A kind of spandex and its preparation method and application

Abstract

The present invention provides spandex, its preparation method, and application. The spandex is obtained by dry spinning a polyurethane prepolymer obtained by reacting an oligomer diol with an organic diisocyanate, and then reacting the polyurethane prepolymer with a mixed amine to obtain a polyurethane stock solution. The oligomer diol contains at least 40 mol% of a polyester diol and up to 60 mol% of a polyether diol. The spandex of the present invention has low raw material cost, good production stability, and superior dyeability, significantly reducing energy consumption in subsequent dyeing and finishing processes, and is easy to set and dye.

Description

Technical Field

[0001] The invention belongs to the technical field of modified spandex fibers, and relates to spandex and a preparation method and application thereof, and in particular to spandex that is easy to shape and dye, and a preparation method and application thereof. Background Art

[0002] More than 50% of the world's textiles and clothing contain spandex, and the dyeing and finishing of spandex-containing fabrics requires a lot of energy. Spandex post-dyeing and finishing companies are facing tremendous pressure to upgrade, which puts forward new requirements for the heat setting efficiency and dyeing difficulty of spandex.

[0003] CN1302164C, CN1170967C and CN109610039B disclose the introduction of functional additives by physical addition to improve the heat setting efficiency of spandex. However, these methods cannot achieve an organic balance in terms of raw material cost, production stability and spandex's easy setting and dyeing properties. CN102517688B, CN101495683B, CN101849048A, CN103255500B and CN106702526B disclose the preparation of spandex with improved heat setting efficiency by chemical modification, which also has the same problem.

[0004] Therefore, in this field, it is desired to develop a spandex that is low in cost, good in production stability, easy to shape and easy to dye. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a spandex and its preparation method and application. The spandex of the present invention has low raw material cost, good production stability, better dyeability, significantly reduced energy consumption in subsequent dyeing and finishing, and is easy to shape and dye.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] On the one hand, the present invention provides a spandex, which is obtained by dry spinning a polyurethane prepolymer obtained by reacting an oligomer diol with an organic diisocyanate, and a polyurethane stock solution obtained by reacting the polyurethane prepolymer with a mixed amine. The oligomer diol contains at least 40 mol% of polyester diol and at most 60 mol% of polyether diol.

[0008] The spandex of the present invention can be heat-set at a temperature 10° C. lower than that of conventional spandex, has better dyeability, and significantly reduces the energy consumption of subsequent dyeing and finishing.

[0009] In the present invention, the oligomer diol contains at least 40% (e.g., 45%, 50%, 55%, 58%, 60%, 65%, 68%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc.) mole percentage of polyester diol and contains up to 60% (e.g., 58%, 55%, 50%, 45%, 40%, 35%, 30%, 20%, 10%, 5%, 0%, etc.) mole percentage of polyether diol. Preferably, the oligomer diol contains greater than 60% mole percentage of polyester diol.

[0010] Preferably, the polyester diol is formed by polycondensation of branched diol, linear diol and organic dicarboxylic acid; and the polyether diol is polytetramethylene ether glycol and / or polypropylene glycol.

[0011] Preferably, the branched diol has one or at least two of the structural features of formula (I), formula (II) and formula (III):

[0012]

[0013] In formula (I), formula (II) and formula (III), R1 is H or C1-C4 alkyl (e.g., C1, C2, C3 or C4 alkyl), and R2 is C1-C4 alkyl (e.g., C1, C2, C3 or C4 alkyl).

[0014] Preferably, the branched diol is 2-butyl-2-ethyl-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, or 3-methyl-1,5-pentanediol.

[0015] Preferably, the linear diol is one or a combination of at least two of diethylene glycol, ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, and 1,9-nonanediol;

[0016] Preferably, the molar ratio of the branched diol to the linear diol is 2:8 to 9:1, more preferably 3:7 to 9:1, for example, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, etc.

[0017] Preferably, the organic dicarboxylic acid is one or a combination of at least two of glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, and terephthalic acid.

[0018] Preferably, the molecular weight of the polyester diol is 1000-5000 (for example, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500 or 5000, etc.), and the kinematic viscosity at 40°C is 1500-6500cp (for example, 1500cp, 1800cp, 2000cp, 2500cp, 3000cp, 4000cp, 5000cp, 6000cp, 6500cp, etc.); the molecular weight of the polyether diol is 1000-3500 (for example, 1000, 1200, 1500, 1800, 2000, 2500, 3000 or 3500, etc.).

[0019] Preferably, the organic diisocyanate is one or a combination of at least two of 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate, cyclohexane-1,4-diisocyanate, and 4,4'-diisocyanate dicyclohexylmethane, preferably 4,4'-diphenylmethane diisocyanate.

[0020] Preferably, the mixed amine comprises a diamine and a monoamine.

[0021] Preferably, the diamine is one or a combination of at least two selected from ethylenediamine, 1,2-propylenediamine, 2-methylpentanediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodiphenylmethane, and 1,4-cyclohexanediamine;

[0022] Preferably, the monoamine is one of diethylamine, dipropylamine, di-n-butylamine, cyclohexylamine, ethanolamine, and diethanolamine, or a combination of at least two of them.

[0023] Preferably, the mixed amine further comprises a triamine;

[0024] Preferably, the triamine is diethylenetriamine.

[0025] Preferably, the fineness of the spandex is 10D-2500D, for example, 10D, 15D, 20D, 40D, 80D, 100D, 300D, 500D, 800D, 1000D, 1300D, 1500D, 2000D or 2500D.

[0026] On the other hand, the present invention provides a method for preparing the spandex as described above, the preparation method comprising the following steps:

[0027] (1) preparing a polyurethane prepolymer by mixing an organic diisocyanate and an oligomer diol;

[0028] (2) dissolving the polyurethane prepolymer with an organic solvent, and then performing a chain extension reaction with a mixed amine solution to obtain a polyurethane stock solution;

[0029] (3) adding optional additives to the polyurethane stock solution, mixing uniformly and then aging to obtain a spinning stock solution;

[0030] (4) The spandex is prepared by dry spinning the spinning solution.

[0031] Preferably, the molar ratio of the organic diisocyanate to the oligomer diol in step (1) is 1.5:1 to 2.5:1, for example, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.4:1 or 2.5:1.

[0032] In the present invention, the temperature of the mixing reaction in step (1) is 45-100°C, for example, 45°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C.

[0033] In the present invention, the mixing reaction time of step (1) is 0.5 to 240 minutes (e.g., 1 minute, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 50 minutes, 60 minutes, 100 minutes, 150 minutes, 200 minutes, 220 minutes, or 240 minutes). The reaction time varies depending on the structure of the oligomer diol and is also affected by the catalyst. The catalysts used include organic tin compounds such as dibutyltin laurate and tin octoate, and organic titanium compounds such as tetrabutyl titanate and isopropyl titanate. In addition, there are no specific requirements for the reaction time as long as it does not deteriorate production stability and product performance.

[0034] Preferably, the organic solvent in step (2) is dimethylacetamide.

[0035] Preferably, the mixed amine solution in step (2) is a dimethylacetamide solution containing mixed amines.

[0036] Preferably, the mass percentage concentration of the mixed amine solution in step (2) is 3.0% to 12.0%, for example, 3.0%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11% or 12%.

[0037] Preferably, the ratio of the molar number of amine groups in the mixed amine in step (2) to the molar number of isocyanate groups in the polyurethane prepolymer is 1:1 to 1.15:1, for example, 1:1, 1.05:1, 1.08:1, 1.1:1, 1.13:1 or 1.15:1. The amine groups are primary and secondary amine groups.

[0038] Preferably, in the mixed amine of step (2), the mass fraction of the triamine in the spandex is 50 to 500 ppm. Triamine may not be added without affecting the effect of the present invention.

[0039] Preferably, the molar ratio of diamine to monoamine in the mixed amine in step (2) is 5:1 to 15:1, for example, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1 or 15:1.

[0040] Preferably, the auxiliary agent in step (3) includes any one of a lubricant, an antioxidant or an anti-hydrolysis auxiliary agent, or a combination of at least two thereof.

[0041] Preferably, the lubricant is one or a combination of at least two of magnesium stearate, butyl stearate, ethylene bisstearamide, oleamide, polyethylene wax, polypropylene wax, cellulose acetate butyrate, and cellulose acetate propionate.

[0042] Preferably, the lubricant is added in an amount of 0.1% to 5.0% by weight of the spandex, for example, 0.1%, 0.3%, 0.5%, 1%, 2%, 3%, 4% or 5%.

[0043] Preferably, the antioxidant is one or a combination of at least two of Antioxidant 245, Antioxidant 1790, Antioxidant 626, and Antioxidant 412S. Preferably, the antioxidant is added in an amount of 0.1% to 2.0% by weight of the spandex, for example, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.8%, or 2%.

[0044] Preferably, the anti-hydrolysis agent is one or a combination of at least two of polycarbodiimide, silica, and cellulose ester. Preferably, the added amount of the anti-hydrolysis agent is 0.2% to 3.0% by weight of the spandex, for example, 0.1%, 0.3%, 0.5%, 1%, 2% or 3%.

[0045] Wherein, functional additives such as matting agents, anti-ultraviolet additives, dyeing additives, etc. may be added to the spandex without affecting the effects of the present invention.

[0046] Preferably, the rotational viscosity of the spinning solution obtained after the aging in step (3) at 40°C is 1000~7000P (for example, 1000P, 1500P, 2000P, 3000P, 4000P, 5000P, 6000P or 7000P), and the solid content is 30%~45%, for example, 30%, 35%, 38%, 40%, 43% or 45%.

[0047] In the present invention, the dry spinning method is to extrude the spinning solution through a spinneret, pass through a high-temperature channel, volatilize the solvent, solidify the polymer, and stretch it to form a filament, which is then oiled and wound to form a spandex package.

[0048] The preparation method of the present invention can ensure that the fineness of the prepared spandex is 10D-2500D.

[0049] In another aspect, the present invention provides use of the spandex described above in textiles.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The spandex of the invention has low raw material cost, good production stability, better dyeability, significantly reduces energy consumption in subsequent dyeing and finishing, and has the characteristics of easy shaping and easy dyeing. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0053] The evaluation method of the ease of setting (SS) described in the present invention is as follows: the spandex is stretched from an initial length L0 = 5 cm to L1 = 15 cm, and then placed in a 190°C oven for 1 minute for heat setting. The sample is then relaxed and the length L2 after setting is tested. The larger L2 is, the easier it is to set.

[0054] The method for evaluating easy dyeing is as follows: the concentration of disperse orange dye is 2%, the amount of dispersant and leveling agent is 1 g / L, the bath ratio is 1:50, the pH of the dye solution is 5.5, and the dye solution is kept at 130° C. for 40 minutes. The maximum absorbance of the dye solution before and after dyeing is tested by an ultraviolet spectrophotometer, and the dye uptake (DR) is calculated by the formula (1-A1 / A0)×100%, wherein A1 is the maximum absorbance of the dye solution before dyeing, and A0 is the maximum absorbance of the residual solution after dyeing.

[0055] The present invention also uses the following methods to evaluate production stability and other key performances of the product.

[0056] Production stability: The number of faults (FN) that occurred between the spinneret and the first guide roller for a 20D product during 10 days of normal production was counted. The greater the number of faults, the worse the spinnability and production stability.

[0057] Alkali resistance (AR): Place the spandex yarn in a 30g / L NaOH solution with a bath ratio of 1:5000 and keep it at 100℃ for 60min. The breaking strength retention rate of the spandex before and after alkali solution treatment is the alkali resistance.

[0058] The implementation process of the present invention is described in detail below with specific examples, but these examples should not be understood as limiting the present invention in any sense.

[0059] Table 1 shows the relationship between the relevant substances and their codes in the Examples and Comparative Examples.

[0060] Table 1 Codes of related substances

[0061] code name Related substances MDI 4,4'-Diphenylmethane diisocyanate BEP 2-Butyl-2-ethyl-1,3-propanediol MBD 3-Methyl-1,3-butanediol MPG 3-Methyl-1,3-propanediol EPTD 2,4-Diethyl-1,5-pentanediol BDO 1,4-Butanediol HDO 1,6-Hexanediol AA 1,6-Hexanedioic acid PE Polyester diol PTMG Polytetramethylene ether glycol EDA Ethylenediamine DEA Diethylamine DETA Diethylenetriamine

[0062] Example 1

[0063] In this embodiment, spandex was prepared by the following method:

[0064] BEP and BDO were mixed in a 1:1 molar ratio and then polycondensed with AA to obtain PE with a molecular weight of 2200 and a kinematic viscosity of 3500 cp at 40°C.

[0065] MDI and PE were mixed at a molar ratio of 1.8:1 and reacted at 80°C for 2 h to obtain an isocyanate-terminated polyurethane prepolymer;

[0066] The polyurethane prepolymer is dissolved in dimethylacetamide to form a polyurethane prepolymer solution, and then a chain extension reaction is carried out with an 8% by mass mixed amine solution containing EDA, DEA, and DETA to obtain a polyurethane stock solution with a solid content of 35.5%, wherein the molar ratio of the mixed amine to the polyurethane prepolymer is 1.05:1, the molar ratio of EDA to DEA is 9:1, and the mass fraction of DETA in the spandex is 150 ppm;

[0067] Then, 1% of antioxidant 245, 0.5% of magnesium stearate, and 1.5% of silica, accounting for the weight of the spandex, were added to the polyurethane stock solution, mixed evenly, and then aged to obtain a spinning stock solution with a rotational viscosity of 5000P at 40°C and a solid content of 35.5%;

[0068] The spinning solution is prepared into single-hole 20D easy-to-shape and easy-to-dye spandex through dry spinning technology.

[0069] Examples 2 to 12:

[0070] The same method as described in Example 1 was used to prepare spandex that is easy to set and dye. The difference lies in the different polymer diols. For details, see Table 2.

[0071] Comparative Examples 1 to 8:

[0072] The same method as described in Example 1 was used to prepare spandex that is easy to set and dye. The difference lies in the different polymer diols. For details, see Table 3.

[0073] Table 2 Examples of different formulations

[0074]

[0075] Table 3 Comparative Examples of Different Formulas

[0076]

[0077] The spandex prepared in the above examples and comparative examples was comprehensively evaluated for production stability, alkali resistance, ease of setting, and ease of dyeing. The specific results are shown in Table 4 below:

[0078] Table 4 Evaluation results of the embodiments of the present invention and the comparative examples

[0079]

[0080] As can be seen from Table 4, the spandex of the present invention has good production stability and is easy to set and dye. When the polyester diol content in the oligomer diol component is low, the polytetramethylene ether glycol content is high, or only polytetramethylene ether glycol is contained (such as in Comparative Examples 1-3), the spandex has poor setting and dyeing properties. When the content of polyester diol in the oligomer diol component is constant, as the molar ratio of branched diol to linear diol increases, the alkali resistance shows a trend of first increasing and then decreasing. This is mainly because the increase in the proportion of branched diols has an improving effect on alkali resistance. When the molar ratio of branched diol to linear diol is not within the preferred ratio range of the present invention (for example, Comparative Example 4), it will lead to a high failure rate and poor alkali resistance; when the content of branched diol is too high (for example, Comparative Example 5), it will cause the product's high temperature resistance to decrease, thereby affecting the alkali resistance, and if the content of branched diol is too high, the production stability will be significantly reduced. An appropriate amount of linear diol has an improving effect on production stability and the high temperature resistance of the product, but when the content of linear diol is too high (for example, Comparative Example 6), the production stability will decrease, and the alkali resistance of the product will not meet the requirements. Comparative Example 7 does not contain a linear diol and has a high PTMEG content, resulting in a high failure rate and poor setting and dyeing properties. In addition, it can be seen from Comparative Example 8 that the overall effect of using MBD as a branched diol is significantly worse than that of BEP, especially in terms of production stability and alkali resistance.

[0081] The applicant declares that while the present invention uses the aforementioned embodiments to illustrate the spandex, its preparation method, and its applications, the present invention is not limited to these embodiments, nor does it necessarily rely on these embodiments for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for raw materials in the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A spandex, characterized in that: The spandex is obtained by dry spinning a polyurethane prepolymer obtained by reacting an oligomer diol with an organic diisocyanate, and a polyurethane stock solution obtained by reacting the polyurethane prepolymer with a mixed amine. The oligomer diol contains at least 65 mol% of polyester diol and at most 35 mol% of polyether diol. The polyester diol is prepared by polycondensation of branched diol, straight-chain diol and organic dicarboxylic acid; The branched diol is 2-butyl-2-ethyl-1,3-propanediol and / or 2,4-diethyl-1,5-pentanediol; The molar ratio of the branched diol to the linear diol is 2:8 to 9:1; The linear diol is any one of diethylene glycol, ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, and 1,9-nonanediol.

2. The spandex according to claim 1, characterized in that The polyether diol is polytetramethylene ether glycol and / or polypropylene glycol.

3. The spandex according to claim 1, characterized in that The organic dicarboxylic acid is one or a combination of at least two of glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, and terephthalic acid.

4. The spandex according to claim 1, characterized in that The molecular weight of the polyester diol is 1000-5000, and the kinematic viscosity at 40° C. is 1500-6500 cp; the molecular weight of the polyether diol is 1000-3500.

5. The spandex according to claim 1, characterized in that The organic diisocyanate is one or a combination of at least two of 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate, cyclohexane-1,4-diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

6. The spandex according to claim 5, characterized in that The organic diisocyanate is 4,4'-diphenylmethane diisocyanate.

7. The spandex according to claim 1, characterized in that The mixed amine comprises a diamine and a monoamine.

8. The spandex according to claim 7, characterized in that The diamine is one selected from ethylenediamine, 1,2-propylenediamine, 2-methylpentanediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodiphenylmethane, and 1,4-cyclohexanediamine, or a combination of at least two thereof.

9. The spandex according to claim 7, characterized in that The monoamine is one of diethylamine, dipropylamine, di-n-butylamine, cyclohexylamine, ethanolamine, and diethanolamine, or a combination of at least two of them.

10. The spandex according to claim 7, characterized in that The mixed amine also contains a triamine.

11. The spandex according to claim 10, characterized in that The triamine is diethylenetriamine.

12. The spandex according to claim 1, characterized in that The spandex has a fineness of 10D-2500D.

13. The method for preparing spandex according to any one of claims 1 to 12, characterized in that: The preparation method comprises the following steps: (1) preparing a polyurethane prepolymer by mixing an organic diisocyanate and an oligomer diol; (2) dissolving the polyurethane prepolymer with an organic solvent, and then performing a chain extension reaction with a mixed amine solution to obtain a polyurethane stock solution; (3) adding optional additives to the polyurethane stock solution, mixing uniformly and then aging to obtain a spinning stock solution; (4) The spandex is prepared by dry spinning the spinning solution.

14. The preparation method according to claim 13, characterized in that The molar ratio of the organic diisocyanate to the oligomer diol in step (1) is 1.5:1 to 2.5:

1.

15. The preparation method according to claim 13, characterized in that The organic solvent in step (2) is dimethylacetamide.

16. The preparation method according to claim 13, characterized in that The mixed amine solution in step (2) is a dimethylacetamide solution containing mixed amines.

17. The preparation method according to claim 13, characterized in that The mass percentage concentration of the mixed amine solution in step (2) is 3.0% to 12.0%.

18. The preparation method according to claim 13, characterized in that The ratio of the molar number of amino groups in the mixed amine in step (2) to the molar number of isocyanate groups in the polyurethane prepolymer is 1:1 to 1.15:1; the amino groups are primary amino groups and secondary amino groups.

19. The preparation method according to claim 13, characterized in that In the mixed amine of step (2), the mass fraction of the triamine in the spandex is 50 to 500 ppm.

20. The preparation method according to claim 13, characterized in that The molar ratio of diamine to monoamine in the mixed amine of step (2) is 5:1 to 15:

1.

21. The preparation method according to claim 13, characterized in that The auxiliary agent in step (3) includes any one of a lubricant, an antioxidant or an anti-hydrolysis auxiliary agent, or a combination of at least two thereof.

22. The preparation method according to claim 21, characterized in that The lubricant is one or a combination of at least two of magnesium stearate, butyl stearate, ethylene bisstearamide, oleamide, polyethylene wax, polypropylene wax, cellulose acetate butyrate, and cellulose acetate propionate.

23. The preparation method according to claim 21, characterized in that The added amount of the lubricant accounts for 0.1% to 5.0% of the weight of the spandex.

24. The preparation method according to claim 21, characterized in that The antioxidant is one of antioxidant 245, antioxidant 1790, antioxidant 626, and antioxidant 412S, or a combination of at least two of them.

25. The preparation method according to claim 21, characterized in that The added amount of the antioxidant accounts for 0.1% to 2.0% of the weight of the spandex.

26. The preparation method according to claim 21, characterized in that The anti-hydrolysis auxiliary agent is one or a combination of at least two of polycarbodiimide, silica, and cellulose ester.

27. The preparation method according to claim 21, characterized in that The added amount of the anti-hydrolysis auxiliary agent accounts for 0.2% to 3.0% of the weight of the spandex.

28. The preparation method according to claim 13, characterized in that The spinning solution obtained after aging in step (3) has a rotational viscosity of 1000 to 7000 P at 40° C. and a solid content of 30% to 45%.

29. Use of the spandex according to any one of claims 1 to 12 in textiles.

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