Mca flame retardant nylon material and molded article capable of eliminating surface skin defect of molded article

Abstract

The present application relates to a kind of MCA flame-retardant nylon material and its molded product that can eliminate the surface skin defect of molded product, and the MCA flame-retardant nylon material that can eliminate the surface skin defect of molded product includes the following raw material components by weight parts: 40~70 parts nylon resin, 5~13 parts MCA flame retardant, 10~40 parts reinforcing filler, 0.5~3 parts other auxiliary agent;Wherein, the nylon resin is the compound of nylon resin A and nylon resin B, and the weight percentage of the nylon resin A and the nylon resin B is 20:1~8:1;The nylon resin A is PA6 and / or PA66, and the nylon resin B is long carbon chain nylon with monomer carbon atom number >10.The MCA flame-retardant nylon material of the present application has good mold surface replication ability itself, and when skin piece is injection molded, no external mold temperature controller can be obtained without skin defect good appearance product, which can save energy and reduce consumption, and also can save mold temperature controller purchase cost for plastic product manufacturer and provide corresponding water and electricity cost of mold temperature.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to an MCA flame-retardant nylon material and its molded articles that can eliminate surface texture defects in molded articles. Background Technology

[0002] Halogen-free flame retardant melamine cyanurate (MCA), due to its high nitrogen content, decomposes upon heating to produce non-flammable gases such as NH3, H2O, N2, CO2, and H2NCN. These gases have endothermic, cooling, and diluting effects on flammable gases and oxygen concentrations, making it commonly used as a flame retardant modifier for thermoplastic resins, particularly suitable for flame-retardant nylon systems. Furthermore, because MCA flame retardants are widely available, they offer higher cost-effectiveness compared to traditional bromine-antimony and organophosphorus flame retardants. Therefore, in the low-voltage electrical appliance industry, MCA flame-retardant nylon materials are widely used to manufacture electrical equipment housings, such as miniature circuit breaker (MCB) housings and socket housings.

[0003] Considering both product appearance quality and injection molding efficiency, current plastic MCB housings are not glossy but designed with a textured, matte finish. This textured surface not only avoids the aesthetic drawbacks of glossy surfaces, such as attracting dust or fingerprints, but also improves injection molding performance. For example, it allows less air between the product surface and the mold cavity surface during injection molding, preventing vacuum adhesion and facilitating subsequent demolding; it also improves ejection stability, avoiding shadows caused by sliders or angled ejectors, thus increasing the yield rate of injection molded products. Taking MCB housings as an example, for reasons of production efficiency and processing costs, circuit breaker manufacturers and their subcontractors typically do not use external mold temperature controllers when using MCA flame-retardant nylon for injection molding of MCB housings. If a mold temperature controller is used, its water circuit is directly connected to cooling water to conduct injection molding at a low mold temperature (below 40°C) to shorten the injection molding cycle and increase production capacity. However, as early as 2017, well-known domestic low-voltage electrical appliance manufacturers such as Chint and Delixi reported that when using MCA flame-retardant nylon material to injection mold MCB housings, large areas of inconsistent color, texture, and reflectivity often appeared on the surface of the housings. This was particularly true for the prominently displayed manufacturer logos, which were furthest from the injection gate during injection molding, making them more prone to inconsistent color and texture. After pad printing, obvious delamination occurred, severely affecting the visual appeal of the MCB housings. To address this, Chint and Delixi, together with several MCA flame-retardant nylon material manufacturers, spent considerable time and effort seeking solutions to overcome this defect. The final solution was to increase the mold temperature to over 60°C to ensure the surface quality of the MCB housings. However, for circuit breaker manufacturers and their subcontractors, this solution not only increased the cost of purchasing mold temperature controllers but also increased water and electricity consumption. Most importantly, increasing the mold temperature would correspondingly extend the product injection molding cycle, reducing the production efficiency of the MCB housings. According to statistics from Chint Group, Delixi Group, and their subcontractors, compared to production modes that do not use external mold temperature controllers or control the mold temperature below 40°C, the average production efficiency of injection molding MCB shell parts produced using the above methods is reduced by nearly 15%.

[0004] For five years, eliminating the texture defects in MCB housings made from MCA flame-retardant nylon injection molding has been achieved at the cost of reduced production efficiency due to increased mold temperatures. As modified engineering plastics manufacturers, if they could approach the issue from the perspective of MCB housing materials, and, while ensuring acceptable material costs, design material formulations to eliminate the inconsistent color, texture, and reflectivity defects on the surface of MCB housings produced during injection molding without external mold temperature controllers or at low mold temperatures, this would undoubtedly be highly favored by circuit breaker manufacturers and their subcontractors, and would have significant research and application value. Summary of the Invention

[0005] The purpose of this invention is to address the technical challenge of surface texture defects in injection-molded products made of existing MCA flame-retardant nylon materials, which are difficult to overcome under low mold temperatures or without an external mold temperature controller. This invention provides an MCA flame-retardant nylon material that can eliminate surface texture defects in molded products.

[0006] The above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0007] A flame-retardant nylon MCA material capable of eliminating surface texture defects in molded products, comprising, by weight, the following raw material components: 40-70 parts of nylon resin, 5-13 parts of MCA flame retardant, 10-40 parts of reinforcing filler, and 0.5-3 parts of other additives; wherein the nylon resin is a compound of nylon resin A and nylon resin B, and the weight percentage of nylon resin A to nylon resin B is 20:1 to 8:1; nylon resin A is PA6 and / or PA66, and nylon resin B is a long-chain nylon with a monomer carbon atom number >10.

[0008] In the above technical solution, the nylon resin B is selected from at least one of PA610, PA612, PA1010, PA1012, PA12 or PA1212.

[0009] This invention introduces long-chain nylon into MCA flame-retardant nylon (PA6 or PA66) material. Because the amide bond (-CONH-) density in the long-chain nylon molecular chain is low, its molecular chain can interpenetrate between PA6 or PA66 molecular chains during melt blending, thereby reducing the crystallinity of PA6 or PA66 molecular chains and slowing down the overall crystallization rate of the material. This allows the melt to have enough time to replicate the texture of the mold during the injection molding process (especially at the molding end), achieving a consistent texture replication effect.

[0010] In the above technical solution, the relative viscosity of the nylon resin A is 2.0~2.4.

[0011] In the above technical solution, the reinforcing filler is a compound of glass fiber and powder reinforcing filler.

[0012] Preferably, the glass fiber is a glass fiber surface-treated with a coupling agent, and more preferably a short-cut glass fiber or a long glass fiber with a diameter of 7-15 μm surface-treated with a silane coupling agent.

[0013] In the above technical solution, the powder reinforcing filler is selected from one or more of the following: wollastonite, zeolite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, asbestos, aluminosilicate, alumina, silicon dioxide, magnesium oxide, zirconium oxide, titanium dioxide, iron oxide, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass beads, glass powder, ceramic beads, ground glass fiber, boron nitride, or silicon carbide.

[0014] As a preferred technical solution, the MCA flame-retardant nylon material comprises the following raw material components by weight: 35-65 parts nylon resin A, 2-6 parts nylon resin B, 6-12 parts MCA flame retardant, 5-20 parts glass fiber, 10-30 parts powder reinforcing filler, and 0.5-3 parts other additives.

[0015] In the above technical solution, the powder reinforcing filler is selected from one or more of wollastonite, kaolin, mica, talc, titanium dioxide, calcium carbonate, montmorillonite, glass beads, glass powder or ground glass fiber.

[0016] A more preferred technical solution, by weight, comprises the following raw material components: 35-60 parts nylon resin A, 3-5 parts nylon resin B, 6-12 parts MCA flame retardant, 5-10 parts glass fiber, 15-30 parts glass powder, and 0.5-3 parts other additives; wherein nylon resin A is PA6, and nylon resin B is one or a mixture of PA12 and PA1012.

[0017] In the above technical solution, the other additives are selected from one or more of antioxidants, heat stabilizers, lubricants, release agents, pigment additives, and impact modifiers.

[0018] Another object of the present invention is to provide the application of the above-mentioned MCA flame-retardant nylon material in the preparation of plastic molded articles.

[0019] In a specific application, this invention specifically protects a plastic molded article, which is obtained by injection molding from the above-mentioned MCA flame-retardant nylon material.

[0020] More specifically, the plastic molded product protected by this invention is a low-voltage electrical appliance housing; after pad printing marking is applied to the surface of the low-voltage electrical appliance housing, there is no problem of skin texture delamination.

[0021] The beneficial effects of this invention are as follows: This invention introduces a specific amount of long-chain nylon with more than 10 monomer carbon atoms into MCA flame-retardant nylon materials with PA6 and / or PA66 as the resin matrix. By compounding the long-chain nylon resin with PA6 and / or PA66, the MCA flame-retardant nylon material is endowed with good ability to replicate the texture of injection molds. This allows it to obtain good appearance parts without texture defects without the need for an external mold temperature controller when injection molding textured parts. This not only saves energy and reduces consumption, but also saves plastic parts manufacturers the cost of purchasing mold temperature controllers and the water and electricity costs for providing the corresponding mold temperature. At the same time, it can ensure the appearance quality of the parts without sacrificing the production efficiency. Attached Figure Description

[0022] Figure 1 This is a real-world image of the surface of the MCB housing made of MCA flame-retardant nylon obtained in Example 1.

[0023] Figure 2 The image shows the surface of the MCB shell part made of MCA flame-retardant nylon obtained from Comparative Example 1.

[0024] Figure 3 The image shows the surface of the MCB housing after the markings have been applied, obtained from Comparative Example 1 and Example 2.

[0025] Figure 4 This is a real-world image of the surface of the MCB housing component molded from MCA flame-retardant nylon obtained in Example 2.

[0026] Figure 5 This is a real-world image of the surface of the MCB housing made of MCA flame-retardant nylon obtained in Example 3.

[0027] Figure 6 The image shows the surface of the MCB shell part made of MCA flame-retardant nylon obtained from Comparative Example 2.

[0028] Figure 7 This is a real-world image of the surface of the MCB housing made of MCA flame-retardant nylon obtained in Example 4.

[0029] Figure 8 The image shows the surface of the MCB shell part made of MCA flame-retardant nylon obtained from Comparative Example 3.

[0030] Figure 9 This is a real-world image of the surface of the MCB housing made of MCA flame-retardant nylon obtained in Example 5.

[0031] Figure 10 This is a real-world image of the surface of the MCB housing made of MCA flame-retardant nylon obtained in Example 6.

[0032] Figure 11 The image shows the surface of the MCB shell part made of MCA flame-retardant nylon obtained from Comparative Example 4.

[0033] Figure 12 This is a real-world image of the surface of the MCB housing part made of MCA flame-retardant nylon obtained in Example 7.

[0034] Figure 13 This is a real-world image of the surface of the MCB housing made of MCA flame-retardant nylon obtained in Example 8.

[0035] Figure 14 This is a real-world image of the surface of the MCB housing made of MCA flame-retardant nylon obtained in Example 9. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The following embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0037] Evaluation method for texture defects: The prepared MCA flame-retardant nylon material is injection molded into an MCB shell part with a matte texture under the condition of no external mold temperature controller or mold temperature set at 40℃. The surface condition of the shell is observed by visual inspection to evaluate the texture defects.

[0038] Example 1

[0039] By weight, 60 parts of PA6 resin (relative viscosity 2.0), 3 parts of PA12 resin, 7 parts of MCA flame retardant, 20 parts of glass fiber, 0.5 parts of calcium stearate, and 0.6 parts of antioxidant 1098 are premixed and fed into the twin-screw extruder through the main feed port. 10 parts of wollastonite are fed into the twin-screw extruder through the side feed port. The mixture is melted, blended, extruded, drawn into strands, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder has a screw speed of 280 rpm / min, and the screw zone temperatures are as follows: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0040] Comparative Example 1

[0041] Compared with Example 1, Comparative Example 1 does not contain PA12 resin in its raw material components, and the amount of PA6 resin component is 63 parts. The rest is exactly the same as in Example 1.

[0042] The MCA flame-retardant nylon materials obtained in Example 1 and Comparative Example 1 were respectively injection molded into MCB shell parts without an external mold temperature controller. The surface conditions of the resulting MCB shell parts are as follows: Figure 1 , Figure 2 As shown.

[0043] The MCB housing parts of Example 1 and Comparative Example 1, respectively, were subjected to pad printing marking. The surface condition of the pad printing marking area of ​​the MCB housing parts of Comparative Example 1 and Example 1 is shown in the figure. Figure 3 .

[0044] Example 2

[0045] By weight, 60 parts of PA6 resin (relative viscosity 2.3), 4 parts of PA12 resin, 6 parts of MCA flame retardant, 5 parts of glass fiber, 0.5 parts of lubricant PETS, and 0.6 parts of antioxidant 1098 are premixed and fed into the twin-screw extruder through the main feed port. 25 parts of glass powder are fed into the twin-screw extruder through the side feed port. The mixture is melted, blended, extruded, drawn into strands, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder has a screw speed of 280 rpm / min, and the screw zone temperatures are as follows: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0046] Example 3

[0047] By weight, 60 parts of PA6 resin (relative viscosity 2.3), 4 parts of PA1010 resin, 6 parts of MCA flame retardant, 5 parts of glass fiber, 0.5 parts of lubricant PETS, and 0.6 parts of antioxidant 1098 are premixed and fed into the twin-screw extruder through the main feed port. 25 parts of glass powder are fed into the twin-screw extruder through the side feed port. The mixture is melted, blended, extruded, drawn into strands, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder has a screw speed of 280 rpm / min, and the screw zone temperatures are as follows: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0048] Example 4

[0049] By weight, 60 parts of PA6 resin (relative viscosity 2.3), 4 parts of PA1012 resin, 6 parts of MCA flame retardant, 5 parts of glass fiber, 0.5 parts of lubricant polyethylene wax, 0.6 parts of antioxidant S-9228, and 1 part of black masterbatch are premixed and fed into the twin-screw extruder through the main feed port. 25 parts of glass powder are fed into the twin-screw extruder through the side feed port. The mixture is melted, blended, extruded, drawn into strands, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder has a screw speed of 280 rpm / min, and the screw zone temperatures are as follows: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0050] Comparative Example 2

[0051] By weight, 64 parts PA6 resin (relative viscosity 2.3), 6 parts MCA flame retardant, 5 parts glass fiber, 0.5 parts PETS lubricant, and 0.6 parts antioxidant 1098 were premixed and fed into the twin-screw extruder through the main feed port. 25 parts glass powder were fed into the twin-screw extruder through the side feed port. The mixture was then melted, blended, extruded, stretched, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder had a screw speed of 280 rpm / min, and the screw zone temperatures were: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0052] The MCA flame-retardant nylon materials obtained in Examples 2-3 were injection molded into MCB shell parts without an external mold temperature controller. The MCA flame-retardant nylon material obtained in Comparative Example 2 was injection molded into MCB shell parts at a mold temperature of 40°C. The surface conditions of the MCB shell parts obtained in Examples 2-3 and Comparative Example 2 are as follows: Figure 4 , Figure 5 and Figure 6 As shown.

[0053] Comparative Example 3

[0054] By weight, 64 parts PA6 resin (relative viscosity 2.3), 6 parts MCA flame retardant, 5 parts glass fiber, 0.5 parts lubricant polyethylene wax, 0.6 parts antioxidant S-9228, and 1 part black masterbatch were premixed and fed into the twin-screw extruder through the main feed port. 25 parts glass powder were fed into the twin-screw extruder through the side feed port. The mixture was melted, blended, extruded, stretched, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder had a screw speed of 280 rpm / min, and the screw zone temperatures were: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0055] The MCA flame-retardant nylon material obtained in Example 4 was injection molded into an MCB shell without an external mold temperature controller. The MCA flame-retardant nylon material obtained in Comparative Example 3 was injection molded into an MCB shell at a mold temperature of 40°C. The surface conditions of the MCB shells obtained in Example 4 and Comparative Example 3 are as follows: Figure 7 and Figure 8 As shown.

[0056] Example 5

[0057] 54 parts by weight of PA6 resin (relative viscosity 2.4), 5 parts of PA1012 resin, 11 parts of MCA flame retardant, 10 parts of glass fiber, 0.5 parts of calcium stearate, and 0.6 parts of antioxidant 245 were premixed and fed into the twin-screw extruder through the main feed port. 20 parts of wollastonite were fed into the twin-screw extruder through the side feed port. The mixture was melted, blended, extruded, stretched, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder had a screw speed of 280 rpm / min, and the screw zone temperatures were: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0058] Example 6

[0059] By weight, 53 parts PA6 resin (relative viscosity 2.4), 6 parts PA1012 resin, 11 parts MCA flame retardant, 10 parts glass fiber, 0.5 parts calcium stearate, and 0.6 parts antioxidant 245 were premixed and fed into the twin-screw extruder through the main feed port. 20 parts wollastonite were fed into the twin-screw extruder through the side feed port. The mixture was melted, blended, extruded, stretched, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder had a screw speed of 280 rpm / min, and the screw zone temperatures were: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0060] Comparative Example 4

[0061] By weight, 56.5 parts of PA6 resin (relative viscosity 2.4), 2.5 parts of PA1012 resin, 11 parts of MCA flame retardant, 10 parts of glass fiber, 0.5 parts of calcium stearate, and 0.6 parts of antioxidant 245 were premixed and fed into the twin-screw extruder through the main feed port. 20 parts of wollastonite were fed into the twin-screw extruder through the side feed port. The mixture was melted, blended, extruded, stretched, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder had a screw speed of 280 rpm / min, and the screw zone temperatures were: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0062] The MCA flame-retardant nylon materials obtained in Examples 5-6 were injection molded into MCB shell parts without an external mold temperature controller. The MCA flame-retardant nylon material obtained in Comparative Example 4 was injection molded into MCB shell parts at a mold temperature of 40°C. The surface conditions of the MCB shell parts obtained in Examples 5-6 and Comparative Example 4 are shown in the figures.

[0063] 9. Figure 10 and Figure 11 As shown.

[0064] Example 7

[0065] By weight, 65 parts PA66 resin (relative viscosity 2.4), 5 parts PA610 resin, 10 parts MCA flame retardant, 5 parts glass fiber, 0.5 parts lubricant A-C540A, and 0.6 parts antioxidant 1098 are premixed and fed into the twin-screw extruder through the main feed port. 15 parts wollastonite are fed into the twin-screw extruder through the side feed port. The mixture is melted, blended, extruded, drawn into strands, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder has a screw speed of 280 rpm / min, and the screw zone temperatures are as follows: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0066] Example 8

[0067] By weight, 56 parts of PA6 resin (relative viscosity 2.0), 3 parts of PA12 resin, 6 parts of MCA flame retardant, 0.5 parts of lubricant A-C540A, and 0.6 parts of antioxidant 1098 were premixed and fed into the twin-screw extruder through the main feed port. 5 parts of glass fiber and 30 parts of glass powder were fed into the twin-screw extruder through the two side feed ports respectively. The mixture was melted, blended, extruded, stretched, cooled, and pelletized to obtain MCA flame-retardant nylon material. The twin-screw extruder had a screw speed of 280 rpm / min, and the screw zone temperatures were: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, with the die head temperature controlled at 265℃.

[0068] Example 9

[0069] By weight, 55 parts PA6 resin (relative viscosity 2.0), 4 parts PA1212 resin, 6 parts MCA flame retardant, 0.5 parts lubricant A-C540A, and 0.6 parts antioxidant 1098 are premixed and fed into the twin-screw extruder through the main feed port. 5 parts glass fiber and 30 parts glass powder are fed into the twin-screw extruder through the two side feed ports respectively. After melting, blending, extrusion, stranding, cooling, and pelletizing, MCA flame-retardant nylon material is obtained. The screw speed of the twin-screw extruder is 280 rpm / min, and the screw zone temperatures are as follows: Zone 1 235℃, Zone 2 235℃, Zone 3 230℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, Zone 9 210℃, and the die head temperature is controlled at 265℃.

[0070] The MCA flame-retardant nylon materials obtained in Examples 7-9 were injection molded into MCB shell parts without an external mold temperature controller. The surface conditions of the resulting MCB shell parts are as follows: Figure 12, Figure 13 and Figure 14 As shown.

[0071] from Figure 1 , Figure 4 , Figure 5 , Figure 7 , Figure 9 , Figure 10 and Figures 12-14 It is evident that when specific amounts of PA610, PA612, PA1010, PA1012, PA12, or PA1212 are introduced into the MCA flame-retardant nylon (PA6 or PA66 as the resin matrix) formulation system, even without an external mold temperature controller, the surface color, texture, and reflectivity of the injection-molded MCB shell parts are consistent, with no skin texture defects; while when the MCA flame-retardant nylon material formulation system contains only PA6 resin matrix (such as... Figure 2 , Figure 6 , Figure 8 Although PA1012 resin is introduced into the formulation system of MCA flame-retardant nylon material, the amount of PA1012 resin used is insufficient (e.g.) Figure 11 When no external mold temperature controller is used or the mold temperature is set to 40℃, obvious watermark-like uneven color texture defects appear on the surface of the injection-molded MCB shell parts. This demonstrates that introducing specific amounts of long-chain nylon resins such as PA610, PA612, PA1010, PA1012, PA12, or PA1212 into the MCA flame-retardant PA6 system can indeed eliminate surface texture defects in MCA flame-retardant nylon molded products.

[0072] The surface condition of the MCB housing parts of Comparative Example 1 and Example 1 after being printed with the manufacturer's logo and other information via pad printing is as follows: Figure 3 As shown. From Figure 3 As can be seen from the image, the MCB housing part injection molded using the technical solution of this application has no delamination problem in the pad printing area. Figure 3 b), while the MCB shell parts injection molded from MCA flame-retardant nylon material without long-chain nylon resin exhibit obvious watermark texture defects in the pad printing area, resulting in a clear delamination phenomenon on the surface after pad printing. Figure 3 a).

Claims

1. A MCA flame-retardant nylon material capable of eliminating surface skin defect of molded product, characterized in that, without external mold temperature controller, the MCA flame-retardant nylon material comprises the following raw material components in parts by weight: 40-70 parts of nylon resin, 5-13 parts of MCA flame retardant, 10-40 parts of reinforcing filler, and 0.5-3 parts of other additives; wherein the nylon resin is a compound of nylon resin A and nylon resin B, the weight percentage of the nylon resin A and the nylon resin B is 20:1-8:1; the nylon resin A is PA6 and / or PA66, and the nylon resin B is long carbon chain nylon with monomer carbon atom number >10, and the nylon resin B is selected from at least one of PA610, PA612, PA1010, PA1012, PA12 or PA1212. The relative viscosity of the nylon resin A is 2.0-2.

4.

2. The MCA flame retardant nylon material capable of eliminating surface skin defects of molded articles according to claim 1, characterized in that, The reinforcing filler is a compound of glass fiber and powder reinforcing filler.

3. The MCA flame retardant nylon material capable of eliminating surface skin defects of molded articles according to claim 1, characterized in that, The glass fiber is glass fiber treated by coupling agent.

4. The MCA flame retardant nylon material capable of eliminating surface skin defects of molded articles according to claim 3, characterized in that, The powder reinforcing filler is selected from one or more of wollastonite, zeolite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, asbestos, aluminosilicate, alumina, silica, magnesia, zirconia, titania, iron oxide, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass bead, glass powder, ceramic bead, ground glass fiber, boron nitride or silicon carbide.

5. The MCA flame retardant nylon material capable of eliminating surface skin defects of molded articles according to claim 3, wherein, The MCA flame-retardant nylon material comprises the following raw material components in parts by weight: 35-65 parts of nylon resin A, 2-6 parts of nylon resin B, 6-12 parts of MCA flame retardant, 5-20 parts of glass fiber, 10-30 parts of powder reinforcing filler, and 0.5-3 parts of other additives.

6. The MCA flame retardant nylon material capable of eliminating surface skin defects of molded articles according to claim 3, characterized in that, The powder reinforcing filler is selected from one or more of wollastonite, kaolin, mica, talc, titania, calcium carbonate, montmorillonite, glass bead, glass powder or ground glass fiber.

7. The MCA flame retardant nylon material capable of eliminating surface skin defects of molded articles according to claim 6, characterized in that, The MCA flame-retardant nylon material comprises the following raw material components in parts by weight: 35-60 parts of nylon resin A, 3-5 parts of nylon resin B, 6-12 parts of MCA flame retardant, 5-10 parts of glass fiber, 15-30 parts of glass powder, and 0.5-3 parts of other additives; the nylon resin A is PA6, and the nylon resin B is one or a mixture of PA12 and PA1012.

8. The MCA flame retardant nylon material capable of eliminating surface skin defects of molded articles according to claim 7, characterized in that, 9. Use of the MCA flame-retardant nylon material according to any one of claims 1-8 in the preparation of plastic molded product. The plastic molded product is prepared by injection molding of the MCA flame-retardant nylon material according to any one of claims 1-8.

10. A plastic molded article, characterized by, The plastic molded product is low-voltage electrical appliance shell part.

11. The plastic molded article according to claim 10, characterized in that, After the surface of the low-voltage electrical appliance shell part is marked by pad printing, there is no skinning delamination problem.

12. The plastic molded article of claim 11, wherein, ​

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