Ultra-high molecular weight polyethylene fiber with self-lubricating property 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 a self-lubricating property 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) mixing ultra-high molecular weight polyethylene, polyethylene wax and a solvent to prepare a spinning solution, 2) extruding the spinning solution to pass through a spinneret plate to form a spinning trickle, and 3) removing at least a part of the solvent from the spinning trickle while stretching the spinning trickle to obtain the ultra-high molecular weight polyethylene fiber. The ratio of the stretching speed to the extrusion speed of the spinning trickle is 1 to 20. The polyethylene wax is added, and a lubricating layer is automatically formed on the surface of the fiber by controlling the migration of the polyethylene wax in the fiber forming process, so that the friction resistance of the fiber is improved.

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 self-lubricating properties, a manufacturing method thereof and applications thereof. Background Art

[0002] Due to the different solvent removal processes, the cross-section of dry-spun ultra-high molecular weight polyethylene fibers presents irregular bean-shaped, waist-shaped and other irregular structures. At the same time, the fiber filaments are thin. During the production and use process, the surface of the friction parts is easily scratched and damaged, forming detached matter, which makes cleaning difficult. Especially in the knitting field, the accumulation of detached matter will cause problems such as clogging of porcelain parts and defects on the cloth surface, affecting its application and promotion.

[0003] Usually, this problem is improved in the art by coating the surface with an oil during the processing. However, the method of coating the oil is that, first, the structure of ultra-high molecular weight polyethylene is simple and dense, and the adhesion to the oil is poor, so the effect is not ideal; second, the oil film is easily uneven, resulting in failure to protect the entire process; third, there will be high-temperature heating and high-multiple drafting during the production process, the oil will be damaged and the performance will be reduced; fourth, the strength of the oil film is not high, and it will quickly fail during continuous friction. The present invention abandons this idea and takes a different approach. A similar compatible substance, polyethylene wax, is added during the spinning process. Through process design, its migration to the surface is controlled to form a self-lubricating layer with excellent compatibility with the fiber, thereby improving the friction resistance of the fiber and solving the problem of shedding caused by fiber friction. Summary of the invention

[0004] The purpose of the present invention is to manufacture a high-friction-resistant ultra-high molecular weight polyethylene fiber with self-lubricating properties in view of the shortcomings of the prior art that ultra-high molecular weight polyethylene fibers are not wear-resistant and fall off during friction, resulting in many application defects in the fields of knitting. In the fiber spinning process of the present invention, because decalin is a good solvent for ultra-high molecular weight polyethylene, polyethylene is dissolved at high temperature to form a spinning solution. The basic molecular weight structural unit of polyethylene wax is the same as that of ultra-high molecular weight polyethylene, so it has very good compatibility and will form a uniform solution in decalin together. In the process of evaporation of the spinning solution solvent to form primary raw silk, because the molecular weight of polyethylene wax is very low and the fluidity is good, it will quickly migrate to the fiber surface with the process of solvent evaporation. Subsequently, the primary fiber is stretched at a temperature of 90-160°C, which is higher than the melting point of polyethylene wax. Therefore, the polyethylene wax on the fiber surface is in a molten liquid state and flows with the drawing of the fiber to form a uniform self-lubricating layer, thereby achieving the purpose of protecting the fiber and improving lubrication, and obtaining a high-friction-resistant ultra-high molecular weight polyethylene fiber.

[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) Mixing ultra-high molecular weight polyethylene, polyethylene wax and solvent to prepare a spinning solution,

[0008] 2) extruding the spinning solution through a spinneret to form a spinning fine stream,

[0009] 3) while stretching the spinning stream, 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 the ultra-high molecular weight polyethylene fiber (referred to as spun fiber),

[0010] The ratio of the drawing speed to the extrusion speed of the spinning fine stream is 1-20 (preferably 2-10).

[0011] 2. The manufacturing method described in any of the preceding or following aspects, wherein in step 1), the amount of the polyethylene wax is 0.5-20 parts by weight (preferably 1-10 parts by weight) relative to 100 parts by weight of the ultra-high molecular weight polyethylene, and the amount of the solvent is at most 2000 parts by weight (preferably 1000-1500 parts by weight).

[0012] 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 and its hydrogenated derivatives decalin, tetralin, kerosene, xylene, toluene, petroleum fractions, halogenated hydrocarbons, cycloalkanes, and cycloolefins, preferably decalin.

[0013] 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), and the viscosity-average molecular weight of the polyethylene wax is 1000-5000 (preferably 1500-3000).

[0014] 5. The manufacturing method described in any of the preceding or following aspects, wherein in step 1), the intrinsic viscosity of the polyethylene wax is 0.05-0.3 g / dl (preferably 0.1-0.2 g / dl), and the intrinsic viscosity of the ultra-high molecular weight polyethylene is 10-45 g / dl (preferably 15-35 g / dl).

[0015] 6. The manufacturing method according to any one of the preceding or following aspects, wherein in step 2), the extrusion temperature is 130-220°C (preferably 150-180°C), and the extrusion speed is 2-20 m / min (3-10 m / min).

[0016] 7. The manufacturing method described in any of the above or the following aspects, wherein the spinning stream is immediately subjected to step 3) after leaving the spinneret.

[0017] 8. The manufacturing method described in any of the preceding or following aspects, wherein in step 3), the operating conditions include: temperature of 70-180°C (preferably 100-140°C), blowing height of not less than 0.2m (preferably 1-8m), and air volume of 50-180m3 / h (preferably 60-100m3 / h).

[0018] 9. The manufacturing method described in any of the above or the following aspects, wherein in step 3), the stretching speed is 2 m / min (preferably 5-15 m / min), and the stretching ratio is not less than 2 (preferably 3-10).

[0019] 10. The manufacturing method described in any of the above or the following aspects, wherein in step 3), the stretching and the solvent removal are carried out simultaneously, and the duration is not less than 2 minutes (preferably 3-10 minutes).

[0020] 11. The manufacturing method described in any of the preceding or following aspects, wherein after step 3), the spun fiber is stretched in one or more stages (such as 1-8 or 2-5 stages) (referred to as post-stretching).

[0021] 12. The manufacturing method described in any one of the above or below aspects 1, wherein the operating conditions of the post-stretching include: the stretching temperature is 90-160°C (preferably 120-140°C), and the (overall) stretching ratio is 2-30 (preferably 10-15).

[0022] 13. An ultra-high molecular weight polyethylene fiber obtained by the production method described in any one of the preceding or following aspects.

[0023] 14. The ultra-high molecular weight polyethylene fiber described in any one of the preceding or following aspects, comprising a core and a self-lubricating layer covering at least a portion (preferably substantially the entire) of the surface of the core.

[0024] 15. The ultra-high molecular weight polyethylene fiber described in any one of the preceding or following aspects, wherein the self-lubricating layer contains polyethylene wax as a main component.

[0025] 16. The ultra-high molecular weight polyethylene fiber according to any one of the preceding or following aspects, wherein the self-lubricating layer is generated in situ.

[0026] 17. The ultra-high molecular weight polyethylene fiber described in any of the preceding or following aspects, wherein the single fiber fineness is 0.7-5 dtex (preferably 1.7-2.7 dtex).

[0027] 18. The ultra-high molecular weight polyethylene fiber described in any of the above or the following aspects has a friction coefficient of 0.05-0.30 (preferably 0.08-0.1) and a breaking strength of 10-45 cN / dtex (preferably 25-40 cN / dtex).

[0028] 19. A fabric comprising or made of the ultra-high molecular weight polyethylene fiber described in any one of the preceding or following aspects.

[0029] 20. 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 adds polyethylene wax and controls its migration during the fiber forming process so that a lubricating layer is automatically formed on the fiber surface, thereby improving the friction resistance of the fiber. The fiber obtained by the present invention has a breaking strength of 10-40 cN / dtex, and the prepared fiber will not produce any falling objects during production, weaving, knitting and the like. The fiber friction coefficient is 0.05μ-0.30μ. The friction resistance test is more than 1 times higher than that of ordinary dry-spun ultra-high molecular weight polyethylene fiber. The fiber can be used in various gloves, outerwear, underwear, woven fabrics, knitted fabrics, ropes, lines, nets and other fields. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] In the context of the present invention, the measuring method of breaking strength and breaking elongation is GB / T 19975.

[0037] In the context of the present invention, the method for measuring the monofilament fineness is GB / T 14343.

[0038] In the context of the present invention, the friction coefficient test was conducted on a USTER ZWEIGLE FRICTION TESTER 5 friction tester, and the friction resistance test was conducted on a filament friction tester LY109D, with a weight of 100 g.

[0039] In the context of the present invention, shedding is characterized by cumulative weighing, recording the weight of shedding when the fibers are knitted into a glove for 8 hours.

[0040] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight and pressure is gauge pressure.

[0041] 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.

[0042] According to one embodiment of the present invention, a method for manufacturing an ultra-high molecular weight polyethylene fiber is provided. According to the present invention, the ultra-high molecular weight polyethylene fiber has a core and a self-lubricating layer covering at least a portion (preferably substantially all) of the surface of the core, thereby having self-lubricating properties. Moreover, the self-lubricating layer is generated in situ, that is, the self-lubricating layer is directly generated by the ultra-high molecular weight polyethylene fiber during its manufacturing process, and is not additionally attached to the fiber by coating or the like.

[0043] According to one embodiment of the present invention, the self-lubricating layer contains polyethylene wax as a main component.

[0044] According to one embodiment of the present invention, the manufacturing method comprises the step 1) of mixing ultra-high molecular weight polyethylene, polyethylene wax and a solvent to prepare a spinning solution.

[0045] According to one embodiment of the present invention, in step 1), the amount of the polyethylene wax is 0.5-20 parts by weight (preferably 1-10 parts by weight) relative to 100 parts by weight of the ultra-high molecular weight polyethylene.

[0046] According to one embodiment of the present invention, in step 1), the amount of the solvent used is at most 2000 parts by weight (preferably 1000-1500 parts by weight) relative to 100 parts by weight of the ultra-high molecular weight polyethylene.

[0047] According to one embodiment of the present invention, in step 1), the solvent is selected from at least one of naphthalene and its hydrogenated derivatives decalin, tetralin, kerosene, xylene, toluene, petroleum fractions, halogenated hydrocarbons, cycloalkanes, and cycloolefins, preferably decalin.

[0048] 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).

[0049] According to one embodiment of the present invention, in step 1), the viscosity average molecular weight of the polyethylene wax is 1000-5000 (preferably 1500-3000).

[0050] According to one embodiment of the present invention, in step 1), the intrinsic viscosity of the polyethylene wax is 0.05-0.3 g / dl (preferably 0.1-0.2 g / dl).

[0051] According to one embodiment of the present invention, in step 1), the intrinsic viscosity of the ultra-high molecular weight polyethylene is 10-45 g / dl (preferably 15-35 g / dl).

[0052] According to one embodiment of the present invention, the manufacturing method comprises step 2) of extruding the spinning solution through a spinneret to form a spinning fine stream.

[0053] According to one embodiment of the present invention, in step 2), the extrusion temperature is 130-220° C. (preferably 150-180° C.), and the extrusion speed is 2-20 m / min (3-10 m / min).

[0054] According to one embodiment of the present invention, the ratio of the stretching speed of the spinning stream to the extrusion speed is 1-20 (preferably 2-10). This step is to promote the diffusion of the polyethylene wax to the surface. If this ratio is too large, the fiber strength will be reduced, and even continuous production will not be possible. If this ratio is too small, the polyethylene wax will not be able to migrate to the surface quickly, and even continuous spinning will not be possible.

[0055] According to one embodiment of the present invention, the manufacturing method includes a step 3) of removing at least a portion of the solvent from the spinning stream while stretching the spinning stream to obtain the ultra-high molecular weight polyethylene fiber (referred to as spun fiber). If the solvent is not removed during the stretching process, the solvent concentration difference from the surface layer to the inner layer cannot be formed, so the polyethylene wax cannot migrate to the surface. Here, the so-called at least a portion is, for example, at least 50wt%, preferably at least 70wt%, at least 80wt%, at least 90wt%, at least 95wt% or at least 97wt%.

[0056] According to one embodiment of the present invention, the spinning stream is immediately subjected to step 3) after leaving the spinneret.

[0057] According to one embodiment of the present invention, in step 3), the operating conditions include: temperature of 70-180°C (preferably 100-140°C), blowing height of not less than 0.2m (preferably 1-8m), air volume of 50-180m3 / h (preferably 60-100m3 / h).

[0058] According to one embodiment of the present invention, in step 3), the stretching speed is 2 m / min (preferably 5-15 m / min), and the stretching ratio is not less than 2 (preferably 3-10).

[0059] According to one embodiment of the present invention, in step 3), the stretching and the solvent removal are carried out simultaneously, and the duration is not less than 2 minutes (preferably 3-10 minutes).

[0060] According to one embodiment of the present invention, after step 3), the spun fiber is stretched in one or more stages (such as 1-8 or 2-5 stages) (referred to as post-stretching).

[0061] According to one embodiment of the present invention, the post-stretching operation conditions include: a stretching temperature of 90-160° C. (preferably 120-140° C.), and an (overall) stretching ratio of 2-30 (preferably 10-15).

[0062] According to one embodiment of the present invention, it relates to an ultra-high molecular weight polyethylene fiber obtained by the manufacturing method described in any one of the preceding or following aspects of the present specification.

[0063] According to one embodiment of the present invention, the single filament fineness of the ultra-high molecular weight polyethylene fiber is 0.7-5 dtex (preferably 1.7-2.7 dtex).

[0064] According to one embodiment of the present invention, the friction coefficient of the ultra-high molecular weight polyethylene fiber is 0.05-0.15 (preferably 0.08-0.1).

[0065] According to one embodiment of the present invention, the breaking strength of the ultra-high molecular weight polyethylene fiber is 20-45 cN / dtex (preferably 25-40 cN / dtex).

[0066] 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 the present specification or made of the ultra-high molecular weight polyethylene fiber described in any one of the preceding or following aspects of the present specification.

[0067] 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.

[0068] Example

[0069] The present invention is further described in detail below using examples and comparative examples, but the present invention is not limited to these examples.

[0070] Example 1

[0071] In this embodiment, an ultra-high molecular weight polyethylene fiber with self-lubricating properties is obtained by the following process:

[0072] Ultra-high molecular weight polyethylene with a viscosity average molecular weight of 4.5 million, polyethylene wax with a viscosity average molecular weight of 2000 and decalin are mixed and swollen in a ratio of 100:2:1300. The characteristic viscosity of ultra-high molecular weight polyethylene is 25g / dl, and the characteristic viscosity of polyethylene wax is 0.15g / dl. After forming a suspension, it is sheared and dissolved by a screw, and extruded at 170°C and an extrusion speed of 3.5m / min to form a spinning fine stream. After the spinning fine stream leaves the spinneret, it is immediately desolventized to remove at least 98% of the solvent. The temperature is 135°C, the blowing height is 7.5m, and the air volume is 90m3 / h. During the desolventization, the stretching speed is 12m / min, the stretching ratio is 3.4, and the stretching and the desolventization are carried out simultaneously, and the duration is 8min to form the initial raw silk. The initial raw silk is stretched in 3 stages, the stretching temperature is 130°C, and the stretching ratio is 13 to make the finished silk.

[0073] Example 2

[0074] The same as Example 1, except that the viscosity average molecular weight of the polyethylene wax is 800.

[0075] Example 3

[0076] The same as Example 1, except that the viscosity average molecular weight of the polyethylene wax is 8000.

[0077] Example 4

[0078] The same as Example 1, except that the polyethylene wax accounts for 0.2% (by weight of ultra-high molecular weight polyethylene).

[0079] Example 5

[0080] The same as Example 1, except that the polyethylene wax accounts for 30% (part by weight of ultra-high molecular weight polyethylene).

[0081] Example 6

[0082] The same as Example 1, except that the solvent removal time is 1 min.

[0083] Example 7

[0084] The same as Example 1, except that the proportion of decalin is 2000.

[0085] Example 8

[0086] Same as Example 1, except that the ratio of the drawing speed of the spinning thread to the extrusion speed is 10.

[0087] Example 9

[0088] Same as Example 1, except that the ratio of the drawing speed of the spinning fine stream to the extrusion speed is 2.

[0089] Example 10

[0090] The same as Example 1, except that the solvent removal temperature is 100°C, the blowing height is 1m, and the air volume is 50m3 / h.

[0091] Comparative Example 1

[0092] The same as Example 1, except that the gel spinning method is used. After the spinning solution exits the spinneret, the solvent is not removed immediately, but it is first cooled at a temperature of 30° C. and a cooling time of ≤1 min.

[0093] Comparative Example 2

[0094] The same as Example 1, except that the extrusion speed is 0.3 m / min and the solvent removal stretching speed is 0.5 m / min.

[0095] Comparative Example 3

[0096] The same as Example 1, except that the solvent removal and stretching are not performed simultaneously, but the stretching step is performed first and then the solvent removal step.

[0097] Comparative Example 4

[0098] The same as Example 1, except that the solvent removal and stretching are not performed simultaneously, but the solvent removal step is performed first and then the stretching step.

[0099] Comparative Example 5

[0100] The fiber is commercially available LY25 400D ultra-high molecular weight polyethylene fiber.

[0101]

Claims

1. A method for producing ultra-high molecular weight polyethylene fiber, comprising the following steps: 1) Mixing ultra-high molecular weight polyethylene, polyethylene wax and solvent to prepare a spinning solution, 2) extruding the spinning solution through a spinneret to form a spinning fine stream, 3) while stretching the spinning stream, 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 the ultra-high molecular weight polyethylene fiber (referred to as spun fiber), The ratio of the drawing speed to the extrusion speed of the spinning fine stream is 1-20 (preferably 2-10).

2. The production method according to claim 1, wherein in step 1), the amount of the polyethylene wax is 0.5-20 parts by weight (preferably 1-10 parts by weight) relative to 100 parts by weight of the ultra-high molecular weight polyethylene, and the amount of the solvent is at most 2000 parts by weight (preferably 1000-1500 parts by weight).

3. 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), and the viscosity average molecular weight of the polyethylene wax is 1000-5000 (preferably 1500-3000).

4. The manufacturing method according to claim 1, wherein in step 1), the intrinsic viscosity of the polyethylene wax is 0.05-0.3 g / dl (preferably 0.1-0.2 g / dl), and the intrinsic viscosity of the ultra-high molecular weight polyethylene is 10-45 g / dl (preferably 15-35 g / dl).

5. The manufacturing method according to claim 1, wherein in step 2), the extrusion temperature is 130-220°C (preferably 150-180°C), and the extrusion speed is 2-20 m / min (3-10 m / min).

6. The manufacturing method according to claim 1, wherein the spinning stream is immediately subjected to step 3) after leaving the spinneret.

7. The manufacturing method according to claim 1, wherein in step 3), the operating conditions include: The temperature is 70-180°C (preferably 100-140°C), the blowing height is not less than 0.2m (preferably 1-8m), and the air volume is 50-180m3 / h (preferably 60-100m3 / h).

8. The manufacturing method according to claim 1, wherein in step 3), the stretching speed is not less than 2 m / min (preferably 5-15 m / min), and the stretching ratio is not less than 2 (preferably 3-10).

9. The manufacturing method according to claim 1, wherein in step 3), the stretching and the solvent removal are carried out simultaneously, and the duration is not less than 2 minutes (preferably 3-10 minutes).

10. The manufacturing method according to claim 1, wherein after step 3), the as-spun fiber is stretched in one or more stages (such as 1-8 or 2-5 stages) (referred to as post-stretching).

11. The manufacturing method according to claim 10, wherein the post-stretching operating conditions include: The stretching temperature is 90-160° C. (preferably 120-140° C.), and the (overall) stretching ratio is 2-30 (preferably 10-15).

12. An ultra-high molecular weight polyethylene fiber obtained by the production method according to claim 1, comprising a core and a self-lubricating layer covering at least a portion (preferably substantially the entire) of the surface of the core.

13. The ultra-high molecular weight polyethylene fiber of claim 12, wherein the self-lubricating layer is generated in situ.

14. A fabric comprising or made of the ultra-high molecular weight polyethylene fiber according to claim 12.

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