Special zinc sulfide for glass fiber reinforced polyolefin composite material as well as preparation method and application of special zinc sulfide

Abstract

The invention provides special zinc sulfide for a glass fiber reinforced polyolefin composite material as well as a preparation method and application of the special zinc sulfide. The zinc sulfide contains a copper element and a manganese element, and the mass content of the copper element in the zinc sulfide is 5-25 ppm; the mass content of the manganese element in the zinc sulfide is 10 to 50 ppm; the mass content of zinc in the zinc sulfide and the D50 particle size of the zinc sulfide meet the following relational expression: 15 < = Wzn / (DznS0.3) < = 23. The mechanical property, antistatic property and wear resistance of the glass fiber reinforced polyolefin composite material are remarkably improved by synergistically regulating the zinc content and the particle size in zinc sulfide and the contents of the doped copper element and manganese element.

Description

Technical Field

[0001] The present invention relates to the technical field of sulfides, in particular to zinc sulfide special for glass fiber reinforced polyolefin composite materials and a preparation method and application thereof. Background Art

[0002] Glass fiber-reinforced polyolefin (GF / PO) composites are high-performance materials commonly used in industries such as automotive, electronics, and construction. They are widely recognized for their excellent mechanical properties, low density, good corrosion resistance, and processability. Glass fiber, as a reinforcing phase, not only significantly improves the tensile strength, rigidity, and heat resistance of the polyolefin matrix material, but also enhances its dimensional stability to a certain extent. However, despite these numerous advantages, GF / PO composites still face technical bottlenecks in certain specialized applications.

[0003] First, the interfacial compatibility between glass fiber and polyolefin matrix is ​​poor due to the difference in polarity. Stress concentration is easily generated at the fiber-matrix interface, which triggers crack propagation under dynamic load. Traditional silane coupling agent treatment can only improve the interfacial adhesion to a limited extent. The tensile strength and impact toughness of the composite material are still somewhat lower than the theoretical value. Secondly, the intrinsic volume resistivity of polyolefin is 10 16 ~10 18 Ω·cm. Although the resistance is partially reduced after glass fiber reinforcement, it is still difficult to meet the anti-static requirements of electronic packaging, mining equipment and other scenarios (the surface resistance needs to be ≤10 9 Ω), while the addition of existing antistatic agents (such as carbon black and metal powders) often leads to reduced toughness or processing fluidity. Furthermore, the low hardness of the polyolefin matrix makes it susceptible to abrasive and adhesive wear under long-term friction conditions. While the hardness of glass fiber can partially improve wear resistance, exposed fiber may act as an abrasive and exacerbate damage to the wearable component.

[0004] Therefore, there is an urgent need to improve glass fiber reinforced polyolefin composites to enhance the mechanical properties, antistatic properties and wear resistance of the materials to meet the demand for high-performance materials. Summary of the Invention

[0005] In view of the defects in the prior art, the present invention proposes zinc sulfide specially used for glass fiber reinforced polyolefin composite materials, as well as a preparation method and application thereof.

[0006] The present invention provides a zinc sulfide specially used for glass fiber reinforced polyolefin composite materials. The zinc sulfide contains copper and manganese elements. The mass content of the copper element in the zinc sulfide is 5 to 25 ppm, preferably 10 to 20 ppm. The mass content of the manganese element in the zinc sulfide is 10-50 ppm, preferably 25-35 ppm; The addition of copper and manganese improves the dispersion of zinc sulfide particles, prevents aggregation between particles, and makes the microstructure of the composite material more uniform. This helps reduce the generation and expansion of cracks and improves the toughness and overall mechanical properties of the composite material.

[0007] "Zinc sulfide" refers to an inorganic compound composed of zinc and sulfur elements, which has good optical, electrical and wear-resistant properties. In the present invention, zinc sulfide is co-doped with copper and manganese elements and used as a functional filler.

[0008] The mass content of zinc in zinc sulfide is related to the D 50 The particle size satisfies the following relationship: ; in, W zn is the mass content of zinc in zinc sulfide material, unit is %; D znS The particle size of zinc sulfide particles is in nm; preferably .

[0009] This formula is derived from the summary of a large amount of experimental data and performance curve fitting, reflecting the law that zinc content and particle size have a synergistic regulatory effect on antistatic and wear resistance.

[0010] In the present invention, the mass contents of copper and manganese elements and the zinc content in the zinc sulfide material can be detected by atomic absorption spectrometry (AAS).

[0011] In the present invention, the mass contents of copper and manganese elements and the zinc content in the zinc sulfide material can be adjusted by screening a suitable zinc sulfide raw material ore; or a synthesis method can be adopted to select a suitable zinc compound and sulfide to synthesize zinc sulfide, and a certain amount of copper and manganese elements can be added by precipitation to adjust the content.

[0012] In some embodiments, the dielectric constant of the zinc sulfide is 9 to 11.5.

[0013] In this application, "dielectric constant" refers to a material's ability to polarize under an electric field and is an important parameter for measuring its electrical properties. Dielectric constant is measured using the capacitance method (parallel plate capacitor method). Dielectric constant is related to a material's polarization ability. A too low dielectric constant results in a weak response to an applied electric field and easy accumulation of surface charge, which is detrimental to improving antistatic properties. A too high dielectric constant can lead to excessively rapid conduction after charge accumulation, creating the risk of localized leakage or breakdown, and in turn reducing the material's stability.

[0014] In some embodiments, the mass content of zinc in the zinc sulfide is 60-70%, preferably 65-68%.

[0015] In some embodiments, the zinc sulfide has a D 50 The particle size is 50 to 150 nm, preferably 50 to 120 nm.

[0016] “D 50 "Particle size" refers to the median particle size of zinc sulfide powder particles, that is, 50% of the particles are smaller than this particle size. The unit is nanometer (nm). In the present invention, the D50 particle size is controlled in the range of 50-150 nm to optimize its dispersibility and interface compatibility.

[0017] The present invention also provides a method for preparing the zinc sulfide, comprising the following steps: Zinc sulfate, copper sulfate and manganese sulfate are taken, dissolved in deionized water and heated respectively, sodium sulfide solution is slowly added dropwise to react, cooled to room temperature, and the precipitate is collected by suction filtration. Dilute hydrochloric acid is added and stirred to remove surface impurities. Subsequently, the precipitate is washed with deionized water until neutral, and dried at high temperature to obtain the zinc sulfide powder sample.

[0018] The present invention also provides application of the zinc sulfide in preparing glass fiber reinforced polyolefin composite materials.

[0019] The present invention also provides a glass fiber reinforced polyolefin composite material, which comprises the following components in parts by weight: 100 parts of glass fiber reinforced polyolefin composite material and 0.1 to 10 parts of zinc sulfide, preferably 2 to 8 parts.

[0020] In the present invention, zinc sulfide is used as a reinforcing phase and is compounded with a glass fiber reinforced polyolefin matrix to increase the mechanical properties, antistatic properties and wear resistance of the material.

[0021] In some embodiments, the mass content of glass fiber in the glass fiber reinforced polyolefin composite material is 10-40%.

[0022] In some embodiments, the polyolefin in the glass fiber reinforced polyolefin composite material includes any one or more of polyethylene, polypropylene, polytetrafluoroethylene, and polyolefin elastomer.

[0023] In some embodiments, the glass fiber reinforced polyolefin composite material further comprises 0 to 2 parts of other additives, wherein the other additives are selected from at least one of lubricants, antioxidants, impact modifiers, flame retardants, fluorescent whitening agents, plasticizers, thickeners, release agents, and nucleating agents.

[0024] In summary, compared with the prior art, the present invention achieves the following technical effects: This invention significantly improves the mechanical properties, antistatic properties, and wear resistance of glass fiber-reinforced polyolefin composites by synergistically regulating the zinc content, particle size, and copper and manganese content of zinc sulfide. The introduction of copper and manganese effectively enhances the interfacial activity and dispersion stability of the zinc sulfide particles, improving the strength, hardness, and wear resistance of the composite. The optimal matching of zinc content and particle size helps optimize the conductive path and interfacial bonding of the composite system, significantly improving antistatic properties and overall structural stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is the X-ray diffraction pattern of the zinc sulfide material of Example 1 of the present invention. DETAILED DESCRIPTION

[0027] In order to help those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts should fall within the scope of protection of the present invention.

[0028] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0029] In the present invention, when referring to numerical ranges, unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Furthermore, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges subsumed therein.

[0030] In the present invention, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0031] The reagents and instruments used in the present invention without indicating the manufacturer are all conventional products that can be purchased from the market.

[0032] Unless otherwise specified, a component in the parallel examples and comparative examples of the present invention is the same commercially available product.

[0033] The zinc sulfide materials were prepared in the embodiments and comparative examples of the present invention, respectively, including the following steps: (1) Weigh zinc sulfate (ZnSO4·7H2O), copper sulfate (CuSO4·5H2O), and manganese sulfate (MnSO4·H2O), dissolve them in deionized water, heat to 60°C, slowly add Na2S·9H2O solution dropwise, control the reaction temperature at 60°C, and react for 2 hours; (2) Cool to room temperature, collect the precipitate by filtration, add dilute hydrochloric acid (0.1 mol / L, 200 mL), and stir for 30 minutes to remove surface impurities; (3) The sample was then washed with deionized water three times until neutral and dried at 80 °C to obtain a ZnS powder sample; (4) Use ultrasonic waves to disperse the agglomerated particles, and then centrifuge to classify and screen the particles to a specific size.

[0034] The D50 particle size was measured using a Horiba LA-960V2 laser particle size analyzer.

[0035] The X-ray diffraction (XRD) pattern of the zinc sulfide material prepared in Example 1 is as follows: Figure 1 As shown in the figures, there are no new impurity peaks after Cu and Mn doping, the sample has good crystallinity and less impurity phases, indicating that the preparation method of the present invention can achieve effective doping of Cu and Mn elements without introducing impurity phases, and maintain good crystal structure and purity of the material.

[0036] The mass contents of iron, copper and zinc in the zinc sulfide materials prepared in each embodiment and comparative example were detected by atomic absorption spectrometry (AAS), and the iron content (ppm), copper content (ppm), and zinc content (ppm) were obtained as shown in Table 1. Zn (%).

[0037] Table 1 Test parameter values ​​of zinc sulfide materials

[0038] The zinc sulfide materials prepared in each embodiment and comparative example were used to prepare glass fiber reinforced polypropylene composite materials according to the following weight parts: 100 parts of polypropylene, 15 parts of glass fiber, 3 parts of zinc sulfide, 1 part of antioxidant 1010; The preparation method of the resin composition is as follows: Polypropylene, glass fiber, zinc sulfide and antioxidant 1010 were added to a twin-screw extruder at one time and mixed at 1000 rpm. The material temperature was raised to 240° C. and the resin composition was obtained by melt mixing and extrusion granulation.

[0039] Test method: 1. Mechanical properties: Izod notched impact strength is tested according to ASTM D256 / (GB / T1843) standard (KJ / M2); Tensile properties test is carried out according to ASTM D638 / (GB / T1040) standard (MPa); The bending performance test is carried out according to ASTM D790 / (GB / T9341) standard (MPa).

[0040] 2. Antistatic properties Sheets produced using a bravender single-screw extruder T-die were cut into 5 cm wide and 5 cm long dimensions and processed according to ASTM D618-61 at 23°C and 50% relative humidity. The resulting sheets were used as test specimens, and the surface resistance was measured using a surface resistance measuring instrument (Ultra-Resistance Meter, Adventest, Japan) according to ASTM D257. The results are listed in Table 1.

[0041] 3. Wear resistance The wear resistance was determined using a needle scratch test, with the following steps: a weight of 710 g was placed on a 0.45 sq needle, and the needle was moved back and forth 300 times on a test sample of 2 mm width, 1 mm thickness, and 100 mm length to measure the thickness of the damaged test sample.

[0042] The test results are shown in Table 2: Table 2 Test results of various properties of glass fiber reinforced polypropylene composites

[0043] As shown in Table 2, the glass fiber reinforced polypropylene composite materials prepared in Examples 1 to 11 of the present application have excellent mechanical properties, with a tensile strength higher than 170 MPa and a notched impact strength higher than 24.5 KJ / M. 2 , bending strength is higher than 270 MPa, and it also has low electrical resistance and excellent wear resistance.

[0044] In order to explore the performance regulation rules of zinc sulfide materials under doping conditions, the test data of each embodiment in Table 2 were collected and regression analysis was performed on the data using OriginLab. The analysis results show that the mass content of zinc element (W Zn ) with zinc sulfide D 50 Particle size (DZnS ) have a significant nonlinear coupling relationship.

[0045] In order to achieve the coordinated optimization of antistatic performance and wear resistance, the following empirical correlation function is constructed: ; Through fitting analysis of different exponents n, the results show that when n = 0.3, the material's antistatic properties and wear resistance are both in the optimal performance range. Therefore, the exponent in the empirical formula is determined to be 0.3, and the performance correlation factor R is defined as follows: .

[0046] According to the data in Table 2, the R values ​​of the embodiments and comparative examples are shown in Table 3: Table 3 R value

[0047] The R value proposed above can effectively characterize the coordination window between the particle size and zinc content in the zinc sulfide material. In each embodiment of the present invention, the R value is range, the comprehensive performance of the material is excellent. On the contrary, in comparative examples 1~2, the R value deviates from this interval, and the glass fiber reinforced polypropylene composite material shows a significant deterioration trend in performance. Specifically, when the R value is too large, the particle size of the ZnS particles is not compatible with the zinc content, which easily leads to particle agglomeration and decreased dispersibility, forming a stress concentration area in the composite system, and then causing the mechanical properties of the material to decline; at the same time, the agglomerated particles hinder the construction of an effective conductive channel, resulting in unstable or ineffective antistatic performance; in addition, the uneven interface also aggravates the friction and wear process, resulting in a significant decrease in wear resistance. When the R value is too small, the ZnS particle size is too large and the zinc content is too low, resulting in a weakening of the effective polar interaction in the material, and insufficient reinforcing effect of the filler on the matrix, which is manifested as a decrease in the mechanical strength of the composite material; at the same time, the electrostatic conductive function of ZnS in the composite system is weakened, and the surface charge cannot be effectively released, resulting in serious electrostatic accumulation and poor antistatic properties; in addition, excessive filler particle size can also easily lead to increased wear, resulting in reduced wear resistance.

[0048] It should be noted that although only polypropylene resin is used as the resin component of the resin composition in the embodiments of the present invention, in fact, when the polypropylene resin is replaced by other polyolefin materials, such as polyethylene, polypropylene, polytetrafluoroethylene and polyolefin elastomers, similar effects of improving mechanical properties, antistatic properties and wear resistance can be achieved.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Zinc sulfide specially used for glass fiber reinforced polyolefin composite materials, characterized in that: The zinc sulfide contains copper and manganese, and the mass content of the copper in the zinc sulfide is 5 to 25 ppm; The mass content of the manganese element in the zinc sulfide is 10 to 50 ppm; The mass content of zinc in zinc sulfide is related to the D 50 The particle size satisfies the following relationship: in, W zn is the mass content of zinc in zinc sulfide material, unit is %; D znS The particle size of zinc sulfide particles is in nm.

2. Zinc sulfide according to claim 1, characterized in that The dielectric constant of the zinc sulfide is 9 to 11.

5.

3. Zinc sulfide according to claim 1, characterized in that The mass content of zinc in the zinc sulfide is 60-70%.

4. Zinc sulfide according to claim 1, characterized in that The zinc sulfide D 50 The particle size is 50~150nm.

5. The method for preparing zinc sulfide according to any one of claims 1 to 4, wherein The steps include: Zinc sulfate, copper sulfate and manganese sulfate are taken, dissolved in deionized water and heated respectively, sodium sulfide solution is slowly added dropwise to react, cooled to room temperature, and the precipitate is collected by suction filtration. Dilute hydrochloric acid is added and stirred to remove surface impurities. Subsequently, the precipitate is washed with deionized water until neutral, and dried at high temperature to obtain the zinc sulfide powder sample.

6. Use of the zinc sulfide according to any one of claims 1 to 4 in the preparation of glass fiber reinforced polyolefin composite materials.

7. A glass fiber reinforced polyolefin composite material, characterized in that: In parts by weight, it comprises the following components: 100 parts of glass fiber reinforced polyolefin composite material and 0.1-10 parts of the zinc sulfide according to claim 1.

8. The glass fiber reinforced polyolefin composite material according to claim 7, characterized in that: In the glass fiber reinforced polyolefin composite material, the mass content of glass fiber is 10-40%.

9. The glass fiber reinforced polyolefin composite material according to claim 7, characterized in that: The polyolefin in the glass fiber reinforced polyolefin composite material includes any one or more of polyethylene, polypropylene, polytetrafluoroethylene and polyolefin elastomer.

10. The glass fiber reinforced polyolefin composite material according to claim 7, characterized in that: The glass fiber reinforced polyolefin composite material further comprises 0 to 2 parts of other additives, wherein the other additives are selected from at least one of lubricant, antioxidant, impact modifier, flame retardant, fluorescent brightener, plasticizer, thickener, release agent, and nucleating agent.

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