Preparation method of bisazo colored soft aramid fiber
By introducing aryl ethers and diazo monomers into aramid fibers and using a wet spinning process, colored soft diazo aramid fibers were prepared, solving the rigidity and brittleness problems of aramid fibers, achieving material softness and color impartation, and improving processing performance and color fastness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2026-03-10
AI Technical Summary
The regular stacking structure of benzene rings in aramid molecules leads to rigidity and brittleness issues, affecting the processing and practical applications. At the same time, dyeing is difficult, and conventional methods are energy-intensive and inflexible.
Colored soft aramid fibers based on diazo monomers were prepared by adding aromatic ethers and diazo monomers via copolymerization and using a wet spinning process. The introduction of aromatic ether structures enhances the flexibility of the molecular chains, and the addition of colored monomers allows for the preparation of colored soft aramid fibers via a wet spinning process.
It achieves material flexibility and color impartation, enhances molecular chain flexibility, maintains high strength and thermal stability, has adjustable color and excellent color fastness, and is suitable for a variety of applications.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of high-performance aromatic polyamide materials, and particularly relates to a preparation method of a double-azo colored soft aramid. BACKGROUND
[0002] Aramid is widely used in aerospace, military, transportation and communication fields due to its excellent flame retardance, mechanical properties, chemical stability and electrical insulation. However, the regular stacking structure of benzene rings and the highly oriented intermolecular hydrogen bonds in the aramid molecules lead to the rigidity of the molecular chain and the brittleness of the material, which affects the processing of the material and the actual application. There are two problems to be noted in the soft modification of aramid, i.e., mechanical strength and thermal stability. Generally, the breaking strength will decrease with the decrease of the elastic modulus, and improving the strength of the material is always contradictory to improving the softness; on the other hand, the thermal stability of the modified aramid will decrease due to the weakening of the stacking effect of benzene rings and the destruction of the regularity between molecular chains.
[0003] In addition, it is difficult to obtain color for aramid by dyeing due to its compact molecular structure and glass transition temperature of 270 DEG C. It is difficult for the dye to be taken up by the conventional dyeing method, and the high-temperature and high-pressure or stock solution coloring method is generally used in industry to prepare colored aromatic polyamide. However, the high-temperature and high-pressure dyeing requires high equipment and consumes a large amount of energy, and the stock solution coloring method also has some problems, such as inflexible production mode, complex process when changing the color of the fiber, unstable product color in small quantity production, etc. SUMMARY
[0004] In view of the above problems, the application provides a preparation method of double-azo colored soft aramid to solve the rigidity and brittleness problems of the aromatic polyamide in the processing and to give the polyamide color. The method adds aryl ether and double-azo monomer in a copolymerization manner, and prepares colored soft aramid through a wet spinning process.
[0005] In order to achieve the above purpose, the application provides a double-azo colored soft aramid, wherein the structure of aramid is shown in the following formula I:
[0006]
[0007] wherein, 86≤x≤93, 6.5≤y≤13, 0.5≤z≤1;
[0008] The structure of Ar1 in formula I includes:
[0009]
[0010]
[0011] The structure of Ar2 in formula I includes:
[0012]
[0013] wherein R1, R2, R3 are selected from hydrogen, halogen, alkyl, nitro or alkoxy.
[0014] Further, in the formula I, 88≤x≤94, 6.5≤y≤10, 0.8≤z≤1.0.
[0015] Further, in the formula I, the structure of Ar1 is any one of the following structures:
[0016]
[0017] Further, in the formula I, the structure of Ar2 is any one of the following structures:
[0018]
[0019] wherein R1, R2, R3 are selected from hydrogen, halogen, alkyl or alkoxy.
[0020] The application also provides a preparation method of the double azo colored soft aramid fiber, which comprises the following steps:
[0021] (1) adding m-phenylenediamine, Br1 and Br2 into an organic solvent, cooling to 0-5℃, adding isophthaloyl dichloride and reacting for 1-2h, then adding a neutralizing agent after warming to 55-65℃, and reacting for 10-20min to obtain a colored soft aramid fiber spinning solution;
[0022] (2) forming the spinning solution through a coagulation bath, washing, drying and heat setting to obtain the colored soft aramid fiber.
[0023] In an embodiment of the application, the structural formula of Br1 in step (1) is shown in the following formula II:
[0024] H2N-Ar1-NH2 Formula II
[0025] The structure of Ar1 in formula II includes:
[0026]
[0027] In an embodiment of the application, the structural formula of Br2 in step (1) is shown in the following formula III:
[0028] H2N-Ar2-NH2 Formula III
[0029] The structure of Ar2 in formula III includes:
[0030]
[0031] R1, R2, R3 are selected from hydrogen, halogen, alkyl, nitro or alkoxy.
[0032] In one embodiment of the present application, the structure of Ar1 in the formula II is any one of the following structures:
[0033]
[0034] In one embodiment of the present application, the structure of Ar2 in the formula III is any one of the following structures:
[0035]
[0036] R1, R2, R3 are selected from hydrogen, halogen, alkyl, nitro or alkoxy.
[0037] In one embodiment of the present application, Br2 in step (1) is a colored monomer, and the wavelength range of color development is 400-700 nm.
[0038] In one embodiment of the present application, the molar ratio of m-phenylenediamine to Br1 in step (1) is 10:0.8-1.0.
[0039] In one embodiment of the present application, the molar ratio of m-phenylenediamine to Br2 in step (1) is 90:0.4-1.2.
[0040] In one embodiment of the present application, the organic solvent in step (1) is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone and dimethyl sulfoxide.
[0041] In one embodiment of the present application, the concentration of m-phenylenediamine in the organic solvent in step (1) is 0.5-1.5 mol / L.
[0042] In one embodiment of the present application, the molar ratio of m-phenylenediamine to phthaloyl chloride in step (1) is 1:1-1.2.
[0043] In one embodiment of the present application, phthaloyl chloride is added twice in step (1); the amount of phthaloyl chloride added for the first time is 70-80% of the total molar amount of phthaloyl chloride, and the remaining phthaloyl chloride is added for the second time; the time interval between the two additions of phthaloyl chloride is 10-30 min.
[0044] In one embodiment of the present application, the neutralizing agent in step (1) is one of calcium oxide, calcium hydroxide or triethylamine.
[0045] In one embodiment of the present application, the molar ratio of m-phenylenediamine to the neutralizing agent in step (1) is 1:1-1.2.
[0046] In one embodiment of the present application, the reaction in step (1) is carried out under nitrogen environment.
[0047] In one embodiment of the present application, the reaction in step (1) is carried out under stirring; the stirring speed is 400-500 r / min.
[0048] In one embodiment of the present application, the coagulation liquid in the coagulation bath in step (2) is a mixture of organic solvent and water; the organic solvent includes N,N-dimethylacetamide; the mass fraction of the organic solvent in the coagulation liquid is 20-40%.
[0049] In one embodiment of the present application, the draft ratio in the coagulation bath forming process in step (2) is 1.5-3.5.
[0050] In one embodiment of the present application, the drying temperature in step (2) is 80-160℃.
[0051] In one embodiment of the present application, the heat setting temperature in step (2) is 200-350℃, and the heat setting draft ratio is 1.2-2.
[0052] The present application provides a double azo colored soft aramid fiber prepared according to the above method.
[0053] The present application provides an application of the double azo colored soft aramid fiber in the fields of textiles, clothing, composite material preparation, building materials and electronic equipment.
[0054] The present application has the following beneficial effects:
[0055] 1. The present application enhances the flexibility of the molecular chain by introducing aryl ether structure on the basis of the original meta-aramid, and retains the strength of the meta-aramid itself. The prepared aromatic polyamide has the characteristics of low modulus, high strength and high elongation at break, which can greatly improve the rigidity and brittleness of the meta-aramid, thereby being more easily processed and shaped.
[0056] 2. The present application imparts color to the meta-aramid by introducing colored monomers into the molecular chain, and the color of the aramid can be controlled by adjusting the monomer ratio, which has good operability. Since the color of the aramid is changed from the molecular structure level, it has excellent color fastness.
[0057] 3. The colored soft aramid provided by the present application has excellent flame retardance and thermal stability, and can be used for a long time under high temperature conditions. BRIEF DESCRIPTION OF DRAWINGS
[0058] Figure 1 The color reflectance curves of Example 1, Example 2, Example 3 and Example 4. DETAILED DESCRIPTION
[0059] The application will be further described in connection with the specific examples, which are only used to explain the application and not to limit the scope of the application.
[0060] Example 1
[0061] A double azo colored soft aramid fiber, the molecular structure of which is as follows:
[0062]
[0063] wherein x = 90, y = 9, and z = 1.
[0064] The preparation steps are as follows:
[0065] (1) 4.5 mol of m-phenylenediamine, 0.45 mol of 4,4'-diaminodiphenyl ether, and 0.05 mol of 5,5'-[(3,3'-dimethyl-1,1'-biphenyl-4,4'-diyl)bis(azo)]bis(6-aminonaphthalene-1-sulfonic acid sodium) are dissolved in 4.5 L of N,N-dimethylacetamide under nitrogen at 0°C, then 4 mol of isophthaloyl chloride is added and reacted for 20 min, 1 mol of isophthaloyl chloride is added and reacted for 1.5 h at 0°C, then the temperature is raised to 60°C, 5 mol of calcium hydroxide is added and reacted for 15 min, to obtain a colored soft aramid fiber spinning solution, the solid content of which is 22% and the viscosity is 320 Po.
[0066] (2) The spinning solution is stretched and formed in a coagulation bath containing 30% N,N-dimethylacetamide, the draw ratio is 3, after washing and drying at 100°C, heat setting is performed at a temperature of 280°C and a draw ratio of 2, after oiling, crimping and cutting, the strength of the obtained short fibers is tested to be above 3.0 cN / dtex, the elongation at break is above 20%, and the color wavelength range is 625-700 nm.
[0067] Example 2
[0068] A double azo colored soft aramid fiber, the molecular structure of which is as follows:
[0069]
[0070] wherein x = 90, y = 9, and z = 1.
[0071] The preparation steps are as follows:
[0072] (1) 4.5 mol of m-phenylenediamine, 0.45 mol of 1,4-bis(4-aminophenoxy)benzene and 0.05 mol of 4,4'-[(3,3'-dichloro-1,1'-biphenyl-4,4'-diyl)bis(azo)]bis(3-aminonaphthalene-2,7-disulfonic acid sodium) are dissolved in 4.5 L of N,N-dimethylacetamide under a nitrogen dry environment at 0°C, then 4 mol of isophthaloyl chloride is added to react for 20 min, 1 mol of isophthaloyl chloride is added to react for 1.5 h at 0°C, then the temperature is raised to 60°C, 5 mol of calcium hydroxide is added to continue to react for 15 min, to obtain a colored soft aramid spinning dope with a solid content of 20% and a viscosity of 280 Po.
[0073] (2) The spinning dope is stretched and formed through a coagulation bath containing 30% N,N-dimethylacetamide, the draw ratio is 2.5, after washing with water, drying is performed at 100°C, then heat setting is performed at a temperature of 280°C, the draw ratio is 1.5, after oiling, crimping and cutting, the obtained short fiber strength can reach above 3.0 cN / dtex, the elongation at break is above 15%, and the color wavelength range is 550-700 nm.
[0074] Example 3
[0075] A colored soft aramid of bis-azo type, the molecular structure of which is as follows:
[0076]
[0077] wherein x = 90, y = 9, and z = 1;
[0078] The preparation steps are as follows:
[0079] (1) 4.5 mol of m-phenylenediamine, 0.45 mol of 1,4-bis(4-aminophenoxy)benzene and 0.05 mol of 3,3'-[(1,1'-biphenyl-4,4'-diyl)bis(azo)]bis(4-aminonaphthalene-1-sulfonic acid sodium) are dissolved in 4.5 L of N,N-dimethylacetamide under a nitrogen dry environment at 0°C, then 4 mol of isophthaloyl chloride is added to react for 30 min, 1 mol of isophthaloyl chloride is added to react for 1.5 h at 0°C, then the temperature is raised to 60°C, 5 mol of calcium hydroxide is added to continue to react for 15 min, to obtain a colored soft aramid spinning dope with a solid content of 20% and a viscosity of 300 Po.
[0080] (2) The spinning dope is stretched into shape by a coagulation bath containing 30% N,N-dimethylacetamide, the draw ratio is 1.5, after washing with water, drying at 120℃, then heat setting at 300℃, the draw ratio is 2, after oiling, crimping and cutting, the strength of the short fiber obtained can reach above 3.0 cN / dtex, the elongation at break is above 20%, and the color wavelength range is 575-700 nm.
[0081] Example 4
[0082] A double azo type colored soft aramid fiber, the molecular structure of which is as follows:
[0083]
[0084] Wherein, x = 90, y = 9, z = 1;
[0085] The preparation steps are as follows:
[0086] (1) 4.5 mol of m-phenylenediamine, 0.45 mol of 1,3-bis(4'-aminophenoxy)benzene and 0.05 mol of 3,3'-[(3,3'-dimethoxy-1,1'-biphenyl-4,4'-diyl)bis(azo)]bis[4-amino-1-naphthalenesulfonic acid] disodium salt are dissolved in 4.5 L of N,N-dimethylacetamide under the condition of nitrogen dry environment below 0℃, then 4 mol of isophthaloyl chloride is added and reacted for 20 min, 1 mol of isophthaloyl chloride is added and reacted for 1.5 h at 0℃, then the temperature is raised to 60℃, 5 mol of calcium hydroxide is added and reacted for 15 min, to obtain a colored soft aramid fiber spinning dope, the solid content is 22%, and the viscosity is 260 Po.
[0087] (2) The spinning dope is stretched into shape by a coagulation bath containing 30% N- methylpyrrolidone, the draw ratio is 2.5, after washing with water, drying at 100℃, then heat setting at 280℃, the draw ratio is 1.5, after oiling, crimping and cutting, the strength of the short fiber obtained can reach above 3.0 cN / dtex, the elongation at break is above 20%, and the color wavelength range is 400-550 nm.
[0088] Comparative Example 1
[0089] The preparation steps are as follows:
[0090] (1) 5 mol of m-phenylenediamine is dissolved in 4.5 L of N,N-dimethylacetamide below 0℃, then 4 mol of isophthaloyl chloride is added and reacted for 20 min, 1 mol of isophthaloyl chloride is added and reacted for 1.5 h at 0℃, then the temperature is raised to 60℃, 5 mol of calcium hydroxide is added and reacted for 15 min, to obtain an aramid fiber spinning dope, the solid content is 22%, and the viscosity is 380 Po;
[0091] (2) The spinning method is the same as in Example 1. The obtained short fiber strength can reach 3.0 cN / dtex or more, and the breaking elongation is 10% or less.
[0092] Comparative Example 2
[0093] A colored soft aramid fiber of bis-azo type has the following molecular structure:
[0094]
[0095] wherein x = 98, y = 1, and z = 1.
[0096] The preparation steps are as follows:
[0097] (1) Except that 4.9 mol of m-phenylenediamine, 0.05 mol of 4,4'-diaminodiphenyl ether, and 0.05 mol of 5,5'-[(3,3'-dimethyl-1,1'-biphenyl-4,4'-diyl)bis(azo)]bis(6-aminonaphthalene-1-sulfonic acid sodium) are dissolved in 4.5 L of N,N-dimethylacetamide, other reaction conditions are the same as in Example 1. A colored soft aramid fiber spinning solution is obtained, with a solid content of 22% and a viscosity of 320 Po.
[0098] (2) The spinning method is the same as in Example 1. The obtained short fiber strength can reach 3.0 cN / dtex or more, and the breaking elongation is 10% or less. The color wavelength range is 625-700 nm.
[0099] Comparative Example 3
[0100] A colored soft aramid fiber of bis-azo type has the following molecular structure:
[0101]
[0102] wherein x = 85, y = 10, and z = 5.
[0103] The preparation steps are as follows:
[0104] (1) Except that 4.25 mol of m-phenylenediamine, 0.5 mol of 4,4'-diaminodiphenyl ether, and 0.25 mol of 5,5'-[(3,3'-dimethyl-1,1'-biphenyl-4,4'-diyl)bis(azo)]bis(6-aminonaphthalene-1-sulfonic acid sodium) are dissolved in 4.5 L of N,N-dimethylacetamide, other reaction conditions are the same as in Example 1. A colored soft aramid fiber spinning solution is obtained, with a solid content of 22% and a viscosity of 120 Po.
[0105] (2) The spinning method is the same as in Example 1. The obtained short fiber strength can reach 3.0 cN / dtex or more, and the breaking elongation is 10% or less. The color wavelength range is 625-700 nm.
[0106] As can be seen from the data in Table 1, the colored soft aramid fiber prepared by the method of the present application has the characteristics of low modulus, high strength and high elongation at break, and also maintains excellent flame retardant performance, and is a high-performance soft material.
[0107] Compared with Comparative Example 1, the elastic modulus of the example is significantly reduced, the elongation at break is greatly improved, and the rigidity and brittleness of aramid fiber are solved. In addition, the aramid fiber of the example can change color according to demand, and the color range covers the full color spectrum of 400-700 nm, which can improve the actual production and processing efficiency and broaden the use field of aromatic polyamide.
[0108] Compared with Comparative Examples 2 and 3 and Example 1, it can be found that after adjusting the amount of raw materials, the elastic modulus of the comparative examples is increased, and the elongation at break is decreased, which shows that in the aramid structural formula of the present application, each group must exist in a certain proportion to achieve high performance.
[0109] Table 1 Comparison of fiber parameters of examples and comparative examples
[0110]
[0111] Table 2 Color fastness of fiber of examples
[0112]
[0113] The examples provided above are not intended to limit the scope of the present application, and the described steps are not intended to limit the execution order. Those skilled in the art can make obvious improvements to the present application in combination with existing common knowledge, which also falls within the protection scope defined by the claims of the present application.
Claims
1. A disazo colored flexible aramid characterized in that, The structure of the aramid is shown in the following formula I: wherein, 86≤x≤93, 6.5≤y≤13, 0.5≤z≤1; The structure of Ar1 in formula I includes: The structure of Ar2 in formula I includes: wherein, R1, R2, R3 are selected from hydrogen, halogen, alkyl, nitro or alkoxy.
2. A process for the preparation of the disazo colored soft aramid fiber as claimed in claim 1, characterized in that, The method comprises the following steps: (1) adding m-phenylenediamine, Br1 and Br2 into an organic solvent, cooling to 0-5℃, adding isophthaloyl dichloride and reacting for 1-2h, then adding a neutralizing agent after warming to 55-65℃ and reacting for 10-20min to obtain a colored soft aramid spinning dope; (2) forming the spinning dope through a coagulation bath, washing, drying and heat setting to obtain a colored soft aramid.
3. The method of claim 2, wherein, The structure of Br1 in step (1) is shown in the following formula II: H2N-Ar1-NH2 Formula II The structure of Ar1 in formula II includes:
4. The method of claim 2, wherein, The structure of Br2 in step (1) is shown in the following formula III: H2N-Ar2-NH2 Formula III The structure of Ar2 in formula III includes: R1, R2, R3 are selected from hydrogen, halogen, alkyl, nitro or alkoxy.
5. The method as claimed in claim 2, wherein, In step (1), the molar ratio of m-phenylenediamine to Br1 is 10:0.6-1.0; and the molar ratio of m-phenylenediamine to Br2 is 90:0.4-1.
2.
6. The method as claimed in claim 2, wherein, In step (1), the organic solvent is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone and dimethyl sulfoxide; and the concentration of m-phenylenediamine in the organic solvent is 0.5-1.5 mol / L.
7. The method as claimed in claim 2, wherein, In step (1), the molar ratio of m-phenylenediamine to phthaloyl dichloride is 1:1-1.2; phthaloyl dichloride is added twice; the amount of phthaloyl dichloride added in the first time is 70-80% of the total molar amount of phthaloyl dichloride, and the remaining phthaloyl dichloride is added in the second time; the time interval between the two times of adding phthaloyl dichloride is 10-30 min.
8. The method of claim 2, wherein, In step (1), the neutralizing agent is one of calcium oxide, calcium hydroxide or triethylamine; and the molar ratio of m-phenylenediamine to the neutralizing agent is 1:1-1.
2.
9. The method as claimed in claim 2, wherein, In step (2), the coagulation liquid in the coagulation bath is a mixture of an organic solvent and water; the organic solvent includes N,N-dimethylacetamide; the mass fraction of the organic solvent in the coagulation liquid is 20-40%; the draw ratio during the coagulation bath forming process is 1.5-3.5; the heat setting temperature is 200-350℃, and the heat setting draw ratio is 1.2-2.
10. The application of the double azo colored soft aramid as claimed in claim 1 and prepared by the method as claimed in any one of claims 2-9 in the fields of textiles, clothing, composite material preparation, building materials and electronic equipment.