises 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 fine 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 raw fibers,

[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), stretching is present or absent, and 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 exists, 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 operation 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 operation 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 operating conditions of the extraction include: with or without stretching, the extraction temperature is 10-150°C (preferably 40-90°C); when stretching is present, the stretching ratio is 1-10 (preferably 2-5). Here, the extractant 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, it relates to an ultra-high molecular weight polyethylene fiber, which is obtained by the manufacturing method described in any one of the preceding or following aspects of this specification. According to the present invention, the fiber strength of the ultra-high molecular weight polyethylene fiber is greater than 35 cN / dtex (preferably greater than 40 cN / dtex), the modulus is greater than 1700 cN / dtex (preferably greater than 1900 cN / dtex), the linear density deviation rate is less than 4% (preferably less than 1.5%), the strength cV is less than 6% (preferably less than 3%), and the strip dryness is less than 5% (preferably less than 3%).

[0067] According to one embodiment of the present invention, it also relates to a fabric, comprising the ultra-high molecular weight polyethylene fiber described in any one of the preceding or following aspects of the present 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 with a viscosity average molecular weight of 4.5 million was mixed with decalin at a ratio of 100:1300 and swelled. The simply supported beam impact strength of ultra-high molecular weight polyethylene is 65 kJ / m 2 , the mixing and swelling is carried out in two steps. First, mix at 30℃ for 25min, then mix at 80℃ for 2h, the swelling ratio of the swollen particles is 2.8, and a suspension is formed. The suspension is sheared and dissolved by a screw, and extruded at 180℃ and a stretching ratio of 10 to form a spinning fine stream. At least 98% of the solvent is removed by evaporation, the evaporation temperature is 3℃ higher than the solvent flash temperature, and the stretching ratio is 3 to form an initial raw silk. The initial raw silk is stretched in 3 stages, the stretching temperature is 145℃, and the stretching ratio is 150 to make a finished silk.

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

[0087] Example 8

[0088] 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] Embodiment 11

[0094] The same as Example 1, except that the initial raw silk 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 silk 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] 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. 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] 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 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, 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 30-120 kJ / m 2 (Preferably 50-90 kJ / m 2 ).

2. The manufacturing 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 (preferably 3 million to 5 million).

3. The manufacturing method according to claim 1, 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).

4. The manufacturing method according to claim 1, wherein in step 1), in the spinning solution, the swelling ratio of the swollen particles is less than 10 (preferably less than 3).

5. 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 fine stream, 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 raw fibers, 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.

6. The manufacturing method according to claim 5, wherein in step 2-1), stretching is present or absent, and the extrusion temperature is 150-250°C (preferably 170-190°C); when stretching is present, the stretching ratio is 0-50 (preferably 2-20).

7. The production method according to claim 5, wherein in step 2-2), at least a portion of the solvent is removed from the spinning stream by evaporation.

8. The manufacturing method according to claim 7, 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).

9. The manufacturing method according to claim 5, 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.

10. The manufacturing method according to claim 5, wherein in step 2-3), the operating conditions of the stretching include: The number of stretching sections is 1-10 (preferably 2-5), the stretching temperature is 90-170° C. (preferably 130-150° C.), and the stretching ratio is 2-500 (preferably 4-250).

11. An ultra-high molecular weight polyethylene fiber obtained by the production method according to claim 1.

12. A fabric comprising the ultra-high molecular weight polyethylene fiber according to claim 11.

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