Double-channel anti-counterfeiting method of polyamide fiber and application of double-channel anti-counterfeiting method

Abstract

The invention particularly relates to a'double-channel 'anti-counterfeiting method for polyamide fibers and application of the'double-channel' anti-counterfeiting method, and belongs to the technical field of functional fiber materials. The'double-channel 'counterfeit detection method for the polyamide fibers specifically comprises the following steps: (1) introducing specific types and contents of anti-counterfeit elements into the polyamide fibers; and (2) carrying out element qualitative authenticity verification and element quantitative authenticity verification on the anti-counterfeiting elements. Wherein the anti-counterfeiting element is formed by combining calcium with one of zinc, aluminum and strontium or combining aluminum with one of strontium and zinc; the qualitative element authenticity detection realizes the judgment of the authenticity of the polyamide fiber by means of element chromogenic reaction of a calcium element detection reagent and an aluminum element detection reagent; the content and the relative proportion of anti-fake elements are detected through an inductively coupled plasma spectrometer; according to the double-channel anti-counterfeiting method for the polyamide fibers, the authenticity of the polyamide fibers can be rapidly judged, the requirement for the accurate detection result can be met, the anti-counterfeiting requirements of all levels are met, and the good industrialization prospect is achieved.

Description

Technical Field

[0001] The present invention specifically relates to a "dual-channel" anti-counterfeiting method for nylon fibers and application thereof, and belongs to the technical field of functional fiber materials. Background Art

[0002] In recent years, the nylon market has continued to expand, and production technology has become increasingly mature. With the improvement of nylon research and development capabilities, the types and functions of nylon fibers have gradually increased, and recycling processes have also made continuous breakthroughs. However, what follows is that the nylon market is mixed, and disputes caused by quality issues are gradually increasing. In order to maintain the healthy and stable development of the nylon market, it is urgent to enhance the anti-counterfeiting function of the fiber to prevent bad merchants from selling inferior products as good ones in the fiber market.

[0003] In the current research results, anti-counterfeiting chemical fibers are mainly prepared by three methods: fluorescence method, element masterbatch method, and element mother liquor method. Patent CN114507420A discloses a functional masterbatch containing a rare earth tracer, which can be used for spinning to prepare anti-counterfeiting polyester fibers. However, this method can only achieve qualitative detection of the tracer, the anti-counterfeiting method is relatively monotonous, and the anti-counterfeiting ability is relatively weak. Patent CN112063122A discloses a method for preparing anti-counterfeiting chemical fibers using element masterbatch as raw material. This method has strong anti-counterfeiting strength, but the sample needs to be sampled and digested during the detection process. The detection method is relatively complicated and it is difficult to quickly obtain the detection results. Patent CN112064140A uses bio-derived oil as a carrier to prepare a series of element mother liquors with anti-counterfeiting functions, and uses this as a raw material for spinning to obtain anti-counterfeiting chemical fibers. However, it is difficult to achieve uniform dispersion of the tracer in the element mother liquor, and the mother liquor may leak during the melt spinning process, making it difficult to ensure the stability of the added content. In summary, the current anti-counterfeiting chemical fibers have problems such as weak anti-counterfeiting capabilities and cumbersome verification methods. Summary of the invention

[0004] In order to solve the problems of high anti-counterfeiting cost, low anti-counterfeiting level and complicated verification methods in the existing technology, the purpose of the present invention is to provide a "dual-channel" anti-counterfeiting method for nylon fiber. This method introduces anti-counterfeiting elements of specific types and contents into the nylon fiber in advance, and then performs qualitative verification and quantitative verification on the anti-counterfeiting elements to achieve "dual-channel" verification of nylon fiber. The verification method is fast, the verification results are accurate and the cost is low.

[0005] The technical solution of the present invention is as follows:

[0006] The present invention provides a "dual-channel" anti-counterfeiting method for nylon fibers, comprising the following steps:

[0007] S1. Prepare nylon fiber containing anti-counterfeiting elements; the anti-counterfeiting elements are composed of calcium and one of zinc, aluminum and strontium, or aluminum and one of strontium and zinc, and the two elements of the anti-counterfeiting elements have any mass ratio;

[0008] S2. using an anti-counterfeiting element detection reagent to conduct a qualitative analysis of the presence of the anti-counterfeiting element;

[0009] S3. The nylon fiber containing the anti-counterfeiting element is fully digested with a mixed acid composed of nitric acid and sulfuric acid, and the obtained digestion solution is subjected to element quantitative analysis by an inductively coupled plasma spectrometer to determine the content and relative proportion of the anti-counterfeiting element in the nylon fiber containing the anti-counterfeiting element.

[0010] Furthermore, the nylon fiber described in step S1 uses nylon shiny slices, dispersants and tracers as raw materials; the nylon shiny slices are one of nylon 6 shiny slices and nylon 66 shiny slices; the dispersant is a polyether ester dispersant or an amide dispersant; the components of the tracer are composed of a combination of calcium carbonate and any one of zinc oxide, strontium oxide, and aluminum oxide, or a combination of aluminum oxide and any one of strontium oxide and zinc oxide. The two inorganic metal compounds constituting the tracer have an arbitrary mass ratio, the average particle size of the inorganic metal compound is between 200 and 500 nm, and the total content of the two inorganic metal compounds in the tracer masterbatch is between 5% and 10%.

[0011] Preferably, the polyetherester dispersant is 330; the amide dispersant is JIAWax-100.

[0012] Furthermore, the specific steps of preparing the nylon fiber containing the anti-counterfeiting element in step S1 are:

[0013] (i) Preparation of nylon tracer masterbatch: 89-94 parts of nylon glossy chips, 1 part of dispersant and 5-10 parts of tracer are mixed, and then the mixed materials are added to a screw extruder for melting to form a melt material strip, and the temperature of the screw extruder is 240-270° C.; the formed melt material strip is plasticized by water cooling and pelletized to obtain a nylon tracer masterbatch;

[0014] (ii) Preparation of nylon fiber containing anti-counterfeiting elements: The obtained nylon tracer masterbatch and nylon glossy chips are dried and dehydrated, and the dried tracer masterbatch and nylon glossy chips are put into a metering pump and a screw extruder for melting, and the temperature of the screw extruder is 260-290°C; the melt is spun through the assembly to form a filament bundle, and then slowly cooled, monomer suction, side blowing cooling, bundling oiling, secondary cooling in the tunnel, stretching and shaping, and finally wound to obtain the nylon fiber containing the anti-counterfeiting element.

[0015] Furthermore, the anti-counterfeiting element detection reagent is one of a calcium element detection reagent and an aluminum element detection reagent.

[0016] Furthermore, the specific steps of using the anti-counterfeiting element detection reagent to perform qualitative analysis on the presence of the anti-counterfeiting element in step S2 are as follows:

[0017] When the security element is composed of a combination of calcium and one of the elements zinc, aluminum, and strontium:

[0018] Dissolve the nylon fiber containing the anti-counterfeiting element in a sulfuric acid solution, adjust the solution pH to between 6 and 8, add a calcium detection reagent to the solution, and after it is fully dissolved, if the calcium color reaction is positive, it proves the presence of the anti-counterfeiting element.

[0019] When the security element is composed of a combination of aluminum and one of the elements strontium, zinc, and calcium:

[0020] Dissolve the nylon fiber containing the anti-counterfeiting element in sulfuric acid solution, adjust the solution pH to between 6 and 7, add aluminum detection reagent to the solution, and after it is fully dissolved, if the aluminum color reaction is positive, it proves the presence of the anti-counterfeiting element.

[0021] Preferably, the component of the calcium detection reagent is o-cresolphthalein complexed copper, and the calcium detection concentration range is 0.02 to 2 mg / L; the positive calcium color reaction means that the solution changes from colorless to purple; the aluminum detection reagent is composed of chrome azuro blue S, polyethylene glycol zinc phenyl ether, and cetylpyridinium bromide, and the aluminum detection concentration range is 0 to 2 mg / L; the positive aluminum color reaction means that the solution changes from colorless to blue.

[0022] The present invention applies the above-mentioned "dual-channel" anti-counterfeiting method of nylon fiber to the anti-counterfeiting of nylon 6 fiber and nylon 66 fiber.

[0023] Different from the prior art, the present invention has the following beneficial effects:

[0024] 1. The "dual-channel" anti-counterfeiting method for nylon fiber provided by the present invention introduces anti-counterfeiting elements of specific types and contents into nylon fiber. The element qualitative counterfeiting verification method of the present invention uses the color development reaction of the anti-counterfeiting elements to quickly determine the authenticity of nylon fiber, and the verification method is convenient.

[0025] 2. The element quantitative verification method of the present invention uses an inductively coupled plasma spectrometer to detect the content and relative proportion of anti-counterfeiting elements. The verification result is accurate, and the proportion of unknown metal elements and unknown elements effectively increases the difficulty of counterfeiting and improves the anti-counterfeiting level.

[0026] 3. Compared with the previous technologies, the nylon fiber "dual-channel" anti-counterfeiting method provided by the present invention can not only realize the rapid judgment of the authenticity of nylon fibers, but also meet the requirements of accurate detection results, and can meet the needs of counterfeiting inspection at all levels.

[0027] 4. The nylon fiber "dual-channel" anti-counterfeiting method provided by the present invention has a low detection limit. The calcium element detection concentration range is 0.02-2 mg / L, and the aluminum element detection concentration range is 0-2 mg / L. It has high detection sensitivity, requires a small amount of metal, has low anti-counterfeiting cost, is friendly to the environment and human health, and has strong industrial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the detection results corresponding to different element detection reagents. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings and preferred embodiments. The given embodiments are only for illustrating the present invention, rather than for limiting the scope of the present invention.

[0030] Unless otherwise specified, the materials, reagents, etc. used in the following examples can be obtained from commercial sources; the methods in the following examples are conventional methods unless otherwise specified.

[0031] Example 1

[0032] This embodiment provides a nylon 6 fiber "dual channel" anti-counterfeiting method, comprising the following steps:

[0033] S1. Preparation of nylon 6 fiber containing anti-counterfeiting elements:

[0034] (i) Preparation of nylon 6 tracer masterbatch: According to the weight percentage, 89 parts of nylon 6 glossy slices, 1 part of 330 dispersant and 10 parts of tracer are mixed evenly. The tracer is obtained by mixing 5 parts of zinc oxide and 5 parts of calcium carbonate evenly. The temperature of the screw extruder is set to 240°C, and then the mixed materials are added to the screw extruder for melting to form a melt strip. The melt strip is plasticized by water cooling and pelletized to obtain a nylon 6 tracer masterbatch.

[0035] (ii) Preparation of nylon 6 fiber containing anti-counterfeiting elements: The obtained nylon 6 tracer masterbatch and nylon 6 glossy chips are dried at 102°C for at least 8 hours to remove moisture; then the melting temperature of the screw extruder is set to 260°C, and the dried nylon 6 tracer masterbatch and nylon 6 glossy chips are put into the metering pump and the screw extruder for melting, and the melt is spun through the assembly to form a filament bundle, and then subjected to slow cooling, monomer suction, side blowing cooling, bundling oiling, secondary cooling in the tunnel, stretching and shaping, and finally winding to obtain nylon 6 fiber containing anti-counterfeiting elements.

[0036] S2. Qualitative verification of nylon 6 fiber containing anti-counterfeiting elements: Dissolve 0.1g of nylon 6 fiber containing anti-counterfeiting elements in 1mL of sulfuric acid solution, adjust the pH of the solution to between 6 and 8, and drip o-cresolphthalein copper complex solution into the solution. Figure 1 As shown, if the color of the solution changes from colorless to purple, it proves the presence of calcium.

[0037] S3. Quantitative verification of nylon 6 fiber containing anti-counterfeiting elements: Take 0.1g of nylon 6 fiber containing anti-counterfeiting elements and use 5mL of mixed acid prepared by sulfuric acid and nitric acid in a volume ratio of 1:2 to fully digest it. The digestion conditions are: heat up from room temperature 25℃ to 125℃ and keep it for 10 minutes, then heat up from 125℃ to 180℃, keep it for 20 minutes, then lower the temperature to 125℃ and keep it for 3h for acid treatment, and take out the mixed solution after the temperature drops to room temperature and make it volume to 10mL. Then, use inductively coupled plasma spectrometer to perform elemental quantitative analysis on the digestion solution to determine the content and relative proportion of zinc and calcium elements.

[0038] Example 2

[0039] This embodiment provides a nylon 6 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 1 in that:

[0040] In step S1, the amount of tracer added is 5 parts, and the tracer is composed of 2.5 parts of calcium carbonate and 2.5 parts of aluminum oxide; the nylon 6 glossy slices are 94 parts; the temperature of the screw extruder for preparing the nylon 6 tracer masterbatch is set to 270°C; the temperature of the screw extruder for preparing the nylon 6 fiber containing anti-counterfeiting elements is set to 290°C;

[0041] The digestion step of the nylon 6 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 1. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of calcium and aluminum elements.

[0042] The preparation steps of nylon 6 fiber and the amount of dispersant added are the same as those in Example 1. The qualitative verification steps of the "dual-channel" anti-counterfeiting method for nylon 6 fiber are the same as those in Example 1 and will not be repeated here.

[0043] Example 3

[0044] This embodiment provides a nylon 6 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 1 in that:

[0045] In step S1, the amount of tracer added is 7.5 parts, and the tracer used is composed of 2.5 parts of calcium carbonate and 5 parts of strontium oxide; the amount of nylon 6 shiny slice added is 90 parts; the temperature of the screw extruder for preparing nylon 6 tracer masterbatch is set to 250°C; the temperature of the screw extruder for preparing nylon 6 fiber containing anti-counterfeiting elements is set to 270°C;

[0046] The digestion step of the nylon 6 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 1. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of calcium and strontium.

[0047] The preparation steps of nylon 6 fiber and the amount of dispersant added are the same as those in Example 1. The qualitative verification steps of the "dual-channel" anti-counterfeiting method for nylon 6 fiber are the same as those in Example 1 and will not be repeated here.

[0048] Example 4

[0049] This embodiment provides a nylon 6 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 1 in that:

[0050] In step S1, the amount of tracer added is 10 parts, and the tracer used is composed of 5 parts of aluminum oxide and 5 parts of strontium oxide;

[0051] Step S2 The specific steps of qualitative verification of nylon 6 fiber containing anti-counterfeiting elements are as follows: dissolve 0.1g nylon 6 fiber containing anti-counterfeiting elements in 1mL sulfuric acid solution, adjust the solution pH to between 6 and 7, take 10mL of the solution and add it to a clean colorimetric tube, add 1mL chrome azuro blue S, shake well and let it stand for 5 minutes, then add 3mL polyethylene glycol zinc phenyl ether reagent, shake well and let it stand for 5 minutes, then add 0.6g hexadecylpyridinium bromide reagent, and slowly shake well to dissolve. Figure 1 As shown, if the color of the solution changes from colorless to blue, it proves the presence of aluminum;

[0052] The digestion step of the nylon 6 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 1. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of aluminum and strontium.

[0053] The preparation steps of nylon 6 fiber and the amount of nylon 6 glossy slices and dispersant added are the same as those in Example 1 and will not be repeated here.

[0054] Example 5

[0055] This embodiment provides a nylon 6 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 4 in that:

[0056] In step S1, the amount of tracer added is 10 parts, and the tracer used is composed of 5 parts of aluminum oxide and 5 parts of zinc oxide;

[0057] The digestion step of the nylon 6 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 4. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of aluminum and zinc elements.

[0058] The preparation steps of nylon 6 fiber and its nylon 6 glossy slices and the amount of dispersant added are the same as those in Example 4. The qualitative verification steps of the nylon 6 fiber "dual-channel" anti-counterfeiting method are the same as those in Example 4 and will not be repeated here.

[0059] Example 6

[0060] This embodiment provides a nylon 6 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 4 in that:

[0061] In step S1, the amount of tracer added is 10 parts, and the tracer used is composed of 5 parts of aluminum oxide and 5 parts of calcium carbonate;

[0062] The digestion step of the nylon 6 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 4. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of aluminum and calcium elements.

[0063] The preparation steps of nylon 6 fiber and its nylon 6 glossy slices and the amount of dispersant added are the same as those in Example 4. The qualitative verification steps of the nylon 6 fiber "dual-channel" anti-counterfeiting method are the same as those in Example 4 and will not be repeated here.

[0064] Example 7

[0065] This embodiment provides a nylon 66 fiber "dual channel" anti-counterfeiting method, comprising the following steps:

[0066] S1. Preparation of nylon 66 fiber containing anti-counterfeiting elements:

[0067] (i) Preparation of nylon 66 tracer masterbatch: 89 parts of nylon 66 glossy chips, 1 part of JIA Wax-100 dispersant, and 10 parts of tracer were mixed by weight, wherein the tracer was obtained by mixing 5 parts of zinc oxide and 5 parts of calcium carbonate; the temperature of the screw extruder was set to 240° C., and then the mixed materials were added to the screw extruder for melting to form a melt strip, and the melt strip was plasticized by water cooling and pelletized to obtain a nylon 66 tracer masterbatch;

[0068] (ii) Preparation of nylon 66 fiber containing anti-counterfeiting elements: The obtained nylon 66 tracer masterbatch and nylon 66 glossy chips are dried at 102°C for at least 8 hours to remove moisture; then the melting temperature of the screw extruder is set to 260°C, and the dried nylon 66 tracer masterbatch and nylon 66 glossy chips are put into a metering pump and a screw extruder for melting, and the melt is spun through the assembly to form a filament bundle, and then slowly cooled, monomer suction, side blowing cooling, bundling oiling, secondary cooling in the tunnel, stretching and shaping, and finally wound to obtain nylon 66 fiber containing anti-counterfeiting elements.

[0069] S2. Qualitative verification of nylon 66 fiber containing anti-counterfeiting elements: Dissolve 0.1g of nylon 66 fiber containing anti-counterfeiting elements in 1mL of sulfuric acid solution, adjust the pH of the solution to between 6 and 8, and drip the solution into o-cresolphthalein complex copper reagent. Figure 1 As shown, if the color of the o-cresolphthalein complexed copper reagent changes to purple, it proves the presence of calcium.

[0070] S3. Quantitative verification of nylon 66 fiber containing anti-counterfeiting elements: Take 0.1g of nylon 66 fiber containing anti-counterfeiting elements and use 6mL of mixed acid prepared by nitric acid and sulfuric acid in a volume ratio of 1:1 to fully digest it. The digestion conditions are: heat up from room temperature 25℃ to 125℃ and keep it for 10 minutes, then heat up from 125℃ to 180℃, keep it for 20 minutes, then lower the temperature to 125℃ and keep it for 3h for acid treatment, and take out the mixed solution after the temperature drops to room temperature and make it volume to 10mL. Then, use inductively coupled plasma spectrometer to perform elemental quantitative analysis on the digestion solution to determine the content and relative proportion of zinc and calcium elements.

[0071] Example 8

[0072] This embodiment provides a nylon 66 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 7 in that:

[0073] In step S1, the amount of tracer added is 5 parts, and the tracer used is composed of 2.5 parts of calcium carbonate and 2.5 parts of aluminum oxide; the amount of nylon 66 glossy slice added is 94 parts; the temperature of the screw extruder for preparing nylon 66 tracer masterbatch is set to 270°C; the temperature of the screw extruder for preparing nylon 66 fiber containing anti-counterfeiting elements is set to 290°C;

[0074] The digestion step of the nylon 66 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 7. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of calcium and aluminum elements.

[0075] The preparation steps of nylon 66 fiber and the amount of dispersant added are the same as those in Example 7. The qualitative verification steps of the "dual-channel" anti-counterfeiting method for nylon 66 fiber are the same as those in Example 7 and will not be repeated here.

[0076] Example 9

[0077] This embodiment provides a nylon 66 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 7 in that:

[0078] In step S1, the amount of tracer added is 7.5 parts, and the tracer used is composed of 2.5 parts of calcium carbonate and 5 parts of strontium oxide; the amount of nylon 66 glossy slice added is 90 parts; the temperature of the screw extruder for preparing nylon 66 tracer masterbatch is set to 250°C; the temperature of the screw extruder for preparing nylon 66 fiber containing anti-counterfeiting elements is set to 270°C;

[0079] The digestion step of the nylon 66 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 7. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of calcium and strontium elements.

[0080] The preparation steps of nylon 66 fiber and the amount of dispersant added are the same as those in Example 7. The qualitative verification steps of the "dual-channel" anti-counterfeiting method for nylon 66 fiber are the same as those in Example 7 and will not be repeated here.

[0081] Example 10

[0082] This embodiment provides a nylon 66 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 7 in that:

[0083] In step S1, the amount of tracer added is 10 parts, and the tracer used is composed of 5 parts of aluminum oxide and 5 parts of strontium oxide;

[0084] Step S2: The specific steps of qualitative verification of nylon fiber containing anti-counterfeiting elements are as follows: dissolve 0.1g of nylon 66 fiber containing anti-counterfeiting elements in 1mL of sulfuric acid solution, and adjust the pH of the solution to between 6 and 7. Take 10mL of the solution and add it to a clean colorimetric tube, add 1mL of chrome azuro blue S, shake well and let it stand for 5 minutes, then add 3mL of polyethylene glycol zinc phenyl ether reagent, shake well and let it stand for 5 minutes, then add 0.6g of hexadecylpyridinium bromide reagent, and slowly shake well to dissolve. Figure 1 As shown, if the color of the solution changes from colorless to blue, it proves the presence of aluminum;

[0085] The digestion step of the nylon 66 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 7. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of aluminum and strontium.

[0086] The preparation steps of nylon 66 fiber and its nylon 66 shiny slices and the amount of dispersant added are the same as those in Example 7. The quantitative verification steps of the "dual-channel" anti-counterfeiting method for nylon 66 fiber are the same as those in Example 7 and will not be repeated here.

[0087] Embodiment 11

[0088] This embodiment provides a nylon 66 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 10 in that:

[0089] In step S1, the amount of tracer added is 10 parts, and the tracer used is composed of 5 parts of aluminum oxide and 5 parts of zinc oxide;

[0090] The digestion step of the nylon 66 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 10. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of aluminum and zinc elements.

[0091] The preparation steps of nylon 66 fiber and its nylon 66 shiny slices and the amount of dispersant added are the same as those in Example 10. The qualitative verification steps of the "dual-channel" anti-counterfeiting method for nylon 66 fiber are the same as those in Example 10 and will not be repeated here.

[0092] Example 12

[0093] This embodiment provides a nylon 66 fiber "dual channel" anti-counterfeiting method, which is different from embodiment 10 in that:

[0094] In step S1, the amount of tracer added is 10 parts, and the tracer used is composed of 5 parts of aluminum oxide and 5 parts of calcium carbonate;

[0095] The digestion step of the nylon 66 fiber containing the anti-counterfeiting element in step S3 is the same as that in Example 10. After obtaining the digestion solution, the digestion solution is subjected to element quantitative analysis using an inductively coupled plasma spectrometer to determine the content and relative proportion of aluminum and calcium elements.

[0096] The preparation steps of nylon 66 fiber and its nylon 66 shiny slices and the amount of dispersant added are the same as those in Example 10. The qualitative verification steps of the "dual-channel" anti-counterfeiting method for nylon 66 fiber are the same as those in Example 10 and will not be repeated here.

[0097] Comparative Example 1

[0098] This comparative example provides a method for preparing nylon 6 fiber, comprising the following steps:

[0099] S1. Preparation of nylon 6 fiber: drying nylon 6 glossy chips at 102° C. for at least 8 hours to remove moisture, then setting the melting temperature of the screw extruder to 260° C., feeding the dried nylon 6 glossy chips into a metering pump and a screw extruder for melting, and spinning the melt through a component to form a tow, and then subjecting the tow to slow cooling, monomer extraction, side-blowing cooling, bundling and oiling, secondary cooling in a tunnel, stretching and shaping, and finally winding to obtain nylon 6 fiber;

[0100] S2. Qualitative verification of nylon 6 fiber:

[0101] (i) Dissolve 0.1 g of nylon 6 fiber in 1 mL of sulfuric acid solution, adjust the pH of the solution to between 6 and 8, and drop the o-cresolphthalein copper complex solution into the solution. Figure 1 As shown, if the color of the solution changes from colorless to purple, it proves the presence of calcium;

[0102] (ii) Dissolve 0.1g of nylon 6 fiber in 1mL of sulfuric acid solution, adjust the solution pH to between 6 and 7, take 10mL of the solution and add it to a clean colorimetric tube, add 1mL of chrome azuro blue S, shake well and let stand for 5 minutes, then add 3mL of polyethylene glycol zinc phenyl ether reagent, shake well and let stand for 5 minutes, then add 0.6g of cetylpyridinium bromide reagent and slowly shake well to dissolve. Figure 1 As shown, if the color of the solution changes from colorless to blue, it proves the presence of aluminum;

[0103] S3. Quantitative verification of nylon 6 fiber: Take 0.1g of nylon 6 fiber containing anti-counterfeiting elements and use 5mL of mixed acid prepared by sulfuric acid and nitric acid in a volume ratio of 1:2 to fully digest it. The digestion conditions are: heat up from room temperature 25℃ to 125℃ and keep it for 10 minutes, then heat up from 125℃ to 180℃, keep it for 20 minutes, then reduce the temperature to 125℃ and keep it for 3h for acid treatment, and take out the mixed solution after the temperature drops to room temperature and make it volume to 10mL. Then, use inductively coupled plasma spectrometer to perform elemental quantitative analysis on the digestion solution to determine the content and relative proportion of calcium, aluminum, strontium and zinc elements.

[0104] Comparative Example 2

[0105] This comparative example provides a method for preparing nylon 66 fiber, comprising the following steps:

[0106] S1. Preparation of nylon 66 fiber: drying nylon 6 glossy chips at 102°C for at least 8h to remove moisture, then setting the melting temperature of the screw extruder to 260°C, feeding the dried nylon 6 glossy chips into a metering pump and a screw extruder for melting, and spinning the melt through a component to form a tow, and then subjecting the tow to slow cooling, monomer suction, side-blowing cooling, bundling and oiling, secondary cooling in a tunnel, stretching and shaping, and finally winding to obtain nylon 66 fiber;

[0107] S2. Qualitative verification of nylon 66 fiber:

[0108] (i) Dissolve 0.1 g of nylon 66 fiber in 1 mL of sulfuric acid solution, adjust the pH of the solution to between 6 and 8, and drop the o-cresolphthalein copper complex solution into the solution. Figure 1 As shown, if the color of the solution changes from colorless to purple, it proves the presence of calcium;

[0109] (ii) Dissolve 0.1g of nylon 66 fiber in 1mL of sulfuric acid solution, adjust the solution pH to between 6 and 7, take 10mL of the solution and add it to a clean colorimetric tube, add 1mL of chrome azuro blue S, shake well and let stand for 5 minutes, then add 3mL of polyethylene glycol zinc phenyl ether reagent, shake well and let stand for 5 minutes, then add 0.6g of cetylpyridinium bromide reagent and slowly shake well to dissolve. Figure 1 As shown, if the color of the solution changes from colorless to blue, it proves the presence of aluminum;

[0110] S3. Quantitative verification of nylon 66 fiber: Take 0.1g of nylon 66 fiber containing anti-counterfeiting elements and use 5mL of mixed acid prepared by sulfuric acid and nitric acid in a volume ratio of 1:2 to fully digest it. The digestion conditions are: heat up from room temperature 25℃ to 125℃ and keep it for 10 minutes, then heat up from 125℃ to 180℃, keep it for 20 minutes, then lower the temperature to 125℃ and keep it for 3h for acid treatment, and take out the mixed solution after the temperature drops to room temperature and make it up to 10mL. Then use inductively coupled plasma spectrometer to perform elemental quantitative analysis on the digestion solution to determine the content and relative proportion of calcium, aluminum, strontium and zinc elements.

[0111] Performance Testing

[0112] The samples of Examples 1, 4, 7, 10 and Comparative Examples 1 and 2 were selected to perform nylon fiber quality test, element qualitative verification test and element quantitative verification test. The nylon fiber quality test results are shown in Table 1.

[0113] Table 1 Fiber quality test of nylon 6 fiber and nylon 66 fiber

[0114]

[0115] The samples tested were all POY (pre-oriented yarn), with specifications of 85D / 24F and 52D / 34F, with a breaking strength between 3.63 and 4.56 cN / dtex, and a breaking elongation between 62.33 and 76.13%. The results showed that the various indicators of nylon 6 anti-counterfeiting fiber and nylon 66 anti-counterfeiting fiber were not significantly different from those of the corresponding conventional nylon fiber in the comparative example; the anti-counterfeiting method used would not have a negative impact on the quality of nylon fiber products.

[0116] The results of element qualitative verification test are shown in Table 2.

[0117] Table 2 Qualitative element verification test of nylon 6 fiber and nylon 66 fiber

[0118]

[0119]

[0120] The results show that: the samples of all embodiments can identify the corresponding anti-counterfeiting elements, while the anti-counterfeiting element detection results of the samples of the control group are negative; the element qualitative authentication method used can quickly and accurately identify whether the nylon fiber contains the corresponding metal elements, and can realize the rapid judgment of the authenticity of the nylon fiber.

[0121] The results of the element quantitative verification test are shown in Table 3.

[0122] Table 3 Quantitative element verification test of nylon 6 fiber and nylon 66 fiber

[0123]

[0124]

[0125] The results show that the experimental results of different metal content ratios in the examples are very close to the theoretical results, and no corresponding elements are detected in the comparative examples; the detection results of the quantitative verification method used are accurate and reliable.

Claims

1. A "dual-channel" anti-counterfeiting method for nylon fiber, characterized in that: The steps include: S1. Prepare nylon fiber containing anti-counterfeiting elements; the anti-counterfeiting elements are composed of calcium and one of zinc, aluminum and strontium, or aluminum and one of strontium and zinc, and the two elements of the anti-counterfeiting elements have any mass ratio; S2. using an anti-counterfeiting element detection reagent to conduct a qualitative analysis of the presence of the anti-counterfeiting element; S3. The nylon fiber containing the anti-counterfeiting element is fully digested with a mixed acid composed of nitric acid and sulfuric acid, and the obtained digestion solution is subjected to element quantitative analysis by an inductively coupled plasma spectrometer to determine the content and relative proportion of the anti-counterfeiting element in the nylon fiber containing the anti-counterfeiting element.

2. A "dual channel" anti-counterfeiting method for nylon fiber according to claim 1, characterized in that: The nylon fiber described in step S1 uses nylon shiny slices, dispersants and tracers as raw materials; the nylon shiny slices are one of nylon 6 shiny slices and nylon 66 shiny slices; the dispersant is a polyether ester dispersant or an amide dispersant; the tracer component is composed of a combination of calcium carbonate and any one of zinc oxide, strontium oxide, and aluminum oxide inorganic metal compounds, or a combination of aluminum oxide and any one of strontium oxide and zinc oxide inorganic metal compounds, and the two inorganic metal compounds constituting the tracer have an arbitrary mass ratio.

3. A "dual channel" anti-counterfeiting method for nylon fiber according to claim 2, characterized in that: The specific steps of preparing the nylon fiber containing the anti-counterfeiting element in step S1 are: (i) Preparation of nylon tracer masterbatch: 89-94 parts of nylon glossy chips, 1 part of dispersant and 5-10 parts of tracer are mixed, and then the mixed materials are added to a screw extruder for melting to form a melt material strip, and the temperature of the screw extruder is 240-270° C.; the formed melt material strip is plasticized by water cooling and pelletized to obtain a nylon tracer masterbatch; (ii) Preparation of nylon fiber containing anti-counterfeiting elements: The obtained nylon tracer masterbatch and nylon glossy chips are dried and dehydrated, and the dried tracer masterbatch and nylon glossy chips are put into a metering pump and a screw extruder for melting, and the temperature of the screw extruder is 260-290°C; the melt is spun through the assembly to form a filament bundle, and then slowly cooled, monomer suction, side blowing cooling, bundling oiling, secondary cooling in the tunnel, stretching and shaping, and finally wound to obtain the nylon fiber containing the anti-counterfeiting element.

4. A "dual channel" anti-counterfeiting method for nylon fiber according to claim 1, characterized in that: The anti-counterfeiting element detection reagent in step S2 is one of a calcium element detection reagent and an aluminum element detection reagent.

5. A "dual channel" anti-counterfeiting method for nylon fiber according to claim 4, characterized in that: The specific steps of using the anti-counterfeiting element detection reagent to perform qualitative analysis on the presence of the anti-counterfeiting element in step S2 are as follows: When the security element is composed of a combination of calcium and one of the elements zinc, aluminum, and strontium: Dissolve the nylon fiber containing the anti-counterfeiting element in a sulfuric acid solution, adjust the solution pH to between 6 and 8, add a calcium detection reagent to the solution, and after it is fully dissolved, if the calcium color reaction is positive, it proves the presence of the anti-counterfeiting element. When the security element is composed of a combination of aluminum and one of the elements strontium, zinc, and calcium: Dissolve the nylon fiber containing the anti-counterfeiting element in sulfuric acid solution, adjust the solution pH to between 6 and 7, add aluminum detection reagent to the solution, and after it is fully dissolved, if the aluminum color reaction is positive, it proves the presence of the anti-counterfeiting element.

6. A "dual channel" anti-counterfeiting method for nylon fiber according to claim 5, characterized in that: The component of the calcium detection reagent is o-cresolphthalein complexed copper, and the calcium detection concentration range is 0.02 to 2 mg / L; the positive calcium color reaction means that the solution changes from colorless to purple; the aluminum detection reagent is composed of chrome azuro blue S, polyethylene glycol zinc phenyl ether, and cetylpyridinium bromide, and the aluminum detection concentration range is 0 to 2 mg / L; the positive aluminum color reaction means that the solution changes from colorless to blue.

7. The nylon fiber "dual channel" anti-counterfeiting method described in claim 1 is applied to the anti-counterfeiting of nylon 6 fiber and nylon 66 fiber.

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