Lightproof spandex and method for preparing the same

Abstract

This invention relates to a light-blocking spandex and its preparation method. The light-blocking spandex comprises polyurethane-urea and a matting agent, wherein the matting agent accounts for 0.5% to 5% of the mass of the light-blocking spandex; the matting agent comprises a mixture of titanium dioxide, silicon dioxide, and acrylate. The preparation method is as follows: a polymeric polyol and a polyisocyanate are reacted to obtain a polyurethane prepolymer, which is then dissolved in a solvent to obtain a polyurethane prepolymer solution; the obtained polyurethane prepolymer solution, a diamine chain extender, and an amine chain terminator are reacted to obtain a polyurethane-urea solution; the polyurethane-urea solution and the matting agent are mixed in a certain proportion as raw materials; dry spinning is performed to obtain a light-blocking spandex with a cross-sectional shape including at least one of circular, trefoil, and cross-shaped. This product maintains conventional physical properties that are basically consistent with those of products of the same specification, making the fiber light-blocking, easy to dye, and solving the problem of light transmission and poor coverage of lightweight spandex-containing fabrics.

Description

Technical Field

[0001] This invention relates to a spandex with light-blocking properties and its preparation method, belonging to the field of polyurethane elastic fiber manufacturing technology. Background Technology

[0002] Spandex, short for polyurethane fiber, is an elastic fiber that not only possesses unique elastic properties but also excellent resistance to acids and alkalis, sweat, washing, and abrasion. Based on surface gloss, it is generally classified into glossy, semi-dull, and matte spandex. It is currently widely used in clothing, home furnishings, sanitary materials, and footwear, typically comprising 5-30% of its composition. With rising per capita income and increasingly demanding performance-oriented clothing, elastic fabrics are gaining greater popularity among consumers.

[0003] Lightweight and breathable clothing is popular in the hot summer for its heat dissipation and sweat-wicking properties. However, unlike winter clothing which uses dark and heavy fabrics, lightweight fabrics often have poor light-blocking properties and insufficient coverage, frequently resulting in embarrassing situations such as underwear and skin exposure. Therefore, improving the light-blocking properties of thin fabrics is a major challenge for textile engineers. Theoretically, this can be addressed by increasing the emission, absorption, and scattering of visible light by textiles, and reducing the transmission of visible light. Specific methods include changing the cross-sectional shape of fibers, adding relevant auxiliaries, coating finishing, and setting fabric structural parameters. Existing mature technologies mainly rely on coating finishing, but for apparel textiles, coating finishing affects wearing comfort and has insufficient durability. Especially in ammonia-containing fabrics, products with a glossy or semi-matte finish are generally used, which has the following disadvantages: ① There is a color difference with other fibers in the fabric. Because spandex has poor dyeing performance (acid dyes generally do not dye), "white showing" often occurs; ② When elastic fabrics are stretched when worn, the gaps become larger. If spandex itself has good light transmission, it will exacerbate the decline in light-blocking performance.

[0004] Patents CN207130385U, CN207130386U, CN207130391U, and CN103409846A all achieve light-blocking effects by adding titanium dioxide, a matting agent, to fabrics, regardless of whether the fiber composition is spandex or non-spandex. Patent CN217324523U achieves good breathability and light-blocking effects by changing the fabric's weave structure. Patent CN220846451U uses matte polyester filaments with irregular cross-sections to achieve light-blocking. Patent CN116024713A uses fully matte polyester and spandex-covered yarns. From the above related patents, it is not difficult to see that most fabrics currently use matte fibers prepared with matting agents to achieve light-blocking effects, with a small portion using optimized fabric weave structures. However, such improvements are not satisfactory. From the perspective of spandex production, excessive addition of inorganic titanium dioxide particles increases the burden on the production grinding system and also affects the mechanical properties of the fiber. From the perspective of downstream weaving, the increase of titanium dioxide increases the friction of the fiber, which can easily cause weaving problems such as "powder shedding", filament jamming, and filament breakage during the textile process. In addition, after the fabric is dyed, spandex still has the problem of being difficult to dye and showing white spots. Summary of the Invention

[0005] Technical problem: The purpose of this invention is to prepare a light-proof spandex and its preparation method. The product maintains the same conventional physical properties as products of the same specifications, so that the fiber is light-proof and easy to dye, solving the problem that lightweight fabrics containing spandex are easy to transmit light and have poor body covering.

[0006] Technical solution: The present invention provides a light-proof spandex comprising polyurethane-urea and a matting agent, wherein the matting agent accounts for 0.5% to 5% of the mass of the light-proof spandex;

[0007] The matting agent comprises a mixture of titanium dioxide, silicon dioxide, and acrylate;

[0008] The matting agent comprises the following components by mass:

[0009] Titanium dioxide 10-30%;

[0010] 10-30% silica;

[0011] Acrylic esters: 40-80%.

[0012] The matting agent further includes stearate and / or talc, with the following composition by mass:

[0013] 10-20% titanium dioxide;

[0014] 10-20% silica;

[0015] 40-70% acrylate;

[0016] Stearates and / or talc 10–20%.

[0017] The mass percentage of stearate in the light-proof spandex, calculated based on the total mass of the light-proof spandex, does not exceed 0.5%.

[0018] The polyurethane-urea comprises the reaction product of polymeric polyol, polyisocyanate, diamine chain extender, and amine chain terminator.

[0019] The polymer polyols include any one or a combination of at least two of polytetramethylene ether glycol, polyethylene glycol, or polypropylene glycol;

[0020] The polyisocyanate includes any one or a combination of at least two of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate;

[0021] Diamine chain extenders include aliphatic and non-aliphatic diamines; the molar ratio of the aliphatic and non-aliphatic diamines is 70:30 to 95:5.

[0022] The aliphatic diamines include aliphatic diamines having 2 to 30 carbon atoms, and further include any one or a combination of at least two of ethylenediamine, propylenediamine, butanediamine, pentanediamine, methylpentanediamine, methylpropylenediamine, hexanediamine, phenylenediamine, phenylenediamine, diaminocyclohexane, or hexamethylenediamine.

[0023] The non-aliphatic diamines include azacyclic diamines, further including any one or a combination of at least two of pyrazine diamine, piperazine diamine, and piperazine diethylamine, and even further including any one or a combination of at least two of 2,5-pyrazine diamine, 3,4-pyrazine diamine, 4,5-diaminopyrazine, 2,3-diaminopiperazine, and 1,4-piperazine diethylamine;

[0024] The amine chain terminator comprises a monoamine having 2 to 20 carbon atoms, and is more preferably any one or a combination of at least two of the following: diethylamine, isopropylamine, n-butylamine, tert-butylamine, hexylamine diethylamine, dimethylamine, di-n-butylamine, di-tert-butylamine, diisobutylamine, diisopropylamine, diethylamine, dipropylamine, cyclohexylamine, or ethanolamine.

[0025] The stearates mentioned include one or more of aluminum stearate, magnesium stearate, zinc stearate, calcium stearate, and barium stearate.

[0026] The acrylates mentioned include at least one of polyether-modified acrylates, polyester-modified acrylates, and epoxy-modified acrylates.

[0027] The polyether-modified acrylates include one or more of polyethylene glycol-modified acrylates, polypropylene glycol-modified acrylates, polyethylene glycol-propylene glycol-modified acrylates, and polytetramethylene ether glycol-modified acrylates.

[0028] The polyester-modified acrylate includes one or more of polycaprolactone-modified acrylate, polycarbonate-modified acrylate, and polyadipate-modified acrylate.

[0029] The epoxy-modified acrylates include one or more of bisphenol A epoxy acrylates, phenolic epoxy acrylates, epoxidized acrylates, and modified epoxy acrylates.

[0030] The method for preparing the light-blocking spandex of the present invention is as follows:

[0031] Step 1. The polymeric polyol and polyisocyanate are reacted to obtain a polyurethane prepolymer. The obtained polyurethane prepolymer is dissolved in a solvent to obtain a polyurethane prepolymer solution. The mass percentage of isocyanate groups (NCO) in the polyurethane prepolymer is 2.0% to 3.5%.

[0032] Step 2. React the obtained polyurethane prepolymer solution, diamine chain extender and amine chain terminator to obtain polyurethane-urea solution; the molar ratio of NCO in the polyurethane prepolymer to the amine groups in the diamine chain extender and amine chain terminator is 1:(1.01~1.10);

[0033] Step 3. Mix polyurethane-urea solution and matting agent in a specified ratio;

[0034] Step 4. The polyurethane-urea solution is cured before spinning, and the curing temperature is 30-45℃.

[0035] Step 5. Dry spinning, which is achieved by adjusting the cross-sectional shape or arrangement of the spinnerets on the spinneret plate in the spinneret assembly during the spraying step. The cross-sectional shape of the light-proof spandex includes at least one of circular, trilobal, and cross-shaped.

[0036] The light-proof spandex was obtained.

[0037] Beneficial effects: Compared with the prior art, the present invention has the advantages of maintaining the conventional physical properties of the product basically consistent with those of the same specification, making the fiber lightproof and easy to dye, and solving the problems of light transmission and poor body covering of lightweight fabrics containing spandex.

[0038] This invention adds a specific matting agent to spandex, giving the spandex fiber excellent light-blocking properties. At the same time, the irregular cross-section further enhances the light-blocking properties of the fiber, and finally a spandex product with excellent light-blocking performance is prepared. Detailed Implementation

[0039] The light-proof spandex comprises polyurethane-urea and a matting agent, wherein the mass percentage of the matting agent in the light-proof spandex is 0.5% to 5%.

[0040] The matting agent comprises a mixture of titanium dioxide, silica, stearate, talc, and acrylate;

[0041] Preferably, the matting agent comprises the following components:

[0042] Titanium dioxide 10-30%;

[0043] 10-30% silica;

[0044] 40-80% acrylate;

[0045] The titanium dioxide and silicon dioxide particles have a particle size of 0.2–10 μm;

[0046] The stearates mentioned include one or more of aluminum stearate, magnesium stearate, zinc stearate, calcium stearate, and barium stearate;

[0047] The acrylates mentioned include at least one of polyether-modified acrylates, polyester-modified acrylates, and epoxy-modified acrylates;

[0048] The polyether-modified acrylates include one or more of polyethylene glycol-modified acrylates, polypropylene glycol-modified acrylates, polyethylene glycol-propylene glycol-modified acrylates, and polytetramethylene ether glycol-modified acrylates.

[0049] The polyester-modified acrylate includes one or more of polycaprolactone-modified acrylate, polycarbonate-modified acrylate, and polyadipate-modified acrylate.

[0050] The epoxy-modified acrylates include one or more of bisphenol A epoxy acrylates, phenolic epoxy acrylates, epoxidized acrylates, and modified epoxy acrylates;

[0051] In some embodiments of the present invention, the acrylate includes polyether-modified acrylate;

[0052] More preferably, the matting agent further includes stearate and / or talc;

[0053] More preferably, the matting agent comprises the following components:

[0054] 10-20% titanium dioxide;

[0055] 10-20% silica;

[0056] 40-70% acrylate;

[0057] Stearates and / or talc 10-20%;

[0058] Preferably, the mass percentage of stearate in the light-proof spandex does not exceed 0.5%, calculated based on the total mass of the light-proof spandex.

[0059] The polyurethane-urea comprises the reaction product of polymeric polyol, polyisocyanate, diamine chain extender and amine chain terminator;

[0060] The polymeric polyols include any one or a combination of at least two of polytetramethylene ether glycol, polyethylene glycol, or polypropylene glycol, and are more preferably polytetramethylene ether glycol.

[0061] The number-average molecular weight of the polymer polyol is 1000-3000;

[0062] The polyisocyanate includes any one or a combination of at least two of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate, and is more preferably diphenylmethane diisocyanate.

[0063] Diamine chain extenders include aliphatic and non-aliphatic diamines;

[0064] The aliphatic diamines include aliphatic diamines having 2 to 30 carbon atoms, and further include any one or a combination of at least two of ethylenediamine, propylenediamine, butanediamine, pentanediamine, methylpentanediamine, methylpropylenediamine, hexanediamine, phenylenediamine, phenylenediamine, diaminocyclohexane, or hexamethylenediamine.

[0065] The non-aliphatic diamines include azacyclic diamines, further including any one or a combination of at least two of pyrazine diamine, piperazine diamine, and piperazine diethylamine, and even further including any one or a combination of at least two of 2,5-pyrazine diamine, 3,4-pyrazine diamine, 4,5-diaminopyrazine, 2,3-diaminopiperazine, and 1,4-piperazine diethylamine;

[0066] Furthermore, the molar ratio of the aliphatic diamine to the non-aliphatic diamine is 70:30 to 95:5;

[0067] The amine chain terminator comprises a monoamine having 2 to 20 carbon atoms, and is more preferably any one or a combination of at least two of the following: diethylamine, isopropylamine, n-butylamine, tert-butylamine, hexylamine diethylamine, dimethylamine, di-n-butylamine, di-tert-butylamine, diisobutylamine, diisopropylamine, diethylamine, dipropylamine, cyclohexylamine, or ethanolamine.

[0068] The polyurethane-urea is prepared by the following method, which includes the following steps:

[0069] 1) The polymer polyol and polyisocyanate are reacted to obtain a polyurethane prepolymer. The obtained polyurethane prepolymer is dissolved in a solvent to obtain a polyurethane prepolymer solution.

[0070] 2) The obtained polyurethane prepolymer solution, diamine chain extender and amine chain terminator are reacted to obtain polyurethane-urea solution.

[0071] Preferably, the isocyanate-based NCO content in the polyurethane prepolymer is 2% to 3.5% by mass.

[0072] The molar ratio of diamine chain extender to monoamine end capping agent is 6:1 to 20:1;

[0073] Preferably, the molar ratio of NCO in the polyurethane prepolymer to the amine groups in the diamine chain extender and amine chain terminator is 1:(1.01~1.10);

[0074] Furthermore, the solvent includes N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and dimethylformamide (DMF); as an example, the solvent is DMAc.

[0075] In some embodiments of the present invention, the mass percentage of the polyurethane prepolymer solution is 30-40%;

[0076] The diamine chain extender and amine chain terminator are mixed with a solvent to obtain a mixed solution, the mass percentage of which is 3-10%.

[0077] In some embodiments of the present invention, the reaction temperature of step 1) is 70–95°C;

[0078] The reaction temperature in step 2) is 0–10°C.

[0079] There are no specific requirements for the reaction time; just ensure that all raw materials react completely.

[0080] The method for preparing the light-proof spandex includes: spinning the light-proof spandex fiber using the polyurethane-urea solution and the matting agent as raw materials;

[0081] Furthermore, the polyurethane-urea solution is cured before spinning, and the curing temperature is 30-45°C.

[0082] The spinning process described is dry spinning;

[0083] The dry spinning process includes the steps of spraying, stretching, and drying.

[0084] Furthermore, other functional additives may be added to the polyurethane-urea solution, as long as they do not degrade the product's performance. These may include one or more of the following: lubricants, antioxidants, UV stabilizers, matting agents, dyeing auxiliaries, and chlorine-resistant auxiliaries.

[0085] Preferably, the cross-sectional shape of the light-proof spandex includes at least one of a circle, a trefoil shape, and a cross shape; more preferably, the cross-sectional shape includes at least one of a trefoil shape and a cross shape.

[0086] Furthermore, the cross-sectional shape can be adjusted by the cross-sectional shape or arrangement of the spinneret holes on the spinneret plate in the spinneret assembly during the spraying step;

[0087] The following embodiments are used to describe the production process of the present invention in detail, but these embodiments should not be construed as limiting the present invention in any way.

[0088] (1) Preparation of polyurethane-urea:

[0089] 1) Add the polymeric polyol and polyisocyanate to a static mixer, control the reaction temperature at 85℃, and the reaction yields a polyurethane prepolymer with an NCO mass percentage of 2.55%;

[0090] The polyurethane prepolymer and solvent DMAc were added to a static mixer and dissolved completely to obtain a polyurethane prepolymer solution with a mass percentage of 40%.

[0091] 2) Add a mixture containing 5% by mass of diamine chain extender and amine chain terminator to the polyurethane prepolymer solution, and control the reaction temperature at 4℃ to obtain a polyurethane-urea solution.

[0092] The molar ratio of diamine chain extender to monoamine end capping agent in the mixture is 15:1.

[0093] The molar ratio of NCO in the polyurethane prepolymer to the amine groups in the diamine chain extender and amine chain terminator is 1:1.01.

[0094] Example 1

[0095] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0096] Matting agents include the following components:

[0097] 10% titanium dioxide;

[0098] 15% silica;

[0099] 55% polyethylene glycol-modified acrylate;

[0100] Aluminum stearate 20%.

[0101] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and diethylamine, with a number average molecular weight of 1800.

[0102] Example 2

[0103] The light-proof spandex comprises 95% polyurethane-urea by weight and 5% matting agent by weight.

[0104] Matting agents include the following components:

[0105] 18% titanium dioxide;

[0106] 10% silica;

[0107] Polypropylene glycol modified acrylate 62%;

[0108] 10% magnesium stearate.

[0109] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and ethanolamine, with a number average molecular weight of 1800.

[0110] Example 3

[0111] The light-proof spandex comprises 98% polyurethane-urea by weight and 2% matting agent by weight.

[0112] Matting agents include the following components:

[0113] 18% titanium dioxide;

[0114] 20% silicon dioxide;

[0115] Polytetramethylene ether glycol modified acrylate 46%;

[0116] Hydrotalcite 16%.

[0117] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, butanediamine and diethylamine, with a number average molecular weight of 1800.

[0118] Example 4

[0119] The light-proof spandex comprises 97% polyurethane-urea by weight and 3% matting agent by weight.

[0120] Matting agents include the following components:

[0121] 18% titanium dioxide;

[0122] 15% silica;

[0123] Polytetramethylene ether glycol modified acrylate 52%;

[0124] 5% magnesium stearate;

[0125] Hydrotalcite 10%.

[0126] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and diethylamine, with a number average molecular weight of 1800.

[0127] Example 5

[0128] The light-proof spandex comprises 98% polyurethane-urea by weight and 2% matting agent by weight.

[0129] Matting agents include the following components:

[0130] 18% titanium dioxide;

[0131] 20% silicon dioxide;

[0132] Polycarbonate-modified acrylate 46%;

[0133] Hydrotalcite 16%.

[0134] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and butanediamine, with a number average molecular weight of 1800.

[0135] Example 6

[0136] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0137] The matting agent differs from the matting agent in Example 1 in that it does not contain aluminum stearate, but all other aspects remain the same.

[0138] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and diethylamine, with a number average molecular weight of 1800.

[0139] Example 7

[0140] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0141] The matting agent differs from the matting agent in Example 1 in that it does not contain titanium dioxide, but all other aspects remain the same.

[0142] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and diethylamine, with a number average molecular weight of 1800.

[0143] Example 8

[0144] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0145] The matting agent differs from the matting agent in Example 1 in that it does not contain silica, but all other aspects remain the same.

[0146] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and diethylamine, with a number average molecular weight of 1800.

[0147] Example 9

[0148] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0149] The matting agent differs from the matting agent in Example 1 in that it does not contain polyethylene glycol-modified acrylate, while all other aspects remain the same.

[0150] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and diethylamine, with a number average molecular weight of 1800.

[0151] Example 10

[0152] The light-proof spandex comprises 95% polyurethane-urea by weight and 5% matting agent by weight.

[0153] Matting agents include the following components:

[0154] Titanium dioxide 16.5%;

[0155] 8.5% silica;

[0156] Polypropylene glycol modified acrylate 60%;

[0157] Magnesium stearate 15%.

[0158] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, ethylenediamine, and ethanolamine, with a number average molecular weight of 1800.

[0159] Example 11

[0160] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0161] Matting agents include the following components:

[0162] 10% titanium dioxide;

[0163] 15% silica;

[0164] 55% polyethylene glycol-modified acrylate;

[0165] Aluminum stearate 20%.

[0166] The polyurethane-urea comprises the reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, diethylamine, ethylenediamine and 2,5-pyrazinediamine with a number average molecular weight of 1800, wherein the molar ratio of ethylenediamine and 2,5-pyrazinediamine is 90:10.

[0167] Example 12

[0168] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0169] Matting agents include the following components:

[0170] 10% titanium dioxide;

[0171] 15% silica;

[0172] 55% polyethylene glycol-modified acrylate;

[0173] Aluminum stearate 20%.

[0174] The polyurethane-urea comprises a reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, diethylamine, ethylenediamine, and 1,4-piperazine diethylamine, with a number average molecular weight of 1800, wherein the molar ratio of ethylenediamine to 1,4-piperazine diethylamine is 95:5.

[0175] Example 13

[0176] The light-proof spandex comprises 99% polyurethane-urea by weight and 1% matting agent by weight.

[0177] Matting agents include the following components:

[0178] 10% titanium dioxide;

[0179] 15% silica;

[0180] 55% polyethylene glycol-modified acrylate;

[0181] Aluminum stearate 20%.

[0182] The polyurethane-urea comprises a reaction product of polytetramethylene ether glycol, diphenylmethane diisocyanate, diethylamine, ethylenediamine, and 2,3-diaminopiperazine, with a number average molecular weight of 1800, wherein the molar ratio of ethylenediamine to 2,3-diaminopiperazine is 75:25.

[0183] Comparative Example 1

[0184] Compared with Example 1, the light-proof spandex does not contain a matting agent, but all other aspects remain unchanged. (2) Preparation of light-proof spandex:

[0185] The polyurethane-urea solutions of Examples 1-13 and the matting agent were mixed, stirred evenly, and matured at 38°C for 24 hours. The matured spinning solution was then transported to the spinning assembly, spinning duct, false twisting device, oiling agent, drying, and formed by a winding machine to obtain light-proof spandex 1-13. In the spinning assembly of Examples 1-13, the spinneret holes were circular.

[0186] In addition, the spinning solution of Example 1 is delivered to the spinning assembly, spinning tunnel, false twisting device, oiling agent, drying, and formed by a winding machine to obtain light-proof spandex 14, wherein the spinneret hole in the spinning assembly is cross-shaped.

[0187] The polyurethane-urea solution of Comparative Example 1 was stirred evenly and aged at 38°C for 24 hours. The aged spinning solution was then transported to the spinning assembly, spinning duct, false twisting device, oiling agent, drying, and wound into comparative spandex 1 by a metering pump. The spinneret orifice was circular.

[0188] The prepared spandex fibers were subjected to the following tests:

[0189] Breaking strength and elongation at break: Tested according to the methods provided in industry standard FZ / T 50006-2013 "Test Method for Tensile Properties of Spandex Filament".

[0190] A nylon-spandex fabric was obtained by blending spandex with nylon at a draw ratio of 2.5. After setting the fabric sample (greater than 5x5cm), it was dyed with an acid dye. After dyeing, the fabric was washed with water, dried, and then subjected to the following tests:

[0191] Dyeability: The Kubelka-Munk dyeing depth of the fabric is tested. The Kubelka-Munk dyeing depth equation establishes a certain functional relationship between the absorption coefficient K and scattering coefficient S of the tested object and the concentration C of the colored substance in the solid sample, which is generally between 0 and 1. The larger the calculated K / S value, the darker the color of the solid sample surface, that is, the higher the concentration of colored substance and the better the dyeability, and vice versa.

[0192] Light transmittance: This measures the degree to which a fabric allows light to pass through, ranging from 0% to 100%. The higher the light transmittance, the easier it is for light to pass through the fabric, and the better the light transmission effect. Conversely, the lower the light transmittance, the more difficult it is for light to pass through, and the lower the light penetration.

[0193] The test results for spandex 1-14, nylon-spandex fabric 1-14, and the control spandex 1 and control nylon-spandex fabric 1 are shown in the table below:

[0194]

[0195] Spandex 10*: Fiber forming and unwinding are poor, and the filament bundles are relatively slippery.

Claims

1. A light-proof spandex, characterized in that, The light-proof spandex comprises polyurethane-urea and a matting agent, wherein the matting agent accounts for 0.5% to 5% of the mass of the light-proof spandex; The matting agent comprises a mixture of titanium dioxide, silicon dioxide, and acrylate; The matting agent comprises the following components by mass: Titanium dioxide 10~30%; 10-30% silica; Acrylic esters 40-80%; The acrylates mentioned include at least one of polyether-modified acrylates, polyester-modified acrylates, and epoxy-modified acrylates.

2. The light-proof spandex according to claim 1, characterized in that, The matting agent further includes stearate and / or talc, with the following composition by mass: Titanium dioxide 10-20%; 10-20% silica; 40-70% acrylate; Stearates and / or talc 10-20%.

3. The light-proof spandex according to claim 2, characterized in that, The mass percentage of stearate in the light-proof spandex, calculated based on the total mass of the light-proof spandex, does not exceed 0.5%.

4. The light-proof spandex according to claim 1, characterized in that, The polyurethane-urea comprises the reaction product of polymeric polyol, polyisocyanate, diamine chain extender and amine chain terminator; The polymer polyols include any one or a combination of at least two of polytetramethylene ether glycol, polyethylene glycol, or polypropylene glycol; The polyisocyanate includes any one or a combination of at least two of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate; Diamine chain extenders include aliphatic and non-aliphatic diamines; the molar ratio of the aliphatic and non-aliphatic diamines is 70:30 to 95:

5.

5. The light-blocking spandex according to claim 4, characterized in that, The aliphatic diamine includes aliphatic diamines with 2 to 30 carbon atoms, the non-aliphatic diamine includes nitrogen-containing heterocyclic diamines, and the amine chain terminator includes monoamines with 2 to 20 carbon atoms.

6. The light-proof spandex according to claim 2, characterized in that, The stearates mentioned include one or more of aluminum stearate, magnesium stearate, zinc stearate, calcium stearate, and barium stearate.

7. The light-proof spandex according to claim 1, characterized in that, The polyether-modified acrylates include one or more of polyethylene glycol-modified acrylates, polypropylene glycol-modified acrylates, polyethylene glycol-propylene glycol-modified acrylates, and polytetramethylene ether glycol-modified acrylates. The polyester-modified acrylate includes one or more of polycaprolactone-modified acrylate, polycarbonate-modified acrylate, and polyadipate-modified acrylate. The epoxy-modified acrylates include one or more of bisphenol A epoxy acrylates, phenolic epoxy acrylates, epoxidized acrylates, and modified epoxy acrylates.

8. The light-proof spandex according to claim 5, characterized in that, The aliphatic diamines having 2 to 30 carbon atoms include any one or a combination of at least two of ethylenediamine, propylenediamine, butanediamine, pentanediamine, methylpentanediamine, methylpropylenediamine, hexanediamine, diaminocyclohexane, or hexamethylenediamine.

9. The light-blocking spandex according to claim 5, characterized in that, The aforementioned azacyclic diamines include any one or a combination of at least two of pyrazine diamine, piperazine diamine, and piperazine diethylamine.

10. The light-proof spandex according to claim 9, characterized in that, The aforementioned azacyclic diamines include any one or a combination of at least two of 2,5-pyrazine diamine, 3,4-pyrazine diamine, 4,5-diaminopyrazine, 2,3-diaminopiperazine, and 1,4-piperazine diethylamine.

11. The light-blocking spandex according to claim 5, characterized in that, The monoamine having 2 to 20 carbon atoms is any one or a combination of at least two of the following: isopropylamine, n-butylamine, tert-butylamine, hexylamine diethylamine, dimethylamine, di-n-butylamine, di-tert-butylamine, diisobutylamine, diisopropylamine, diethylamine, dipropylamine, cyclohexylamine, or ethanolamine.

12. A method for preparing the light-blocking spandex as described in claims 1, 2, 3, 4 or 5, characterized in that, The preparation method is as follows: Step 1. The polymeric polyol and polyisocyanate are reacted to obtain a polyurethane prepolymer. The obtained polyurethane prepolymer is dissolved in a solvent to obtain a polyurethane prepolymer solution. The mass percentage of isocyanate groups (NCO) in the polyurethane prepolymer is 2.0%~3.5%. Step 2. React the obtained polyurethane prepolymer solution, diamine chain extender and amine chain terminator to obtain polyurethane-urea solution; the molar ratio of NCO in the polyurethane prepolymer to the amine groups in the diamine chain extender and amine chain terminator is 1:(1.01~1.10); Step 3. Mix polyurethane-urea solution and matting agent in a specified ratio; Step 4. The polyurethane-urea solution is cured before spinning, and the curing temperature is 30~45℃; Step 5. Dry spinning, which is achieved by adjusting the cross-sectional shape or arrangement of the spinnerets on the spinneret plate in the spinneret assembly during the spinning step. The cross-sectional shape of the light-proof spandex includes at least one of circular, trilobal, and cross-shaped shapes. The light-proof spandex was obtained.

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