A naphthyl ring nylon heat yellowing resistance agent and its preparation method and application

Abstract

The invention discloses a naphthyl ring nylon anti-heat yellowing agent and a preparation method and application, wherein the anti-heat yellowing agent has a carboxyl group and a hydrazide group, and the preparation method of the anti-heat yellowing agent comprises placing a 1,8-naphthalene dicarboxylic anhydride ethanol solution and unsymmetrical dimethyl hydrazine in pure water and stirring evenly, then reacting at 30-45°C for 1-3 hours to obtain a product, cooling to room temperature after the reaction is completed, adjusting the product concentration, and obtaining the naphthyl ring nylon anti-heat yellowing agent. The fabric after being finished with the anti-heat yellowing agent of the present invention will not absorb surrounding formaldehyde during use and storage, and has a good anti-yellowing effect, a simple preparation method process, not only a low formula cost, but also no special requirements for equipment, and is easy to realize industrialization.

Description

Technical Field

[0001] The invention belongs to the field of textiles, and specifically relates to the technical field of nylon fabric finishing auxiliaries, and in particular to a naphthyl ring nylon heat-resistant yellowing agent and a preparation method and application thereof. Background Art

[0002] Nylon fabrics are abrasion resistant, strong, elastic and comfortable to wear. They are widely used in high value-added underwear and swimsuit fabrics. Because nylon fiber molecular chains contain a large number of reactive groups such as amino groups, they tend to turn yellow during high-temperature setting or storage, affecting the quality of finished products, especially fluorescent whitening fabrics and light-colored fabrics. Therefore, nylon fabrics need to be treated with anti-yellowing finishing during dyeing and finishing. In the dyeing and finishing of nylon fabrics, two high-temperature heat setting processes, pre-setting and post-setting, are often required. Pre-setting is to maintain the dimensional stability of the fabric and prevent it from curling and deformation during subsequent processing. The setting temperature is often above 190°C. Post-setting is to give the fabric a specified unit area mass and feel style to prevent the fabric from yellowing due to film pressing and phenol yellowing during storage during subsequent production. The setting temperature is often 150°C or above. Anti-yellowing agents are required in both setting processes to ensure the whiteness or original color of the fabric.

[0003] At present, there are many heat-resistant yellowing agent products for nylon fabric finishing on the market, but they are often high in manufacturing cost, complex in ingredients, and poor in heat-resistant yellowing effect. Products with better use effects basically contain ADH (adipic acid dihydrazide). ADH is a bifunctional compound with a symmetrical structure, mainly used in coating additives, metal deactivators, water treatment agents, inks, adhesives and other industries. ADH has relatively active chemical properties. Its terminal amine group forms a hydrazone link with formaldehyde in a C=N structure, which can undergo an acylation reaction with aldehyde and be used as a formaldehyde scavenger. However, the acylation reaction between ADH and formaldehyde is reversible, and formaldehyde will be released under certain conditions. When nylon fabrics are treated with heat-resistant yellowing agent products containing ADH, the ADH in the fabric will adsorb formaldehyde in the storage environment, especially when finished clothing is mixed with clothes finished with free-iron resin containing free formaldehyde or displayed in newly renovated stores, it is particularly easy to have excessive formaldehyde content in the later detection of clothing. Formaldehyde has a strong irritating effect on the protoplasm of biological cells and can cause respiratory inflammation and dermatitis. Therefore, it has been identified as a carcinogen and teratogen by the World Health Organization. The laws and regulations or standards of various countries have strictly controlled the free formaldehyde content in textile products. Summary of the invention

[0004] Based on the above technical problems, the present invention provides a low-cost, pollution-free, high-safety naphthalene ring nylon anti-heat yellowing agent and its application in nylon fabric finishing. The present invention also provides a preparation method of the naphthalene ring nylon anti-heat yellowing agent, which has a simple preparation process, low raw material cost, no special requirements for equipment, greatly reduces costs, and realizes industrialization.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A naphthyl ring nylon anti-heat yellowing agent, the chemical structure of the anti-heat yellowing agent has:

[0007]

[0008] Preferably, the nitrogen of the hydrazide group in the chemical formula of the nylon fabric anti-yellowing agent is connected to two methyl end caps.

[0009] Based on the same inventive concept, the present invention also provides a method for preparing the naphthyl ring nylon anti-heat yellowing agent as described above, comprising: firstly dissolving 1,8-naphthalene dicarboxylic anhydride in an alcohol solvent, then placing the 1,8-naphthalene dicarboxylic anhydride alcohol solution and unilateral dimethyl hydrazine in pure water, stirring evenly, and then reacting at 30-45° C. for 1-3 hours to obtain the product. The reaction temperature should not be too high, as too high a temperature may cause the appearance of impurities. After the reaction is completed, the product is cooled to room temperature, and the product concentration is adjusted to obtain the naphthyl ring nylon anti-heat yellowing agent.

[0010] In a preferred embodiment of the present invention, the molar ratio of the 1,8-naphthalene dicarboxylic anhydride alcohol solution to unilateral dimethylhydrazine is 1:1-3, more preferably 1:1.

[0011] In a preferred embodiment of the present invention, the alcohol solvent is an ethanol solvent with a volume ratio of ethanol to pure water of 5-12:10, wherein the total amount of ethanol and pure water is 2-4 times the total weight of the raw material monomers.

[0012] In a preferred embodiment of the present invention, for the purpose of anti-yellowing effect and cost calculation, the concentration of the product is adjusted by using pure water, and the mass concentration of the product is 20-30%.

[0013] Based on the same inventive concept, the present invention also provides an application of a naphthalene ring nylon heat-resistant yellowing agent, wherein the naphthalene ring nylon heat-resistant yellowing agent as described above or the heat-resistant yellowing agent obtained by the preparation method is used to finish nylon fabrics by a rolling-baking-calcining process.

[0014] The pad-bake-baking process is specifically as follows: after the nylon fabric is dipped in the anti-yellowing agent finishing liquid, it is pre-baked at 100-110° C. for 2-4 minutes, and then baked at a temperature of 185-200° C. for 30-120 seconds;

[0015] After padding, the liquid carrying rate of the nylon fabric is 45-60%.

[0016] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0017] The naphthalene ring nylon heat yellowing resistance agent of the invention has good water solubility, good anti-yellowing effect, high product quality, no yellowing of nylon fabric after finishing, good product quality, can well maintain the color of white and light-colored nylon fabrics, is friendly to human body and environment, and has broad market prospects.

[0018] The naphthyl ring nylon anti-heat yellowing agent of the present invention is prepared by using 1,8-naphthalene dicarboxylic anhydride and unsymmetrical dimethyl hydrazine as materials, preferably in a 1:1 molar ratio. The product has a novel structure, which is different from the existing nylon anti-heat yellowing agent, and has a single component and stable performance. In particular, unsymmetrical dimethyl hydrazine is used as a raw material, and the active hydrogen on the hydrazide group of the synthesized anti-heat yellowing agent is blocked with a dimethyl group. The finished nylon fabric will not absorb surrounding formaldehyde during use and storage, thereby improving the safety of the product. At the same time, the carboxylic acid-containing structure allows the finished nylon fabric to be placed in an acidic atmosphere, and together with the hydrazide structure, it has a synergistic anti-heat yellowing effect.

[0019] Compared with the prior art, the naphthyl ring nylon heat-resistant yellowing agent prepared by the method of the present invention has the following beneficial effects: simple synthesis, high reaction efficiency, no need for any catalyst, no generation of any pollutants, low formulation cost, no special requirements for equipment, very simple manufacturing process, and easy industrialization. DETAILED DESCRIPTION

[0020] The following is a further detailed description of the naphthyl ring nylon heat yellowing resistance agent, preparation method and application of the present invention in conjunction with specific embodiments. The advantages and features of the present invention will become more apparent from the following description.

[0021] Embodiment 1:

[0022] First, 1,8-naphthalene dicarboxylic anhydride is dissolved in an ethanol solvent, and then the 1,8-naphthalene dicarboxylic anhydride ethanol solution and unsymmetrical dimethylhydrazine in a molar ratio of 1:1 are placed in pure water, stirred evenly, and then reacted at 35°C for 2.5 hours to obtain the product, and cooled to room temperature after the reaction. The volume ratio of ethanol to pure water in the ethanol solvent used is 1:1, and the total amount of ethanol solvent and pure water is twice the weight of the monomer.

[0023] After removal of solvent and purification, the product was used 1 H NMR and HR-MS were used to verify the results: 1H NMR (500MHz, Chloroform-d) δ 10.90 (s, 1H), 7.78-8.36 (m, 6H), 7.12 (s, 1H), 2.60 (s, 6H).C 14 H 14 N2O3 HR-MS detection value: 258.1020; calculated value: 258.1004. This indicates that the chemical structure of the obtained product contains The two chemical bonds of the nitrogen of the hydrazide group connect the two methyl end caps.

[0024] The product content is adjusted to 20% by weight with water to obtain a nylon anti-yellowing agent.

[0025] Embodiment 2:

[0026] This embodiment is the same as the first embodiment, except that "the product content is adjusted to 20% by weight with water to obtain a nylon anti-heat yellowing agent" is changed to "the product content is adjusted to 30% by weight with water to obtain a nylon anti-heat yellowing agent".

[0027] Embodiment three:

[0028] First, 1,8-naphthalene dicarboxylic anhydride is dissolved in an ethanol solvent, and then the 1,8-naphthalene dicarboxylic anhydride ethanol solution and unsymmetrical dimethylhydrazine in a molar ratio of 1:1 are placed in pure water, stirred evenly, and then reacted at 40°C for 1.5 hours to obtain the product, and cooled to room temperature after the reaction. The volume ratio of ethanol to pure water in the ethanol solvent used is 8:10, and the total amount of ethanol solvent and pure water is 3 times the weight of the monomer.

[0029] After removal of solvent and purification, the product was used 1 H NMR and HR-MS were used to verify the results: 1 H NMR (500MHz, Chloroform-d) δ 10.89 (s, 1H), 7.78-8.36 (m, 6H), 7.13 (s, 1H), 2.59 (s, 6H).C 14 H 14 N2O3 HR-MS detection value: 258.1001; calculated value: 258.1004. This indicates that the chemical structure of the obtained product contains The two chemical bonds of the nitrogen of the hydrazide group connect the two methyl end caps.

[0030] The product content is adjusted to 20% by weight with water to obtain a naphthyl ring nylon heat-resistant yellowing agent.

[0031] Embodiment 4:

[0032] This embodiment is the same as the third embodiment, except that "the total amount of ethanol solvent and pure water used is 3 times the weight of the monomer" is changed to "the total amount of ethanol solvent and pure water used is 2 times the weight of the monomer".

[0033] Embodiment five:

[0034] First, 1,8-naphthalene dicarboxylic anhydride is dissolved in an ethanol solvent, and then the 1,8-naphthalene dicarboxylic anhydride ethanol solution and unsymmetrical dimethylhydrazine in a molar ratio of 1:1 are placed in pure water, stirred evenly, and then reacted at 30°C for 3 hours to obtain the product, and cooled to room temperature after the reaction. The volume ratio of ethanol to pure water in the ethanol solvent used is 5:10, and the total amount of ethanol solvent and pure water is 3 times the weight of the monomer.

[0035] After removal of solvent and purification, the product was used 1 H NMR and HR-MS were used to verify the results: 1 H NMR (500MHz, Chloroform-d) δ 10.89 (s, 1H), 7.78-8.36 (m, 6H), 7.13 (s, 1H), 2.61 (s, 6H).C 14 H 14 N2O3 HR-MS detection value: 258.0992; calculated value: 258.1004. This indicates that the chemical structure of the obtained product contains The two chemical bonds of the nitrogen of the hydrazide group connect the two methyl end caps.

[0036] The product content is adjusted to 20% by weight with water to obtain a nylon anti-yellowing agent.

[0037] Embodiment six:

[0038] This embodiment is the same as the fifth embodiment, except that "the volume ratio of ethanol to pure water used is 5:10" is changed to "the volume ratio of ethanol to pure water used is 12:10".

[0039] 1. Thermal yellowing resistance test

[0040] The following is an experimental example of the use effect of the nylon heat-resistant yellowing agent obtained in the above 6 embodiments. Taking white nylon woven fabric as an example, the white nylon woven fabric is subjected to an anti-yellowing test after high-temperature baking.

[0041] Finishing process 1: The naphthyl ring nylon heat-resistant yellowing agent of the present embodiment 1-6 is configured into a finishing solution of 30g / L, and the white nylon woven fabric is twice dipped and twice rolled in the finishing solution (liquid carrying rate 55%), pre-baked at 110°C for 2 minutes in a heat setting machine and then baked at 185°C for 120s, and finally the whiteness of the white nylon fabric treated with and untreated with the heat-resistant yellowing agent is tested.

[0042] Finishing process 2: The naphthyl ring nylon heat-resistant yellowing agent of the present embodiment 1-6 is configured to a finishing solution of 30 g / L, and the white nylon woven fabric is twice dipped and twice rolled in the finishing solution (liquid carrying rate 55%), pre-baked at 110°C for 2 minutes in a heat setting machine and then baked at 195°C for 60s, and the whiteness of the white nylon fabric treated with and untreated with the heat-resistant yellowing agent is tested at last.

[0043] Fabric whiteness test: Datacolor 750 colorimeter was used to test the whiteness of the original and finished fabrics. According to GB 8424.2-2001 Textile color fastness test - Instrumental evaluation method for relative whiteness, the sample was folded into 4 layers, and different points were measured 4 times to take the average value.

[0044] Table 1 Changes in whiteness values ​​of nylon fabrics treated with anti-yellowing agents and untreated nylon fabrics

[0045] Finishing agent As is Not used Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Finishing process 1 77.1 61.2 74.1 75.3 74.3 74.3 74.6 74.8 Finishing process 2 77.1 60.2 74.0 75.2 74.1 74.2 74.4 74.6

[0046] It can be seen from Table 1 that the addition of the naphthyl ring nylon anti-heat yellowing agent of the embodiment of the present invention can effectively improve the high-temperature yellowing phenomenon of nylon fabric. The reason is that the anti-yellowing agent of the embodiment of the present invention covers the surface of nylon, blocking the relevant active groups in the fiber from contacting and reacting with oxygen, nitrogen dioxide, etc. in the air during high-temperature processing, thereby preventing the fabric from yellowing; secondly, the chemical structure of the anti-yellowing agent of the embodiment of the present invention contains carboxylic acid and hydrazide groups. The carboxylic acid-containing structure puts the nylon fabric in an acidic atmosphere after finishing, and has a synergistic anti-heat yellowing effect together with the hydrazide structure.

[0047] 2. Formaldehyde adsorption test

[0048] Fabric adsorption formaldehyde test: Prepare 500ppm formaldehyde solution and place it at the bottom of the sealed dryer, place the sample on the upper part of the partition, and place the whole in a 30℃ oven for 3.5h. The formaldehyde concentration in the air of the sealed dryer was tested using an air formaldehyde test box, which was about 1.5mg / m 3 , far exceeding the national standard indoor air formaldehyde concentration limit of 0.1mg / m 3 At such a high concentration, the difference in formaldehyde adsorption by nylon after treatment with different thermal yellowing agents can be more clearly seen.

[0049] Table 2 Adsorption of formaldehyde by nylon fabrics treated with anti-yellowing agent and untreated nylon fabrics at higher concentrations

[0050]

[0051] It can be seen from the above two tables that the nylon heat-resistant yellowing agent that does not absorb formaldehyde according to the embodiment of the present invention can effectively reduce the adsorption of formaldehyde in the surrounding environment by the fabric compared with the commonly used high-temperature heat-resistant yellowing agent ADH on the market. The reason is that the active hydrogen on the hydrazide group of the heat-resistant yellowing agent in the embodiment of the present invention is blocked with a dimethyl group, and the finished nylon fabric will not absorb the surrounding formaldehyde during use and storage, thereby improving the safety of the product.

[0052] The above is a detailed description of the implementation of the present invention in conjunction with the specific embodiments, but the present invention is not limited to the above implementation. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. An application of a naphthyl ring nylon heat-resistant yellowing agent, characterized in that: Using the pad-bake-cook process, the naphthalene ring nylon heat-resistant yellowing agent is used to perform heat-resistant yellowing finishing on nylon fabric; The chemical structure of the anti-yellowing agent includes: The preparation method of the naphthyl ring nylon heat-resistant yellowing agent comprises: Firstly, 1,8-naphthalene dicarboxylic anhydride is dissolved in an alcohol solvent, and then the 1,8-naphthalene dicarboxylic anhydride alcohol solution and unsymmetrical dimethyl hydrazine are placed in pure water, stirred evenly, and then reacted at 30-45° C. for 1-3 hours to obtain a product. After the reaction is completed, the product is cooled to room temperature and the concentration of the product is adjusted to obtain the naphthyl ring nylon anti-yellowing agent; The molar ratio of the 1,8-naphthalene dicarboxylic anhydride alcohol solution to unsymmetrical dimethylhydrazine is 1:

1.

2. The use of the naphthyl ring nylon heat-resistant yellowing agent according to claim 1, characterized in that: The alcohol solvent is an ethanol solvent with a volume ratio of ethanol to pure water of 5-12:10, wherein the total amount of the alcohol solvent and the pure water is 2-4 times the weight of the raw material monomer.

3. The use of the naphthyl ring nylon heat-resistant yellowing agent according to claim 1, characterized in that: The concentration of the product is adjusted with pure water, and the mass concentration of the product is 20-30%.

4. The use of the naphthyl ring nylon heat-resistant yellowing agent according to claim 1, characterized in that: The pad-bake-baking process is specifically as follows: after the nylon fabric is dipped in the anti-yellowing agent finishing liquid, it is pre-baked at 100-110° C. for 2-4 minutes, and then baked at a temperature of 185-200° C. for 30-120 seconds; After padding, the liquid carrying rate of the nylon fabric is 45-60%.

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