Preparation method of antistatic spandex and antistatic spandex

Abstract

The present application discloses a preparation method of antistatic spandex and the antistatic spandex. The preparation method includes the following steps: a prepolymer preparation step, a prepolymer dissolution step, a prepolymer chain extension reaction step, and a spinning step. In the prepolymer dissolution step, the prepolymer is dissolved by using DMAC in which an antistatic agent is dispersed. By uniformly dispersing the antistatic agent in DMAC and then dissolving the prepolymer with DMAC containing the antistatic agent, the antistatic agent is uniformly dispersed in the whole system, so that the antistatic agent can be uniformly and firmly attached to the spandex molecular chain.

Description

Technical Field

[0001] This application belongs to the technical field of spandex preparation. Specifically, it relates to a method for preparing antistatic spandex and antistatic spandex. Background Art

[0002] As a synthetic fiber with high elasticity, abrasion resistance and fatigue resistance, spandex is widely used in fields such as clothing, household items, and industrial products.

[0003] However, traditional spandex is prone to generating static electricity during use. In the subsequent use process, the static electricity will cause the fibers to attract each other, and it will also adsorb dust and short fiber fluffs, affecting weaving. Static electricity not only affects the comfort of wearing clothes, but may also cause damage to electronic devices.

[0004] Antistatic spandex has excellent antistatic performance, durability and stability, and can be widely used in fields such as clothing, household items, and industrial products. Especially in fields sensitive to static electricity such as electronics and aerospace, antistatic spandex will have broad application prospects and market space.

[0005] Currently, there are already multiple methods for preparing antistatic spandex disclosed. One is to directly add an antistatic agent to the auxiliary materials in spandex production. Another is to adopt a core-shell structure and add an antistatic agent to the skin layer or core layer. There is also a method of preparing a special antistatic agent and adding it to the spinning dope in the form of an auxiliary material to prepare antistatic spandex fibers.

[0006] However, the problem with the above methods is that when the spandex fibers are stretched, the antistatic effect will be weakened or lost. Summary of the Invention

[0007] The technical problem to be solved by this application is: to provide a method for preparing antistatic spandex to solve the problem that the antistatic effect is weakened or lost when the antistatic spandex fibers are stretched.

[0008] To solve the above problems of this application, this application provides a method for preparing antistatic spandex, including a prepolymer preparation step, a prepolymer dissolution step, a prepolymer chain extension reaction step, and a spinning step. Among them, in the prepolymer dissolution step, the prepolymer is dissolved using DMAC dispersed with an antistatic agent.

[0009] The solution provided by this application disperses the antistatic agent evenly in DMAC, and then uses DMAC containing the antistatic agent to dissolve the prepolymer, so that the antistatic agent is evenly dispersed in the whole system. Thus, the antistatic agent can be evenly and firmly attached to the spandex molecular chain, solving the problem in the prior art that directly adding the antistatic agent to the spinning dope affects the adsorption of the antistatic agent on the spandex molecular chain, resulting in the weakening or loss of the antistatic effect when the antistatic spandex fibers are stretched.

[0010] As a preferred option for adding an antistatic agent in the step of dissolving the prepolymer in this application, the addition amount of the antistatic agent is 1%-5% of the solid content of the spinning dope obtained after the prepolymer is chain-extended.

[0011] When the addition amount of the antistatic agent is too small, the antistatic performance will be affected. When the addition amount of the antistatic agent is too high, the quality control of the spandex will be affected.

[0012] As a preferred way of adding an antistatic agent in the step of dissolving the prepolymer in this application, the antistatic agent is added in the form of an antistatic agent dispersant. The antistatic agent is dispersed in DMAC and then added to the prepolymer to dissolve the prepolymer.

[0013] By dispersing the antistatic agent in DMAC and then adding it to the prepolymer to dissolve the prepolymer, the antistatic agent can be evenly dispersed in the polymerization system, so that the antistatic agent can be evenly and firmly adsorbed on the spandex molecular chain.

[0014] As an improvement in the above prepolymer chain-extension stage of this application, in the prepolymer chain-extension reaction step, carbon black accounting for 0.3%-0.6% of the solid content of the spinning dope is added to the reactants, so that the prepolymer chain-extension reaction step forms a black spinning dope with an antistatic agent.

[0015] As an improvement in the preparation method of the above antistatic spandex in this application, after the spinning is completed, after the spandex tow passes through the first roller, an antistatic agent dispersion liquid is coated on the spandex tow by a coating roller to coat the antistatic agent on the spandex tow again, further improving the antistatic performance of the spandex. After passing through a water roller for water washing, the spandex tow is dried and cured to obtain an antistatic spandex fiber with excellent antistatic performance.

[0016] After the spandex tow is coated with the antistatic agent dispersion liquid by the coating roller, the tow is passed through an antistatic agent dispersion liquid collection device to collect the excess antistatic agent dispersion liquid that has not adhered to the spandex tow. The antistatic agent dispersion liquid collection device can be set as an antistatic agent dispersion liquid collection plate.

[0017] As a preferred option, after the above spinning is completed, the preparation method of the antistatic agent dispersion liquid used in the post-treatment process of the tow is: by mass, H2O: 1-3 parts, DMAC: 7-9 parts, a dispersion liquid of H2O and DMAC is mixed, and then the antistatic agent is evenly dispersed in the dispersion liquid at a mass concentration of 1%-10% to obtain an antistatic agent dispersion liquid.

[0018] By preparing the antistatic agent dispersion through this method, it is possible to avoid the situation where a dispersion with too high H2O content cannot be well coated on the surface of spandex filaments (spandex filaments mainly exhibit hydrophobicity); avoid the dissolution and breakage of spandex filaments by excessive DMAC; this antistatic agent dispersion can evenly coat and embed the antistatic agent on the surface of spandex filaments, and this antistatic agent dispersion can enable the antistatic agent added inside the spandex to form a continuous antistatic interlayer with the antistatic agent embedded on the surface, improving the antistatic performance of spandex filaments and also improving the washability of spandex filaments.

[0019] As an option for the above antistatic agent of this application, the antistatic agent is at least one or a combination of carbon black, graphene, carbon nanotubes, or nano silver.

[0020] According to the above improvement of this application, a method for preparing antistatic spandex provided by this application includes:

[0021] Prepolymer preparation step: React polytetramethylene ether glycol and diphenylmethane diisocyanate at a molar ratio of 1:1.5 - 2 at 65 - 90 °C to form a prepolymer;

[0022] Prepolymer dissolution step: Add DMAC dispersed with an antistatic agent to the prepolymer to dissolve the prepolymer;

[0023] Prepolymer chain extension reaction step: At 10 - 40 °C, use a mixed amine to extend the chain of the prepolymer after dissolving the antistatic agent, and add carbon black and auxiliary materials accounting for 0.3% - 0.6% of the solid content of the spinning dope to form a black spinning dope with an antistatic agent;

[0024] Spinning step: Perform dry spinning on the antistatic black spandex spinning dope obtained by chain extension.

[0025] As an option in the above chain extension step of this application, the mixed amine is ethylenediamine, propylenediamine, pentamethylenediamine, diethylenetriamine, or diethylamine.

[0026] The beneficial effects of this application are as follows:

[0027] In this application, the antistatic agent is evenly dispersed in DMAC, and then the prepolymer is dissolved with DMAC containing the antistatic agent, so that the antistatic agent is evenly dispersed in the whole system, thereby enabling the antistatic agent to be evenly and firmly attached to the spandex molecular chain, solving the problem in the prior art that directly adding the antistatic agent to the spinning dope affects the adsorption of the antistatic agent on the spandex molecular chain, resulting in a weakened or lost antistatic effect when the antistatic spandex fiber is stretched.

[0028] The technical solution of this application can also solve the problem in the prior art that the antistatic agent is prone to agglomeration and causes blockage of the spinning holes in the adopted manner.

[0029] In the post-treatment stage of the tow, the antistatic agent dispersion is coated on the surface of the tow through a coating roller. The antistatic agent dispersion is prepared by mixing H2O: 1-3 parts and DMAC: 7-9 parts by mass to form an H2O and DMAC dispersion, and then uniformly dispersing the antistatic agent in the dispersion at a mass concentration of 1%-10%. By preparing the antistatic agent dispersion in this way, it can be avoided that the dispersion with too high H2O content cannot be well coated on the surface of the spandex filament; it can be avoided that too much DMAC dissolves and breaks the spandex filament; the antistatic agent dispersion can evenly coat and embed the antistatic agent on the surface of the spandex filament, and the antistatic agent dispersion can make the antistatic agent added inside the spandex form a continuous antistatic interlayer with the antistatic agent embedded on the surface, improving the antistatic performance of the spandex filament and also improving the washability of the spandex filament.

[0030] The antistatic spandex disclosed in this application is successfully prepared by dissolving a carbon black combined antistatic agent and a DMAC solution prepolymer containing an antistatic agent and coating the antistatic agent on the surface of the spandex filament, resulting in an antistatic spandex with excellent antistatic performance. This antistatic spandex not only solves the problem of static electricity generation in traditional spandex but also has good durability and stability, providing a new choice of high-performance material for fields such as textiles, electronics, and aerospace. Brief Description of the Drawings

[0031] Figure 1 It is a schematic diagram of a preparation method of an antistatic spandex in an embodiment of this application;

[0032] Figure 2 It is a schematic diagram of a wire collecting system used in a preparation method of an antistatic spandex in an embodiment of this application;

[0033] Description of the Reference Numerals:

[0034] 1, duct; 2, first roller; 3, coating roller; 4, antistatic agent dispersion tank; 5, antistatic agent dispersion collecting plate; 6, water roller; 7, water tank; 8, second roller; 9, hot air device; 10, wire collecting roller. Detailed Description of the Embodiments

[0035] The embodiments of the technical solutions of this application will be described in detail below. The following embodiments are only used to more clearly illustrate the technical solutions of this application, so they are only examples and cannot be used to limit the protection scope of this application. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] The present application provides a method for preparing antistatic spandex, including a prepolymer preparation step, a prepolymer dissolution step, a prepolymer chain extension reaction step, and a spinning step. Among them, in the prepolymer dissolution step, the prepolymer is dissolved using DMAC in which an antistatic agent is dispersed.

[0037] Those skilled in the art know that in the process of preparing spandex, the prepolymer preparation process is that polyether diol and diisocyanate form a prepolymer at a specific molar ratio under certain reaction temperature and time conditions. The prepolymer dissolution process is to dissolve the prepolymer using an organic solvent. The prepolymer chain extension is to add an amine to the prepolymer dissolved in the solvent for a chain growth chain extension reaction to form a spinning dope of a block copolymer solution, and then spin.

[0038] In the prepolymer dissolution step, the addition amount of the antistatic agent is 1%-5% of the solid content of the spinning dope. In the prepolymer dissolution step, the antistatic agent is added in the form of an antistatic agent dispersant, and the antistatic agent is uniformly dispersed in DMAC and then added to the prepolymer to dissolve the prepolymer.

[0039] As an optional antistatic agent, it can be selected as at least one or a combination of carbon black, graphene, carbon nanotubes, or nano silver.

[0040] The amine in the prepolymer chain extension reaction step can be selected from one or more of ethylenediamine, propylenediamine, pentamethylenediamine, diethylenetriamine, and diethylamine.

[0041] Combined with Figure 2 Schematic take-up system, in an optional embodiment of the present application, after spinning is completed, when the filament bundle passes through the first roller 2, it then passes through the coating roller 3 to coat the antistatic agent dispersion liquid, then passes through the water roller for water washing, and is dried and cured to obtain antistatic spandex fibers with excellent antistatic performance. Specifically, the filament bundle coming out of the duct 1 passes through the first roller 2 and then passes through the coating roller 3 to coat the antistatic agent dispersion liquid placed in the antistatic agent dispersion liquid tank 4 on the filament bundle. It is optional to set an antistatic agent dispersion liquid collection plate 5 to collect the excess antistatic agent dispersion liquid that does not adhere to the spandex filament bundle. Then, it passes through the water roller 6, is washed in the water tank 7, and then passes through the second roller 8. The filament bundle is dried and cured using the hot air device 9 to obtain antistatic spandex, and then taken up using the take-up roller 10. In this optional embodiment, the preparation method of the antistatic agent dispersion liquid is: by mass, H2O: 1-3 parts, DMAC: 7-9 parts, a dispersion liquid of H2O and DMAC is mixed, and then the antistatic agent is uniformly dispersed in the dispersion liquid at a mass concentration of 1%-10% to obtain the antistatic agent dispersion liquid.

[0042] Optionally, after coating the antistatic agent dispersion liquid through the coating roller, the filament bundle is collected by a dispersant collection device to collect the excess antistatic agent dispersion liquid, then washed with water, and then dried and cured.

[0043] According to the above method, a preparation method of antistatic spandex includes the following steps:

[0044] Prepolymer preparation step: Polytetramethylene ether glycol and diphenylmethane diisocyanate are fully reacted at a molar ratio of 1:1.5 - 2 at 65 - 90 °C to form a prepolymer;

[0045] Prepolymer dissolution step: DMAC dispersed with an antistatic agent is added to the prepolymer to dissolve the prepolymer;

[0046] Prepolymer chain extension reaction step: At 10 - 40 °C, the prepolymer after dissolving the antistatic agent is chain - extended with a mixed amine, and carbon black and auxiliary materials accounting for 0.3% - 0.6% of the solid content of the spinning dope are added to form a black spinning dope with an antistatic agent; the auxiliary materials can be selected from additives such as ultraviolet light absorbers, antioxidants, lubricants, and delustering agents. In the following examples, in order to evaluate the technical effects of this application, the auxiliary materials used in the following examples are all the same ultraviolet light absorber, antioxidant, and delustering agent added according to a mass ratio of 1:1:1.

[0047] Spinning step: The antistatic black spandex spinning dope obtained by chain extension is dry - spun to obtain antistatic spandex.

[0048] According to the embodiments provided in this application, some specific tests have been carried out on this application. That is, an example of preparing antistatic spandex by uniformly dispersing an antistatic agent in DMAC and then using DMAC containing the antistatic agent to dissolve the prepolymer is adopted. On this basis, an example of preparing antistatic spandex by coating the antistatic agent dispersion provided in this application on the surface of the tow by a coating roller is also given, and some comparative examples are given. From these examples and comparative examples, it can be seen that the solution provided in this application has obtained good effects. It should be noted that the following examples are only used to illustrate the present invention in detail and do not limit the protection scope of the invention in any way.

[0049] Example 1

[0050] S1. Prepolymer preparation step: 1000 g of polytetramethylene ether glycol (molecular weight 1800) and 210 g of diphenylmethane diisocyanate are fully reacted at 70 °C ± 5 °C for 3 hours to form a prepolymer;

[0051] S2. Prepolymer dissolution step: DMAC dispersed with an antistatic agent is added to the prepolymer to dissolve the prepolymer. The antistatic agent is added at 1% of the solid content of the spinning dope. The preparation method of the antistatic dispersant of DMAC dispersed with the antistatic agent is: 17 g of graphene antistatic agent is dispersed in 1800 g of DMAC to obtain;

[0052] S3. Prepolymer chain extension reaction step: At 10 - 40 °C, 430 g of a 7% concentration mixed amine is used to extend the chain of the prepolymer after dissolving the antistatic agent, and 114 g of a solution containing 0.3% carbon black and auxiliary materials dissolved in DMAC is added to form a black spinning dope with an antistatic agent; the mixed amine is a mixed amine of ethylenediamine, propylenediamine, and diethylamine in a mass ratio of 1:1:1;

[0053] S4. Spinning step: The antistatic black spandex spinning dope obtained by chain extension is dry-spun to obtain antistatic spandex.

[0054] The performance of the obtained antistatic spandex is tested according to the surface resistivity technical requirements of GB / T 12703.4 - 2010, and the test results are shown in Table 5.

[0055] Examples 2 - 10

[0056] The same preparation method of antistatic spandex as in Example 1 is used, except that the preparation conditions are different in each step of the preparation of antistatic spandex. Specifically: In the prepolymer preparation step, the addition amounts and reaction temperatures of polytetramethylene ether glycol and diphenylmethane diisocyanate are different. The control conditions in this step of the preparation method of antistatic spandex are shown in Table 1;

[0057] In the step of dissolving the prepolymer, the addition ratio of the antistatic agent to the solid content of the spinning dope is different. In the preparation of the antistatic dispersant, the amounts of the antistatic agent and DMAC are different. The control conditions in this step of the preparation method of antistatic spandex are shown in Table 2;

[0058] In the prepolymer chain extension reaction step, the dosage, concentration, and composition of the mixed amine are different, and the addition amount of carbon black is different. The control conditions in this step of the preparation method of antistatic spandex are shown in Table 3.

[0059] In Examples 2 - 6, no antistatic dispersion liquid is coated on the tow during the spinning step. In Examples 7 - 10, an antistatic dispersion liquid is coated on the tow during the spinning step.

[0060] Among them, in Example 7, the S4 spinning step is: The antistatic black spandex spinning dope obtained in S3 is dry-spun. When the tow passes through the first roller, it is coated with an antistatic agent dispersion liquid through a coating roller, and then passes through a dispersant collection device and a water roller for post-treatment of the fiber, and then through drying and curing treatment to obtain antistatic spandex fiber. The preparation method of the antistatic agent dispersion liquid in this step is to mix 50 g of H2O and 450 g of DMAC to form an H2O and DMAC dispersion liquid, and then disperse graphene in the above dispersion liquid at a concentration of 5% to obtain the antistatic agent dispersion liquid.

[0061] Examples 8 to 15 are different from step 4 in Example 7 in that the proportions of the components in the antistatic agent dispersion liquid are different, the concentration of the antistatic agent in the dispersion liquid is different, and the types of the antistatic agents are different. For the specific control conditions in this step in the preparation method of the antistatic spandex, please refer to Table 4.

[0062] Comparative Examples 1 to 6

[0063] Comparative Example 1 is different from Example 1 in that no antistatic dispersant was added in step S2.

[0064] Comparative Example 2 is different from Example 1 in that no antistatic dispersant was added in step S2, and 17 g of graphene and 3.9 g of carbon black were added in S3.

[0065] Specifically, Comparative Example 2 is as follows:

[0066] S1. Prepolymer preparation step: 1000 g of polytetramethylene ether glycol (molecular weight 1800) and 210 g of diphenylmethane diisocyanate were fully reacted at 70 °C ± 5 °C for 3 hours to form a prepolymer;

[0067] S2. Prepolymer dissolution step: 1800 g of DMAC was added to the prepolymer to dissolve the prepolymer;

[0068] S3. Prepolymer chain extension reaction step: At 10 - 40 °C, 430 g of a 7% concentration mixed amine was used to extend the chain of the prepolymer after dissolving the antistatic agent, and a solution of 17 g of graphene, 0.39 g of carbon black, and 39 g of auxiliary materials dissolved in DMAC was added to form a black spinning dope with an antistatic agent; the mixed amine is a mixed amine of ethylenediamine, propylenediamine, and diethylamine in a mass ratio of 1:1:1;

[0069] S4. Spinning step: The antistatic black spandex spinning dope obtained by chain extension was dry-spun to obtain antistatic spandex.

[0070] Comparative Example 3 is different from Example 7 in that no antistatic dispersant was added in step S2.

[0071] Comparative Example 4 is different from Example 7 in that no antistatic dispersant was added in step S2 and no carbon black was added in S3.

[0072] Comparative Example 5 is different from Example 7 in that in step S4, the mass ratio of H2O and DMAC in the dispersion liquid used for the antistatic agent dispersion liquid is 5:5.

[0073] Comparative Example 6 is different from Example 7 in that in step S4, the mass ratio of H2O and DMAC in the dispersion liquid used for the antistatic agent dispersion liquid is 0:10.

[0074] For the process control conditions of each step in Comparative Examples 1 to 6, please refer to Tables 1 to 4.

[0075] The antistatic spandex obtained in Examples 1 to 15 and the spandex obtained in Comparative Examples 1 to 6 were tested for spandex performance according to the surface resistivity technical requirements of GB / T 12703.4-2010. The test results are shown in Table 5 in detail.

[0076] Table 1 Control conditions for the preparation steps of the antistatic spandex prepolymer

[0077]

[0078]

[0079] Table 2 Control conditions for the step of dissolving the prepolymer in the preparation method of the antistatic spandex

[0080]

[0081] Table 3 Control conditions for the prepolymer chain extension reaction step in the preparation method of the antistatic spandex

[0082]

[0083]

[0084] Table 4 Control conditions for the spinning step in the preparation method of the antistatic spandex

[0085]

[0086]

[0087] Table 5 Performance of spandex tested according to the surface resistivity technical requirements of GB / T 12703.4-2010

[0088] Example Surface resistance Surface resistance after washing with water Remarks Example 1 <![CDATA[10 11 Ω / cm]]> <![CDATA[10 12 Ω / cm]]> Example 2 <![CDATA[10 11 Ω / cm]]> <![CDATA[10 12 Ω / cm]]> Example 3 <![CDATA[10 10 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Example 4 <![CDATA[10 12 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Example 5 <![CDATA[10 11 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Example 6 <![CDATA[10 11 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Example 7 <![CDATA[10 9 Ω / cm]]> <![CDATA[10 11 Ω / cm]]> Elongation at break of spandex fiber (%) is: 508 Example 8 <![CDATA[10 8 Ω / cm]]> <![CDATA[10 10 Ω / cm]]> Example 9 <![CDATA[10 7 Ω / cm]]> <![CDATA[10 8 Ω / cm]]> Example 10 <![CDATA[10 9 Ω / cm]]> <![CDATA[10 11 Ω / cm]]> Example 11 <![CDATA[10 10 Ω / cm]]> <![CDATA[10 11 Ω / cm]]> Example 12 <![CDATA[10 7 Ω / cm]]> <![CDATA[10 9 Ω / cm]]> Example 13 <![CDATA[10 8 Ω / cm]]> <![CDATA[10 9 Ω / cm]]> Example 14 <![CDATA[10 9 Ω / cm]]> <![CDATA[10 11 Ω / cm]]> Example 15 <![CDATA[10 9 Ω / cm]]> <![CDATA[10 10 Ω / cm]]> Comparative example 1 <![CDATA[10 12 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Comparative example 2 <![CDATA[10 12 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Comparative example 3 <![CDATA[10 11 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Comparative example 4 <![CDATA[10 12 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Comparative example 5 <![CDATA[10 12 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Comparative example 6 <![CDATA[10 11 Ω / cm]]> <![CDATA[10 13 Ω / cm]]> Elongation at break of spandex fiber (%) is: 221

[0089] It can be seen from the above examples and comparative examples that adding an antistatic agent to the spandex spinning dope or coating an antistatic agent on the spandex filaments can both prepare antistatic spandex filaments with antistatic functions and meet the C-level antistatic requirements.

[0090] It can be seen from Example 1 and Comparative Example 1 that no antistatic dispersant was added in step S2 of Comparative Example 1, and the surface resistivity of the antistatic spandex obtained in Example 1 was lower than that of the spandex obtained in Comparative Example 1.

[0091] From Example 1 and Comparative Example 2, it can be seen that in Comparative Example 2, the antistatic dispersant was not added in step S2, 17 g of antistatic agent and 0.39 g of carbon black were added in step 3, and the surface resistivity of the antistatic spandex obtained in Example 1 was lower than that of the spandex obtained in Comparative Example 2. From Example 1 and Comparative Example 2, it can be seen that although the total amounts of antistatic agent and carbon black added in Example 1 and Example 2 were the same, since the antistatic agent was only added to the auxiliary materials in the production of spandex in Comparative Example 2, the antistatic agent could not be evenly and firmly attached to the spandex molecular chain. In Example 1, the antistatic agent was uniformly dispersed in DMAC, and then the prepolymer was dissolved with DMAC containing the antistatic agent, so that the antistatic agent was uniformly dispersed in the whole system, and thus the antistatic agent could be evenly and firmly attached to the spandex molecular chain. Since the spandex filaments were washed with water, the spandex filaments were hydrophobic, so their surface resistance remained unchanged.

[0092] From Example 7 and Comparative Example 3 and Comparative Example 4, it can be seen that the antistatic dispersant was not added in step S2 in Comparative Example 3, the antistatic dispersant was not added in step S2 in Comparative Example 4, and carbon black was not added in S3. The surface resistivity of the antistatic spandex obtained in Example 7 was much lower than that of the spandex obtained in Comparative Example 3 and Comparative Example 4. The surface resistivity of the spandex obtained in Example 7 was 10 9 Ω / cm, meeting the antistatic requirement of Class B and still meeting the antistatic requirement of Class C after washing with water.

[0093] From Example 1 and Example 7, it can be seen that an antistatic agent dispersion liquid was coated on the surface of the spandex filaments in Example 7, and the surface resistivity of the obtained antistatic spandex was lower than that in Example 1, indicating that coating the antistatic agent on the surface of the spandex filaments can improve the antistatic effect of the spandex filaments.

[0094] From Example 7 and Comparative Example 5, it can be seen that the surface resistivity of the antistatic spandex obtained in Example 7 was much lower than that of the spandex obtained in Comparative Example 5 because in Comparative Example 5, the content of H2O in the antistatic agent dispersion liquid was too high, and due to the hydrophobicity of the surface of the spandex filaments, the coated antistatic agent dispersion liquid in Comparative Example 5 could not be well dispersed on the spandex filaments.

[0095] From Example 7 and Comparative Example 6, it can be seen that the antistatic performance of the spandex obtained in Comparative Example 6 decreased, and in Comparative Example 6, all the solutes in the antistatic agent dispersion liquid were DMAC, which would cause DMAC to dissolve the surface layer of the spandex filaments, resulting in a decrease in the breaking elongation of the spandex filaments.

[0096] From the examples and comparative examples provided in this application, it can be seen that in the stage of dissolving the prepolymer in the examples of this application, by uniformly dispersing the antistatic agent in DMAC and then using the DMAC containing the antistatic agent to dissolve the prepolymer, the antistatic agent is uniformly dispersed in the whole system; thus, the antistatic agent can be uniformly and firmly attached to the polyurethane fiber molecular chain, solving the problem in the prior art that directly adding the antistatic agent to the spinning dope affects the adsorption of the antistatic agent on the polyurethane fiber molecular chain, resulting in the weakening or loss of the antistatic effect when the antistatic polyurethane fiber is stretched.

[0097] In the post-treatment stage of the tow in Examples 7 - 15 of this application, the antistatic agent dispersion is coated on the surface of the tow through a coating roller. The antistatic agent dispersion is prepared by mixing H2O: 1 - 3 parts and DMAC: 7 - 9 parts by mass to form a dispersion of H2O and DMAC, and then dispersing the antistatic agent in the dispersion at a mass concentration of 1% - 10%. By preparing the antistatic agent dispersion in this way, it can be avoided that the dispersion with too high H2O content cannot be well coated on the surface of the polyurethane fiber; and it can be avoided that too much DMAC dissolves and breaks the polyurethane fiber. The antistatic agent dispersion can uniformly coat and embed the antistatic agent on the surface of the polyurethane fiber. The antistatic agent dispersion can enable the antistatic agent added inside the polyurethane fiber and the antistatic agent embedded on the surface to form a continuous antistatic interlayer, improving the antistatic performance of the polyurethane fiber and also improving the water wash resistance of the polyurethane fiber.

[0098] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing examples, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of antistatic spandex, including a prepolymer preparation step, a prepolymer dissolution step, a prepolymer chain extension reaction step, and a spinning step, characterized in that in the prepolymer dissolution step, an antistatic agent is added in the form of an antistatic agent dispersant; the antistatic agent dispersant is obtained by dispersing an antistatic agent in DMAC.

2. The preparation method of the antistatic spandex according to claim 1, characterized in that, In the prepolymer dissolution step, the addition amount of the antistatic agent is 1%-5% of the solid content of the spinning dope obtained after the prepolymer chain extension.

3. The preparation method of the antistatic spandex according to claim 1, wherein, In the prepolymer chain extension reaction step, carbon black accounting for 0.3%-0.6% of the solid content of the spinning dope is added to the reactants, so that the prepolymer chain extension reaction step forms a black spinning dope with an antistatic agent.

4. The preparation method of the antistatic spandex according to claim 1, characterized in that, After spinning is completed, after the spandex tow passes through the first roller, an antistatic agent dispersion liquid is coated on the spandex tow by using a coating roller to coat the antistatic agent on the spandex tow again. After passing through a water roller for water washing, the spandex tow is dried and cured to obtain antistatic spandex fibers with excellent antistatic performance.

5. The preparation method of the antistatic spandex according to claim 4, characterized in that, After the spandex tow is coated with the antistatic agent dispersion liquid by the coating roller, the tow is collected by a dispersant collection device to collect the excess antistatic agent dispersion liquid that is not adhered to the spandex tow, and then washed with water, and then dried and cured.

6. The preparation method of the antistatic spandex according to claim 4, wherein The preparation method of the antistatic agent dispersion liquid is as follows: By mass, H2O: 1-3 parts, DMAC: 7-9 parts, are mixed to form an H2O and DMAC dispersion liquid, and then the antistatic agent is uniformly dispersed in the dispersion liquid at a mass concentration of 1%-10% to obtain the antistatic agent dispersion liquid.

7. The preparation method of the antistatic spandex according to any one of claims 1 to 6, characterized in that, The antistatic agent is at least one or a combination of carbon black, graphene, carbon nanotubes or nano silver.

8. The preparation method of the antistatic spandex according to any one of claims 1 to 6, characterized in that, The preparation process of the preparation method of the antistatic spandex is as follows: Prepolymer preparation step: Polytetramethylene ether glycol and diphenylmethane diisocyanate are fully reacted at a molar ratio of 1:1.5-2 at 65-90 °C to form a prepolymer; Prepolymer dissolution step: DMAC dispersed with an antistatic agent is added to the prepolymer to dissolve the prepolymer; Prepolymer chain extension reaction step: At 10-40 °C, the prepolymer after dissolving the antistatic agent is chain-extended with a mixed amine, and carbon black and auxiliary materials accounting for 0.3%-0.6% of the solid content of the spinning dope are added to form a black spinning dope with an antistatic agent; Spinning step: The antistatic black spandex spinning dope obtained by chain extension is subjected to dry spinning.

9. An antistatic spandex, characterized in that, Obtained by using the preparation method of the antistatic spandex according to any one of claims 7-8.

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