A laser-markable nylon material and its preparation method

Abstract

This invention discloses a laser-markable nylon material and its preparation method. The laser-markable nylon material comprises the following raw material components in parts by weight: 93-99.5 parts nylon resin; 0.5-5.0 parts composite laser-sensitive system; 0.1-1.0 parts antioxidant; and 0.1-1.0 parts lubricant. Research shows that the laser-markable nylon material of this invention overcomes the problem of yellowing in laser-markable nylon materials prepared by adding carbon black in existing technologies. Furthermore, the laser-markable nylon material obtained by adding the composite laser-sensitive system composed of the core-shell structure inorganic laser-sensitive particles and laser marking aids of this invention exhibits a significantly higher marking contrast than laser-markable nylon materials prepared using conventional laser-sensitive additives. Simultaneously, samples prepared using the laser-markable nylon material of this invention have a minimum clear linewidth consistent with the laser spot size, achieving micron-level high-precision marking.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a nylon material that can be laser-marked and its preparation method. Background Technology

[0002] Laser marking technology (also known as laser engraving) is a marking method that uses a high-energy laser beam to irradiate the surface of a material, triggering physical or chemical changes to create visible text, graphics, barcodes, or QR codes. Compared with traditional inkjet printing and mechanical etching, laser marking has significant advantages such as non-contact processing, permanent marking, high precision, environmental friendliness, and high degree of automation, and has been widely used in automotive parts, electronics, medical devices, anti-counterfeiting and traceability, and other fields.

[0003] Nylon 6 (PA6), one of the five major engineering plastics, possesses excellent properties such as high mechanical strength, good toughness, wear resistance, and chemical corrosion resistance, and is widely used in automobiles, general machinery, electronics, electrical appliances, and home appliances. In these applications, product surfaces often require markings such as trademarks, model numbers, specifications, and QR codes. With the increasing demand for product traceability and anti-counterfeiting, achieving high-contrast, high-definition light-colored markings (commonly known as "black engraving on white") or dark-colored markings ("white engraving on black") on the surface of black nylon products has become an important industry requirement.

[0004] However, pure nylon materials have weak absorption of near-infrared laser light at a wavelength of 1064 nm, making it difficult to directly induce clear markings through laser. Therefore, it is necessary to add laser-sensitive additives to improve the laser response performance of nylon materials. Carbon black is the most commonly used and lowest-cost black colorant, and also a highly efficient laser absorber. By adding carbon black to the nylon matrix, black nylon materials can be prepared and laser-marked. Studies have shown that the marking effect is optimal when the carbon black content is between 0.1% and 0.2%. However, the carbon black system has inherent defects: when the carbon black content is too low, the laser energy absorption is insufficient, and the marking is not obvious; when the carbon black content is too high (>0.3%), the excessive absorption of laser energy by the carbon black leads to excessively high local temperatures, causing over-carbonization of the nylon matrix, resulting in yellowing and darkening of the marked area and decreased contrast. In addition, the particle size of carbon black has a significant impact on dispersibility and marking effect; particles that are too small tend to agglomerate, while particles that are too large result in sparse absorption points, both of which are detrimental to obtaining uniform and clear markings. Summary of the Invention

[0005] In order to overcome at least one technical problem existing in the prior art, the present invention provides a nylon material that can be laser-engraved and marked and a method for preparing the same.

[0006] The technical solution of the present invention is as follows:

[0007] This invention first provides a nylon material that can be laser-engraved and marked, which comprises the following raw material components in parts by weight:

[0008] 93-99.5 parts nylon resin; 0.5-5.0 parts composite laser-sensitive system; 0.1-1.0 parts antioxidant; 0.1-1.0 parts lubricant.

[0009] Preferably, the nylon resin is selected from nylon 6.

[0010] Preferably, the composite laser-sensitive system comprises core-shell structured inorganic laser-sensitive particles and organic laser labeling aids.

[0011] Preferably, the weight ratio of the core-shell structured inorganic laser-sensitive particles to the laser labeling agent is 1:0.2-5.

[0012] Preferably, the weight ratio of the core-shell structured inorganic laser-sensitive particles to the laser labeling agent is 1:2-4.

[0013] Most preferably, the weight ratio of the core-shell structured inorganic laser-sensitive particles to the laser labeling agent is 1:3.

[0014] Preferably, the core-shell structured inorganic laser-sensitive particles are prepared by the following method:

[0015] (1) Take the inner core material and add it to water. After dispersing it evenly, a dispersion is obtained.

[0016] (2) Add tin tetrachloride pentahydrate and sodium hydroxide to the dispersion and react at 60-80℃ for 2-4h; after the reaction is completed, separate the solid and vacuum dry the solid at 80-120℃ to obtain core-shell structured particles.

[0017] (3) Disperse the core-shell structured particles in an organic solvent, then add polymer reaction monomers and initiators to carry out a polymerization reaction; after the reaction is completed, centrifuge to separate the solid, and then vacuum dry it at 60~80℃ to obtain the core-shell structured inorganic laser sensitive particles.

[0018] Preferably, the inner core material in step (1) is antimony trioxide.

[0019] Preferably, in step (1), the weight ratio of the inner core material to water is 5-8:100-200.

[0020] Most preferably, in step (1), the weight ratio of the inner core material to water is 6:180.

[0021] Preferably, in step (2), the weight ratio of the dispersion to tin tetrachloride pentahydrate and sodium hydroxide is 100-200:20-40:10-20.

[0022] Most preferably, in step (2), the weight ratio of the dispersion to tin tetrachloride pentahydrate and sodium hydroxide is 180:25:16.

[0023] Preferably, in step (3), the weight ratio of the core-shell structure particles to the organic solvent and the polymer reaction monomer is 1:10-15:3-6.

[0024] Most preferably, in step (3), the weight ratio of the core-shell structure particles to the organic solvent and the polymer reaction monomer is 1:12:4.

[0025] Preferably, the initiator in step (4) is selected from benzoyl peroxide.

[0026] Preferably, the weight of the initiator is 0.1-1% of the weight of the polymer reactant monomer.

[0027] Most preferably, the weight of the initiator is 0.5% of the weight of the polymer reactant monomer.

[0028] Preferably, the polymerization temperature is 90-100℃ and the polymerization time is 4-8h.

[0029] The most preferred method is to use a polymerization temperature of 95°C and a polymerization time of 6 hours.

[0030] Preferably, the organic solvent is selected from ethylbenzene.

[0031] Preferably, the laser marking aid is selected from laser marking masterbatch or laser engraving powder with polyamide as the carrier.

[0032] Preferably, the laser marking masterbatch with polyamide as the carrier is selected from Iriotec® 8212.

[0033] Preferably, the antioxidant is selected from one or more of hindered phenolic antioxidants (such as antioxidant 1010) and phosphite antioxidants (such as antioxidant 168).

[0034] Preferably, the lubricant is selected from one or more of calcium stearate, zinc stearate, and ethylene bis-stearamide.

[0035] The present invention also provides a method for preparing the above-mentioned laser-markable nylon material, which includes the following steps:

[0036] The nylon material that can be laser-engraved and marked is obtained by uniformly mixing nylon resin, composite laser-sensitive system, antioxidant and lubricant, and then melt-extruding it through a twin-screw extruder.

[0037] Beneficial effects: This invention provides a novel nylon material that can be laser-marked; research shows that the nylon material that can be laser-marked obtained by adding the core-shell structured inorganic laser-sensitive particles and laser marking aids of this invention to the composite laser-sensitive system overcomes the problem of yellowing of nylon materials that can be laser-marked by adding carbon black in the prior art.

[0038] Furthermore, the laser-sensitive nylon material obtained by incorporating a composite laser-sensitive system consisting of the core-shell structured inorganic laser-sensitive particles and laser marking additives of this invention into laser-markable nylon material exhibits significantly higher marking contrast than laser-markable nylon materials prepared using conventional laser-sensitive additives. Simultaneously, samples prepared using the laser-markable nylon material of this invention achieve a minimum clear linewidth consistent with the laser spot size, realizing micron-level high-precision marking. Detailed Implementation

[0039] The present invention will be further explained below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the embodiments.

[0040] Example 1: Preparation of laser-markable nylon material

[0041] Raw material composition by weight:

[0042] Nylon 6 97.6 parts; composite laser-sensitive system 2 parts; antioxidant 0.2 parts; lubricant 0.2 parts;

[0043] The antioxidant is antioxidant 1010; the lubricant is calcium stearate;

[0044] The composite laser-sensitive system consists of core-shell structured inorganic laser-sensitive particles in a weight ratio of 1:3 and a laser labeling agent.

[0045] The laser marking agent is selected from Iriotec® 8212;

[0046] The core-shell structured inorganic laser-sensitive particles were prepared by the following method:

[0047] (1) Take the inner core material and add it to water. After dispersing it evenly, a dispersion is obtained. The weight ratio of the inner core material to water is 6:180. The inner core material is antimony trioxide.

[0048] (2) Add tin tetrachloride pentahydrate and sodium hydroxide to the dispersion and react at 70°C for 3 hours. After the reaction is completed, separate the solid and dry it under vacuum at 100°C to obtain core-shell structured particles. The weight ratio of the dispersion to tin tetrachloride pentahydrate and sodium hydroxide is 180:25:16.

[0049] (3) The core-shell structured particles are dispersed in an organic solvent, and then polymer reactive monomers and initiators are added and polymerized at 95°C for 6 hours. After the reaction, the solid is separated by centrifugation and vacuum dried at 70°C to obtain the core-shell structured inorganic laser sensitive particles. The weight ratio of the core-shell structured particles to the organic solvent and polymer reactive monomers is 1:12:4. The initiator is selected from benzoyl peroxide. The weight of the initiator is 0.5% of the weight of the polymer reactive monomers.

[0050] Preparation method: After the above-mentioned raw materials in parts by weight are mixed evenly, they are melt-extruded through a twin-screw extruder to obtain the laser-markable nylon material.

[0051] Comparative Example 1: Preparation of Nylon Material Capable of Laser Marking

[0052] Raw material composition by weight:

[0053] Nylon 6 99.3 parts; Carbon black 0.3 parts; Antioxidant 0.1 parts; Lubricant 0.1 parts;

[0054] The antioxidant is antioxidant 1010; the lubricant is calcium stearate;

[0055] Preparation method: After the above-mentioned raw materials in parts by weight are mixed evenly, they are melt-extruded through a twin-screw extruder to obtain the laser-markable nylon material.

[0056] Comparative Example 2: Preparation of Nylon Material Capable of Laser Marking

[0057] Raw material composition by weight:

[0058] Nylon 6 98 parts; laser marking agent 2 parts; antioxidant 0.2 parts; lubricant 0.2 parts;

[0059] The antioxidant is antioxidant 1010; the lubricant is calcium stearate;

[0060] The laser marking agent is selected from laser marking agent 433.

[0061] Comparative Example 3: Preparation of Nylon Material Capable of Laser Marking

[0062] Raw material composition by weight:

[0063] Nylon 6 98 parts; core-shell structured inorganic laser-sensitive particles 2 parts; antioxidant 0.2 parts; lubricant 0.2 parts;

[0064] The antioxidant is antioxidant 1010; the lubricant is calcium stearate;

[0065] The preparation method of the core-shell structured inorganic laser-sensitive particles is the same as in Example 1.

[0066] Comparative Example 4: Preparation of Nylon Material Capable of Laser Marking

[0067] Raw material composition by weight:

[0068] Nylon 6 98 parts; laser marking agent 2 parts; antioxidant 0.2 parts; lubricant 0.2 parts;

[0069] The antioxidant is antioxidant 1010; the lubricant is calcium stearate;

[0070] The laser marking agent is selected from Iriotec® 8212.

[0071] The laser-markable nylon materials prepared in Example 1 and Comparative Examples 1-4 were injection molded into test sample strips, and laser marking was performed on the test sample strips. The laser wavelength was 1064 nm, the power was 20 W, the current was 11 A, the linear velocity was 800 mm / s, and the frequency was 40 kHz. After laser marking, the color difference value |ΔL| between the laser-marked area and the unmarked area of ​​each example and comparative example sample was measured using a spectrophotometer. The results are shown in Table 1. The edge sharpness and minimum sharp line width of the marked lines of each sample were observed using a metallographic microscope. The results are shown in Table 2.

[0072] Table 1. Color difference values ​​of laser-markable nylon materials | ΔL | Test results

[0073]

[0074] As can be seen from the experimental results in Table 1, the sample prepared using the laser-markable nylon material of Example 1 has a deep black marking color and clear edges; while the sample prepared using carbon black as an additive in Comparative Example 1 has yellow edges. This indicates that the laser-markable nylon material obtained by adding the core-shell structured inorganic laser-sensitive particles and laser marking aids of this invention to the composite laser-sensitive system overcomes the problem of yellowing in laser-markable nylon materials prepared by adding carbon black in the prior art.

[0075] The experimental results in Table 1 also show that the ΔL of sample 1 is significantly higher than that of samples 2 and 3. This indicates that the laser-markable nylon material obtained by adding a composite laser-sensitive system composed of the core-shell structure inorganic laser-sensitive particles and laser marking additives of this invention to the laser-markable nylon material has a significantly higher marking contrast than the laser-markable nylon material prepared using conventional laser-sensitive additives.

[0076] The experimental results in Table 1 also show that the ΔL of sample 1 is significantly higher than that of samples 4 and 5. This indicates that the core-shell structured inorganic laser-sensitive particles prepared by the novel method of this invention must be used in combination with the laser marking agent Iriotec® 8212 to achieve a significantly higher marking contrast than the laser-markable nylon material prepared using conventional laser-sensitive additives. Adding the core-shell structured inorganic laser-sensitive particles prepared by the novel method of this invention in combination with the laser marking agent Iriotec® 8212 to the laser-markable nylon material of this invention can synergistically improve the marking contrast of the laser-markable nylon material.

[0077] Table 2. Test results of edge sharpness and minimum sharp line width of laser-markable nylon materials

[0078]

[0079] As can be seen from the experimental results in Table 2, the sample prepared using the laser-markable nylon material of Example 1 has a minimum clear line width that is consistent with the laser spot size, achieving micron-level high-precision marking.

[0080] The experimental results in Table 2 also show that the minimum clear linewidth of sample 1 is significantly smaller than that of samples 2 and 3. This indicates that the minimum clear linewidth of the laser-markable nylon material obtained by adding a composite laser-sensitive system composed of the core-shell structure inorganic laser-sensitive particles and laser marking additives of this invention to the laser-markable nylon material is significantly smaller than that of the laser-markable nylon material prepared using conventional laser-sensitive additives.

[0081] The experimental results in Table 2 also show that the minimum clear linewidth of sample 1 is significantly smaller than that of samples 4 and 5. This indicates that the core-shell structured inorganic laser-sensitive particles prepared by the novel method of this invention must be used in combination with the laser marking agent Iriotec® 8212 to achieve a minimum clear linewidth significantly smaller than that of laser-markable nylon materials prepared using conventional laser-sensitive additives. Adding the core-shell structured inorganic laser-sensitive particles prepared by the novel method of this invention in combination with the laser marking agent Iriotec® 8212 to the laser-markable nylon material of this invention can synergistically reduce the minimum clear linewidth of the laser-markable nylon material.

Claims

1. A nylon material capable of laser engraving and marking, characterized in that, The raw material components comprise the following parts by weight: 93-99.5 parts nylon resin; 0.5-5.0 parts composite laser-sensitive system; 0.1-1.0 parts antioxidant; 0.1-1.0 parts lubricant.

2. The laser-markable nylon material according to claim 1, characterized in that, The composite laser-sensitive system comprises core-shell structured inorganic laser-sensitive particles and laser labeling aids.

3. The laser-markable nylon material according to claim 2, characterized in that, The weight ratio of core-shell structured inorganic laser-sensitive particles to organic laser labeling aids is 1:0.2-5.

4. The laser-markable nylon material according to claim 2, characterized in that, The core-shell structured inorganic laser-sensitive particles were prepared by the following method: (1) Take the inner core material and add it to water. After dispersing it evenly, a dispersion is obtained. (2) Add tin tetrachloride pentahydrate and sodium hydroxide to the dispersion and react at 60-80℃ for 2-4h; after the reaction is completed, separate the solid and vacuum dry the solid at 80-120℃ to obtain core-shell structured particles. (3) Disperse the core-shell structured particles in an organic solvent, then add polymer reaction monomers and initiators to carry out a polymerization reaction; after the reaction is completed, centrifuge to separate the solid, and then vacuum dry it at 60~80℃ to obtain the core-shell structured inorganic laser sensitive particles.

5. The laser-markable nylon material according to claim 4, characterized in that, In step (1), the inner core material is antimony trioxide.

6. The laser-markable nylon material according to claim 4, characterized in that, In step (1), the weight ratio of the inner core material to water is 5-8:100-200.

7. The laser-markable nylon material according to claim 4, characterized in that, In step (2), the weight ratio of the dispersion to tin tetrachloride pentahydrate and sodium hydroxide is 100-200:20-40:10-20.

8. The laser-markable nylon material according to claim 4, characterized in that, In step (3), the weight ratio of the core-shell structure particles to the organic solvent and the polymer reaction monomer is 1:10-15:3-6.

9. The laser-markable nylon material according to claim 2, characterized in that, The laser marking agent is selected from laser marking masterbatch or laser engraving powder with polyamide as the carrier.

10. The method for preparing the laser-markable nylon material according to any one of claims 1-9, characterized in that, The process includes the following steps: mixing nylon resin, composite laser-sensitive system, antioxidant and lubricant evenly, and then melting and extruding the mixture through a twin-screw extruder to obtain the laser-markable nylon material.

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