Metal sulfide and use thereof, and resin composition containing metal sulfide

Abstract

Disclosed in the present invention are a metal sulfide and use thereof, and a resin composition containing the metal sulfide, relating to the technical field of sulfides. The metal sulfide of the present invention is a zinc sulfide material, the zinc sulfide material containing cobalt and iron, the mass content of cobalt in the zinc sulfide material being 200-500 ppm, and the mass content of iron in the zinc sulfide material being 3-200 ppm; and the zinc content and the pH value of the zinc sulfide material satisfy the following relational expression: 1.2≤pH-2.5×lg(WZn)≤3.3, wherein pH is the pH value of the zinc sulfide material, and WZn is the mass content of zinc in the zinc sulfide material. The present invention controls the content of cobalt and iron while also reasonably limiting the zinc content and the pH value of the metal sulfide, such that the resin composition containing the metal sulfide has high color stability and has a low whiteness value change rate after treatment with water over a long time.

Description

Metal sulfide and its application, and resin composition containing metal sulfide Technical Field

[0001] The present invention relates to the technical field of sulfides, and in particular to a metal sulfide and application thereof, and a resin composition containing the metal sulfide. Background Art

[0002] With the widespread use of plastic products in home appliances, power tools, and outdoor equipment, consumers are increasingly demanding higher standards for plastic appearance. Typically, pigments are added to plastics to achieve specific appearance effects, such as adding white pigment to produce white or light-colored plastic products. Zinc sulfide (ZnS), as a white pigment, has a high refractive index and high opacity, and is easily dispersed and resists agglomeration. Its application in plastics can provide excellent hiding and whitening effects.

[0003] However, for white plastic products used in aquatic environments, such as toys and equipment in water parks and aquarium accessories, prolonged exposure to water can cause discoloration of the plastic products due to dissolution, bleaching, diffusion of the white pigment, or reactions with chemicals in the water, affecting their appearance. Furthermore, high water temperatures can accelerate color changes.

[0004] Therefore, it is necessary to provide a zinc sulfide material with little change in whiteness after water treatment so as to be applied to plastic products with high color requirements.

[0005] Summary of the Invention

[0006] The present invention aims to overcome the shortcomings of the prior art and provide a metal sulfide and its application, as well as a resin composition containing the metal sulfide. By controlling the content of cobalt and iron elements and reasonably limiting the zinc content and pH value in the metal sulfide, the resin composition containing the metal sulfide has high color stability and a low whiteness value change rate after long-term water treatment.

[0007] To achieve the above objectives, in a first aspect of the present invention, a metal sulfide is provided, wherein the metal sulfide is a zinc sulfide material, wherein the zinc sulfide material contains cobalt and iron, wherein the mass content of the cobalt element in the zinc sulfide material is 200 to 500 ppm, and the mass content of the iron element in the zinc sulfide material is 3 to 200 ppm;

[0008] The mass content of zinc in the zinc sulfide material and the pH value satisfy the following relationship:

[0009] 1.2≤pH-2.5×lg(W Zn )≤3.3;

[0010] Wherein, the pH is the pH value of the zinc sulfide material; the W Zn It is the mass content of zinc in zinc sulfide material, in %.

[0011] As a preferred embodiment of the present invention, the mass content of the cobalt element in the zinc sulfide material is 250 to 400 ppm.

[0012] As a preferred embodiment of the present invention, the mass content of the iron element in the zinc sulfide material is 6 to 150 ppm.

[0013] As a preferred embodiment of the present invention, the mass content of zinc in the zinc sulfide material and the pH value satisfy the following relationship: 1.5≤pH-2.5×lg(W Zn )≤3.0.

[0014] As a preferred embodiment of the present invention, the mass content of zinc in the zinc sulfide material is 62.0-67.1%, preferably 63.5-67.0%.

[0015] As a preferred embodiment of the present invention, the pH value of the zinc sulfide material is 5.5 to 8.0; preferably 6.1 to 7.5.

[0016] As a preferred embodiment of the present invention, the zinc sulfide material further contains chromium, and the mass content of chromium in the zinc sulfide material is 10 to 25.2 ppm.

[0017] As a preferred embodiment of the present invention, the zinc sulfide material has a heating loss of ≤0.5% at 105°C.

[0018] In a second aspect of the present invention, the present invention provides a use of the metal sulfide described above in preparing a resin composition.

[0019] In a third aspect of the present invention, the present invention provides a resin composition comprising the following components in parts by weight:

[0020] 100 parts of resin and 0.5 to 10 parts of the above-mentioned metal sulfide.

[0021] As a preferred embodiment of the present invention, the resin includes at least one of polyethylene (PE), polypropylene (PP), polyamide (PA), polycarbonate (PC), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), epoxy resin (EP), acrylonitrile-butadiene-styrene copolymer (ABS), and styrene-acrylonitrile copolymer (AS).

[0022] The beneficial effects of the present invention are:

[0023] The metal sulfide of the present invention has appropriate cobalt and iron content, and the zinc content and pH value in the metal sulfide are reasonably limited, so that the resin composition containing the metal sulfide has high color stability and a low whiteness value change rate after long-term water treatment. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0025] 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.

[0026] 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.

[0027] In the present invention, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0028] The reagents and instruments used in the present invention without indicating the manufacturer are all conventional products that can be purchased from the market.

[0029] An embodiment of the present invention provides a metal sulfide, wherein the metal sulfide is a zinc sulfide material, wherein the zinc sulfide material contains cobalt and iron, wherein the mass content of the cobalt element in the zinc sulfide material is 200 to 500 ppm, and the mass content of the iron element in the zinc sulfide material is 3 to 200 ppm;

[0030] The mass content of zinc in the zinc sulfide material and the pH value satisfy the following relationship:

[0031] 1.2≤pH-2.5×lg(W Zn )≤3.3;

[0032] Wherein, the pH is the pH value of the zinc sulfide material; the W Zn It is the zinc content in zinc sulfide material, in %.

[0033] For zinc sulfide materials, the purity of zinc sulfide is usually difficult to reach 100%, and it will contain a certain amount of impurity elements, such as cobalt and iron. The present application found that both cobalt and iron will have a certain impact on the color and stability of zinc sulfide materials. Pure zinc sulfide is usually white or light yellow, while zinc sulfide materials containing a certain amount of cobalt elements often show a light blue or light green hue, and zinc sulfide materials containing a certain amount of iron elements tend to be yellowish or brownish in color; when the iron or cobalt content is too high, a large amount of iron ions and cobalt ions may cause oxidation reactions or decomposition reactions, resulting in a decrease in the stability of the resin composition containing the zinc sulfide material, thereby causing the color to change.

[0034] Therefore, when a zinc sulfide material containing a large content of cobalt or iron is added to the resin, the resulting resin composition often exhibits a significant change in whiteness when used in an aqueous environment.

[0035] However, the present application has found that the lower the content of cobalt and iron elements, the better. Appropriate content of cobalt and iron elements contributes to higher stability of zinc sulfide and lower color change rate of the resin composition containing zinc sulfide. When a resin composition containing zinc sulfide material is applied to an aqueous environment, cobalt and iron elements are prone to ionization to obtain cobalt ions and iron ions, which may replace zinc ions or sulfur ions in the zinc sulfide lattice and introduce additional lattice defects such as vacancies or substitutional ions. In addition, when cobalt and iron are ionized and inserted into the zinc sulfide lattice, the surrounding zinc sulfide ions may be displaced to adapt to the size and charge of the cobalt ions and iron ions. This displacement may cause relaxation of the lattice, that is, the parameters of the zinc sulfide lattice (such as the lattice constant) change. Appropriate distortion and defects in zinc sulfide crystals may hinder the growth and grain boundary diffusion of zinc sulfide crystals, limit the size and morphology of the crystals, make them more uniform and dense, and thus reduce the voids and cracks inside the crystals; in addition, defects may also change the energy band structure of zinc sulfide, adjust its electronic energy level and energy gap, thereby affecting its chemical reactivity, thereby improving the stability of zinc sulfide, and affecting the stability of the resin composition containing zinc sulfide.

[0036] In the present invention, the mass content of the cobalt element in the zinc sulfide material is controlled to be 200-500 ppm, and the mass content of the iron element is controlled to be 3-200 ppm. On the basis of not affecting the color of the zinc sulfide material itself, the stability of the zinc sulfide material is improved and the color change rate of the resin composition containing the zinc sulfide material is reduced.

[0037] This study found that the pH value of the zinc sulfide material not only affects the acidity and alkalinity of the resin composition containing the zinc sulfide material, but also affects the color stability of the resin composition in an aqueous environment. After the zinc sulfide material is added to the resin, changes in the pH value of the resin system may cause changes in the interaction between the zinc sulfide and the resin. An appropriate pH value will strengthen the interfacial bonding between the zinc sulfide and the resin without degrading the performance of the resin itself, which helps the resin composition containing zinc sulfide have better color stability. When the pH is too high or too low, it may cause the performance of the resin composition to deteriorate, reduce stability, or produce other chemical reactions, resulting in excessive color changes in the material.

[0038] In addition, the pH value of zinc sulfide material is also related to the zinc content. When the mass content of zinc in the zinc sulfide material is high, the concentration of zinc ions in the aqueous solution will also be high, which will increase the acidity of the solution and reduce the pH value. Therefore, the zinc content of zinc sulfide needs to be controlled in coordination with the pH value. This study found that when the pH value and zinc content satisfy the relationship: 1.2≤pH-2.5×lg(W Zn )≤3.3, the pH and zinc content of the zinc sulfide material are both within an appropriate range, and the color stability of the resin composition containing the zinc sulfide material is relatively higher.

[0039] It should be noted that the pH value of zinc sulfide is related to many factors, such as the synthesis method of zinc sulfide, the post-treatment process, etc., that is, the pH value of zinc sulfide is not linearly correlated with the zinc content.

[0040] In the present invention, the mass content of the iron element, the mass content of the cobalt element and the mass content of the zinc in the zinc sulfide material can all be detected by atomic absorption spectrometry (AAS).

[0041] In the present invention, the pH value of zinc sulfide can be detected by the following method: the zinc sulfide material is dispersed in water to form a suspension sample under ultrasonic stirring; a calibrated pH electrode is immersed in the suspension sample to ensure that the electrode is in full contact with the sample, and the reading is recorded after the measurement is stable.

[0042] In the present invention, pH=2.5×1g(W Zn ) can be 1.2, 1.3, 1.5, 1.8, 2.0, 2.5, 3.0, 3.3, or an interval formed by any two of the above values.

[0043] In the present invention, the mass content of the cobalt element in the zinc sulfide material can be 200 ppm, 210 ppm, 220 ppm, 250 ppm, 300 ppm, 400 ppm, 500 ppm, or an interval formed by any two of the above values.

[0044] In the present invention, the mass content of the iron element in the zinc sulfide material can be 3 ppm, 10 ppm, 20 ppm, 50 ppm, 100 ppm, 150 ppm, 200 ppm, or an interval range formed by any two of the above values.

[0045] In one embodiment, the mass content of the cobalt element in the zinc sulfide material is 250 to 400 ppm.

[0046] In one embodiment, the mass content of the iron element in the zinc sulfide material is 6 to 150 ppm.

[0047] In the above preferred mass contents of cobalt and / or iron, the stability of the zinc sulfide material is relatively better, and the color change rate of the resin composition containing the zinc sulfide material is relatively smaller.

[0048] In one embodiment, the mass content of zinc in the zinc sulfide material and the pH value satisfy the following relationship: 1.5≤pH-2.5×1g(W Zn )≤3.0.

[0049] When the relationship is within the above preferred range, the mass content of zinc in the zinc sulfide material and the pH value are relatively more balanced, and the stability of the zinc sulfide material is better.

[0050] In one embodiment, the mass content of zinc in the zinc sulfide material is 62.0-67.1%, for example, it can be 62.0%, 62.5%, 63.0%, 64.0%, 65.0%, 67.1%, or an interval range formed by any two of the above values.

[0051] In one preferred embodiment, the mass content of zinc in the zinc sulfide material is 63.5-67.0%.

[0052] The zinc content in zinc sulfide materials is related to the purity of the zinc sulfide. The higher the purity, the higher the zinc content, while the lower the purity of the zinc sulfide, the lower the zinc content. Generally speaking, a higher zinc content results in a lighter color and a better performance as a white pigment. However, a higher zinc content, while indicating a higher purity of the zinc sulfide, may also result in a corresponding decrease in the proportion of cobalt and iron. Furthermore, a higher zinc content may also cause a corresponding decrease in pH, thereby affecting the color stability of the resin composition containing zinc sulfide.

[0053] In one embodiment, the pH of the zinc sulfide material is 5.5 to 8.0, for example, 5.5, 5.8, 6.0, 6.5, 7.0, 7.5, 8.0, or an interval formed by any two of the above values.

[0054] In one preferred embodiment, the pH of the zinc sulfide material is 6.1-7.5.

[0055] When the pH value of zinc sulfide material is in the neutral to acidic range, it helps the material maintain a high stability, and after being added to the resin, it will not have a significant negative impact on the performance of the resin itself.

[0056] In one embodiment, the zinc sulfide material further contains chromium, and the mass content of chromium in the zinc sulfide material is 10 to 25.2 ppm, for example, 10 ppm, 15 ppm, 18 ppm, 20 ppm, 25.2 ppm, or an interval formed by any two of the above values.

[0057] The presence of chromium in zinc sulfide materials can improve the heat resistance and oxidation resistance of zinc sulfide. Chromium reacts with oxygen to form chromium oxide (Cr2O3), which adheres to the surface of zinc sulfide particles. Chromium oxide has high thermal stability and oxidation resistance, which can reduce the decomposition or oxidation of zinc sulfide and improve its stability. Furthermore, chromium can occupy some vacancies in the zinc sulfide crystal lattice, stabilizing the lattice structure and thus improving the heat resistance of the zinc sulfide material. However, high chromium content may cause the zinc sulfide to appear light green or lavender, which may affect the color of the resin composition containing zinc sulfide.

[0058] In the present invention, the mass content of chromium in the zinc sulfide material can be detected by atomic absorption spectrometry (AAS).

[0059] In the present invention, the mass contents of cobalt, iron, and chromium, as well as the zinc content, in the zinc sulfide material can be adjusted by screening suitable zinc sulfide raw material ores. Alternatively, the zinc sulfide can be synthesized by selecting suitable zinc compounds and sulfides, and then a certain amount of cobalt, iron, and chromium can be added by precipitation to adjust the content. Furthermore, the cobalt, iron, and chromium content in the zinc sulfide material may also be introduced by the equipment used in the zinc sulfide preparation process.

[0060] In one embodiment, the weight loss of the zinc sulfide material upon heating at 105° C. is ≤0.5%, for example, it may be 0.5%, 0.4%, 0.3%, 0.2%, 0.15%, 0.1%, or an interval formed by any two of the above values.

[0061] The heating loss of zinc sulfide material can be detected by conventional methods in the field, for example, the following method can be used: take an appropriate amount of zinc sulfide material sample, accurately weigh its mass, and record it as m1; place the sample in a heating device, set the temperature to 105°C, control the relative humidity to less than 10% RH, and heat it until the sample weighs a constant weight; after the sample cools to room temperature, accurately weigh its mass again, and record it as m2; 105°C heating loss = (m1-m2) / m1*100%.

[0062] The weight loss of zinc sulfide upon heating to 105°C primarily reflects its moisture content. Low moisture content in zinc sulfide slows its decomposition and improves its stability. Furthermore, when added to the resin, zinc sulfide with low moisture content bonds more tightly to the resin, making it less likely to separate from the resin and discolor the resin composition.

[0063] In the present invention, the weight loss of the zinc sulfide material upon heating at 105° C. can be adjusted by performing a suitable drying treatment on the zinc sulfide material.

[0064] One embodiment of the present invention provides use of the metal sulfide described above in preparing a resin composition.

[0065] One embodiment of the present invention provides a resin composition comprising the following components in parts by weight:

[0066] 100 parts of resin and 0.5 to 10 parts of the above-mentioned metal sulfide.

[0067] In one embodiment, the resin includes at least one of polyethylene (PE), polypropylene (PP), polyamide (PA), polycarbonate (PC), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), epoxy resin (EP), acrylonitrile-butadiene-styrene copolymer (ABS), and styrene-acrylonitrile copolymer (AS).

[0068] In practical applications, according to actual performance requirements, the resin composition may further include 0 to 10 parts by weight of other additives, wherein the other additives are selected from at least one of lubricants, yellowing inhibitors, antioxidants, heat stabilizers, light stabilizers, other polymers, impact modifiers, flame retardants, fluorescent whitening agents, plasticizers, thickeners, antistatic agents, release agents, and nucleating agents.

[0069] It should be noted that the preparation method of the resin composition is not particularly limited in the present invention, and those skilled in the art can prepare it into a resin composition according to conventional methods.

[0070] Exemplarily, the preparation method of the resin composition is:

[0071] The resin, metal sulfide and other additives are mixed and added to an extruder, and the mixture is melt-mixed and extruded into granules to obtain the resin composition.

[0072] Specifically, the extruder may be a twin-screw extruder, the screw aspect ratio of the twin-screw extruder is 36-72:1, the screw speed is 100-500 rpm, and the melting temperature of the twin-screw extruder is 180-280°C.

[0073] After the 25°C water treatment test, the whiteness value change rate of the above-mentioned resin composition is ≤8%, wherein the specific conditions of the 25°C water treatment test are: after the resin composition is injection-molded into a 2 cm thick sample, it is placed in a 25°C water tank and immersed for 12 hours, the sample is taken out and dried, and then placed at room temperature for 12 hours, and then immersed in a 25°C water tank again, which is one cycle; a total of 50 cycles are performed.

[0074] After the 50°C water treatment test, the whiteness value change rate of the above-mentioned resin composition is ≤15%, wherein the specific conditions of the 50°C water treatment test are: after the resin composition is injection-molded into a 2 cm thick sample, it is placed in a 50°C water tank and immersed for 12 hours, the sample is taken out and dried, and then placed at room temperature for 12 hours, and then immersed in a 50°C water tank again, which is one cycle; a total of 50 cycles are performed.

[0075] The present invention is further described below with specific embodiments:

[0076] Examples and Comparative Examples

[0077] The embodiments and comparative examples of the present invention each prepare a zinc sulfide material, and the preparation of the zinc sulfide material includes the following steps:

[0078] S1. Dissolve zinc sulfate and sodium sulfide in water and react at 50 to 80°C with stirring. Use sulfuric acid to control the pH of the reaction system to 4 to 7.

[0079] S2. After the reaction is completed, the product is cooled, separated and removed;

[0080] S3. The separated product was added to dilute hydrochloric acid and acidified to obtain an acidified product;

[0081] S4. The acidified product is washed with deionized water three times and dried to obtain a zinc sulfide material.

[0082] By screening zinc sulfate and sodium sulfide with specific cobalt / iron / chromium contents and controlling the molar ratio of zinc sulfate and sodium sulfide, the cobalt content, iron content, chromium content and zinc content in the zinc sulfide material can be adjusted; by controlling the temperature and time of the acidification treatment, the pH value of the zinc sulfide material can be adjusted; by controlling the drying adjustment, the heating loss of the zinc sulfide material at 105°C can be adjusted.

[0083] The mass contents of cobalt, iron, chromium and zinc in the prepared zinc sulfide material were detected by atomic absorption spectrometry, and the cobalt content (ppm), iron content (ppm), chromium content (ppm) and zinc content (ppm) were obtained as shown in Table 1. Zn (%);

[0084] The following method is used to test the 105°C heating loss of zinc sulfide material: take an appropriate amount of zinc sulfide material sample, accurately weigh its mass, and record it as m1; place the sample in a heating device, set the temperature to 105°C, control the relative humidity to less than 10% RH, and heat it until the sample weighs a constant weight; after the sample cools to room temperature, accurately weigh its mass again, and record it as m2; 105°C heating loss = (m1-m2) / m1*100%, and the 105°C heating loss is obtained as shown in Table 1;

[0085] The pH value of the zinc sulfide material was tested using the following method: the zinc sulfide material was dispersed in water to form a suspension sample under ultrasonic stirring; a calibrated pH electrode was immersed in the suspension sample to ensure full contact between the electrode and the sample, and the reading was recorded after the measurement stabilized to obtain the pH value shown in Table 1.

[0086] Specifically, the test parameter values ​​of the zinc sulfide materials of Examples 1 to 10 and Comparative Examples 1 to 5 are shown in Table 1.

[0087] Table 1 Detection parameter values ​​of zinc sulfide materials

[0088] The zinc sulfide materials prepared in the examples and comparative examples were used as white pigments to prepare resin compositions according to the following component contents (parts by weight): 100 parts of polyethylene resin, 3 parts of white pigment, and 1 part of antioxidant 1010;

[0089] The preparation method of the resin composition is as follows:

[0090] The polyethylene resin, white pigment (zinc sulfide material) and antioxidant 1010 were mixed and added to a twin-screw extruder with a screw speed of 300 rpm and a melting temperature of 260° C. The resin composition was obtained by melt mixing and extrusion granulation.

[0091] The color stability of the resin composition was tested. The results are shown in Table 2. The specific method of testing is as follows:

[0092] Room-temperature whiteness value change rate: After the resin composition is injection-molded into a 2 cm thick sample, the whiteness value (W1) is measured, and then the resin composition is subjected to a 25°C water treatment test. The specific conditions of the 25°C water treatment test are as follows: the sample is immersed in a 25°C water tank for 12 hours, the sample is taken out and dried, and then placed at room temperature for 12 hours, and then immersed in a 25°C water tank again, which constitutes one cycle; a total of 50 cycles are performed; the whiteness value (W2) after the 25°C water treatment test is again measured, and the room-temperature whiteness value change rate (ΔWa) is calculated, ΔWa = (W1-W2) / W1*100%;

[0093] High-temperature whiteness value change rate: After the resin composition is injection-molded into a 2-cm-thick sample, the whiteness value (W3) is tested, and then the resin composition is subjected to a 50°C water treatment test. The specific conditions of the 50°C water treatment test are: the sample is immersed in a 50°C water tank for 12 hours, the sample is taken out and dried, and then placed at room temperature for 12 hours, and then immersed in a 50°C water tank again, which is one cycle; a total of 50 cycles are performed; the whiteness value (W4) after the 50°C water treatment test is tested again, and the high-temperature whiteness value change rate (△Wb) is calculated, △Wb = (W3-W4) / W3*100%.

[0094] The whiteness value is tested as follows:

[0095] The chromaticity of the sample was measured using a spectrophotometer SD5000 (manufactured by Nippon Denshoku Industries Co., Ltd.), and the lightness (L), redness value (a), and yellowness value (b) were calculated using the Hunter color difference formula; the whiteness (W) was calculated according to the following formula: W = 100 - [(100 - L)] 2 +a 2 +b 2 ] 1 / 2 .

[0096] Table 2 Color stability of resin composition

[0097] As can be seen from Table 2, the zinc sulfide materials of each embodiment of the present invention can effectively improve the color stability of the resin composition. After the water treatment test at 25°C, the whiteness value change rate of the resin composition is ≤8%. After the water treatment test at 50°C, the whiteness value change rate of the resin composition is ≤15%.

[0098] According to the test results of Example 5 and Examples 1-4, when the chromium content in the zinc sulfide material is low, the color stability of the resin composition is poor, especially the rate of change in whiteness value is high at high temperatures. According to Examples 6-8, the cobalt content of the zinc sulfide material is preferably 250-400 ppm by weight, the iron content is preferably 6-150 ppm by weight, and the weight loss of the zinc sulfide material upon heating at 105°C is preferably no greater than 0.5%.

[0099] From the test results of Examples 9 to 10 and Examples 1 to 4, it can be seen that when the content of each element is within the appropriate range, pH-2.5×1g(W Zn ) further satisfies 1.5 to 3.0, the whiteness value of the resin composition changes less under normal temperature or high temperature water treatment conditions.

[0100] From the test results of Comparative Examples 1 to 5, it is not difficult to see that when the cobalt or iron elements of the zinc sulfide material exceed the range specified in the present invention, or the pH is -2.5×1g(W Zn ) is too large or too small, the obtained resin composition will produce a large color change.

[0101] It should be noted that although only polyethylene resin is used as the resin component of the resin composition in the embodiments of the present invention, in fact, when the polyethylene resin is replaced by other thermoplastic resins or thermosetting resins, such as polyethylene, polyamide, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, epoxy resin, acrylonitrile-butadiene-styrene copolymer or styrene-acrylonitrile copolymer, similar color stability effects can be achieved.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A metal sulfide, characterized in that: The metal sulfide is a zinc sulfide material, the zinc sulfide material contains cobalt and iron, the mass content of the cobalt element in the zinc sulfide material is 200-500 ppm, and the mass content of the iron element in the zinc sulfide material is 3-200 ppm; The mass content of zinc in the zinc sulfide material and the pH value satisfy the following relationship: 1.2≤pH-2.5×lg(W Zn )≤3.3; Wherein, the pH is the pH value of the zinc sulfide material; Zn It is the mass content of zinc in zinc sulfide material, in %.

2. The metal sulfide according to claim 1, characterized in that: The mass content of the cobalt element in the zinc sulfide material is 250-400 ppm.

3. The metal sulfide according to claim 1, characterized in that: The mass content of the iron element in the zinc sulfide material is 6 to 150 ppm.

4. The metal sulfide according to claim 1, characterized in that: The mass content of zinc in the zinc sulfide material and the pH value satisfy the following relationship: 1.5≤pH-2.5×lg(W Zn )≤3.

0.

5. The metal sulfide according to claim 1, characterized in that: The mass content of zinc in the zinc sulfide material is 62.0-67.1%.

6. The metal sulfide according to claim 1, characterized in that: The pH value of the zinc sulfide material is 5.5-8.

0.

7. The metal sulfide according to claim 1, characterized in that: The zinc sulfide material also contains chromium element, and the mass content of the chromium element in the zinc sulfide material is 10-25.2 ppm.

8. The metal sulfide according to claim 1, characterized in that: The zinc sulfide material has a heating loss of ≤0.5% at 105°C.

9. Use of the metal sulfide according to any one of claims 1 to 8 in the preparation of a resin composition.

10. A resin composition, characterized in that The composition comprises the following components in parts by weight: 100 parts of resin and 0.5 to 10 parts of the metal sulfide according to any one of claims 1 to 8.

11. The resin composition according to claim 10, characterized in that: The resin includes at least one of polyethylene, polypropylene, polyamide, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, epoxy resin, acrylonitrile-butadiene-styrene copolymer, and styrene-acrylonitrile copolymer.

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