Laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material and preparation method thereof

Abstract

The present invention provides a laser-markable, light-colored and colorful, high-performance organophosphorus flame-retardant polyamide composite material. The composite material comprises the following components: polyamide, modified glass fiber, an organophosphorus flame retardant, modified titanium dioxide, a laser marking aid, and an additive. The modified glass fiber is obtained by reacting glass fiber, a silane coupling agent, and double-bond-terminated polyamide ester; and the modified titanium dioxide is obtained by reacting titanium dioxide and trihydroxyethane. The modified glass fiber of the present invention introduces groups such as polyamide ester and aromatic groups into the glass fiber, thereby enhancing its compatibility with organic components and preventing the adverse effects of glass fiber aggregation on product performance. Furthermore, the modified titanium dioxide grafts organic groups containing a large number of hydroxyl groups onto the titanium dioxide, preventing titanium dioxide from agglomerating and enabling uniform dispersion of the titanium dioxide and the laser marking aid encapsulating the titanium dioxide. The modified titanium dioxide also enhances the bonding strength with other components through intermolecular forces, thereby improving product performance.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and mainly relates to a laser-markable, light-colored and colorful, high-performance organic phosphorus flame-retardant polyamide composite material and a preparation method thereof. Background Art

[0002] Laser-markable, light-colored, and colorful high-performance organophosphorus flame-retardant polyamide composites are polymer materials with specific functions and properties. Their main components include a polyamide matrix, an organophosphorus flame retardant, and laser marking additives. These laser-markable, light-colored, and colorful high-performance organophosphorus flame-retardant polyamide composites generally use polyamide as the matrix material. Polyamide, also commonly known as nylon, is an important class of polymer materials with excellent mechanical properties, wear resistance, chemical resistance, and thermal stability. These provide the fundamental physical and mechanical properties of the composite material and serve as the foundation for the other components to function. Organophosphorus flame retardants are key functional additives in composites, exhibiting excellent flame retardancy. Through various mechanisms of action, including vapor-phase and condensed-phase flame retardancy, they effectively inhibit combustion, reduce flammability and burning rate, and improve fire safety. Common organophosphorus flame retardants include phosphates, phosphonates, and phosphites. Laser marking additives enable the composite material to achieve laser marking capabilities. These additives undergo specific physical or chemical changes under laser irradiation, resulting in noticeable marking effects such as color changes and surface morphology changes. Laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite materials have good comprehensive properties and are widely used in many fields such as electronics, automobiles, aerospace, etc.

[0003] However, laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composites also have some disadvantages, such as: (1) ordinary laser marking additives can easily cause organophosphorus flame-retardant polyamide to discolor; (2) uneven dispersion of glass fibers has a negative impact on the mechanical properties of polyamide materials; (3) agglomerated titanium dioxide has a negative impact on the mechanical properties of glass fiber reinforced polyamide materials.

[0004] Therefore, there is an urgent need to develop a new type of laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material to solve the current problems. Summary of the Invention

[0005] The present invention provides a laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material and a preparation method thereof. By preparing modified glass fiber and modified titanium dioxide to improve the compatibility of each component, the present invention can effectively solve the problems existing in existing products, such as common laser marking additives easily causing discoloration of organophosphorus flame-retardant polyamide, uneven dispersion of glass fiber having a negative impact on the mechanical properties of polyamide materials, and agglomerated titanium dioxide having a negative impact on the mechanical properties of glass fiber-reinforced polyamide materials.

[0006] One object of the present invention is to provide a laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material, wherein the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material comprises the following components in mass fraction:

[0007]

[0008] Wherein, the modified glass fiber is obtained by reacting glass fiber, silane coupling agent and double-bond terminated polyamide ester;

[0009] The modified titanium dioxide is obtained by reacting titanium dioxide and trihydroxyethane.

[0010] Furthermore, the silane coupling agent is a silane coupling agent containing a double bond.

[0011] Furthermore, the organophosphorus flame retardant is a diethyl aluminum hypophosphite composite flame retardant.

[0012] Furthermore, the auxiliary agent is selected from one or more of lubricants, antioxidants, weathering agents, and pigments.

[0013] Furthermore, the laser marking auxiliary agent is titanium dioxide coated zinc sulfide.

[0014] Another object of the present invention is to provide a method for preparing the above-mentioned laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material, the method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material comprising the following steps:

[0015] S1, mixing glass fiber and nitric acid and heating to obtain activated glass fiber, then mixing and heating with a silane coupling agent to react to obtain an intermediate product, and finally mixing and heating with a double-bond terminated polyamide ester and an initiator to react to obtain a modified glass fiber;

[0016] S2, mixing titanium dioxide and trihydroxyethane, and drying to obtain modified titanium dioxide;

[0017] S3. Blend the polyamide, the modified glass fiber, the organophosphorus flame retardant, the modified titanium dioxide, the laser marking aid, and the additives, add them into a twin-screw extruder, and melt-extrude and granulate at 200-280° C. to obtain the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material.

[0018] Furthermore, in step S1, the mass ratio of the activated glass fiber to the silane coupling agent is (3-10):(2-10), and the mass ratio of the intermediate product to the double-bond terminated polyamide ester is (3-10):(15-50).

[0019] Furthermore, in step S1, the temperature of the blending heating reaction is 70-90°C, and the temperature of the blending heating and stirring reaction is 50-90°C.

[0020] Furthermore, in step S2, the mass ratio of the titanium dioxide to trihydroxyethane is 100:(0.2-1).

[0021] Furthermore, in step S2, the stirring temperature is 30-40°C.

[0022] The present invention has the following beneficial effects:

[0023] The present invention prepares modified glass fiber through the reaction of glass fiber, a silane coupling agent, and double-bond terminated polyamide ester with a hyperbranched structure. Polyamide ester, aromatic groups and the like are introduced into the glass fiber, thereby enhancing its compatibility with organic components, especially significantly enhancing its compatibility with the main component polyamide, allowing for uniform dispersion, thereby avoiding the adverse effect of glass fiber aggregation on product performance. The introduced polyamide ester chain segments can also be entangled with other components, thereby enhancing the stability of the three-dimensional cross-linked structure and improving the mechanical properties of the product. The present invention also prepares modified titanium dioxide through the reaction of titanium dioxide and trihydroxyethane, wherein the titanium dioxide is grafted with organic groups containing a large number of hydroxyl groups, thereby preventing the titanium dioxide from agglomerating, enabling the titanium dioxide and a laser marking auxiliary agent wrapped around the titanium dioxide to be uniformly dispersed, and also enhancing the bonding strength with other components through intermolecular forces, thereby improving various performances of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The product of Example 1 marked with a laser having a wavelength of 355 nm is shown.

[0025] Figure 2 The product of Example 2 marked with a laser having a wavelength of 355 nm is shown. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical solutions of the present invention, the following examples are given. Unless otherwise stated, the raw materials, reactions and post-processing methods mentioned in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0027] The terms "preferred," "preferably," "more preferred," and the like, used herein, refer to embodiments of the invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

[0028] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties to be obtained by the present invention.

[0029] The following raw materials are used in the embodiments of the present invention:

[0030] PA6, polyamide, molecular weight 15000-20000, purchased from Suzhou Putes Electronic Materials Co., Ltd.;

[0031] Glass fiber, diameter 9-20 μm, purchased from Boligen (Xiamen) Composite Materials Co., Ltd.

[0032] Organic phosphorus flame retardant, a composite flame retardant of diethyl aluminum hypophosphite and melamine polyphosphate with a mass ratio of 2:1, was purchased from Jiangsu Liside New Materials Co., Ltd.

[0033] Titanium dioxide, particle size 100-200 nm, purchased from Dongguan Tuonuo Titanium Industry Co., Ltd.

[0034] The additives included lubricant zinc stearate and pigments in a mass ratio of 1:5, which were purchased from Shandong Shouhua Chemical Co., Ltd.

[0035] Dibenzoyl peroxide, initiator, was purchased from Guangzhou Yuanchuang Chemical Co., Ltd.

[0036] The preparation method of the laser marking auxiliary agent comprises the following steps:

[0037] M1. Dissolve 4 ml of tetraisopropyl titanate in 8 ml of glacial acetic acid, stir for 0.5 h, add 25 ml of distilled water and stir to obtain a hydrated titanium dioxide sol;

[0038] M2. Add 25 g of zinc sulfide to 250 ml of distilled water, then add 20 mg of sodium lauryl sulfate, sonicate for 20 min, and adjust the pH value of the solution to 2.2 with 30 wt % hydrochloric acid to obtain a suspension;

[0039] M3. At 30°C, slowly add hydrated titanium dioxide sol to the suspension and stir for 4 hours. After the reaction stops, separate, wash, dry at 100°C for 12 hours, and calcine at 500°C for 2 hours to obtain zinc sulfide with a titanium dioxide film coated on the surface, which is a laser marking auxiliary agent.

[0040] The preparation method of double-bond terminated polyamide ester comprises the following steps:

[0041] L1, 8.646g of trimellitic anhydride was dissolved in 40mL of DMAc, and 5.994g of diisopropanolamine was dissolved in 40mL of DMAc, and then the two were mixed and stirred at room temperature for 3h to obtain a polymerized monomer;

[0042] L2, add 30mL toluene, 0.746g triethanolamine, and 0.054g p-toluenesulfonic acid to the polymerization monomer, heat to 130°C, condense and reflux for 24h, separate, reduce pressure, distill, and purify to obtain a hydroxyl-terminated hyperbranched polymer;

[0043] L3. Add 40 ml of N,N-dimethylformamide and 5.165 g of methyl acrylate to the terminal hydroxyl hyperbranched polymer, then repeatedly evacuate and pass nitrogen to remove air, add 0.5% of the total mass of the reactants as an initiator, sodium p-toluenesulfonate, keep the temperature at 80°C for 8 hours, then remove the solvent and vacuum dry to obtain a double-bond terminated polyamide ester.

[0044] The structure of the double-bond terminated polyamide ester is:

[0045]

[0046] Wherein, m and n are both positive integers.

[0047] Example 1

[0048] A laser-markable, light-colored and colorful high-performance organic phosphorus flame-retardant polyamide composite material comprises the following components in mass fractions:

[0049]

[0050]

[0051] The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material comprises the following steps:

[0052] S1. Heat the glass fiber to 500°C and keep it for 3 hours. Then, blend the glass fiber and 65wt% nitric acid at a mass ratio of 4:45, heat it to 70°C and keep it for 5 hours, wash it with a mixed solution of deionized water and anhydrous ethanol (volume ratio of 1:1) until it is neutral and dry it. Blend the dried glass fiber, deionized water and anhydrous ethanol at a mass ratio of 4:50:5, ultrasonicate it for 30 minutes and dry it to obtain activated glass fiber. Blend the activated glass fiber and KH-570 at a mass ratio of 4:3. The pH value was adjusted to 5 by dropwise addition of glacial acetic acid, ultrasonication was performed for 30 minutes, the mixture was heated to 80° C. and stirred for 1 hour, and the mixture was centrifuged, washed, and dried to obtain an intermediate product. The intermediate product, double-bond terminated polyamide ester, and anhydrous ethanol were blended in a mass ratio of 4:20:250, and stirred for 10 minutes. Dibenzoyl peroxide (the mass ratio of the intermediate product to dibenzoyl peroxide was 4:0.5) was added, and the mixture was condensed and refluxed, heated to 50° C. and stirred for 30 minutes, and heated to 85° C. for reaction for 6 hours. The mixture was centrifuged and dried to obtain a modified glass fiber.

[0053] S2. Titanium dioxide, trihydroxyethane, and deionized water were mixed at a mass ratio of 100:0.5:250 at 40° C. and stirred for 30 min, dried at 120° C. for 24 h, and crushed to obtain modified titanium dioxide;

[0054] S3. According to the above mass fractions, the polyamide, the modified glass fiber, the organophosphorus flame retardant, the modified titanium dioxide, the laser marking auxiliary agent, and the auxiliary agent are blended and added into a twin-screw extruder for melt extrusion and granulation (feeding temperature 200°C, melting temperature 220°C, extrusion temperature 220°C) to obtain the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material.

[0055] Figure 1 The product of Example 1 marked with a laser having a wavelength of 355 nm is shown.

[0056] from Figure 1 As you can see, the product is white, the logo is clear, and the color is black.

[0057] Example 2

[0058] A laser-markable, light-colored and colorful high-performance organic phosphorus flame-retardant polyamide composite material comprises the following components in mass fractions:

[0059]

[0060] The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material comprises the following steps:

[0061] S1. Heat the glass fiber to 500°C and keep it warm for 3 hours. Then, blend the glass fiber and 65wt% nitric acid at a mass ratio of 4:45, heat it to 75°C and keep it warm for 5 hours, wash it with a mixed solution of deionized water and anhydrous ethanol (volume ratio of 1:1) until it is neutral and dry it. Blend the dried glass fiber, deionized water and anhydrous ethanol at a mass ratio of 4:50:5, ultrasonicate it for 30 minutes and dry it to obtain activated glass fiber. Blend the activated glass fiber and KH-570 at a mass ratio of 4:3. The pH value was adjusted to 5 by dropwise addition of glacial acetic acid, ultrasonication was performed for 30 minutes, the mixture was heated to 80° C. and stirred for 1 hour, and the mixture was centrifuged, washed, and dried to obtain an intermediate product. The intermediate product, double-bond terminated polyamide ester, and anhydrous ethanol were blended in a mass ratio of 4:20:250, and stirred for 10 minutes. Dibenzoyl peroxide (the mass ratio of the intermediate product to dibenzoyl peroxide was 4:0.5) was added, and the mixture was condensed and refluxed, heated to 50° C. and stirred for 30 minutes, and heated to 85° C. for reaction for 6 hours. The mixture was centrifuged and dried to obtain a modified glass fiber.

[0062] S2. Titanium dioxide, trihydroxyethane, and deionized water were mixed at a mass ratio of 100:0.5:250 at 40° C. and stirred for 30 min, dried at 125° C. for 24 h, and crushed to obtain modified titanium dioxide;

[0063] S3. According to the above mass fractions, the polyamide, the modified glass fiber, the organophosphorus flame retardant, the modified titanium dioxide, the laser marking auxiliary agent, and the auxiliary agent are blended and added into a twin-screw extruder for melt extrusion and granulation (feeding temperature 200°C, melting temperature 220°C, extrusion temperature 220°C) to obtain the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material.

[0064] Figure 2 The product of Example 2 marked with a laser having a wavelength of 355 nm is shown.

[0065] from Figure 2 As you can see, the product is orange, the logo is clear, and the color is white.

[0066] Example 3

[0067] A laser-markable, light-colored and colorful high-performance organic phosphorus flame-retardant polyamide composite material comprises the following components in mass fractions:

[0068]

[0069] The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material comprises the following steps:

[0070] S1. Heat the glass fiber to 500°C and keep it for 3 hours. Then, blend the glass fiber and 65wt% nitric acid at a mass ratio of 4:45, heat it to 70°C and keep it for 5 hours, wash it with a mixed solution of deionized water and anhydrous ethanol (volume ratio of 1:1) until it is neutral and dry it. Blend the dried glass fiber, deionized water and anhydrous ethanol at a mass ratio of 4:50:5, ultrasonicate it for 30 minutes and dry it to obtain activated glass fiber. Blend the activated glass fiber and KH-570 at a mass ratio of 4:5. The pH value was adjusted to 5 by dropwise addition of glacial acetic acid, ultrasonication was performed for 30 minutes, the mixture was heated to 80° C. and stirred for 1 hour, centrifuged, washed, and dried to obtain an intermediate product, the intermediate product, double-bond terminated polyamide ester, and anhydrous ethanol were blended in a mass ratio of 4:20:250, stirred for 10 minutes, and dibenzoyl peroxide was added (the mass ratio of the intermediate product to dibenzoyl peroxide was 4:0.5), condensed and refluxed, heated to 50° C. and stirred for 30 minutes, heated to 90° C. and reacted for 6 hours, centrifuged, and dried to obtain a modified glass fiber;

[0071] S2. Titanium dioxide, trihydroxyethane, and deionized water were mixed at a mass ratio of 100:0.6:250 at 40° C. and stirred for 30 min, dried at 120° C. for 24 h, and crushed to obtain modified titanium dioxide;

[0072] S3. According to the above mass fractions, the polyamide, the modified glass fiber, the organophosphorus flame retardant, the modified titanium dioxide, the laser marking auxiliary agent, and the auxiliary agent are blended and added into a twin-screw extruder for melt extrusion and granulation (feeding temperature 200°C, melting temperature 220°C, extrusion temperature 220°C) to obtain the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material.

[0073] Comparative Example 1

[0074] The difference between Comparative Example 1 and Example 1 is that the modified glass fiber is replaced by the intermediate product, and the other preparation methods and ingredients are the same as those of Example 1.

[0075] Comparative Example 2

[0076] The difference between Comparative Example 2 and Example 1 is that the modified titanium dioxide is replaced by titanium dioxide treated with KH560, and S2 is modified into the following steps:

[0077] S2. Titanium dioxide and 95 wt% ethanol were blended in a mass ratio of 5:95, ultrasonicated for 30 min, KH560 was added (the mass ratio of titanium dioxide and KH560 was 100:1), the pH was adjusted to neutral, stirred evenly, and heated to 80° C. for 2 h to obtain titanium dioxide treated with KH560;

[0078] Other preparation methods and ingredients are the same as those in Example 1.

[0079] Test Example 1

[0080] The mechanical properties, flame retardant properties and laser marking effects of Examples 1-3 and Comparative Examples 1-2 were tested.

[0081] Test Method

[0082] The mechanical properties and flame retardant properties are tested with reference to ISO 527, ISO 178, ISO 180 and UL-94.

[0083] Table 1 shows the results of the test.

[0084] Table 1 Test results and laser marking effects of Examples 1-3 and Comparative Examples 1-2

[0085]

[0086]

[0087] As can be seen from Table 1, all the properties of Examples 1-3 are better than those of Comparative Examples 1-2.

[0088] The various properties of Examples 1-3 are better than those of Comparative Example 1. The reason is that Comparative Example 1 replaces the modified glass fiber with glass fiber without polyamide ester, which reduces the compatibility and synergistic effect between the components, making it difficult to evenly disperse the glass fiber and significantly reducing the material strength.

[0089] The various properties of Examples 1-3 are better than those of Comparative Example 2. The reason is that in Comparative Example 2, the modified titanium dioxide is replaced with titanium dioxide treated with KH560, which reduces the compatibility of titanium dioxide, laser marking additives and other components, makes them easily agglomerated, and reduces the performance.

[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0091] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material, characterized in that: The laser-markable, light-colored and colorful high-performance organic phosphorus flame-retardant polyamide composite material comprises the following components in mass fraction: Polyamide 25-70% Modified glass fiber 10-45% Organophosphorus flame retardant 15-20% Modified titanium dioxide 0.5-5% Laser marking additives 0.5-3% Other additives 0.5-3%; Wherein, the modified glass fiber is obtained by reacting glass fiber, silane coupling agent and double-bond terminated polyamide ester; The modified titanium dioxide is obtained by reacting titanium dioxide and trihydroxyethane; The silane coupling agent is a silane coupling agent containing a double bond; The laser marking auxiliary agent is titanium dioxide coated zinc sulfide.

2. The laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material according to claim 1, characterized in that: The organic phosphorus flame retardant is a diethyl aluminum hypophosphite composite flame retardant.

3. The laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material according to claim 1, characterized in that: The other additives are selected from one or more of lubricants, antioxidants, weathering additives, and pigments.

4. The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material according to any one of claims 1 to 3, characterized in that: The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material comprises the following steps: S1, mixing glass fiber and nitric acid and heating to obtain activated glass fiber, then mixing and heating with a silane coupling agent to react to obtain an intermediate product, and finally mixing and heating with a double-bond terminated polyamide ester and an initiator to react to obtain a modified glass fiber; S2, mixing titanium dioxide and trihydroxyethane, and drying to obtain modified titanium dioxide; S3. Blend the polyamide, the modified glass fiber, the organophosphorus flame retardant, the modified titanium dioxide, the laser marking additive, and other additives, add the mixture into a twin-screw extruder, and melt-extrude and granulate at 200-280° C. to obtain the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material.

5. The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material according to claim 4, characterized in that: In step S1, the mass ratio of activated glass fiber to silane coupling agent is (3-10):(2-10), and the mass ratio of intermediate product to double-bond terminated polyamide ester is (3-10):(15-50).

6. The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material according to claim 4, characterized in that: In step S1, the temperature of the blending heating reaction is 70-90°C, and the temperature of the blending heating and stirring reaction is 50-90°C.

7. The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material according to claim 4, characterized in that: In step S2, the mass ratio of the titanium dioxide to trihydroxyethane is 100:(0.2-1).

8. The method for preparing the laser-markable, light-colored and colorful high-performance organophosphorus flame-retardant polyamide composite material according to claim 4, characterized in that: In step S2, the stirring temperature is 30-40°C.

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