Stainless steel particle reinforced nylon composite material feed and preparation method thereof

Abstract

The invention discloses a stainless steel particle reinforced nylon composite material feed and a preparation method thereof, and the stainless steel particle reinforced nylon composite material feed comprises the following components in parts by weight: 20-60 parts of nylon, 40-80 parts of stainless steel particles, 0.5-5 parts of a surface modifier, 0.5-2 parts of a lubricant and 0.1-1.5 parts of an antioxidant. According to the preparation method, the stainless steel particles are pretreated, so that the interfacial compatibility and bonding performance of the stainless steel metal particles and a nylon high polymer material can be effectively improved; by adding the lubricant, the flowability and machinability of the nylon composite material can be improved, and by adding the antioxidant, oxidative degradation of nylon and catalytic reaction of metal ions can be effectively inhibited. The method can realize efficient preparation of the nylon composite material product with high density, uniform density and excellent wear resistance, and has the advantages of low production cost, easiness in industrialization and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of injection molding, and particularly relates to a stainless steel particle reinforced nylon composite material feedstock and a preparation method thereof. BACKGROUND

[0002] Nylon materials have been widely used in the fields of automobile parts (such as gears and bearings), electronic device housings, industrial machinery linings, and sports equipment, etc. due to their high strength, wear resistance, chemical corrosion resistance, self-lubrication and other characteristics, and have gradually become an important choice for lightweight metal replacement. However, its high-temperature resistance is limited (service temperature is usually lower than 120℃), and it is prone to thermal deformation and mechanical property degradation under high load or extreme working conditions, and its high water absorption rate may lead to insufficient dimensional stability, etc., which limits its application in precision parts or harsh environments. In order to break through the above bottleneck, researchers have improved the performance of nylon materials in various ways: for example, by adding chopped glass fibers (content 15%-40%) to nylon materials, the rigidity (flexural strength increased by 50%-80%) and heat resistance (thermal deformation temperature increased to more than 200℃) of nylon can be significantly improved; another method is to generate dispersed distribution of nano-alumina particles (particle size <100 nm) in situ during the polymerization of nylon monomers to enhance the phase, and the use of chemical bonding to improve the interfacial bonding force can increase the tensile strength of nylon 6 by 30%, while reducing the water absorption rate, etc. However, the nylon composite materials prepared by the above-mentioned technologies usually have the limitations of low density, anisotropy of mechanical properties, complex preparation process and difficulty in dispersing nano-particles, etc., and also have the problems of high production cost and low production efficiency.

[0003] With the rapid development of new energy vehicles, new generation communication technology (such as 6G) and aerospace fields, related equipment is facing more severe service environment challenges, and higher requirements for the mechanical strength, wear resistance and functional integration of nylon-based composite materials. Under this background, the development of high-performance nylon composite materials with high efficiency and low-cost preparation process is not only a key technical path to solve the performance degradation problem of traditional materials in extreme temperature (-50~200℃), heavy load and multi-physical field coupling environment, but also a core driving force to promote the upgrading of high-end equipment manufacturing, new energy systems and electronic information industry.

[0004] Injection molding process is an advanced manufacturing technology that realizes precise molding of components through high-temperature melting, high-pressure mold filling and rapid cooling. With its high efficiency, high precision and excellent mechanical properties of the products, injection molding has become one of the most important preparation methods for nylon material parts. However, the nylon composite material feedstock used for injection molding usually has the problems of poor compatibility between different materials, poor thermal stability and uneven dispersion, which is very unfavorable for the production of high-performance nylon products with high efficiency, and also limits the application scenarios of nylon materials. SUMMARY

[0005] The present application aims to overcome the deficiencies in the prior art and provide a stainless steel particle reinforced nylon composite material feed for injection molding process and a preparation method thereof, which can realize efficient preparation of a nylon composite material product with high density, uniform density and excellent wear resistance, and has the advantages of low production cost and easy industrial application.

[0006] To this end, according to one aspect of the present application, a method for preparing a high-performance stainless steel particle reinforced nylon composite material feed is provided,

[0007] The technical scheme of the present application is:

[0008] A stainless steel particle reinforced nylon composite material feed, by weight fraction, comprises the following components:

[0009] Nylon 20-60 parts

[0010] Stainless steel particles 40-80 parts

[0011] Surface modifier 0.5-5 parts

[0012] Lubricant 0.5-2 parts

[0013] Antioxidant 0.1-1.5 parts

[0014] Further, the nylon is selected from at least one of PA6, PA66, PA610, PA1010, PA46, PA6T, PA11, PA12 or PA612;

[0015] Further, the stainless steel particles are selected from at least one of 201, 304, 316, 17-4PH, 410, 420, 430 or 440;

[0016] Further, the particle size of the stainless steel particles is 50-200 μm;

[0017] Further, the surface modifier is at least one of KH-550, KH-560, KH-590, SCA-1113 or SCA-403 silane coupling agent, or ST-1, ST-2, ST-6 or ST-7 maleic anhydride grafted polyolefin.

[0018] Further, the lubricant is at least one of zinc stearate, calcium stearate, ethylene bis-stearamide, dendritic hyperbranched lubricant or silicone oil.

[0019] Further, the antioxidant is at least one of antioxidant 1098, antioxidant 168, antioxidant 412S or antioxidant 9228.

[0020] A preparation method of the above-mentioned stainless steel particle reinforced nylon composite material feed, comprising the following steps:

[0021] (1) Weighing: the components of the stainless steel particle reinforced nylon composite material feed are weighed according to the proportion;

[0022] (2) Stainless steel particle pretreatment: the surface modifier is prepared into a solution by adding water or ethanol, and then the stainless steel particles are added and stirred uniformly, and dried, the drying temperature is 80-120 DEG C, and the drying time is 30-120 min;

[0023] (3) Mixing and preheating: the nylon particles are first added to the preheated mixing machine, the preheating temperature is not less than 150 DEG C, the mixing machine speed is 1-15 r / min during the preheating process, and the preheating time is 10-120 min;

[0024] (4) Melt blending and mixing: the preheated nylon particles are mixed in the mixing machine, the mixing temperature is 200-300 DEG C, and the mixing machine speed is 20-60 r / min; after being melted to a completely plasticized state, a small amount of pretreated stainless steel particles are slowly added in multiple times, the adding times are not less than 3 times; at the same time, lubricant and antioxidant are added, the mixing time is 10-90 min, and the speed is 30-50 r / min;

[0025] (5) Breaking and granulating: the material obtained in step (4) is added to the crusher to obtain the feed for injection molding;

[0026] (6) Injection molding: the feed obtained in step (5) is injection molded in the injection machine to obtain a stainless steel particle reinforced nylon composite material product, the injection temperature is 220-305 DEG C, the injection pressure is 50-140 MPa, and the mold temperature is 80-120 DEG C.

[0027] The present application can effectively improve the interfacial compatibility and bonding performance of the stainless steel metal particles and the nylon high polymer material by pretreating the stainless steel particles, can improve the flowability and processability of the nylon composite material by adding the lubricant, and can effectively inhibit the oxidation degradation of the nylon and the metal ion catalytic reaction by adding the antioxidant.

[0028] Compared with the prior art, the present application has the following characteristics and advantages:

[0029] (1) The nylon composite material prepared by the present application can significantly improve the rigidity, wear resistance and thermal conductivity of the nylon material by adding the stainless steel particles; and can be used for valve body sealing parts, engine peripheral sealing parts, oil pump gears and the like, which can withstand high temperature oil environment and prolong the service life;

[0030] (2) The stainless steel particle reinforced nylon composite material feed developed by the application adopts injection molding, and can realize mass production, low cost, good density, uniform density and high size precision of high-performance nylon products;

[0031] (3) The high-performance nylon composite material feed developed by the application has simple preparation process, and is suitable for popularization and application and batch production. DETAILED DESCRIPTION

[0032] The application will be further described in detail below in combination with examples.

[0033] In order to facilitate understanding of the application, the application lists examples and comparative examples as follows. Any non-essential change and replacement made by those skilled in the art on the basis of the application shall fall within the scope of the application.

[0034] The raw materials used in the following examples and comparative examples are commercially available, and part of the raw material information is as follows:

[0035] Nylon: PA6 is Balin Petrochemical YH800, PA66 is Shenma EPR27, and PA46 is Shuyuan TW341;

[0036] 304, 316 and 420 stainless steel particles: produced by Hunan Hengji Powder Technology Co., Ltd.;

[0037] KH-550 and KH-560 silane coupling agents: produced by Dongguan Dinghai Plastic Chemical Co., Ltd.;

[0038] ST-6 maleic anhydride grafted polyolefin: produced by Zhejiang Changhong Plastic Raw Material Co., Ltd.;

[0039] CYD-604 dendritic hyperbranched lubricant: produced by Weihai Chen Yuan Molecular New Material Co., Ltd.;

[0040] Zinc stearate: produced by Guangzhou Dongzheng Chemical Co., Ltd.;

[0041] Antioxidant: 168 is BASF Irganox 168, and 9228 is Doverphos S-9228;

[0042] Ethylene bis-stearamide: Kawabata EB-FF. Example 1

[0043] The embodiment provides a stainless steel particle reinforced nylon composite material, and preparation raw materials of the stainless steel particle reinforced nylon composite material include the following components in parts by weight: 35 parts of PA6 nylon

[0044] 62 parts of 316 stainless steel particles (particle size 51.3 μm)

[0045] 2 parts of KH-550 silane coupling agent

[0046] Zinc stearate lubricant 0.5 parts

[0047] Irganox 168 antioxidant 0.5 parts

[0048] The method for preparing the stainless steel particle reinforced nylon composite material feed comprises the following steps:

[0049] (1) The components of the stainless steel particle reinforced nylon composite material feed are weighed according to the proportions;

[0050] (2) The KH-560 surface modifier is prepared into a solution by adding water, then the 316 stainless steel particles are added and stirred uniformly, and dried at a temperature of 100°C for 60 minutes;

[0051] (3) The PA6 nylon particles are first added to a preheated mixer, the preheating temperature is not less than 150°C, the mixer speed is 10 r / min during the preheating process, and the preheating time is 30 minutes;

[0052] (4) The preheated PA6 nylon particles are mixed in a mixer at a temperature of 230°C and a mixer speed of 30 r / min; when they are completely plasticized, the pretreated 316 stainless steel particles are slowly added in four equal weights; at the same time, zinc stearate lubricant and Irganox 168 antioxidant are added, the mixing time is 40 minutes, and the speed is 40 r / min;

[0053] (5) The material obtained by mixing in step (4) is added to a crusher to obtain a feed for injection molding;

[0054] (6) The feed obtained in step (5) is injection molded in an injection machine to obtain a stainless steel particle reinforced nylon composite material product, the injection temperature is 235°C, the injection pressure is 70 MPa, and the mold temperature is 80°C.

[0055] Example 2:

[0056] The stainless steel particle reinforced nylon composite material provided in this example is prepared from the following components in the following weight proportions: PA66 nylon 40 parts

[0057] 304 stainless steel particles (particle size 53.7 μm) 58 parts

[0058] KH-560 silane coupling agent 1.3 parts

[0059] CYD-604 dendritic hyperbranched lubricant 0.5 parts

[0060] Irganox 168 antioxidant 0.2 parts

[0061] The preparation method of the stainless steel particle reinforced nylon composite material feed comprises the following steps:

[0062] (1) The components of the stainless steel particle reinforced nylon composite material feed are weighed according to the proportion;

[0063] (2) The KH-550 surface modifier is prepared into a solution by adding water, then the 304 stainless steel particles are added and stirred uniformly, and dried, the drying temperature is 100 DEG C, and the drying time is 60 min;

[0064] (3) The PA66 nylon particles are first added to a preheated mixer, the preheating temperature is not less than 180 DEG C, the preheating process mixer speed is 10 r / min, and the preheating time is 30 min;

[0065] (4) The preheated PA66 nylon particles are mixed in a mixer, the mixing temperature is 260 DEG C, the mixer speed is 30 r / min; when it is melted to a completely plasticized state, the pretreated 304 stainless steel particles are slowly added in the same weight for four times; the CYD-604 dendritic hyperbranched lubricant and the Irganox 168 antioxidant are added at the same time, the mixing time is 40 min, and the speed is 40 r / min;

[0066] (5) The material obtained by mixing in step (4) is added to a crusher to obtain a feed for injection molding;

[0067] (6) The feed obtained in step (5) is injection molded in an injection machine to obtain a stainless steel particle reinforced nylon composite material product, the injection temperature is 275 DEG C, the injection pressure is 80 MPa; the mold temperature is 100 DEG C.

[0068] Example 3:

[0069] The stainless steel particle reinforced nylon composite material provided in this embodiment has the following components by weight:

[0070] 420 stainless steel particles (particle size 56.5 μm) 52 parts

[0071] ST-6 maleic anhydride grafted polyolefin 2 parts

[0072] EB-FF ethylene bis-stearamide lubricant 0.5 parts

[0073] Doverphos S-9228 antioxidant 0.5 parts

[0074] The preparation method of the stainless steel particle reinforced nylon composite material feed comprises the following steps:

[0075] (1) The stainless steel particle reinforced nylon composite feed material is prepared according to the proportion of each component;

[0076] (2) The KH-550 surface modifier is prepared into a solution by adding water, and then the 420 stainless steel particles are added and stirred uniformly, and dried at a temperature of 100°C for 60 minutes;

[0077] (3) The PA46 nylon particles are first added to a preheated mixer, and the preheating temperature is not less than 200°C, the preheating process mixer speed is 10 r / min, and the preheating time is 30 minutes;

[0078] (4) The preheated PA46 nylon particles are mixed in a mixer at a temperature of 320°C and a mixer speed of 30 r / min; when they are completely plasticized, the pretreated 420 stainless steel particles are slowly added in the same weight for four times; at the same time, zinc stearate lubricant and Doverphos S-9228 antioxidant are added, and the mixing time is 40 minutes and the speed is 40 r / min;

[0079] (5) The material obtained by mixing in step (4) is added to a crusher to obtain a feed material for injection molding;

[0080] (6) The feed material obtained in step (5) is injection molded in an injection machine to obtain a stainless steel particle reinforced nylon composite product, the injection temperature is 305°C, the injection pressure is 90 MPa, and the mold temperature is 120°C.

[0081] Example 4:

[0082] The embodiment provides a stainless steel particle reinforced nylon composite feed material, which is different from example 1 in that the particle size of the stainless steel particles is changed to 102.3 μm, and the other raw materials, contents and preparation methods are the same as those of example 1.

[0083] Example 5:

[0084] The embodiment provides a stainless steel particle reinforced nylon composite feed material, which is different from example 1 in that the content of the KH-550 surface modifier is 1 part.

[0085] Example 6:

[0086] The embodiment provides a stainless steel particle reinforced nylon composite feed material, which is different from example 1 in that the content of the KH-550 surface modifier is 3 parts.

[0087] Example 7:

[0088] This example provides a stainless steel particle reinforced nylon composite feedstock, which is different from example 1 in that the content of KH-550 surface modifier is 4 parts.

[0089] Example 8:

[0090] This example provides a stainless steel particle reinforced nylon composite feedstock, which is different from example 1 in that the content of zinc stearate lubricant is 1 part.

[0091] Example 9:

[0092] This example provides a stainless steel particle reinforced nylon composite feedstock, which is different from example 1 in that the content of zinc stearate lubricant is 1.5 parts.

[0093] Example 10:

[0094] This example provides a stainless steel particle reinforced nylon composite feedstock, which is different from example 1 in that the content of zinc stearate lubricant is 2 parts.

[0095] Example 11:

[0096] This example provides a stainless steel particle reinforced nylon composite feedstock, which is different from example 1 in that the content of Irganox 168 antioxidant is 0.1 part.

[0097] Example 12:

[0098] This example provides a stainless steel particle reinforced nylon composite feedstock, which is different from example 1 in that the content of Irganox 168 antioxidant is 1 part.

[0099] Comparative Example 1:

[0100] As a preparation method of a stainless steel particle reinforced nylon composite feedstock of the present application, the only difference between this comparative example and example 1 is that step (2) is not included, i.e. the stainless steel powder is not subjected to surface modification treatment.

[0101] Comparative Example 2:

[0102] As a preparation method of a stainless steel particle reinforced nylon composite feedstock of the present application, the only difference between this comparative example and example 1 is that no zinc stearate lubricant is added.

[0103] Comparative Example 3:

[0104] As a preparation method of a stainless steel particle reinforced nylon composite feedstock of the present application, the only difference between this comparative example and example 1 is that no Irganox 168 antioxidant is added.

[0105] Comparative Example 4:

[0106] As a preparation method of a stainless steel particle reinforced nylon composite material feedstock of the present application, the only difference between this comparative example and Example 1 is that the particle size of the stainless steel particles is 10.8 μm.

[0107] Comparative Example 5:

[0108] As a preparation method of a stainless steel particle reinforced nylon composite material feedstock of the present application, the only difference between this comparative example and Example 1 is that the particle size of the stainless steel particles is 10.8 μm.

[0109] Comparative Example 6: As a preparation method of a stainless steel particle reinforced nylon composite material feedstock of the present application, the only difference between this comparative example and Example 1 is that a single component PA6 nylon is used as the feedstock for injection molding, and the injection process is the same as that of Example 1.

[0110] The above Examples 1-12 and Comparative Examples 1-5 were subjected to performance testing, and the performance evaluation method and implementation standard are as follows:

[0111] Tensile properties: ISO 527, sample 1B type sample bar;

[0112] Wear resistance: ISO 9352, 10N load friction 500 times, grinding ball diameter 4mm;

[0113] Melt index: ISO 1183, 275°C / 2.16kg.

[0114] Bending properties: ISO 178, sample size 80x10x4mm;

[0115] Banbury kneading into a mass condition: observed by naked eye.

[0116] The comprehensive mechanical properties of the sample were evaluated by the values of tensile strength, elongation at break, bending strength, friction coefficient and mass wear amount obtained by testing; the molding flow properties of the material were evaluated by the melt index value of the material; the Banbury kneading into a mass condition was observed and determined by naked eye; and the test results are shown in Table 1.

[0117] Table 1 Performance test results of stainless steel particle reinforced nylon composite material

[0118]

[0119] From the test results, it can be seen that:

[0120] Through comparative analysis of Example 1, Example 4 and Comparative Example 5, it can be known that the mechanical properties and fluidity of the stainless steel particle diameter nylon composite material, when the particle size is too small, the specific surface area of the particles is large, leading to heat generation during the mixing process and friction with the nylon, and thus the nylon is overheated and decomposed, so that the nylon cannot be formed into a group; when the particle size is large, the specific surface area of the particles is small, the melt index of the composite material is high, but due to the limited hindrance to the movement of molecular chains caused by the large distance between the particles, and the stress concentration area formed around the large particles, cracks are easily caused, so that the strength of the material is reduced. Therefore, the appropriate stainless steel particles need to be selected to obtain the best performance combination.

[0121] Through comparative analysis of Example 1, Example 5-7 and Comparative Example 1, it can be known that with the increase of the content of the surface modifier, the tensile strength, yield strength and wear resistance of the stainless steel particle reinforced nylon composite material all show a trend of first increasing and then decreasing, and at a content of 3%, the interface strengthening, wear resistance improvement and processing fluidity can be considered.

[0122] Through comparative analysis of Example 1, Example 8-10 and Comparative Example 2, it can be known that the appropriate amount of lubricant can improve the melt fluidity, reduce the shear heat in the processing process, avoid excessive rupture of the nylon molecular chain, and thus improve the strength thereof; when the lubricant is excessive, the surface of the stainless steel is excessively covered, the mechanical interlocking action between the particles and the nylon is reduced, the interface is easily peeled off, and the strength and wear resistance of the material are deteriorated. However, the increase of the content of the lubricant can significantly reduce the melt viscosity, reduce the entanglement between the nylon molecular chains, and linearly improve the fluidity with the increase of the content, but there is a risk of phase separation.

[0123] Through comparative analysis of Example 1, Example 11-12 and Comparative Example 3, it can be known that the appropriate amount of antioxidant can inhibit the thermal oxidative degradation of the stainless steel particle reinforced nylon composite material in the high-temperature processing, reduce the rupture of the nylon molecular chain, and thus maintain the integrity of the matrix structure; at the same time, it can also be found that within the appropriate range, the change of the content of the antioxidant has little effect on the strength, wear resistance and fluidity of the stainless steel particle reinforced nylon composite material.

[0124] Through comparative analysis of Example 1 and Comparative Examples 4 and 6, it can be known that the direct melt blending of nylon and stainless steel particles cannot be normally formed into a group; by adding the stainless steel particles into the nylon, the tensile strength, bending strength and wear resistance of the nylon material can be significantly improved.

[0125] In summary, by selecting and combining the types and contents of nylon, stainless steel particles and additives, the preparation of the high-strength, high-wear-resistant and good-fluidity nylon composite material feed can be realized, the preparation process is simple and convenient to operate, the production cost can be effectively reduced and the production efficiency can be improved, which has a positive significance for widening the application field of the nylon composite material.

Claims

1. A stainless steel particulate reinforced nylon composite feedstock, characterized in that, The composite feedstock comprises the following components by weight: Nylon 20-60 parts Stainless steel particles 40-80 parts Surface modifier 0.5-5 parts Lubricant 0.5-2 parts Antioxidant 0.1-1.5 parts.

2. A stainless steel particulate reinforced nylon composite feedstock as claimed in claim 1, wherein, The nylon is selected from at least one of PA6, PA66, PA610, PA1010, PA46, PA6T, PA11, PA12 or PA612.

3. A stainless steel particulate reinforced nylon composite feedstock as claimed in claim 1, wherein, The stainless steel particles are selected from at least one of 201, 304, 316, 17-4PH, 410, 420, 430 or 440.

4. A stainless steel particulate reinforced nylon composite feedstock as claimed in claim 1, wherein, The particle size of the stainless steel particles is 50-200 μm.

5. A stainless steel particulate reinforced nylon composite feedstock as claimed in claim 1, wherein, The surface modifier is at least one of KH-550, KH-560, KH-590, SCA-1113 or SCA-403 silane coupling agent, or ST-1, ST-2, ST-6 or ST-7 maleic anhydride grafted polyolefin.

6. A stainless steel particulate reinforced nylon composite feedstock as claimed in claim 1, wherein, The lubricant is at least one of zinc stearate, calcium stearate, ethylene bis-stearamide, dendritic hyperbranched lubricant or silicone oil.

7. A stainless steel particulate reinforced nylon composite feedstock as claimed in claim 1, wherein, The antioxidant is at least one of antioxidant 1098, antioxidant 168, antioxidant 412S or antioxidant 9228.

8. A method of making a stainless steel particulate reinforced nylon composite feedstock according to any one of claims 1 to 7, characterised in that, The method comprises the following steps: (1) Weighing: weighing the components of the composite feedstock according to the proportions; (2) Pretreatment of stainless steel particles: the surface modifier is dissolved in water or ethanol, then the stainless steel particles are added and stirred until uniform, and dried at a temperature of 80-120°C for 30-120 min; (3) Mixing and preheating: the nylon particles are added to a preheated mixer, the preheating temperature is not less than 150°C, the mixer speed is 1-15 r / min, and the preheating time is 10-120 min; (4) Melt blending and mixing: the preheated nylon particles are mixed in a mixer at a temperature of 200-300°C and a speed of 20-60 r / min; when they are completely plasticized, the pretreated stainless steel particles are slowly added in small amounts and multiple times, the number of additions is not less than 3; at the same time, the lubricant and antioxidant are added, the mixing time is 10-90 min, and the speed is 30-50 r / min; (5) Breaking and granulating: the material obtained in step (4) is added to a crusher to obtain a feedstock for injection molding; (6) Injection molding: the feedstock obtained in step (5) is injection molded in an injection machine to obtain a stainless steel particle reinforced nylon composite product, the injection temperature is 220-305°C, the injection pressure is 50-140 MPa, and the mold temperature is 80-120°C.

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